Manual Materials Laboratory

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Copyright©Saudi Aramco 2013. All rights reserved.

Materials Laboratory Manual

16 July 2013

Consulting Services Materials Laboratory Manual

Document Responsibility: CSD / Materials Engineering and Corrosion Operations

Support Group

Document Responsibility: CSD / Materials Engineering and Corrosion Operations Support Group

Issue Date: 16 July 2013

Next Planned Update: TBD Consulting Services Materials Laboratory Manual

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PREFACE

Consulting Services Materials Laboratory Manual (CSMLM) has been developed

by the Consulting Services Department (CSD) to provide uniform and

standardized guidelines for performing specific materials examination, failure

analysis and mechanical testing activities. CSMLM is an instructional document

that will aid Saudi Aramco laboratory technicians in preparing, performing and

documenting all laboratory work activities. This manual also serves as a reference

for new CSD engineers and technicians for their developmental program as

laboratory technicians or metallurgical engineers.

Interpretation of, or recommended revisions to this manual should be addressed in

writing to the Head of the Operational Support Division of CSD, Dhahran.

Approved by:




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Table of Contents

Preface 2

1 Introduction 4

2 Definitions/Abbreviations 4

3 Material Sample Management 6

4 Dimensional Measurement 16

5 Non-Destructive Testing 17

6 Metallography 21

7 Optical Microscopy 53

8 Chemical Analysis 56

9 Mechanical Testing 58

10 Heat Treatment 68

11 Fractography 71

12 Corrosion Testing 99

13 Failure Analysis Process 102

14 Laboratory Management 104

15 References 108

16 Appendices 109




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1. Introduction

This manual describes the activities and services undertaken by the materials laboratory of the

Consulting Services Department to support operational facilities and the capital program.

These services include metallurgical failure analysis, mechanical testing and chemical

composition checks. The prime objective of the functions of the laboratory is integral to Saudi

Aramco’ commitment to Operational Excellence to proactively prevent plant failures and

optimize the life cycle cost of assets without compromise to mechanical integrity, safety and

the environment.

2. Definitions/Abbreviations

Charpy V Notch Test: A mechanical test that measures the resistance to impact.

CSD: Consulting Services Department.

CSD Engineer: Metallurgical, Welding or Mechanical Engineer working in CSD.

Energy Dispersive Analysis: A method of chemical analysis that identifies and measures

elements by their characteristic radiation.

FA Request: Failure Analysis form used to initiate the work request and shows complete

background of the failed equipment.

Fractography: The examination of fracture surfaces by means of optical or electron

microscopes. Group Leader: Experienced Engineer within ME&COS to assign new FA

requests to Engineers and review the completed reports.

Grain: Most metals are composed of many tiny crystals that are called grains.

Laboratory Team Leader: Experienced Technician within ME&COS Laboratory to assign

new FA requests to Technicians.

Laboratory Technician: Technician working in the Metallurgical Laboratory of CSD and

trained in field metallography testing.

Long and Short Transverse: The directions that are perpendicular to rolling directions in

sheet or plate.

Macro-etchant: A chemical solution (usually an acid) that is used to reveal grain flow or other

directional features.

Metallograph: An optical microscope that examines microstructure of metals.

Metallographic Examination: Microscopic examination of a metal to determine its

microstructure.




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Microstructure: Unique microscopic features that are representative of a given metal or alloy.

Optical Microscope: A microscope that uses optical lenses for analysis (see metallographic

above) of materials.

Proponent: Plant engineer, supervisor or manager for whom the work is being conducted.

Rolling Direction: The direction of rolling that is found in metal sheet and plate.

Scanning Electron Microscope (SEM): A microscope that uses a scanning electron beam for

analysis on materials surfaces.

SRN: Service Request Number; this is a sequential number generated by the database

FileMaker Pro for every failure analysis request.

Stereomicroscope: A low-power binocular optical microscope.

Tensile Test: A mechanical test that measures strength.

Transition Curve: The Charpy energy curve that shows how energy varies with temperature.




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3. Material Sample Management

Laboratory failure analysis flowchart and workflow are shown below.




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Failure Analysis Flow Chart

No

Yes

Yes

No

Complete FA request by Proponent with management signature

Send the FA Request form with failed sample(s) to Lab Team Leader

FA Report accepted by Group Leader?

Evaluate FA Request and assign MEU Lab Technician by Lab Team Leader

Is FA Request Accepted?

Photograph the received sample(s) and send the required information to MEU Group Leader

Write the FA Report by Engineer and send to Group Leader to review and initial

Send the signed FA Report to the Proponent and Save in e-Cabinet by MEU Clerk

FA Report returns to Engineer with comments to incorporate

FA Request returns to Proponent with comments for correction

Evaluate FA Request and assign MEU Engineer by Group Leader

Complete the CSD Materials Lab Tests Sheet by the Engineer to be performed by Lab Technician

Sign the initialed FA Report by MEU Supervisor

https://ecmapps.aramco.com.sa/eds/component/main?__dmfClientId=1336459141786




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Failure Analysis Procedural Workflow

The laboratory operates a sample control management system to ensure quality assurance and

traceability. Customers submit their samples with a completed service request form signed by

their management. See below typical example of this form.

There are three categories of urgency and approval for the service requests, as follows:

1. Critical: Manager Approval – Job to be completed within one week

2. Urgent: Superintendent approval- Job to be completed within three weeks

3. Routine: Supervisor approval – Job to be completed within 1½ month

These levels are dependent on the nature of the failure and the impact it has on safety and Saudi

Aramco business. Normally, these categories are selected by the customer at request submittal.

3.1. Receiving

Upon arrival at the laboratory, samples are stored in the external yard or inside the laboratory

depending on job urgency or size.

3.2. Assigning a Job Service Request Number and Staff

The samples are then assigned a sequential 4-digit Service Request Number (SRN), e.g., SRN-

1234, from the FileMaker Pro laboratory database. Technicians and engineers working on the

job are designated by the laboratory group leader and the Supervisor, respectively. See below

snapshot of typical job card example from FileMaker Pro.

3.3. Sample and Micro Labeling System

The submitted samples are inscribed with the assigned SRN, e.g., SRN-1234 using a permanent

marker. If more than one sample for the same job is received, the samples are inscribed with

the same SRN followed by a sequential number commencing with one, etc.,

e.g., SRN-1234-1, SRN-1234-2, etc. The assigned engineer to the job is responsible to keep a

detailed record of all samples received and micros mounted as shown in the example below:

Sample Component Customer Micro ID Micro Location

SRN-1234 Boiler F-1001

Superheater Tubes UGP

SRN-1234-1 Tube #5 UGP 1234-1-A Hot side

1234-1-B Cold side

1234-1-C Crack tip

SRN-1234-2 Tube #69 UGP 1234-2-A Bulge cross-section




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3.4. Micro Storage

All micros are stored in air-tight cabinets with active desiccant. Engineers are usually assigned

one cabinet each to store their micros. Technicians are tasked to periodically verify that the

desiccant is replaced well-prior to its used-up period. Fresh desiccant is usually blue; but once

used-up, i.e., absorbs moisture, it turns to pink. The laboratory group leader is accountable for

the freshness of the desiccant in all cabinets where micros are stored.

3.5. Deposit Analysis

When required by the engineer, deposits from the samples received may be sent to the R&DC for

analysis of corrosion product or contaminants to support the failure analysis. Normally, X-Ray

Diffraction (XRD) or X-Ray Fluorescence (XRF) or both are carried out by R&DC.

An example R&DC request for XRD-XRF is shown below.

3.6. Sample Disposal

Metal samples are kept in the yard or inside the laboratory for a maximum period of 30 days;

thereafter, they will be scrapped if unclaimed by the engineer or the customer. In some cases,

some samples are kept for longer periods if they are deemed to be good teaching tools for

training and development of technicians and engineers.




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Failure Analysis Request Form




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Materials Testing Request Form




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Typical example of File Maker Pro job card showing job details, service request number, assigned staff and customer




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Laboratory Testing and Examination Instructions Sheet




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Example of R&DC Deposit Analysis Request Form




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3.7. Macro-Examination

3.7.1. Visual

Visual inspection of the external condition of the obtained samples is extremely important, and

is a source of useful information for failure analysis. The main check contents are cracking,

voids, scratching, burn marks, damage to external pins, adherence of foreign matter,

discoloration, etc. For failure analysis, visual inspection is performed to gain an overall

understanding of the fracture, to determine the fracture sequence, to locate the fracture origin or

origins, and to detect any macroscopic features relevant to fracture initiation or propagation.

Visually examine the sample

Examine the sample with unaided eye, hand lens and/or low magnification field microscopes.

Note the condition of the accessible surface documenting all sorts of anomalies, searching for

cracks, corrosion damage, the presence of foreign material, erosion or wear damage, or

evidence of impact or other distress. Also, consider the condition of protective coatings.

Manufacturing defects are important. If pipe failure is involved, it is important to carefully

measure wall thicknesses both at the failure site and some distance away from it at four

locations 90 degrees apart around the pipe circumference, starting a the failure site. At the same

time, note the presence of any corrosion and map its general distribution.

3.7.2. Stereoscopy

The stereo microscope is an optical microscope variant designed for low magnification

observation or a sample.




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The stereo microscope is an optical microscope variant designed for low magnification

observation or a sample using incident light illumination rather than transillumination. It uses

two separate optical paths with two objectives and two eyepieces to provide slightly different

viewing angles to the left and right eyes. In this way, it produces a three-dimensional

visualization of the sample being examined.

The stereo microscope is used to study the fracture surfaces of solid specimens or to carry out

close work such as sorting, dissection, watch-making, small circuit board manufacture or

inspection, and the like.

The stereo microscope should not be confused with a compound microscope equipped with

double eyepieces and a binoviewer. In such a microscope both eyes see the same image, but the

binocular eyepieces provide greater viewing comfort. However, the image in such a microscope

is no different from that obtained with a single monocular eyepiece.

4. Dimensional Measurement

4.1. Micrometer and Vernier Calipers

Micrometer Caliper: Instrument that measures the thickness or the diameter of relatively

small parts; it produces finer results than a vernier caliper.

How to Use a Metric Micrometer?

The metric micrometer looks very similar to a standard inch micrometer until you look at the

graduations on the sleeve and the barrel.

Figure 1 - 0-25 Millimeter Micrometer

There are two separate rows of lines on the sleeve of the metric micrometer.

When reading a metric micrometer you have to remember to add the half- millimeter

graduations of the upper row to the reading. The lower row represents whole millimeter

graduations. The upper row represents one-half millimeter. Each complete turn of the thimble

moves the spindle 1⁄2 millimeter (0.5 mm). The circumference of the thimble is separated into

50 equal divisions or .01 mm.




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Vernier Caliper: The vernier, dial, and digital calipers give a direct reading of the distance

measured with high accuracy and precision. They are functionally identical, with different ways

of reading the result. These calipers comprise a calibrated scale with a fixed jaw, and another

jaw, with a pointer, that slides along the scale. The distance between the jaws is then read in

different ways for the three types.

How to Measure with a Vernier Caliper?

Calipers are comprised of two jaws, one attached to a fixed scale and the other attached to a

sliding (Vernier) scale. In order to measure an object’s width, the object is simply placed

between the caliper’s two jaws. The sliding tooth is then moved until the object is pressed

tightly between the jaws. Using both scales, the width can be read to the nearest 0.005 cm

(or 0.05 mm).

4.2. Pit Gauge

The Basic Pit Gauge is the most economical Dial Indicator Pit Gauge. The Knife Edge Blade is

2 ¼” long (57mm), with the Dial Indicator Installed in the Centre of the Blade. This model will

often cover most inspectors’ needs when they are inspecting isolated pits.

5. Non-Destructive Testing

Non-destructive testing is carried out based on the request from the relevant failure analysis

engineers. The main non-destructive testing performed in the lab are Dye penetrant testing and

Magnetic particle testing. The technicians, performing these non-destructive testing, are

minimum qualified to the requirements of ASNT SNT TC-1A level II.

5.1. Dye Penetrant Testing

Penetrants improve the sensitivity of visual inspection by increasing the contrast of the surface

breaking discontinuities with the background color of the test surface.

Penetrants are liquids of intense color which flow into the surface cracks and cavities by

capillary action. After a suitable contact time around 15-30 minutes, excess penetrant on

the surface is carefully removed.

http://en.wikipedia.org/wiki/Accuracy_and_precision




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Penetrant left within the cracks and cavities bleeds onto the surface. A fine coating of

white developer powder is applied to the surface to increase the bleedout and improve

contrast.

The equipments or tools used for the dye penetrant testing are simple aerosol cans.

There are three aerosol cans which are being used.

The first aerosol can contain the penetrant which is sprayed onto the test surface and left

for 15-30 minutes.

The second aerosol can contains the solvent cleaner which is sprayed onto a cleaning

cloth and wiped over the test surface, firstly to remove any surface contaminants prior

to testing and secondly to remove the excess penetrant. The cleaner shall be never

sprayed directly onto the test surface, if it is so, the cleaner quickly dissolves away

penetrant inside the cracks and cavities and will lead to loss of indications.

The third aerosol can contains a non-aqueous wet developer in which a fine white

powder is suspended in a volatile solvent. After spraying a thin coating of developer

onto the test surface, the solvent quickly evaporates leaving the powder to draw the

penetrant out of cracks and cavities. Development result should be reviewed over a

period of thirty minutes.

The advantages and disadvantages of Dye Penetrant testing are given below:

Advantages

a. Penetrants are very simple to use

b. Can be used on all kinds of ferrous, non-ferrous metals and also on plastics and glass.

c. No power supply required

d. Very sensitive and cheaper method to check the surface breaking indications.

e. Any geometry or shape of material can be inspected.

Disadvantages

a. Can be used only for defects open to surface

b. Pre cleaning of test surface is essential.

5.2. Magnetic Particle Testing

Magnetic Particle Inspection (MPI) is another NDT method used in the lab but only on

the ferro-magnetic materials. This method uses magnetic particles to detect the surface

and sub-surface discontinuities in the magnetized test surface.

This method relies on the contrast between magnetic particles caught in the magnetic

flux leakage around discontinuities and the background color of the test surface.

The amount of flux leakage and the contrast of indication are dependent upon the

following.




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The large difference in magnetic permeability between the discontinuity and the parent

metal.

Magnetic permeability is the ratio of flux density(B) to the applied magnetic field(H).

A crack in a magnetized steel plate is a(air) gap which breaks the magnetic circuit.

The permeability of air is unity and for mild steel is eight hundred. For a given value of

H, the flux density in the air gap is 1/800th of the flux density in the parent plate.

The magnetic flux will therefore leak from the surface, creating poles which will attract

the magnetic particles.

Orientation of planar discontinuities to the magnetic field. Maximum flux leakage can

be expected where the field is perpendicular to the plane of the defect. Minimum flux

leakage can be expected where the field is at 45 degree to the planar defect.

The density of flux near the test surface. Flux density will be high in strong magnetic

fields and in materials of high magnetic permeability. The use of alternating magnetic

fields increases the density of flux near the surface because of skin effect.

The equipments used for magnetic particle inspection is given below:

5.2.1. Magnetizing Apparatus

Electro and permanent magnets, which produce longitudinal magnetic fields.

Permanent magnets have the advantage of not requiring power; however, the recent

standards restrict their use.

Electro magnets on the other hand give improved sensitivity by inducing alternating and

pulsed magnetic fields.

Prods and flexible cables which produce circular magnetic fields although cables can be

looped to produce longitudinal fields. High amperage currents are required and so




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heavy transformers are necessary.

Prods are electrodes which supply current directly to the test piece.

Care must be taken not to cause arcing or burning at the prod contacts.

Flexible cables can be arranged in a variety of configurations to give a magnetic field.

5.2.2. Directing Medium

Magnetic particles can be used as dry powders or as suspensions in paraffin or water.

The colors can be red, black or fluorescent.

Black particles are normally used after applying a thin coating of white contrast paint to

the test surface.

Fluorescent particles give high contrast without contrast paint. They are preferred for

inspecting forgings with a complex shape which are being tested in a magnetizing

bench unit.

Ink concentrations should be carefully monitored and kept within limits specification by

testing standards. Magnetic particles have a high specific gravity and agitation should

be continual to keep them suspended in the inks.

5.2.3. Accessories

Flux indicators are used to indicate the strength and direction of the applied magnetic

field. They don’t indicate the flux density inside the test piece and therefore, the

strength of any flux leakage. Since they ignore the nature of test material, they give

misleading indications on non-magnetic materials.

Flux meters give an accurate measure of the applied magnetic field.

Demagnetizers are often necessary to remove the residual magnetic fields during a

magnetizing sequence or before most MPI processes.

Sediment flasks are necessary for measuring ink concentrations.

Black lights need to be used with fluorescent inks and should be checked regularly with

a black light monitor.

Advantages of Magnetic Particle Testing

a. Simple to use

b. Can detect surface as well as sub-surface defects

Disadvantages of Magnetic Particle Testing

a. Can be used only on ferromagnetic materials

b. High magnetizing currents may cause arcing or burning

c. Demagnetization may be required in many cases




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6 Metallography

Metallography consists of the study of the constitution and microstructure of metals and alloys.

Much can be learned through specimen examination with the naked eye, but more refined

techniques require magnification and preparation of the material's surface. Optical microscopy

is sufficient for general purpose examination. Advanced examination and research laboratories

often contain electron microscopes (SEM and TEM), x-ray and electron diffractometers and

possibly other scanning devices.

Incorrect techniques in preparing a sample may result in altering the true microstructure and

will most likely lead to erroneous conclusions. It necessarily follows that the microstructure

should not be altered. Hot or cold working can occur during the specimen preparation process if

the metallurgist is not careful. Expertise at the methods employed to produce high-quality

metallographic samples requires training and practice. The basic techniques can be learned

through patient persistence in a matter of hours.

Preparation for metallography involves five major steps as below.

Sectioning

Mounting (optional)

Grinding

Polishing

Etching




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6.1 Sectioning

The first thing to remember when cutting samples, is to preserve the sample axes

orientation. Cut the sample in such a manner that important sample directions, like the

Rolling Direction, Transverse Direction and Sample normal are not lost.

The second thing to remember that the cutting process must not damage or change the

sample as this would lead to erroneous results

Failed parts may best be studied by selecting a specimen that intersects the origin of the

failure, if the origin can be identified on the surface. Depending on the type of failure, it

may be necessary to take several specimens from that area of the failure and from

adjacent areas.

Avoid aggressive cutting methods that generate heat or cause deformation at the cut

surface. Severe damage induced at this stage may extend so deep into the material that it

is not removed by subsequent grinding and polishing.

Heating caused during cutting may cause changes to the microstructure -phase

transformations or precipitation/diffusions mechanisms may become active.

Therefore, heating must be avoided at all costs.

Operations such as shearing produce severe cold work, which can alter the

microstructure of a sample.

Abrasive cutting (sectioning) offers the best solution to eliminate these undesirable

features; the resultant surface is smooth, and the sectioning task is quickly

accomplished. Low-speed cut-off wheels are utilized in cases where the heat created by

standard abrasive cutters must be avoided. Ample coolant and proper speed control are

essential in all sectioning operations.

The selection of abrasive wheel is therefore important to avoid introducing unnecessary

levels of damage when cutting materials.

The most widely used sectioning devices in metallographic laboratories are abrasive

cutoff machines, ranging from small, thin-sectioning machines employing abrasive or

diamond-rimmed wheels approximately 4 in. in diameter and a few mils thick to large

floor-model machines employing abrasive or diamond-rimmed wheels up to 12 in. in

diameter and 1/16 in. thick.

An advanced design of automatic cutoff machine for laboratory use employs abrasive

wheels 6 to 12 in. in diameter.

Abrasive-wheel cutting may produce deformation damage to a depth as great as 0.04 in.

Deformation damage can be minimized by using thin cutoff wheels.

A hard wheel is usually best for cutting soft stocks, whereas a soft wheel is preferred for

cutting hard materials.




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A good general purpose cutoff wheel is a medium-hard silicon carbide abrasive wheel.

All abrasive-wheel sectioning should be done wet.

An ample flow of water or water soluble oil coolant should be directed onto cut.

Some laboratory cutoff machines provide for submerged wet cutting.

Wet cutting will produce a smooth surface finish and, most important, will guard

against excessive surface damage caused by overheating.

Abrasive Blade Selection Guidelines Chart

Materials (Alloys) Classification Abrasive/Bond

Aluminum, Brass, Zinc, etc. Soft non-ferrous SiC/Rolled rubber

Heat treated alloys Hard non ferrous Alumina/Rubber resin

<Rc 45 steel Soft ferrous Alumina/Rubber resin

> Rc 45 steel Hard ferrous Alumina/Rubber resin

Superalloys High Ni-Cr alloys SiC/Rolled rubber

Diamond Wafer Blade Selection Guidelines

Material Characteristic Speed (rpm) Load (grams) Blade (grit/conc)

Silicon substrate soft/brittle <300 <100 Fine/Low

Gallium arsenide soft/brittle <200 <100 Fine/Low

Boron composites very brittle 500 250 Fine/Low

Ceramic fiber composites very brittle 500 250 Fine/Low

The Sawing method is still used today as manual hacksawing, power hacksawing, or

band hacksawing.

Surface damage with sawing is primarily mechanical deformation; usually relatively

little damage results from frictional heat.

Saw blades are generally made of hardened steel and are used to cut only materials

softer than saw blade.

Oil or water-soluble oil should be used as a cutting fluid to avoid premature wear of the

saw teeth, as well as to minimize frictional heat, which may soften the saw teeth or alter

the microstructure of the specimen below the cut surface.




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Band Saw Cutting Machine High Speed Cut-off Machine

6.2 Mounting

The primary purpose of mounting specimens is for convenience in handling specimens

of difficult shapes or sizes during the subsequent steps of preparation and examination.

A secondary purpose is to protect and preserve extreme edges or surfaces defects during

preparation.

Specimens also may require mounting to accommodate various types of devices used in

laboratories or to facilitate placement on the microscope stage.

An added benefit of mounting is the ease with which a mounted specimen can be

identified by name, alloy number, or laboratory code number for storage by scribing the

surface of the mount without damage to the specimen.

Small specimens generally require mounting so that the specimen is supported in a

stable medium for grinding and polishing. The medium chosen can be either a cold

curing resin or a hot mounting compound.

Characteristics of the mounting material include:

Good abrasion characteristics and sufficient hardness such that the edges of the sample

are protected, i.e., the rate at which abrasion takes place should be even across the face

of the mount and the specimen.

The mounting should be stable and adherent to sample. This is important, if the

mounting material has poor adhesion or high shrinkage, gaps may open up between the

mounting material and the sample surface.

When this happens, it is very difficult to prevent cross-contamination of one abrasive to

another, causing heavy scratching in the finished section.




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Also, any friable surface layers (oxide layers, etc.) should be held adhered to the surface

and not pulled off.

Proper curing -insufficient time and temperature can lead to partially cured specimen

mounts. Under these conditions the properties of the mounting material are not properly

developed and the material may be loose and powdery.

Generally, if the material is improperly cured, the hardness and abrasion characteristics

are poor and the material is adversely affected by etches and solvents.

Further, the characteristics under vacuum are very poor with out-gassing a major

problem. If the mounting stage is suspected to be at fault, it is best to break the sample

out and start again.

Stable in vacuum -no out-gassing or vapor to cause contamination. This is particularly

important for high magnification work, long map acquisition times and microscopes

with high vacuum requirement.

The mounting operation accomplishes three important functions:

Protects the specimen edge and maintains the integrity of a materials surface features

Fills voids in porous materials and

Improves handling of irregular shaped samples, especially for automated specimen

preparation without damage to the specimen.

The majority of metallographic specimen mounting is done by encapsulating the specimen into

a compression mounting compound (thermosets -phenolics, epoxies, diallyl phthalates or

thermoplastics -acrylics), casting into ambient castable mounting resins (acrylic resins, epoxy

resins, and polyester resins), and gluing with a thermoplastic glues. An added benefit of

mounting is the ease with which a mounted specimen can be identified by name, alloy number,

or laboratory code number for storage by scribing the surface of the mount.

6.2.1 Mount Size and Shape

As the size of the specimen increases, so does the difficulty of keeping the specimen

surface area flat during grinding and polishing. A saving in the time required for the

preparation of one large metallographic specimen may be realized by sectioning the

specimen into two or more smaller specimens. A specimen having an area of

approximately 1/4 sq in. is perhaps the most suitable; the maximum area should be

limited to about 4 sq in. if possible.

Thickness of the mount should be sufficient to enable the operator to hold the mount

firmly during grinding and polishing and thereby to prevent a rocking motion and to

maintain a flat surface. Circular mounts are commonly 1 to 2 in. in diameter and are the

most easily handled. The length-to-width ratio of rectangular mounts should be limited

to approximately 2 to 1 to facilitate handling.




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6.2.2 Mounting Methods

The method of mounting should in no way be injurious the microstructure of the specimen.

Mechanical deformation and the heat are the most likely sources of injurious effects.

The mounting medium and the specimen should be compatible with respect to hardness and

abrasion resistance. A great difference in hardness or abrasion resistance between mounting

media and specimen promotes differential polishing characteristics, relief, and poor edge

preservation. The mounting medium should be chemically resistant to the polishing and etching

solutions required for the development of the microstructure of the specimen.

Different types of mounting methods are given below:

Clamp Mounting

Compression Hot Mounting

Cold Mounting

Conductive Mounting

o Cold Sample Mounting

o Hot Sample Mounting

6.2.2.1 Clamp Mounting

Clamps are used most often for mounting thin sheets of metal when preparing

metallographic cross sections. Several specimens can be clamped conveniently in

sandwich form. The two clamp plates are frequently made from 1/4 in. thick steel; in

general, the hardness of the clamp should be approximate or exceed the hardness of the

specimen. The clamp plates are cut longer and wider than specimens to be clamped.

Then two holes are drilled and tapped in the face of one clamp plate outboard of the

specimen area; corresponding holes are drilled in the other clamp plate. Machine bolts

are inserted through these latter holes and into the tapped holes; the clamp plates with

the specimen or specimens are drawn tightly up means of these bolts.

Sometimes, a third bolt positioned near the top of the clamp midway between the ends

is useful for maintaining a uniform vertical separation between the clamp plates.

Clamp mounting affords a means of rapid mounting, and of very good edge

preservation by virtue of the intimate contact between specimens. On the other hand,

hairline separations between specimens occur frequently and entrap abrasive particles or

liquid solutions during preparation.




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Sometimes, the particle and liquids can be removed by soaking the mount in alcohol and

then thoroughly drying it. If this cannot be done, the liquid eventually seeps out and stains

the polished surface, and often obscures the true microstructure after etching. One solution

to this difficulty is the insertion of one thickness of transparent plastic wrapping film at each

interface. (The plastic must be one that is inert to alcohol and etchants).

Under clamping pressure, the plastic flows readily and seals all hair-line separations.

Since the film is only a fraction of a mil thick, specimen edges are preserved by

adjoining specimens or clamp edges. Alternatively, soft, thin sheets of metal of the

same type as that be examined can be used instead of the plastic film, or the mount can

be vacuum impregnated.

Clamp Mounting




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6.2.2.2 Compression (Hot) Mounting

Compression mounting, the most common mounting method, involves molding around the

specimen by heat and pressure such molding materials as Bakelite, diallyl phthalate resins,

and acrylic resins. Bakelite and diallylic resins are thermosetting, and acrylic resins are

thermoplastic. Both thermosetting and thermoplastic materials require heat and pressure

during the molding cycle, but after curing, mounts made of thermosetting materials may be

ejected from the mold at maximum temperature. Thermoplastic materials remain molten at

the maximum molding temperature and must cool under pressure before ejection.

Mounting presses equipped with molding tools and a heater is necessary for

compression mounting. Readily available molding tools for mounts having diameters of

1, 1 1/4 and 1 1/2 in. consist of a hollow cylinder of hardened steel, a base plug, and a

plunger. A specimen to be mounted is placed on the base plug, which is inserted in one

end of the cylinder. The cylinder is nearly filled with molding material in powder form,

and the plunger is inserted into open end of the cylinder.

A cylindrical heater is placed around the mold assembly, which has been positioned

between the platens of the mounting press. After the prescribed pressure has been

exerted and maintained on the plunger to compress the molding material until it and the

mold assembly has been heated to the proper temperature, the finished mount may be

ejected from the mold by forcing the plunger entirely through the mold cylinder.

Not all materials or specimens can be mounted in thermosetting or thermoplastic

mounting mediums. The heating cycle may cause changes in the microstructure, or the

pressure may cause delicate specimens to collapse or deform. The size of selected

specimen may be too large to be accepted by the available mold sizes. These difficulties

are usually overcome by cold mounting.

For metals, compression mounting is widely used. Phenolics are popular because they

are low cost, whereas the diallyl phthalates and epoxy resins find applications where

edge retention and harder mounts are required. The acrylic compression mounting

compounds are used because they have excellent clarity.




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6.2.2.3 Cold Mounting

Cold mounting requires no pressure and little heat, and is a means of mounting large numbers

of specimens more rapidly than by compression mounting.

Materials for cold mounting are classified as polyesters, epoxides and acrylics. Polyesters are

transparent and usually water clear; epoxides are almost transparent and straw color; acrylics

are opaque.

Cold mounting materials of all three classifications are two component systems that

consist of resin and a hardener; both the resin and the hardener can be liquid, both can

be solids, or one can be liquid and the other a solid. Mixing of the resin and the

hardener produces exothermic polymerization, and therefore, this operation is critical in

producing a satisfactory cure and limiting the temperature to a permissible level.

The temperature rise may reduce at the expense of longer curing time.

Cold mounting is a casting method; because each of the three classifications of cold

mounting materials is liquid after the resin and hardener are mixed (two-solid systems

are melted before mixing). The casting molds can be of any size or shape desired. For

round molds, either Bakelite ring forms, or ring sections cut from plastic or metal tubes

or pipes are suitable.

The mold material may become part of the mount in the form of an outer shell, or mold

release agents may be used to permit the mount the mount to be ejected from the mold.

Rectangular molds are formed readily by wrapping heavy-duty aluminum foil around

wood blocks of the desired size. The aluminum foil can be removed from the mount by

peeling it away, grinding it off, or using a mold release agent. Molds any size or shape

can be prepared from silicone rubber materials. The flexibility of silicone rubber molds

allows cured cold mounts to be removed easily.




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Epoxy resins are the most widely used cold mounting materials. They are hard and

adhere tenaciously to most metallurgical, mineral and ceramic specimen. They also

exhibit lower volume shrinkage then either polyesters or acrylics and are very useful for

impregnating porous structures or cracks by vacuum method. Epoxy resin mounts may

be cured in a low-temperature or placed in a low temperature oven for fast curing,

depending on the mixture ratio of resin to hardener.

Polyester resins have greater volume shrinkage the epoxies. They provide water-clear or

slightly colored transparent mounts, which strip readily from glass casting surfaces and

metal molds.

Acrylic materials are fast curing, and the mixing and casting process for the acrylics is

quick and simple. The fast curing rate results from the relatively high rate heat

evolution during exothermic polymerization, but some control of the exothermal

temperature rise can be accomplished by varying the sizes of the specimen and the

mount. Stripping acrylic mounts from metal OD glass molds is not difficult.

Cartable mounting resins are commonly used for electronic and ceramic materials.

Castable mounting resins are recommended for brittle and porous materials.

These mounting compounds are typically two component systems (1-resin and

1-hardener). Typical curing times range from minutes to hours with the faster curing

resins producing higher exothermic temperature which causes the mounting material to

shrink away from the edge during curing.

For example, the Acrylic Cold Mounting Resins cure in less than 10 minutes and Epoxy

Castable Resins cure in approximately 4-6 hours. Note that the Epoxy Castable Resin

curing cycle can be enhanced by adding an external energy source such as heat or

microwave energy. It is recommended that the room temperature be less than 85°F to

avoid overheating and uncontrollable curing of the mounting compound.




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6.2.2.3.1 Conductive Mounting

For specimens requiring metallographic preparation by electrolytic techniques, an electrically

conductive mount affords a convenient means of completing the electrical circuit through the

specimen; merely an electrical contact with the mount, rather than with specimen, is required.

Most conductive mounting materials are mixtures of a metal, usually copper or iron powder,

and thermosetting or thermoplastic molding materials.

Technique for making a mount with a conducting plastic (large dots) at the back of the

specimen and a different plastic (small dots) at the section surface.

During compression mounting the metal powder particles are compacted sufficiently to provide

electrical continuity throughout the mount. An equally convenient method is to attach a copper

wire to the back of the specimen and to format and a helix to stand upright in the mounting

press mold with its top in contact with the center of plunger. After ejection of the mount the

free end of the helix may be dug out of the mount for electrical connection.




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6.2.2.3.2 Cold Sample Mounting

Epoxy resin types generally have the best characteristics with respect to hardness and

shrinkage. However, epoxy resins tend to be slower curing and adequate time should be

allowed to ensure that the material is fully cured before proceeding. Epoxies often take

a considerable period of time after initial 'setting' to develop full hardness. It is not

generally possible to make cold curing resins conductive suitable for SEM examination.




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Cold Mounted specimens (a) Mounted with polyester (b) Mounted with acrylic

(c) Mounted with acrylic and mineral fillers




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6.2.2.4 Hot Mounting

Hot mounting uses a thermosetting compound, cured in a mounting press which exerts

both heat and high pressure. This mounting method produces hard mounts in a short

space of time. However, the heating (generally, in the order of 120°C) and considerable

pressure applied may be unsuitable for delicate, soft or low melting point specimens.

Techniques may be used to protect a delicate sample from the effects of pressure, such

as placing the sample under a supporting structure within the molding cavity. Such a

supporting structure can protect the sample from the initial pressure applied when the

mounting material is in a granular form, and most likely to inflict damage. When the

mounting material becomes fluid, infiltration should occur to encapsulate the sample

which will then be subject to hydrostatic pressure.




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Hydrostatic pressure can be applied to all but the most delicate of samples without

problem. In the case of very soft or thermally sensitive materials, hot mounting is not

appropriate. Conductive mounting resins are available, which are good for SEM

examination, although the adhesion and hardness characteristics are not as good as

those of epoxy hot set compounds. If the edges of the specimen are not of interest, then

nonconductive mounting materials can be used. In general, hot mounting is preferable

to cold setting resins, when the sample is not affected by temperature and pressure

(200ºC and 50 kN). However, not all specimens can tolerate this.

Non-conductive mounts must be covered with adhesive conductive tape or coated with

a conductive medium (the sample area can be masked if sputter coating, or using an

evaporator. Aluminum foil or glass cover slips are useful for this purpose. Note: many

adhesive metal tapes have non-conductive adhesive, so the use of carbon/silver

conductive paint may be required at seams. Whilst very thin films of carbon can be

tolerated on the sample, the ideal is that the sample surface should be bare.

Hot Mounting may be unacceptable, if the effect of temperature and pressure are

expected to be inappropriate for the sample under investigation. Generally, the materials

employed for cold setting cannot match the hardness of materials traditionally used in

Hot Mounting. This may lead to compromises in the degree of edge protection and

support that the mount provides for the sample. Further, the abrasion characteristics

may need to be taken into account during the preparation.

Specimen Mounting




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6.3 Grinding

Grinding is a most important operation in specimen preparation. During grinding the

operator has the opportunity of minimizing mechanical surface damage that must be

removed by subsequent polishing operations. Even if sectioning is done in a careless

manner, resulting is severe surface damage, the damage can be eliminated by prolonged

grinding. However, prolonged polishing will do little toward eliminating severe surface

damage introduced by grinding.

Grinding is accomplished by abrading the specimen surface through a sequence of

operations using progressively finer abrasive grit. Grit sizes from 40 mesh through

150 mesh are usually regarded as coarse abrasives and grit sizes from 180 mesh through

600 mesh as fine abrasives.

Grinding should commence with coarse grit size that will establish an initial flat surface

and remove the effects of sectioning within a few minutes. An abrasive grit size 150 or

180 mesh is coarse enough to use on specimen surfaces sectioned by an abrasive cutoff

wheels. Hacksawed, band sawed or other rough surfaces usually require abrasive grit

sizes in the range 80 to 150 mesh. The abrasive used for each succeeding grinding

operation should be one or two grit size smaller than that used in the preceding

operation. A satisfactory grinding sequence might involve grit sizes of 180, 240, 400

and 600 meshes.

As in abrasive-wheel sectioning, all grinding should be done wet, provided water has no

adverse effects on any constituents of the microstructure. Wet grinding minimizes

loading of the abrasive with metal removed from the specimen being prepared.

Water flushes away most of the surface removal products before they become

embedded between adjacent abrasive particles. Thus, the sharp edges of the abrasive

particle remain exposed to the surface of the specimen throughout the operation. Use of

worn-out abrasives and dulled cutting edges is detrimental to good preparation.

Wet grinding provides effective control of overheating. The abraded surface of a

specimen may become embedded with loose abrasive particles during grinding.

These particles may persist in the surface and appear to be nonmetallic inclusions in the

polished specimen.

The purpose of grinding is to lessen the depth of deformed metal to the point where the

last vestiges of damage can be removed by series of polishing steps. The scratch depth

and the depth of cold worked metal underneath the scratches decrease with decreasing

particle size of abrasive. However, the depth of cold worked metal is roughly inversely

proportional to the hardness of the specimen and may be 10 to 50 times the depth of

penetration of the abrasive particle. It is imperative that each grinding steps completely

remove the deformed metal produced by the previous step. The operator usually can

assume this is accomplished if he or she grinds more than twice as long as the time

required to remove the scratches incurred by the previous step.




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To ensure the complete elimination of the previous grinding scratches found by visual

inspection, the direction of grinding must be changed 45 to 90 degrees between

successive grit sizes. In addition, microscopic examination of the various ground

surfaces during the grinding sequence may be worthwhile in evaluating the effect of

grinding. Each ground surface should have scratches that are clean-cut and uniform in

size, with no evidence of previous grinding scratches.

Success in grinding depends in part on the pressure applied to the specimen. A very light

pressure removes insufficient metal. Somewhat heavier pressure produce polishing, while

still heavier pressure brings about the desired grinding action. Very heavy pressure results

in non-uniform scratch size, deep gouges, and embedded abrasive particles. Generally, a

medium to moderately heavy pressure applied firmly gives the best results.

Most grinding of metallographic specimen is performed by manually holding the

specimen with its surface against a grinding material. To establish and maintain a flat

surface over the entire area being ground, the operator must apply equal pressure on

both sides of the specimen and avoid any rocking motion that will produce a convex

surface. If grinding operation is interrupted -the operator must re-establish contact with

grinding material carefully in order to resume grinding in the plane already established.

Specimens should be cleaned after each grinding steps to avoid any carryover of

abrasive particles to the next step. Water solutions containing detergents are excellent

cleaners and ultrasonic cleaning is an effective technique. Cleanness of the operator's

hands is as important as cleanness of specimen. Contamination of the grinding

equipment by flying abrasive particles must be avoided

The grinding abrasives commonly used in the preparation of specimens are silicon

carbide (SiC), aluminum oxide (Al2O3), emery (Al2O3 -Fe3O4), diamond particles, etc.

Usually are generally bonded to paper or cloth backing material of various weights in the

form of sheets, disks and belts of various sizes. Limited use is made of grinding wheels

consisting of abrasives embedded in a bonding material. The abrasive may be used also in

powder form by charging the grinding surfaces with loose abrasive particles.

Silicon carbide has a hardness of 9.5 on the Mohs scale, which is near the hardness of

diamond. Silicon carbide abrasive particles are angular and jagged in shape and have

very sharp edges and corners. Because of these characteristics, silicon carbide is very

effective grinding abrasive and is preferred to other abrasives for metallographic

grinding of almost all types of metal.

Aluminum oxide abrasive material has a trigonal crystal structure and a hardness of 9.1

on the Mohs scale and is a synthetic corundum.

Emery is an impure, fine-grained variety of natural corundum containing 25 to 45

admixed iron oxide. The hardness of emery is Mohs 8.0. Emery abrasive particles have

much smoother surfaces than either silicon carbide or aluminum oxide abrasive

particles. For this reason, emery particles do not feel as coarse as silicon carbide or

aluminum oxide particles of equivalent grit size and the cutting rate of emery is inferior

to that of either of the two other abrasives.




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Another abrasive material used occasionally for grinding specimens is boron carbide,

which has a hardness of nearly 10 on Mohs scale. Boron carbide is used primarily for

grinding ceramic and other extremely hard materials.

Increasing use is being made of diamond as grinding medium as well as polishing

medium. Carefully sized diamond abrasive particles are available from 280 microns

(about 60 meshes) to 0.25 microns in size. The coaser grades of diamond are used in the

form of resin-bonded cloth-backed disks, metal bonded lapping surfaces, and loose

particles for charging of grinding surfaces.

Diamond abrasives of all sizes are available as suspensions in oil-soluble and water-

soluble paste vehicles known as diamond compounds. The extreme hardness (Mosh 10)

and sharp cutting edges of diamond particles impart at high cutting rate to diamond

abrasives. Diamond abrasives are particularly suitable for grinding the harder alloys and

refractory materials.




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6.3.1 Hand Grinding

Manual Preparation -In order to insure that the previous rough grinding damage is

removed when grinding by hand, the specimen should be rotated 90 or 45 degrees and

continually ground until all the scratches from the previous grinding direction are

removed. If necessary the abrasive paper can be replace with a newer paper to increase

cutting rates.

A simple setup for hand grinding can be provided by a piece of plate glass, or other

material with hard, flat surface, on which an abrasive sheet rests. The specimen is held

by hand against the abrasive sheet as the operator moves specimen in rhythmic style

away from and toward him in a straight line. Heavier pressure should be applied on the

forward stroke than on the return stroke. The grinding can be done wet by sloping the

plate glass surface toward the operator and providing a copious flow of water over the

abrasive sheet.

Planar Grinding -or course grinding is required to planarize the specimen and to reduce

the damage created by sectioning. The planar grinding step is accomplished by

decreasing the abrasive grit/ particle size sequentially to obtain surface finishes that are

ready for polishing. Care must be taken to avoid being too abrasive in this step, and

actually creating greater specimen damage than produced during cutting (this is

especially true for very brittle materials such as silicon).




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The machine parameters which effect the preparation of metallographic specimens

includes: grinding/polishing pressure, relative velocity distribution, and the direction of

grinding/polishing.

Grinding Pressure -Grinding/polishing pressure is dependent upon the applied force

(pounds or Newtons) and the area of the specimen and mounting material. Pressure is

defined as the Force/Area (psi, N/m² or Pa). For specimens significantly harder than the

mounting compound, pressure is better defined as the force divided by the specimen

surface area. Thus, for larger hard specimens higher grinding/polishing pressures increase

stock removal rates; however, higher pressure also increases the amount of surface and

subsurface damage. Note for SiC grinding papers, as the abrasive grains dull and cut rates

decrease, increasing grinding pressures can extend the life of the SiC paper.

Higher grinding/polishing pressures can also generate additional frictional heat which

may actually be beneficial for the chemical mechanical polishing (CMP) of ceramics,

minerals and composites. Likewise for extremely friable specimens such as nodular cast

iron, higher pressures and lower relative velocity distributions can aid in retaining

inclusions and secondary phases.

Relative Velocity -Current grinding/polishing machines are designed with the

specimens mounted in a disk holder and machined on a disk platen surface. This disk on

disk rotation allows for a variable velocity distribution depending upon the head speed

relative to the base speed.

In practice, a combination of a high velocity distribution (150 rpm head speed/300 -600 rpm

base speed) for the initial planarization or stock removal step, followed by a moderate speed

and low velocity distribution (120-150 rpm head speed/150 rpm base speed) step is

recommended for producing relatively flat specimens. For final polishing under chemical

mechanical polishing (CMP) conditions where frictional heat can enhance the chemical

process, high speeds and high relative velocity distributions can be useful as long as brittle

phases are not present (e.g., monolithic ceramics such as silicon nitride and alumina).




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Grinding Direction -The orientation of the specimen can have a significant impact on

the preparation results, especially for specimens with coatings. In general, when

grinding and polishing materials with coatings the brittle component should be kept in

compression. In other words, for brittle coatings the direction of the abrasive should be

through the coating and into the substrate. Conversely, for brittle substrates with ductile

coatings, the direction of the abrasive should be through the brittle substrate into the

ductile coating.

For metallic specimen grinding, sequential grinding with silicon carbide (SiC) abrasive

paper is the most efficient and economical rough grinding process. Although extremely

coarse grit abrasive papers can be found, it is recommended that a properly cut

specimen not be rough ground with an abrasive greater than 120 grit SiC paper.

A typical abrasive grinding procedure would consist of 120 or 240 grit SiC paper

followed by decreasing the size of the SiC paper (320, 400, and 600 grit). Finer papers

are also available for continued abrasive paper grinding (800 and 1200 grit).

In addition to the correct sequence and abrasive size selection, the grinding parameters

such as grinding direction, load and speed can affect the specimen flatness and the

depth of damage.

The basic idea is to remove all of the previous specimen damage before continuing to

the next step while maintaining planar specimens.

6.3.2 Automatic Grinding

As the name implies, is done without hand assistance. All automatic grinding devices use

lap surfaces on which paper-backed disks are placed or abrasive powder is charged. The lap

is either a rotating or a vibrating disk. Use of a latter is described as vibratory grinding.

The key to successful automated preparation is to thoroughly clean the specimens

between each abrasive grit size used. The tracking of the specimens should also

uniformly break down the SiC paper, otherwise, non-uniform grinding will occur

(especially for hard specimens in soft mounts). In other words, the specimen should

track across the entire diameter of the SiC paper.

6.3.2.1 Coarse Grinding

Grinding can be achieved in a variety of ways, using a variety of abrasives.

Fixed abrasive surfaces are available using diamond or cubic boron nitride (CBN)

abrasives. The method used to bind the abrasives to the wheel affects the grinding

characteristics, the harder or more rigid the bonding medium, the more aggressive the

grinding action of the surface. Therefore, metal bonded fixed abrasive wheels are the

most aggressive grinding surfaces, whereas resin bonded wheels are less aggressive.




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Coarse grit Silicon Carbide or Alumina abrasives may be used, but the durability or

characteristics of such materials may be inappropriate for certain materials. Generally, in

order to maintain sharp abrasive particles, grinding papers need frequent changing.

Follow the manufacturer's recommendations and advice.

Automatic Grinding Machine

Fine Grinding




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Silicon Carbide (SiC) paper is the traditional method used for fine grinding and is

adequate when used properly. SiC paper blunts quickly and therefore, should be

discarded after a short period of grinding in order to maintain efficient 'stock' removal.

Grinding on a surface that has blunt abrasives causes a great deal of surface damage by

smearing, 'burnishing' and local heating.

Ensure that sharp abrasives are used and follow the manufacturer’s instructions with

regard to grinding speeds, direction, force, times and lubricants used. Damage injected

during grinding may be invisible in the polished surface. Remember that different

materials have different abrasion characteristics. The selection of grinding material and

conditions can therefore be specific to a given sample.

After every grinding stage it is advisable to inspect the ground surface using a light

microscope in order to ensure that all damage from the previous stage, whether that be a

cutting or grinding stage, is completely removed. Advance in this manner to the finest

abrasive size required, ready for polishing. Care at this stage will greatly reduce the

amount of polishing required to achieve a good surface.

6.4 Polishing

Diamond polishing compounds or slurries are good for preliminary stages for most

materials. Polishing is a similar action to grinding, accept that the supporting medium

used to hold the abrasive is capable far greater 'shock absorbency', i.e., the ability of the

medium to allow the abrasive to move to some degree and conform to the surface

aspirates of the specimen. Thus, different polishing surface materials have differing

characteristics: soft cloths allow the greatest shock absorbency and therefore, allow for

gentle polishing with little damage associated.

However, soft cloths allow the abrasive to abrade different areas at different rates,

giving rise to relief'. Relief' is the term used to describe the undulations that form in a

polished surface. Extreme undulations or relief in the polished surface is to be avoided,

although a certain amount can be tolerated (or even desirable) because the SEM

generally has high depth of field. Harder polishing surfaces or cloths, conversely,

produce a flatter or 'plane' surface, but may leave polishing damage in the surface of the

material, and promote superficial scratching.




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Therefore, it is usually the case that polishing is started on a hard cloth with a coarser

abrasive and finished on a softer cloth with a finer abrasive. Final polishing should not

be prolonged, but just sufficient to achieve the desired surface finish without causing

excessive relief.

Polishing is the final step in production a surface that is flat, scratch free, and mirror

like in appearance. Such a surface is necessary for subsequent accurate metallographic

interpretation, both qualitative and quantitative. The polishing technique used should

not introduce extraneous structure such as disturbed metal, pitting, dragging out of

inclusions, comet tails and staining.

Before final polishing is started, the surface condition should be at least as good that

obtained by grinding with a 400-grit (25 microns) abrasive.

High quality preparation of most metallographic specimens often can be expedited by

the use of automatic polishers. Automatic polishing equipment usually allows the

preparation of several specimens simultaneously. Some methods of specimen

preparation can be done only with automatic polishers, such as remote polishing of

radioactive materials, chemical-mechanical polishing, and polishing in special

atmospheres. There is no ideal automatic polisher; each has its merits and shortcomings

and each metallographer must determine which is best for his particular requirements.

One of the most popular cloths for final polishing of most metals is composed of

densely packed, vertically aligned, synthetic fibers bonded to a suitable backing.

For some metals or for particular types of polishing, other cloths, such as velvets, satins,

cashmeres or cottons, may be required. The ability to select the proper combination of

cloth, abrasive, carrier, polishing speed (rotational speed of the polishing wheel), and

pressure applied can be acquired only by experience.




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Polishing usually involves the use one or more of five types of abrasive: aluminum

oxide (Al2O3), magnesium oxide (MgO), chromic oxide (Cr2O3), iron oxide (Fe2O3),

and diamond compound. With the exception of diamond compound these abrasives are

normally used in a distilled water suspension, but if the metal to be polished is not

compatible with water, other suspensions, such as ethylene glycol, alcohol, kerosene or

glycerin, may be required. The diamond compounds should be extended only with the

carrier recommended by the manufacturer.

Aluminum oxide (aluminia) is the polishing abrasive most widely used for general

metallographic polishing. The alpha grade aluminum oxide is used in a range of particle

sizes from 15 microns to 0.3 micron. For some hard materials the 0.3 micron size is

sufficient for a final polish. The gamma grade of aluminum oxide is available in a

0.05 micron particle size for final polishing.

Magnesium oxide (magnesia) is recommended for final polishing, especially for the

preparation of magnesium and aluminum, and their alloys. Only the metallographic

grades, which contain no water soluble alkalis, should be used; otherwise, any free

alkalis present could stain and chemically attack the specimen. Magnesium oxide also

reacts slowly with water to form magnesium hydroxide. This in turn reacts with carbon

dioxide present in the atmosphere and in tap water to form magnesium carbonate, which

can contaminate the polishing lap.

Diamond polishing compounds are becoming increasingly popular for preparing

metallographic specimen. Diamond is the only substance hard enough and with good

enough cutting qualities to be used for mechanical polishing of materials such as boron

carbide and sintered tungsten. Specimens that have both hard and soft constituents, such

as graphite in cast iron and silicon in aluminum, can be polished without causing relief,

with diamond compounds on an appropriate lap. These polishing compounds are

available either in water soluble and oil soluble carriers or in the form of dry diamond

powder in particle size down to 0.25 microns.

Rough Polishing-The purpose of the rough polishing step is to remove the damage

produced during cutting and planar grinding. Proper rough polishing will maintain

specimen flatness and retain all inclusions or secondary phases. By eliminating the

previous damage and maintaining the microstructural integrity of the specimen at this

step, a minimal amount of time should be required to remove the cosmetic damage at

the final polishing step. Rough polishing is accomplished primarily with diamond

abrasives ranging from 9 micron down to 1 micron diamond. Polycrystalline diamond

because of its multiple and small cutting edges, produces high cut rates with minimal

surface damage, therefore, it is the recommended diamond abrasive for metallographic

rough polishing on low napped polishing cloths.




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6.5 Electrolytic Polishing

In electrolytic polishing (electropolishing), the specimen is the anode in an electrolytic

cell. Direct current from an external cell is applied to the electrolytic cell under specific

conditions, and anodic dissolution results in a leveling and brightening of the specimen

surface. The most widely accepted theory postulated to explain the leveling action

concerns the layer of viscous material (usually visible) that is present on the specimen

surface during electropolishing. This layer is composed of products that result from the

reaction between the metal and the electrolyte, and is, according to the theory, necessary

for proper electropolishing.

Electropolishing does not disturb any metal on the specimen surface and therefore, is

ideally suited for the metallographic preparation of soft metals, most single-phase alloys,

and alloys that work harden readily. The disadvantages of electro polishing include

preferential attack in multiphase alloys caused by differences in electrical potential

between phases, and chemical attack of nonmetallic inclusions by the electrolyte.

Proper choice of electrolyte and operating conditions will minimize these disadvantages.

6.6 Etching

After polishing, the specimen should be etched to develop additional contrast to reveal

the microstructure.

The purpose of etching is to optically enhance the microstructural features such as grain

size and phase features. Etching selectively alters these microstructural features based

on composition, stress, or crystal structure. The most common technique for etching is

selective chemical etching.

Selection of the proper etchant depends largely depends upon alloy composition, heat

treatment, and processing. The etchants for metallographic examination are solutions of

acids and other chemicals that are applied selectively to attack a highly polished

surface, thus permitting microstructural examination.

The following two methods are mainly used for at the lab etching:

6.6.1 Chemical Etching using Swabbing

The sample is swabbed with cotton that has been immersed in the etchant.

Metallograhic specimens are usually chemically etched with solution composed of

organic or inorganic acids or with basic solution, combined with another substance that

may influence the selectivity of the etchant, all in a solvent of either water, alcohol,

glycerin, glycol, or some combination of these etchants are typically prepared in small

batches for each use. Solution that is used frequently may be prepared in larger

quantities and stored such as 2% Nital, Vilalla’s 10% oxalic acid. However, a note of

caution is in order here: There are certain etchant that cannot be stored even if they are




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used frequently. They must be used “fresh,” either because they lose their potency in

storage or because in storage, they may form an explosive mixture (for example, equa

regia and picral or picric acid).

The most commonly used chemical etchants are given in the table below:

EE Composition Application Condition

Kellers Etch

190 ml Distilled water

5 ml Nitric acid

3 ml Hydrochloric acid

2 ml Hydrofluoric acid

Aluminum

alloys

10-30 second immersion.

Use only fresh etchant

Kroll's

Reagent


6 ml Nitric acid

2 ml Hydrofluoric acid

Titanium 15 seconds

Nital 100 ml Ethanol

1-10 ml Nitric acid

Carbon steels,

tin and nickel

alloys

Seconds to minutes

Kallings

Reagent


2 grams Copper chloride (CuCl2)


40-80 ml Ethanol (85%) or Methanol (95%)

Wrought

stainless steel,

Fe-Ni-Cr alloys

Immerse or swab for few

seconds to a few minutes

Murakami

Reagent

100 ml Distilled Water

10 grams K3Fe(CN)8

10 grams NaOH or KOH

Wrought

Stainless steel,

tungsten alloys,

silver alloys,

SiC, B4C

Immerse or swab for

seconds to minutes

Picral 100 ml Ethanol

2-4 grams Picric acid

Carbon and low-

alloy steels

Vilella's

Reagent

45 ml Glycerol

15 ml Nitric acid


Stainless steel,

carbon steel,

cast iron

Seconds to minutes

Chemical Etching




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6.6.2 Electrolytic Etching

In electrolytic or anodic etching, an electrical potential is applied to the specimen by

means of an external circuit. Typical setup consist, the specimen (anode) and its counter

electrode (cathode) immersed in an electrolyte.

During the process of electrochemical etching of metallic specimen, reduction and

oxidation process (redox process) take place. All metals in contact with the solution

have a pronounced tendency to become ionized by releasing (losing) electrons.

The degree to which this reaction takes place may be recorded by measuring the

electrochemical potential. This is done by comparing the potential of metal versus the

standard potential of a reference electrode.




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7 Optical Microscopy

Microscopes are required for the examination of the microstructure of the metals.

Optical microscopes are used for resolutions down to roughly the wavelength of light

(about half a micron) and electron microscope are used for detail below this level, down

to atomic resolution.

The most commonly used microscope is the conventional light microscope. In principle,

optical microscopes may be used to look through specimens (‘in transmission’) as well

as at them (‘in reflection’). Many materials, however, do not transmit light and so we

are restricted to looking at the surface of the specimens with an optical microscope.

With optical microscopy, the light microscope is used to study the microstructure;

optical illumination systems are its basic elements. For materials that are opaque to

visible light (all metals, many ceramics and polymers), only the surface is subject to

observation, and the light

Microscope must be used in a reflective mode. Contrasts in the image produced result

from differences in reflectivity of the various regions of the microstructure.

Careful and meticulous surface preparations are necessary to reveal the important details

of the microstructure. The specimen surface must first be ground and polished to a

smooth and mirror like finish. This is accomplished by using successively finer abrasive

papers and powders. The microstructure is revealed by a surface treatment using an

appropriate chemical reagent in a procedure termed etching. The etching reagents depend

on the material used and after etching the specimen must be washed with alcohol and

ether to remove the grease. The atoms at the grain boundaries are chemically more active,

and consequently dissolve more readily than those within the grains forming small

grooves. These grooves become discernible when viewed under a microscope because

they reflect light at an angle different from that of the grains themselves.

Microscopy can give information concerning a material’s composition, previous

treatment and properties. Particular features of interest are grain size, phases present,

chemical homogeneity, distribution of phases, elongated structures formed by plastic

deformation.

7.1.1 Photography

Once the polished and etched sample is prepared, it is viewed under microscope.

Microstructures of various magnifications can be viewed and every magnification

viewed microstructures can be saved in the local hard disk as photographs to present in

the failure analysis reports.

The microstructures can also be compared with ASM Handbook Volume 9 for cross

references whenever required.




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7.1.2 Grain Size Measurement

Grain size is measured with microscope by counting the number of grains within a given area,

by determining the number of grains that intersect a given length of random line, or by

comparison with standard charts. The average grain diameter D can be determined from

measurements along random lines by the equation;

N

LD

where L is the length of the line and N is the number of intercepts which the grain boundary

makes with the line. This can be related to the ratio of the grain-boundary surface area S to the

volume of the grains, V, by the equation;

A

l

L

N

V

S 42

where l is the total length of grain boundary n a random plane of polish and A is the total area

of the grains on a random plane of polish. A very common method of measuring grain size is to

compare the grains at a fixed magnification with the American Society for Testing and




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Materials (ASTM) grain-size charts. The ASTM grain-size number n is related to N, the

number of grains per square inch at a magnification of 100X by the relationship:

12* nN

The table below compares the ASTM grain-size numbers with several other useful measures of

grain size.

Comparison of Grain-Size Measuring Systems (ASM Metals Handbook.)

ASTM # Grains/in2

@ 100X Grains/mm2 Grains/mm3

Average Grain

Diameter (mm)

-3

-2

-1

0

1

2

3

4

5

6

7

8

9

10

11

12

0.06

0.12

0.25

0.5

1

2

4

8

16

32

64

128

256

512

1024

2048

1

2

4

8

16

32

64

128

256

512

1024

2048

4096

8200

16400

32800

0.7

2

5.6

16

45

128

360

1020

2990

8200

23000

65000

185000

520000

1200000

1500000

1.00

0.75

0.50

0.35

0.25

0.18

0.125

0.091

0.062

0.044

0.032

0.022

0.016

0.011

0.008

0.00096




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8 Chemical Analysis

8.1 Texas Nuclear

This analytical test is used to identify the elements in a sample by exiting inner shell

electrons using x-rays.

The limitation of Nuclear analyzer is that they won’t be able to analyze the carbon content,

whereas spectro analyzer can analyze all elements including carbon content.




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8.2 Arc-Met

All elements have specific characteristics wavelengths similar as finger prints.

Emission spectrographic analysis of a material results in a characteristic wavelength

spectrum which is used to identify the actual elements that are present in the sample.

Spectro analysis is faster compared to chemical analysis and the equipment is portable

through a trolley in many cases.




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9 Mechanical Testing

Mechanical testing provides data which can be used to assess the property of the materials

against the design data value.

The material properties can be determined by mechanical testing are yield strength, ultimate

tensile strength, ductility, hardness and toughness. The main tests performed in the lab are

Hardness, tensile and impact tests.

9.1 Hardness Testing

9.1.1 Macro Hardness Testing

Hardness is the resistance of material against penetration, measured by indentation under a

constant load. There are two main types of macro hardness tests, Rockwell and Brinell tests.

9.1.1.1 Rockwell Hardness Test

Rockwell is a fast method, developed to be used for production control and has a direct readout.

The Rockwell hardness (HR) is calculated by measuring the depth of an indent, after an

indenter has been forced into the specimen material at a given load. The indenter material is a

conical diamond, a sintered carbide or steel ball, depending on the scale being used. A minor

preload is applied before the main load is put on and thereafter unloaded. The readout of the

hardness value is performed while the minor preload is still applied.

There are two types of Rockwell tests:

Regular Rockwell where the minor load is 10 kgf, the major load is 60, 100 or 150 kgf; and

Superficial Rockwell, used for thinner specimens where the minor load is 3 kgf and major loads

are 15, 30 or 45 kgf. Generally, the tested material should not be mounted in resin, because the

Rockwell test uses the motion of the indenter to measure the hardness and not the indentation

area. The influence hereof however, depends on the machine used.

Rockwell hardness values are expressed as a combination of a hardness number and a scale

symbol representing the indenter and the minor and major loads. The hardness number is

expressed by the symbol HR and the scale designation.

There are 30 different scales. The majority of applications are covered by the Rockwell C and

B scales for testing steel, brass, and other metals. However, the increasing use of materials

other than steel and brass as well as thin materials necessitates a basic knowledge of the factors

that must be considered in choosing the correct scale to ensure an accurate Rockwell test.

The choice is not only between the regular hardness test and superficial hardness test, with

three different major loads for each, but also between the diamond indenter and the 1/16, 1/8,

1/4 and 1/2 in. diameter steel ball indenters.




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Rockwell harness test can be used for most materials but typically only for larger sized

specimens due to the high loads and the indenters used.

9.1.1.2 Brinell (BHN) Hardness Tests

Brinell indentation gives a relatively large impression with a tungsten carbide ball, denotation

HBW (W is the chemical symbol for tungsten). The size of the indent is read optically in order

to determine the hardness. Typical Applications are forgings and castings where the structural

elements are large and inhomogeneous or structures too coarse for other methods

(Rockwell/Vickers) to give a representative result.

Load Range: 1-3000 kgf. Indenter Types: 1 / 2.5 / 5 / 10 mm diameter balls.

The Brinell harness is calculated by the following formula:

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Brinell is suitable for inhomogeneous metals and metals containing coarse structural elements,

as for example castings and forgings. Limited to larger specimens due to high loads and

indenters used – in particular cast irons, steel and aluminum.

9.2 Micro Hardness Testing

9.2.1 Vickers Hardness (HV)

Vickers Hardness test is calculated by measuring the diagonal lengths of an indent left by

introducing a diamond pyramid indenter with a given load into the sample material. The size of

the indent is read optically in order to determine the hardness. The hardness value can be

obtained from a table or formula after determining the mean value of the two measured

diagonals or directly in an automatic hardness tester. The Vickers scale ranges from 10 gf to

100 kgf. For Vickers hardness testing, the obtained hardness value is relatively unaffected by

the applied load.

The Vickers hardness test is calculated by the formula:

HV = 2F sin (136 ° /2)

d²

where F is the force and d is the mean diagonal.

Vickers is the most versatile method, due to only one indenter and can be used for all materials

and many applications, but requires a relatively good surface finish.




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Universal Hardness Testing Machine

9.3 Tensile Testing

The most common type of test used to measure the mechanical properties of a material is the

Tensile Test. This test is widely used to provide basic design information on the strength of

materials and is an acceptance test for the specification of materials. The major parameters that

describe the stress-strain curve obtained during the tension test are the tensile strength (UTS),

yield strength or yield point (σy), elastic modulus (E), percent elongation (ΔL%) and the

reduction in area (RA%). Toughness, Resilience, Poisson’s ratio(ν) can also be found by the

use of this testing technique.

9.3.1 Specimen Machining

Tensile specimens are machined from the material to be tested in the desired orientation and

according to the standards, i.e., ASTM A370 and API 5L. The cross section of the specimen is

usually round, square or rectangular. For metals, a piece of sufficient thickness can be obtained

so that it can be easily machined; a round specimen is commonly used. For sheet and plate

stock, a flat specimen is usually employed. The change in the gage length of the sample as




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pulling proceeds is measured from either the change in actuator position (stroke or overall

change in length) or a sensor attached to the sample (called an extensometer). The standard

dimension for all weld tensile test specimens is given below.

9.3.2 Testing

A tensile load is applied to the specimen until it fractures. During the test, the load required to

make a certain elongation on the material is recorded. A load elongation curve is plotted by an

x-y recorder, so that the tensile behavior of the material can be obtained. An engineering stress-

strain curve can be constructed from this load-elongation curve by making the required

calculations. Then, the mechanical parameters that we search for can be found by studying on

this curve.

A typical engineering stress-strain diagram and the significant parameters are shown on the figure.

Engineering Stress is obtained by dividing the load by the original area of the cross section of

the specimen.

Stress σ = P/Ao (Load/Original cross-sectional area)

Strain = e = Δl/lo (Elongation/Original gage length)

Engineering stress and strain are independent of the geometry of the Specimen.

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Elastic Region: The part of the stress-strain curve up to the yielding point.

Elastic deformation is recoverable. In the elastic region, stress and strain are related to each

other linearly.

Hooke’s Law: σ = Ee

The linearity constant E is called the elastic modulus which is specific for each type of material.

Plastic Region: The part of the stress-strain diagram after the yielding point.

At the yielding point, the plastic deformation starts. Plastic deformation is permanent. At the

maximum point of the stress-strain diagram (σUTS), necking starts. Tensile Strength is the

maximum stress that the material can support.

σUTS = Pmax/Ao

Because the tensile strength is easy to determine and is a quite reproducible property,

it is useful for the purposes of specifications and for quality control of a product.

Extensive empirical correlations between tensile strength and properties such as hardness and

fatigue strength are often quite useful. For brittle materials, the tensile strength is a valid

criterion for design. A typical Stress- Strain Diagram for a ductile material is below.

Tensile Testing Machine




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Yield Strength is the stress level at which plastic deformation starts. The beginning of first

plastic deformation is called yielding. It is an important parameter in design of materials for

any application. The stress at which plastic deformation or yielding is observed to begin

depends on the sensitivity of the strain measurements. With most materials there is a gradual

transition from elastic to plastic behavior, and the point at which plastic deformation begins is

hard to define with precision. Various criteria for the initiation of yielding are used depending

on the sensitivity of the strain measurements and the intended use of the data. 0,2% off-set

method is a commonly used method to determine the yield strength. σy(0.2%) is found by

drawing a parallel line to the elastic region and the point at which this line intersects with the

stress-strain curve is set as the yielding point. An illustration of 0,2% off-set method is shown

in the appendix part.

Ductility is the degree of plastic deformation that a material can withstand before fracture.

A material that experiences very little or no plastic deformation upon fracture is termed brittle.

In general, measurements of ductility are of interest in three ways:

To indicate the extent to which a metal can be deformed without fracture in

metalworking operations such as rolling and extrusion.

To indicate to the designer, in a general way, the ability of the metal to flow plastically

before fracture.

To serve as an indicator of changes in impurity level or processing Conditions.

Ductility measurements may be specified to assess material quality even though no direct

relationship exists between the ductility measurement and performance in service. Ductility can

be expressed either in terms of percent elongation (z) or percent reduction in area (q);

z = %Δl = [(lf-lo)/lo]*100

q = %RA = [(Ao-Af)/Ao]*100

9.4 Impact Testing

The purpose of impact testing is to know the toughness and ductile to brittle transition

temperature of materials. Charpy impact testing is the main method used in the laboratory.

9.4.1 Sample Preparation

The standard Charpy V notch specimen is 55 mm long, 10 mm square and has a 2 mm deep

notch with a tip radius of 0.25 mm machined on one face. Also, Charpy impact specimen may

be used with a key hole or a U notch for testing of brittle materials such as cast iron or plastics.




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The standard dimension of specimens is given below.

The notch profile can be cross verified usually by shadow masters for the correct dimension

prior to actual testing.

9.4.2 Testing

The Charpy impact test involves striking standard specimen with a controlled weight pendulum

traveling at a speed. The amount of energy absorbed in fracturing the test piece is measured and

gives an indication of notch toughness of the material. The test allows the material to be

classified as being either brittle or ductile. A brittle material will absorb a small amount of

energy and a ductile material will absorb large amount of energy. It must be noted that the

impact test results only can be compared with each other or with a requirement in the

specification, but cannot be used to calculate the fracture toughness of the weld or parent

material.




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Charpy Impact Testing Machine

From impact tests, it’s also possible to measure the percentage of crystallinity and lateral

expansion. The appearance of fracture surface gives information about the type of fracture that

has occurred. A brittle fracture is bright and crystalline and the ductile fracture is dull and

fibrous. The percentage of crystallinity is therefore, a measure of amount of brittle fracture,

determined by estimating the amount of crystalline or brittle fracture on the surface of the

broken specimen.




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Lateral expansion is a measure of the ductility of the specimen. When a ductile metal is broken

the test piece deforms before breaking. The amount by which the specimen deforms is

measured and expressed as millimeters of lateral expansion.




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10 Heat Treatment

Heat treatment is nothing but controlled heating and cooling, normally to extreme temperatures

to achieve the desired mechanical properties or to relieve the residual stresses in a metal or

weld. For C-Mn steels, the knowledge of Iron carbon phase diagram is important to understand

the heat treatment.




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There are various types of heat treatment to achieve the required mechanical properties as given

below.

Annealing

Normalizing

Quenching

Tempering

10.1 Annealing

The material is heated to elevated temperature (above the recrystallization temperature) where

there is full austenization for an extended time period and then slowly cooled (maximum of

20 degrees Celsius per hour) in the furnace. Annealing is carried out to relieve the stresses,

increase the softness and ductility and reduce the chemical segregation and inhomogenity.

The microstructure resulted from annealing for Carbon Manganese steel is pearlite and ferrite.




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10.2 Normalizing

For normalizing, the material is heated above the upper critical temperature (A3) in furnace to

have full austenite stabilization and then air cooled after removal from furnace. The purpose of

normalizing is to relieve the internal stresses and to have good ferrite pearlite microstructure.

Normalizing results in grain refinement and gives good toughness.

10.3 Tempering

Tempering is nothing but heating the quenched or hardened materials below the lower critical

temperature so that there is no phase changes. The material is soaked at this temperature and

then cooled very slowly. The choice of tempering temperature depends on the required

properties and the soaking time for tempering is usually 1-2 hrs per 2.5 cm section thickness.

Tempering treatment relives stresses developed during hardening and restores the ductility and

toughness.

10.4 Quenching

Quenching is a hardening process in which the plain carbon steel is heated above the upper

critical temperature (in austenitic range) and then rapidly quenched in water or other suitable

coolant which result in an increase in hardness with reduction in ductility and toughness due to

the formation of hard martensite, a metastable phase, formed due to rapid cooling of austenite.

Solution annealing of austenitic stainless steels involves quenching from a similar temperature,

but this doesn’t exhibit a phase change, there is no hardening. The purpose in this stainless steel

is to take carbides into solid solution.




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11 Fractography

Fractography is critical to failure analysis of metals and plastics. Fractography of plastics is a

relatively new field with many similarities to metals. Using case histories, various aspects of

failure analysis and fractography of metals and plastics are compared and contrasted.

Failure modes common to both metals and plastics include ductile overload, brittle fracture,

impact, and fatigue. Analogies can also be drawn between stress-corrosion cracking (SCC) of

metals and stress cracking of polymers. Other metal/plastic failure analogies include corrosion/

chemical aging, dealloying/ scission, residual stress/frozen-in stress, and welds/knit lines.

Stress raisers, microstructure, material defects, and thermomechanical history play important

roles in both types of materials. Although the light (optical) microscope can be used to examine

fracture surfaces, most fracture examinations at magnifications above 50 × (microfractography)

are conducted with the scanning electron microscope.

11.1 Scanning Electron Microscopy

The scanning electron microscope (SEM) uses a focused beam of high-energy electrons to

generate a variety of signals at the surface of solid specimens. The signals that derive from

electron-sample interactions reveal information about the sample including external

morphology (texture), chemical composition, and crystalline structure and orientation of

materials making up the sample. In most applications, data are collected over a selected area of

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the surface of the sample, and a 2-dimensional image is generated that displays spatial

variations in these properties. Areas ranging from approximately 1 cm to 5 microns in width

can be imaged in a scanning mode using conventional SEM techniques (magnification ranging

from 5X to approximately 30,000X, spatial resolution of 50 to 100 nm). The SEM is also

capable of performing analyses of selected point locations on the sample; this approach is

especially useful in qualitatively or semi-quantitatively determining chemical compositions

(using Energy Dispersive Spectrometer (EDS).

Analyze via Fractography: Fractography is used to determine the mode of fracture

(intergranular, cleavage, or shear), the origin of fracture, and location and nature of flaws that

may have initiated failure. With this information, the answer as to why a part failed can usually

be determined. The major use of fractography is to reveal the relationship between physical and

mechanical processes involved in the fracture mechanism. The size of fracture characteristics

range from gross features, easily seen with the unaided eye, down to minute features just a few

micrometers across. Light and electron microscopy are the two more common techniques used in

fractography. An important advantage of electron microscopy over conventional light microscopy

is that the depth of field in the SEM is much higher; thus the SEM can focus on all areas of a

three-dimensional object identifying characteristic features such as striations or inclusions.

The texture of a fracture surface, that is, the roughness and the color, gives a good indication of

the interactions between the fracture path and the microstructure of the alloy. For instance, at low

stress a fatigue fracture is typically silky and smooth in appearance. Stress corrosion fractures

show extensive corrosion features and corrosion “beach marks.” A discontinuous ductile fracture

shows some stages of crack tip blunting, crack arrest and “pop-in”.

11.1.1 Scanning Electron Microscope Operating Procedure

Specimen Preparation

The microscopist must know the objectives of an SEM examination before preparing a

specimen. Different preparation protocols are used, depending on whether SEM is required

alone or in combination with x-ray analysis, particularly when the specimen is too large for the

specimen chamber or is nonconductive. In some litigation cases, use of an inappropriate

preparation method can be disastrous. The least aggressive method of preparation should be

selected for any fracture specimen.

The major criteria for SEM specimen preparation are that the specimen be conductive, clean,

and small enough to enter the specimen chamber. If the specimen is too large, replicas

composed of cellulose acetate or dental-impression media are prepared and coated with a

conductive thin film. Cellulose acetate replicas are also used to remove and simultaneously

preserve oxidation products that obscure the specimen surface. The fracture surface

morphology can be analyzed by direct examination of the fracture, and the products held within

the replica can be identified by coating the replica with thin carbon film. The handling and

cleaning of fracture surfaces are the most important aspects of fracture specimen preparation.

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In most cases, a metal fracture can be directly examined in the scanning electron microscope.

After cleaning, the specimen is mounted in a specimen holder or on substrate using conductive

paint or tape. Substrates include aluminum stubs and carbon planchets; the latter is preferred

for x-ray analysis. The paint or tape must be positioned such that the area of interest is not

obscured. With large specimens, it is helpful to identify the area of interest with small arrows

cut from metallic tape; their position and orientation can be indicated on both the

macrophotograph and low-magnification micrographs to facilitate correlations. At higher

magnifications, these overviews can be used as maps to pinpoint location and orientation.

Replicas and other nonconductive specimens are coated with a conductive thin film for SEM

examination. Nonconductive specimens accumulate a net negative charge that interferes with

imaging unless examined at very low accelerating voltages (~5 keV). Coating the specimen

permits use of higher voltages (15 to 20 keV), which significantly enhances image quality.

Metallic coatings (gold or chromium) are preferred for imaging purposes because they increase

the image-forming electron yield; such coatings are prepared by thermal evaporation or sputter

coating. Carbon coatings prepared by evaporation are used for x-ray analysis because the

surface film is nearly transparent to x-rays.

The SEM Procedure is given in Appendix 10.

11.1.2 Energy Dispersive Spectrometer (EDS)

Confirm Material Composition and Identify Contaminants through EDS Analysis

EDS (Energy-Dispersive Spectroscopy) is an analytical method based on the differences in

energy of the characteristic x-rays emitted by the various elements. It is used in conjunction

with scanning electron microscopy (SEM) to identify the elements present at a particular spot

on a sample. Advantages of EDS are that it is easily performed and is reliable as a qualitative

method. Limitations are that it is only marginally useful as a quantitative method.

EDS Basic Operation

Liquid Nitrogen Filling Procedure

Note: Before you use the EDS you have to filling the mini-cup tank with Liquid Nitrogen, to do so, please follow the following procedure:

1. Confirm the “ Power” lights

2. Confirm the “EVAC” lights

3. Press the “ start “ at the Detector controller you will hear Beep after 15 minutes`

4. “ EVAC” to lit continuously from blinking (Pour LN2 within 10 minutes)

5. “COOL” to be lit continuously from blinking (Beep will stop) the system will be ready

after 50 minutes approx.




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Gun Alignment

HT must be ready

Switch on the HT

Conduct a filament saturation (get the first and the second beaks)

Tilt Adjustment: set the spot size to 20 and below, adjust the tilt X, Y until you get the

max brightness.

Shift adjustment: set the spot size 50 and above, adjust the tilt X, Y until you get the

max brightness.

Adjust stigmatisms and Wobblers (Wobblers should be carried out at high mag. 5000

and above). EDS analysis.

Filling the liquid nitrogen tank with liquid nitrogen, make sure the EDS ready before

start the analysis.

Performing EDS Analysis

1. Make sure that the WD is 10 mm and the KV at least 15 KV or higher.

2. Get an image from the SEM and freeze it

3. Send the image to the EDS, system will ask you to create and project no. for this take,

Please does so.

4. Set the analysis conditions (CPS should be between 1500-5000)-blue and green color

are acceptable. If the CPS is not foiling in this range you need to adjust WD/SS and

filament saturation.

General Information

Right click on the mouse for course adjustment, Lift click on the mouse for fine

adjustment.

If the specimen has different level, set up the aperture at No. 1.

To see two different images (SE-BE) at the same screen (center of the screen) click on

Tool-Mulilive image- Flexible window image.

For higher resolution, you need to set the aperture at position no. 1.

The aperture should be set on position 2 or 3 for analysis purpose




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Aperture sizes:

1-20 micron higher resolution

2-30 micron general purposes

3-100 microm when you have difficulty in getting higher CPS, it is recommended to set

the aperture at position 3.

WD is related to the KV

Low Vacuum Mode

After the evacuation completed, set up the pressure at 10 PA and click on start (you will find

the low vacuum control key at the right side on the screen).

Note-1

If the sample gets charging, increase the pressure until you get red out the charging.

At low vacuum mode, if we conducted an analysis on low vacuum mode and noticed

that the CPS is low (less than 1500 CPS) then you need to increase the spot size.

Increase the spot size, if the image becomes so dark and CPS is not increasing then

adjusts the contrast and brightness using the course knob (backscatter). Then, adjust the

gun alignment shift.

Recipe Icon: This is to save all conditions for certain project, after you are done with all

adjustments and freeze the photo. Press the Recipe icon and add the name for your sample

press OK. Then, all condition will be saving for you, and you can come back again and use

same condition for smaller samples.

If you missed one of the imaging icons from the main screen, go to the setup and select

icon setup- select the missing icon and apply.(1)

Note-2

The accuracy of the EDS analysis is 0.01% for all elements except the light elements, so

any element is greater than the 0.01% should be detected by the EDS.

The quantitative analysis results should show the mass % is greater than the error %,

If the error % is greater than the mass % for certain element, that element is not exist.

VID (visual identification) technique used to determine the present of an element or not.

Press the VID icon you will see two lines, one is yellow and the other one is black, the

yellow is the back ground and the black is the compare generator spectrum, if the back

ground is filling the black line profile, the element is exist.




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If you want to add an element to the analysis list click on the “Ptbl” (Periodic table)

icon and the element and press play which is located under tool.

To change the color of the mapping screen go Tool-Edit Element Palette –Rest –

select Mono color –OK-Auto- Apply Now- OK.

To report mapping:

After saving the mapping data, click on OVER icon –select the element you want to

be shown on the report and drag it to the right side of the screen-Press analysis-

show spectra –Press Quantify – Previews- Export to word.

Measurements:

To do measurement, first you have to freeze the image-select Text/Scaler-select

ruler and do your measurements.

SRT (scan rotation)

If you want to rotate the live image-Press SRT icon and adjust the sliding bar

between -180+180. (This icon is located at the top tool bar, if it not there you can

add) see Note (1).

At any spectrum you can change the color, font, and lines of spectrum by clicking

on the Tool-Setup.

To know the energy level of any elements go to the Predict table and select the

element and Press Label icon at the same menu.

Multiview Sequential analysis:

The Multiview sequential analysis use to analyze different areas in sequins, if you

want to conduct a sequential analysis first get images from all areas of inters, and

send to the EDS. Press the SEQ (sequential analysis) icon- set the conditions at the

SEQ window as shown below:

® ZAF ® Standard less ® Pure ® HT turn off HT when analysis finish

Then, Press Start and wait until the analysis completed

Highlighted all images

On the analysis station window Press file-Page setup- Map/Thumbnail—OK

Press File—Print Preview.

To remove JEOL Logo- Select Hand Icon- Right Click on the logo then

Delete

To report the data, highlights the EDS results-Right click-Show compare




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11.2 Fracture Modes

Fracture in engineering alloys can occur by a transgranular (through the grains) or an

intergranular (along the grain boundaries) fracture path. However, regardless of the fracture

path, there are essentially only four principal fracture modes: dimple rupture, cleavage, fatigue,

and decohesive rupture. Each of these modes has a characteristics fracture surface appearance

and a mechanism or mechanisms by which the fracture propagates.

In this section, the fracture surface characteristics and some of the mechanisms associated with

the fracture modes will be presented and illustrated. Most of the mechanisms proposed to

explain the various fracture modes are often based on dislocation interactions, involving

complex slip and crystallographic relationships. The discussion of mechanisms in this section

will not include detailed dislocation models or complex mathematical treatment, but will

present the mechanisms in more general terms in order to impart a practical understanding as

well as an ability to identify the basic fracture modes correctly.

Dimple Rupture

When overload is the principal cause of fracture, most common structural alloys fail by a process

known as microvoid coalescence. The microvoids nucleate at regions of localized strain

discontinuity, such as that associated with second-phase particles, inclusions, grain boundaries,

and dislocation pile-ups. As the strain in the material increases, the microvoids grow, coalesce,

and eventually form a continuous fracture surface (Fig. 1). This type of fracture exhibits

numerous cuplike depressions that are the direct result of the microvoid coalescence. The cuplike

depressions are referred to as dimples, and the fracture mode is known as dimple rupture.

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Fig. 1 Influence of direction of maximum stress (σmax) on the shapes of dimples formed by

microvoid coalescence. (a) In tension, equiaxed dimples are formed on both fracture

surfaces. (b) In shear, elongated dimples point in opposite directions on matching

fracture surfaces. (c) In tensile tearing, elongated dimples point toward fracture origin

on matching fracture surfaces

The size of the dimple on a fracture surface is governed by the number and distribution of

microvoids that are nucleated. When the nucleation sites are few and widely spaced, the

microvoids grow to a large size before coalescing and the result is a fracture surface that

contains large dimples. Small dimples are formed when numerous nucleating sites are activated

and adjacent microvoids join (coalesce) before they have an opportunity to grow to a larger

size. Extremely small dimples are often found in oxide dispersion strengthened materials.




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The distribution of the microvoids nucleation sites can significantly influence the fracture

surface appearance. In some alloys, the nonuniform distribution of nucleating particles and the

nucleation and growth of isolated microvoids early in the loading cycle produce a fracture

surface that exhibits various dimple sizes (Fig. 2). When microvoids nucleate at the grain

boundaries (Fig. 3), intergranular dimple rupture results.

Fig. 2 Examples of the dimple rupture mode of fracture. (a) Large and small dimples on the

fracture surface of a martempered type 234 tool steel saw disk. The extremely small

dimples at top left are nucieated by numerous, closely spaced particles. (D.-W. Huang,

Fuxin Mining Institute, and C.R. Brooks, University of Tennessee). (b) Large and small

sulfide inclusions in steel that serve as void-nucleating sites. (R.D. Buchheit, Battelle

Columbus Laboratories)






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Fig. 3 Intergranular dimple rupture in a steel specimen resulting from microvoid coalescence at

grain boundaries.

Dimple shape is governed by the state of stress within the material as the microvoids form and

coalesce. Fracture under conditions of uniaxial tensile load (Fig. 1a) results in the formation of

essentially equiaxed dimples bounded by a lip or rim (Fig. 3 and 4a). Depending on the

microstructure and plasticity of the material, the dimples can exhibit a very deep, conical shape

(Fig. 4a) or can be quite shallow (Fig. 4b). The formation of shallow dimples may involve the

joining of microvoids by shear along slip bands.









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Fig. 4 Different types of dimples formed during microvoid coalescence. (a) Conical equiaxed

dimples in a spring steel specimen. (b) Shallow dimples in a maraging steel specimen

Fracture surfaces that result from tear (Mode I) or shear (Modes II and III) loading conditions

(Fig. 5) exhibit elongated dimples. The characteristics of an elongated dimple are that it is, as

the name implies, elongated (one axis of the dimple is longer than the other) and that one end

of the dimple is open; that is, the dimple is not completely surrounded by a rim. In the case of a

tear fracture (Fig. 6a), the elongated dimples on both fracture faces are oriented in the same

direction; and the closed ends point to the fracture origin. This characteristic of the tear dimples

can be used to establish the fracture propagation direction in thin sheet that ruptures by a full-

slant fracture (by combined Modes I and III), which consists entirely of a shear lip and exhibits

no macroscopic fracture direction indicators, such as chevron marks. A shear fracture, however,

exhibits elongated dimples that point in opposite directions on mating fracture faces (Fig. 6b).

Examples of typical elongated dimples are shown in Fig. 7.








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Fig. 5 Fracture loading modes. Arrows show loading direction and relative motion of

mating fracture surfaces.

Fig. 6 Formation of elongated dimples under tear and shear loading conditions.

(a) Tear fracture. (b) Shear fracture




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Fig. 7 Elongated dimples formed on shear and torsion specimen fracture surfaces. (a) Shear

fracture of a commercially pure titanium screw. Macrofractograph shows spiral-textured

surface of shear-of screw. Typical deformation lines are fanning out on the thread.

(b) Higher-magnification view of (a) shows uniformly distributed elongated shear

dimples. (O.E.M. Pohler, Institut Straumann AG). (c) Elongated dimples on the surface

of a fractured single-strand copper wire that failed in torsion. (d) Higher-magnification

view of the elongated dimples shown in (c). (R.D. Lujan, Sandia National Laboratories)

It should be noted that the illustrations representing equiaxed and elongated dimple formation and

orientation were deliberately kept simple in order to convey the basic concepts of the effect on

dimple shape and orientation of loading or plastic-flow directions in the immediate vicinity where

the voids form, such as at the crack tip. In reality, matching dimples on mating fracture faces are

seldom of the same size or seldom show equivalent angular correspondence. Because actual




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fractures rarely occur by pure tension or shear, the various combinations of loading Modes I, II,

and III, as well as the constant change in orientation of the local plane of fracture as the crack

propagates, result in asymmetrical straining of the mating fracture surfaces.

Figure 8 shows the effect of such asymmetry on dimple size. The surface (B) that is strained

after fracture exhibits longer dimples than its mating half (A). When fracture occurs by a

combination of Modes I and II, examination of the dimples on mating fracture surfaces can

reveal the local fracture direction. As illustrated in Fig. 8, the fracture plane containing the

longer dimples faces the region from which the crack propagated, while the mating fracture

plane containing the shorter dimples faces away from the region. With the different

combinations of Modes I, II, and III, there could be as many as 14 variations of dimple shapes

and orientation on mating fracture surfaces.

Fig. 8 Effect of asymmetry on dimple size

Metals that undergo considerable plastic deformation and develop large dimples frequently

contain deformation markings on the dimple walls. These markings occur when slip-planes at

the surface of the dimples are favorably oriented to the major stress direction. The continual

straining of the free surfaces of the dimples as the microvoids enlarge produces slip-plane

displacement at the surface of the dimple, as shown in Fig. 9. When first formed, the slip traces

are sharp, well defined, and form an interwoven pattern that is generally referred to as

serpentine glide (Fig. 10). As the slip process proceeds, the initial sharp slip traces become

smooth, resulting in a surface structure that is sometimes referred to as ripples.








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Fig. 9 Slip step formation resulting in serpentine glide and ripples on a dimple wall

Fig. 10 Serpentine glide formation (arrow) in oxygen-free high-conductivity copper

specimen

Oval-shaped dimples are occasionally observed on the walls of large elongated dimples.

An oval dimple is formed when a smaller subsurface void intersect the wall of a larger void

(dimple). The formation of oval dimples is shown schematically in Fig. 1(b) and 6(b).






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Cleavage

Cleavage is a low-energy fracture that propagates along well-defined low-index

crystallographic planes known as cleavage planes. Theoretically, a cleavage fracture should

have perfectly matching faces and should be completely flat and featureless.

However, engineering alloys are polycrystalline and contain grain and subgrain boundaries,

inclusions, dislocations, and other imperfections that affect a propagating cleavage fracture so

that true, featureless cleavage is seldom observed. These imperfections and changes in crystal

lattice orientation, such as possible mismatch of the low-index planes across grain or subgrain

boundaries, produce distinct cleavage fracture surface features, such as cleavage steps, river

patterns, feather markings, chevron (herringbone) patterns, and tongues.

As shown schematically in Fig. 11, cleavage fractures frequently initiate on many parallel

cleavage planes. As the fracture advances, however, the number of active planes decreases by a

joining process that forms progressively higher cleavage steps. This network of cleavage steps

is known as a river pattern. Because the branches of the river pattern join in the direction of

crack propagation, these markings can be used to establish the local fracture direction.

Fig. 11 Schematic of cleavage fracture formation showing the effect of subgrain boundaries.

(a) Tilt boundary. (b) Twist boundary





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A tilt boundary exists when principal cleavage planes form a small angle with respect to one

another as a result of a slight rotation about a common axis parallel to the intersection

(Fig. 11a). In the case of a tilt boundary, the cleavage fracture path is virtually uninterrupted,

and the cleavage planes and steps propagate across the boundary. However, when the principal

cleavage planes are rotated about an axis perpendicular to the boundary, a twist boundary

results (Fig. 11b). Because of the significant misalignment of cleavage planes at the boundary,

the propagating fracture reinitiates at the boundary as a series of parallel cleavage fracture

connected by small (low) cleavage steps. As the fracture propagates away from the boundary,

the numerous cleavage planes join, resulting in fewer individual cleavage planes and higher

steps. Thus, when viewing a cleavage fracture that propagates across a twist boundary, the

cleavage steps do not cross but initiate new steps at the boundary (Fig. 11b). Most boundaries,

rather than being simple tilt or twist, are a combination of both types and are referred to as tilt-

twist boundaries. Cleavage fracture exhibiting twist and tilt boundaries are shown in Fig. 12(a)

and 13, respectively.

Fig. 12 Examples of cleavage fractures. (a) Twist boundary, cleavage steps, and river patterns

in an Fe-0.01C-0.24Mn-0.02Si alloy that was fractured by impact. (b) Tongues (arrows)

on the surface of a 30% Cr steel weld metal that fractured by cleavage









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Fig. 13 Cleavage fracture in Armco iron showing a tilt boundary, cleavage steps, and

river patterns. TEM p-c replica

Feather markings are a fan-shaped array of very fine cleavage steps on a large cleavage facet

(Fig. 14a). The apex of the fan points back to the fracture origin. Large cleavage steps are

shown in Fig. 14(b).






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Fig. 14 Examples of cleavage fractures. (a) Feather pattern on a single grain of a chromium

steel weld metal that failed by cleavage. (b) Cleavage steps in a Cu-25 at.% Au alloy

that failed by transgranular stress-corrosion cracking. (B.D. Lichter, Vanderbilt

University)

Tongues are occasionally observed on cleavage fracture (Fig. 12b). They are formed when a

cleavage fracture deviates from the cleavage plane and propagates a short distance along a twin

orientation.

Wallner lines (Fig. 15) constitute a distinct cleavage pattern that is sometimes observed on

fracture surfaces of brittle nonmetallic materials or on brittle inclusions or intermetallic

compounds. This structure consists of two sets of parallel cleavage steps that often intersect to

produce a crisscross pattern. Wallner lines result from the interaction of a simultaneously

propagating crack front and an elastic shock wave in the material.






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Fig. 15 Wallner lines (arrow) on the surface of a fractured WC-Co specimen. TEM formvar

replica. Etched with 5% HCl. (S.B. Luyckx, University of the Witwatersrand)

Fatigue

A fracture that is the result of repetitive or cyclic loading is known as a fatigue fracture.

A fatigue fracture generally occurs in three stages: it initiates during Stage I, propagates for

most of its length during Stage II, and proceeds to catastrophic fracture during Stage III.

Fatigue crack initiation and growth during Stage I occurs principally by slip-plane cracking due

to repetitive reversals of the active slip systems in the metal. Crack growth is strongly

influenced by microstructure and mean stress, and as much as 90% of the fatigue life may be

consumed in initiating a viable fatigue crack. The crack tends to follow crystallographic planes,

but changes direction at discontinuities, such as grain boundaries. At large plastic-strain

amplitudes, fatigue cracks may initiate at grain boundaries. A typical State I fatigue fracture is

shown in Fig. 16. State I fatigue fracture surfaces are faceted, often resemble cleavage, and do

not exhibit fatigue striations. Stage I fatigue is normally observed on high-cycle low-stress

fractures and is frequently absent in low-cycle high-stress fatigue.





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Fig. 16 Stage I fatigue appearance. (a) Cleavagelike, crystallographically oriented State I

fatigue fracture in a cast Ni-14Cr-4.5Mo-1Ti-6Al-1.5Fe-2.0(Nb + Ta) alloy. (b) Stair-

step fracture surface indicative of Stage I fatigue fracture in a cast ASTM F75 cobalt-

base alloy. SEM. (R. Abrams, Howmedica, Div. Pfizer Hospital Products Group Inc.)

The largest portion of a fatigue fracture consists of Stage II crack growth, which generally

occurs by transgranular fracture and is more influenced by the magnitude of the alternating

stress than by the mean stress or microstructure. Fatigue fractures generated during Stage II

fatigue usually exhibit crack-arrest marks known as fatigue striations (Fig. 17, 18, 19, 20, 21,

22), which are a visual record of the position of the fatigue crack front during crack

propagation through the material.

Fig. 17 Uniformly distributed fatigue striations in an aluminum 2024-T3 alloy. (a) Tear ridge

and inclusion (outlined by rectangle). (b) Higher-magnification view of the region

outlined by the rectangle in (a) showing the continuity of the fracture path through and

around the inclusion. Compare with Fig. 18.











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Fig. 18 Local variations in striation spacing in a Ni-0.04C-21Cr-0.6Mn-2.5Ti-0.7Al

alloy that was tested under rotating bending conditions. Compare with

Fig. 17(b).

Fig. 19 Fatigue striations in a 2024-T3 aluminum alloy joined by tear ridges





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Fig. 20 Fatigue striations on adjoining walls on the fracture surface of a commercially

pure titanium specimen. (O.E.M. Pohler, Institut Straumann AG)

Fig. 21 Fatigue striations on the fracture surface of a tantalum heat-exchanger tube.

The rough surface appearance is due to secondary cracking caused by high-cycle

low-amplitude fatigue. (M.E. Blum, FMC Corporation)




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Fig. 22 High-magnification views of fatigue striations. (a) Striations (arrow) on the fracture

surface of an austenitic stainless steel. (C.R. Brooks and A. Choudhury, University of

Tennessee). (b) Fatigue striations on the facets of tantalum grains in the heat-affected

Creep

Creep rupture is a time-dependent failure that results when a metal is subjected to stress for

extended periods at elevated temperatures that are usually in the range of 40 to 70% of the

absolute melting temperature of the metal. With few exceptions, creep ruptures exhibit

intergranular fracture surface. Transgranular creep ruptures, which generally result from high

applied stresses (high strain rates), fail by a void-forming process similar to that of microvoid

coalescence in dimple rupture. Because transgranular creep ruptures show no decohesive

character, they will not be considered for further discussion. Intergranular creep rupture, which

occur when metal is subjected to low stresses (often well below the yield point) and to low

strain rates, exhibit decohesive rupture and will be discussed in more detail.

Creep can be divided into three general stages: primary, secondary, and tertiary creep.

The fracture initiates during primary creep, propagates during secondary or steady-state creep,

and becomes unstable, resulting in failure, during tertiary or terminal creep. From a practical

standpoint of the service life of a structure, the initiation and steady-state propagation of creep

ruptures are of primary importance, and most efforts have been directed toward understanding

the fracture mechanisms involved in these two stages of creep.




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As shown schematically in Fig. 34, intergranular creep ruptures occur by either of two fracture

processes: triple-point cracking or grain-boundary cavitation. The strain rate and temperature

determine which fracture process dominates. Relatively high strain rates and intermediate

temperatures promote the formation of wedge cracks (Fig. 34a). Grain-boundary sliding as a

result of an applied tensile stress can produce sufficient stress concentration at grain-boundary

triple points to initiate and propagate wedge cracks. Cracks can also nucleate in the grain

boundary at locations other than the triple point by the interaction of primary and secondary

slip steps with a sliding grain boundary. Any environment that lowers grain-boundary cohesion

also promotes cracking. As sliding proceeds, grain-boundary cracks propagate and join to form

intergranular decohesive fracture (Fig. 35 a and b).

Fig. 34 Triple-point cracking (a) and cavitation (b) in intergranular creep rupture.

Small arrows indicate grain-boundary sliding.







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Fig. 35 Examples of intergranular creep fractures. (a) Wedge cracking in Inconel 625.

(b) Wedge cracking in Incolay 800. (c) Intergranular creep fracture resulting

from grain-boundary cavitation in PE-16.

At high temperatures and low strain rates, grain-boundary sliding favors cavity formation

(Fig. 34b). The grain-boundary cavities resulting from creep should not be confused with

microvoids formed in dimple rupture. The two are fundamentally different; the cavities are

principally the result of a diffusion-controlled process, while microvoids are the result of

complex slip. Even at low strain rates, a sliding grain boundary can nucleate cavities at

irregularities, such as second-phase inclusion particles. The nucleation is believed to be a

strain-controlled process, while the growth of the cavities can be described by a diffusion

growth model and by a power-law growth relationship. Irrespective of the growth model, as

deformation continues, the cavities join to form an intergranular fracture. Even though the

fracture resulting from cavitation creep exhibits less sharply defined intergranular facets

(Fig. 35c), it would be considered a decohesive rupture.

Instead of propagating by a cracking or a cavity-forming process, a creep rupture could occur

by a combination of both. There may be no clear distinction between wedge cracks and

cavities. The wedge cracks could be the result of the linkage of cavities at triple points.

The various models proposed to describe the creep process are mathematically complex and

were not discussed in detail. Comprehensive reviews of the models are available in.






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Unique Fractures

Some fractures, such as quasi-cleavage and flutes, exhibit a unique appearance but cannot be

readily placed within any of the principal fracture modes. Because they can occur in common

engineering alloys under certain failure conditions, these fractures will be briefly discussed.

Quasi-cleavage fracture is a localized, often isolated feature on a fracture surface that exhibits

characteristics of both cleavage and plastic deformation (Fig. 36 and 37). The term quasi-

cleavage does not accurately describe the fracture, because it implies that the fracture

resembles, but is not, cleavage. The term was coined because, although the central facets of a

quasi-cleavage fracture strongly resembled cleavage their identity as cleavage planes was not

established until well after the term had gained widespread acceptance. In steels, the cleavage

facets of quasi-cleavage fracture occur on the {100}, {110}, and possibly the {112} planes.

The term quasi-cleavage can be used to describe the distinct fracture appearance if one is aware

that quasi-cleavage does not represent a separate fracture mode.

Fig. 36 Examples of quasi-cleavage. (a) Fracture surface of an austenitized Fe-0.3C-0.6Mn-

5.0Mo specimen exhibiting large quasi-cleavage facets, such as at A; elsewhere, the

surface contains rather large dimples. (b) Charpy impact fracture in on Fe-0.18C-

3.85Mo steel. Many quasi-cleavage facets are visible. The rectangle outlines a tear

ridge.






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Fig. 37 Small and poorly defined quasi-cleavage facets connected by shallow dimples on the

surface of a type 234 tool steel. (D.-E. Huang, Fuxin Mining Institute, and C.R. Brooks,

University of Tennessee).

A quasi-cleavage fracture initiates at the central cleavage facets; as the crack radiates, the

cleavage facets blend into areas of dimple rupture, and the cleavage steps become tear ridges.

Quasi-cleavage has been observed in steels, including quench-and-temper hardenable,

precipitation-hardenable, and austenitic stainless steels; titanium alloys; nickel alloys; and even

aluminum alloys. Conditions that impede plastic deformation promote quasi-cleavage

fracture—for example, the presence of a triaxial state of stress (as adjacent to the root of a

notch), material embrittlement (as by hydrogen or stress corrosion), or when a steel is subjected

to high strain rates (such as impact loading) within the ductile-to-brittle transition range.




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12 Corrosion Testing

12.1 Sensitization Testing

Sensitization of austenitic stainless steels (SS) is defined in terms of the characteristic

parameters of the chromium depletion zones: coverage (proportion of the grain boundary length

covered by chromium depletion zones), width, and depth (the minimum level of chromium in

the depletion zones). A sample matrix was developed that provides heat-treated samples of

Type 304 SS (UNS S30400) having the same coverage developed at four different temperatures

of heat treatments. The coverage was measured by quantitative metallography (ASTM A262,

Practice C).

In austenitic stainless steels (SS), exposure to the temperature range of 500°C to 800°C causes

chromium and carbon to react at grain boundaries to form chromium-rich carbides,

concomitant with the formation of chromium depletion zones at and adjacent to the grain

boundaries. This process of forming a chromium depletion zone is called “sensitization.”

Sensitized Stainless Steel Sample




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12.2 Hydrogen Induced Cracking Test - HIC Test

Hydrogen induced cracking testing apparatus ( HIC test ) to test and accurately determine the

hydrogen induced cracking over exposed test specimens as per NACE standards requirements.

HIC testing is recommended to evaluate the resistance of pipeline and pressure vessel plate

steels to hydrogen induced cracking corrosion caused by hydrogen absorption from aqueous

sulfide corrosion. Unstressed test specimens are exposed to a solution at temperature of 25°C

with continuous H2S gas flow. The test specimens are finally removed and evaluated.

Test specimens determine susceptibility of metals in H2S service. HIC testing apparatus meet

requirements of ASTM / NACE Standard TM0284 and suitable to test material as per

requirements of NACE MR0175.

HIC test specimens are machined with thickness of 5-30 mm, width 20 mm, and length of

100 mm is suitable for testing as per the NACE Standard.

HIC test apparatus is suitable to use NACE TM0284 specified Solution A or Solution B.

Solution A is acidified brine. Solution B is simulated seawater prepared in accordance with

ASTM D1141. In either case, H2S is bubbled through the solution constantly throughout the

test period. NACE TM0284 specifies test duration of 96 hours. The test requires evaluation of

pH values of the test solution before exposure and after the exposure. HIC test specimens are

cut into sections and examined under a microscope for hydrogen-induced corrosion cracks.

The dimensions of any such cracks are recorded and used to compute the values in percentage

for Crack Length Ratio (CLR), Crack Thickness Ratio (CTR) and Crack Sensitivity Ratio

(CSR) as per the NACE Standard.

Per Saudi Aramco Specifications 01-SAMSS-016 and 32-SAMSS-035, only Solution A may be

used to qualify materials for use in wet sour environment.

https://standards.aramco.com.sa:10009/docs/Samss/PDF/01-SAMSS-016.PDF

https://standards.aramco.com.sa:10009/docs/Samss/PDF/32-SAMSS-035.PDF




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Hydrogen Induced Cracking (HIC) in Drum

Hydrogen Induced Cracking (HIC) in Pipe




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13 Failure Analysis Process

13.1 Procedural

A failure analysis flow chart is given in Section 3. The following steps are to be followed when

undertaking failure analysis:

a. Complete the FA Request form by the Proponent with management signature.

b. Send the FA request form along with the failed sample(s) to ME&COS Lab Team Leader.

c. Evaluate FA Request and assign an ME&COS Lab Technician by Lab Team Leader.

If the FA Request is not acceptable (e.g., missing information), then the FA Request is

returned back to the proponent with comments.

d. Photograph the received sample and send the required information to ME&COS Group

Leader.

e. Evaluate FA Request and assign an ME&COS Engineer by the Group Leader.

f. Complete the CSD Materials Lab Tests Sheet by the Engineer.

g. Conduct the requested tests by the Lab Technician and send results to the Engineer for

evaluation. The Engineer will then decide to conduct further tests or write the FA report.

h. Write the FA report by the Engineer and send it to the ME&COS Group Leader to

review and initial. If the FA report needs improvement, the FA report is returned to the

Engineer with comments to incorporate.

i. Sign the initialed FA report by the ME&COS Supervisor.

j. Send the signed FA report to the Proponent by ME&COS Clerk.

k. Save a soft copy of the signed FA report into e-Cabinet by ME&COS Clerk.

13.2 Roles and Responsibilities

13.2.1 ME&COS Lab Team Leader

a) Receive the failed sample from the Proponent, log the request in the FA System, Assign

ME&COS Technician and communicate with Proponent in case there is any missing

information.

b) Send new FA Request to the ME&COS Group Leader with all relevant information.

c) Follow up with assigned technician to perform the required CSD Materials Lab Tests

(Attachment IV) completed by the Engineer.

d) Update the FA log system when the FA report is issued as well as send monthly update

report of all pending FA Requests to ME&COS Group Leader.




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13.2.2 ME&COS Group Leader

a) Evaluate new FA Requests and assign an Engineer.

b) Follow up on the status of all FA Requests and provide technical support to Engineers

when necessary.

c) Review and Initial the completed FA Report.

13.2.3 ME&COS Engineer

a) Perform comprehensive evaluation to FA Requests and communicate with the

proponent if additional clarification is needed.

b) Involve other Subject Matter Experts (SME) if needed.

c) Fill out the CSD Materials Lab Tests Sheet with all necessary tests to be performed by

the Technician.

d) Communicate the preliminary findings and recommendation with Proponent if necessary.

e) Prepare and submit the final FA Report which shall contain the following:

i. General Information such as the operating conditions, compliance to material’s

mechanical and chemical properties as well as the various examination procedures

taken.

ii. The Mode(s) of Failure and associated root case(s) contributing to the failure.

iii. Recommendations (i.e., Corrective Actions) needed to be taken to avoid the

recurrence of failure.

13.2.4 ME&COS Supervisor

a) Review and Sign the completed FA Reports.

b) Follow up on the status of pending FA Requests among the Unit.

13.2.5 ME&COS Clerk

a) Distribute the signed FA Report to the Proponent.

b) Save the FA Report in e-Cabinet.

https://ecmapps.aramco.com.sa/eds/component/main?__dmfClientId=1336459141786




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14 Laboratory Management

14.1 Quality Assurance

The laboratory maintains a quality assurance system to ensure testing apparatus are adequately

calibrated and the results obtained are valid. Calibration is periodically undertaken by either the

apparatus/equipment manufacturer himself or by 3rd

party calibration/accreditation body.

The laboratory as such is not yet accredited by an industry accreditation body. CSD will pursue

this accreditation to elevate the standard of services offered by the laboratory to industry levels

or higher.

14.2 Safety Management

A detailed description of the materials laboratory safety requirements is given in Appendix 4.

Each individual working in a laboratory has a responsibility to learn the health and safety hazards

associated with the materials and the equipment used. These include, but not limited to, chemical,

electrical, radiation, cryogenic liquids, light and heavy machinery, dust inhalation, slips and trips,

manual handling of heavy loads, etc. Technicians and engineers working in the laboratory must

be very familiar with the safety requirements of the laboratory and must have received adequate

training in First Aid, including handling the following health and safety situations:

Stoppage of breathing, resuscitation

Severe bleeding

Thermal burns

Chemical burns

Traumatic shock

Head or back injuries

Chemical spills

Technicians, engineers and visitors to the laboratory are required to be kitted with Personal

Protection Equipment, including, laboratory coats, safety shoes, safety glasses and protective

gloves. Additional health and safety laboratory requirements include the following:

Do not wear contact lenses in the laboratory. Fumes, gases, and vapors can easily be

absorbed by the lens or trapped between the lens and eyes resulting in chemical burns or

abrasive injury.

Use a hood for hazardous, volatile, and noxious chemicals.

Handle liquid nitrogen very carefully. The boiling point of liquid nitrogen is -196°C;

this extremely low temperature can produce an effect on the skin similar to a burn




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caused by a hot object. Eyes must be protected with a face shield or safety glasses.

Gloves must be worn.

Upon entering the laboratory note the location of the closest fire extinguisher, first aid

kit, eye wash station and chemical shower. Their location is specified on the laboratory

door main entrance door

Technicians and engineers may not work alone in a laboratory.

Eating, drinking and smoking are prohibited in the main working areas of the laboratory.

In the event of an emergency, the following procedure shall be followed:

Alert personnel in the immediate vicinity.

Confine the fire or emergency, if possible.

Evacuate the laboratory and building and report to munster point.

Report pertinent information to responding emergency personnel.

CSD management undertakes quarterly safety visits to the laboratory to review the health and

safety aspects of the laboratory and highlight areas for improvements. The laboratory group

leader is tasked to implement any health and safety item raised by CSD management.

The laboratory may also periodically be audited by the company’s Auditing Department.

Procedural or safety items raised during this audit are always taken extremely seriously and

dealt with promptly in a satisfactory manner. Accountability for closure of audit items rests

with the Head of Operations Support Division.

14.3 Chemical Management

Chemicals are used either for cleaning of deposits to uncover the underlying material or as

etchants to reveal microstructural features. Various chemicals are stored in fire-proof cabinets

in the laboratory. A system is maintained in the laboratory to monitor consumption and expiry

dates for timely replenishing.

The Materials Safety Data Sheets (MSDSs) for all chemicals are kept in the laboratory.

An MSDS is a document that contains information on the potential hazards (health, fire,

reactivity and environmental) and how to work safely with the chemical product. It is an

essential starting point for the development of a complete health and safety program. It also

contains information on the use, storage, handling and emergency procedures all related to the

hazards of the material. MSDSs are prepared by the supplier or manufacturer of the material.

It is intended to tell what the hazards of the product are, how to use the product safely, what to

expect if the recommendations are not followed, what to do if accidents occur, how to

recognize symptoms of overexposure, and what to do if such incidents occur.




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The Materials Safety Data Sheets for all chemicals used are filed in the laboratory; these are also

available on the worldwide web. An example MSDS for picric acid, a chemical routinely used in

the laboratory as etching agent when mixed with other chemicals, is shown in Appendix 5.

14.4 Technician Training Development

To ensure the continuous development of technician staff operating in the laboratory, various

IK/OOK training courses are routinely offered, as follows:

Introduction to Laboratory Practices

Metallography – ASM Certification

Microscopy (Optical and SEM)

Practical Fractography

Mechanical Testing

Software Tools

o Microsoft Office Suite (Word, Excel, Powerpoint)

o FileMaker Pro

ICQ Communication Skills

Principles of Machining

First Aid

Basic Life Support

Driver Improvement

Chemical Handling Safety

Electrical Safety

Abrasive Wheel and Cutting Machinery Safety

Cryogenic Safety

Crane Operation Safety

H2S Safety

Confined Space Entry Safety

Nitrogen Ashyxiation Safety

Work Permit Receiving

Level 1 and 2 Certification in:

o Liquid Penetrant Testing

o Magnetic Particle Testing

o Ultrasonic Thickness Measurement




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COE-101 Corrosion Basics

COE-110 Materials Selection and Failure Analysis

Heat Treatment – ASM Certification

These courses are part of the CSD Competency Map (CMap) (Appendix 6) and Individual

Development Plans (IDPs) for technicians.

14.5 Filing/Record Keeping

All work undertaken in the laboratory is documented via either test reports or examinations

recorded in notebooks by the technicians or engineer. The results of all tests carried out are

then documented in a report that is peer reviewed by either senior staff or the group leader, then

submitted to customers. All reports are filed in the corporate e-Cabinet portal in a folder titled

“Failure Analysis Reports. This portal is search-enabled.

14.6 Failure/Testing Database

The laboratory maintains a failure/testing database to map out historical failures in the

company and perform statistical studies to proactively derive the following information:

Top or chronic corrosion challenges/failures

Process severity / composition

Operational location

Materials of construction

Service history

Construction date

Design and operating variables

Business line

Cost impact of failure

Asset type

This information is extremely valuable in that it allows the identification of common

corrosion/failure trends in the company so that efforts are focused on relevant technologies to

prevent recurrence.




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15 References

● ASM Handbooks – ASM Online

● ASTM E3 Guide for Preparation of Metallographic Specimens

● ASTM A380 Standard Practice for Micro-etching Metals and Alloys

● ASTM A370 Test Methods and Definitions for Mechanical Testing of Steel Products

● ASTM E8 Standard Test Methods for Tension Testing of Metallic Materials

● ASTM E23 - 12c Standard Test Methods for Notched Bar Impact Testing of Metallic

Materials

● ASTM 380 Standard Practice for Cleaning and Descaling Stainless Steel Parts,

Equipment, and Systems’

● NACE Standard TM0284 and suitable to test material as per requirements of

NACE MR0175

● ASTM A262 Standard Practices for Detecting Susceptibility to Intergranular Attack

in Austenitic Stainless Steels

Revision Summary

16 July 2013 New Saudi Aramco Materials Laboratory Manual.




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Appendix 1- Fixed Asset Inventory

No. Asset # Equipment Model Brand Name Local Agent Name

1 A02901066000 WELDING ARC DATA MONITOR GM-L-48-116 HALLIBURTON N/A

2 A05808183000 TRACING LATHE TI505 TENSILKUT N/A

3 A05808318000 GRINDING METALLOGRAPHIC SYSTEM

95-2808-222 BUEHLER ABDULLA FOUAD

4 A05808392000 LATHE, GEARED HEAD MACHINE WITH COOLING SYSTEM

AJ 260E Ajax KANO

5 A05808393000 CUT-OFF MACHINE TO HARD STEEL SAMPLES

10-1075-260 BUEHLER ABDULLA FOUAD

6 A05808475000 SAW MACHINE LONG BED BAND (25: LX 28:H)

25 Marvel N/A

7 A05808557000 GRINDER, HYDRAULIC SURFACE AJ600H Ajax KANO

8 A05808919000 MILLING SPECIAL VERTICAL MACHINE AT DH. CONSULTING

SERIES 11 SP Bridge Port N/A

9 A07612485000 SURFACE SAMPLING DEVICE, FOR CIBSYKTUBG SERVICES

SSAM-2 ROLLS ROYCE RR Intr Turbine SA

10 A08803907000 LAB. HEAT TREATING FURNACE F46248CM THEMOLYNE N/A

11 A08804300000 MICROSCOPE REICHERT METALLOGRAPHIC

REICH.MEF4A LEICA Al-TUWAIRQI TRAD. EST

12 A08804828000 TESTER UNIVERSAL IMPACT 180454 TINIUS OLSEN NAIZAK

13 A088X04439 UNIVERSAL HARDNESS TESTER 7551 INSTRON NAIZAK

14 145781 ROCKWELL HARDNESS TESTER B2000 INSTRON Abdulla Fouad CO. LTD.

15 101032 TESTING MACHINE, MODEL 5593 5593 INSTRON NAIZAK

16 101456 INVERTED OPTICAL MICROSCOPE WITH DIGITAL IMAGE ANA

LEICS MEF4A LEICA Al-TUWAIRQI TRAD. EST

17 104508 TESTING MICRO HARDNESS MACHINE AT DH. CONSULTING

LEICAVMHTMOT LEICA Al-TUWAIRQI TRAD. EST

18 106295 CABINET SEALED DESICCATOR N/A ALLIED N/A

19 107475 FILED METALLOGRAPHIC KIT TransPol-5 STRUERS Rajab & A. Silsilah

20 111652 FILM, PROJECTOR V-12B NIKON N/A

21 123971 TESTER, THERMAL SPRAY EXAMINING KIT

ATHIOIE P.A.T Painting Materials& Equip. Center Co.




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No. Asset # Equipment Model Brand Name Local Agent Name

22 130397 MICROSCOPY for nonmetallic LEICA Al-TUWAIRQI TRAD. EST

23 134787 MACHINE, MOUNTING ProntoPress STRUERS Rajab & A. Silsilah

24 134788 MACHINE, CUT-OFF (SECOTOM-10) S-20 STRUERS Rajab & A. Silsilah

25 164620 PORTABLE X- RAY TUBE ANALYZER XTPS2545 OXFORD AL-OTHMAN

26 164925 BENCH TOP TYPE ARC-MET EMISSION ANALYZER

IAXX SPECTRO ISAM ANNAI TECHNICAL

27 167227 PROGRAMMABLE MOUNTING PRESS WITH TWO CYLINDERS

CITOPRESS-20 STRUERS Rajab & A. Silsilah

28 167230 MACHINE, AUTOMATIC CUT-OFF MACHINE

AXITOM STRUERS Rajab & A. Silsilah

29 171383 ANALYTICAL SCANNING ELECTRON MICROSCOPE WITH EDS

JSM-6490LA JEOL AL-GOSABI

30 14729 Prepamatic2 fully automatic (samples preparation)

Prepamatic2 STRUERS Rajab & A. Silsilah

31 178029 CUTTING MACHINE, AUTOMATIC & MANUAL CUT-OFF

DISCOTOM-6 STRUERS Rajab & A. Silsilah

32 186667

FT-IR SPECTROMETER 660-IR VARIAN Gulf Scientific Corporation

33 192633 DSC 200 F3 THERMAL ANALYSIS DSC 200 F3 NETZSCH Gulf Scientific Corporation




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Appendix 2A – Low Value Asset Control Procedure

Scope

This document describes the internal procedure to control Low Value Assets (LVA) and

provides the roles and responsibilities of all parties involved.

Document Responsibility

Responsibility for this document rests with the group leader of the Materials Engineering and

Corrosion Operations Support of CSD. This document shall be reviewed and approved every

2 years.

Definitions

o Low-Value Asset

Any asset satisfying the following criteria is considered of a low value:

a) Monetary value between $500 – $20,000

b) Purchased to support a department business function

c) Not a consumable material

o Custodian

A custodian is a CSD employee, usually the CSD Laboratory Team Leader, whom has

acknowledged (by signature) receipt of a LVA asset and is thus held accountable for it.

Roles and Responsibilities

o Custodian

1. Responsible for completing the “Add/Delete/Relocate LVA Form” (Attachment 1)

and route it for approval. A copy of the form should be sent to Administrative Staff

Group for their record. A tag must be created and affixed on the new asset by the

custodian.

2. Maintains and surveys the LVA inventory semi-annually basis (January and July).

3. Responsible for the proper usage and safe keeping of LVAs as well as the affixed

tag. If the tag is damaged, loose, or missing, the custodian shall replace it with a

new one.




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4. Initiates the “Add/Delete/Relocate Low Value Asset Form”, with approval from the

unit and division heads, when an LVA is no longer required or considered either

obsolete or unusable.

5. Notifies promptly the unit head when an LVA is lost or damaged.

o Unit Head

Maintains an up-to-date list in the LVA Database.

Keeps record of hardcopy documents of new LVA forms, relocation of custody

forms, and deletion forms.

Reviews and endorses the semi-annual of the LVAs physical inventory.

Reports loss or theft of LVA to the CSD Business Manager and Division Head.

Coordinates repair of damaged LVAs with the proper maintenance organization.

Transfers accountability to another custodian in the event when the previous

custodian leaves or transfers out of the Unit.

o Division Head

Ensures that this procedure is clearly understood and implemented by the custodian

and unit head.

Ensures that all LVAs within the Division are used by the division personnel

properly.

Ensures that all LVAs within his division are kept in a safely manner.

Ensures that lost or stolen LVAs assigned to his organization are reported promptly.

Ensures custody transfer of LVAs from the custodian transferring out of the

division.

Ensures that the new custodian completes inventory for all LV‘s reported under

custody.

Ensures that the summary of physical inventory findings and discrepancies has been

properly taken care of by the concerned personnel.

Has the sign-off authority to delete or write-off any obsolete or lost LVA as detailed

above.




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Attachment 1

Addition, Deletion, Relocation of Low Value Asset Form

Date: _____________ Purpose: Add Relocate Delete

Tag #: ____________

Asset Name/Type: ___________________________________________

Brand/Model: __________________________________________ Serial: ______________________________________

Description (include list of attached tools and software):

_________________________________________________________________________________________________________________

_________________________________________________________________________________________________________________

_________________________________________________________________________________________________________________

Custodian Name: __________________________________ Unit Head Name: ________________________________

Signature and Date: _______________________________ Signature and Date: _____________________________

Unit Head Name: _________________________________

Signature and Date: ______________________________




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Appendix 2B - Low Value Asset Inventory

Line item

Assist Deceptions Serial No. ME&COS

Code Location

Bldg. 2291

1 Low Temperature Bath 25839 0001 HA124

2 Hardness tester Macromet I 5193 0002 HA124

3 X-Ray viewer N/A 0003 HA121

4 Electrode Stabilizer Oven 10BVTE 0004 HA121

5 Portable Oxygen Analyzer 147567 0005 HA121

6 Automatic voltage regulator 050518526 0006 HA121

7 Olympus Lamp (220V) 406120 0007 HA121

8 Stereo Microscope (Olympus) SZ-STU1 0008 HA121

9 Olympus controller 0091553 0009 HA121

10 Olympus Lamp (120V) 102149 0010 HA121

11 Stereo Microscope (LEICA) MZ75 0011 HA121

12 Bend Test Machine 11005800 0012 HA121

13 Electrode Stabilizer Oven 160 0013 HA121

14 Electrode Stabilizer Oven 2-NM 0014 HA121

15 Portable Trace Oxygen Analyzer 146243 0015 HA121

16 Stereo Zoom 5 micro 312767 0016 HA122

17 Contour Probe (Magnetic Particle Testing) 12325 0017 HA118

18 Contour Probe (Magnetic Particle Testing) 12212 0018 HA118

19 Branson (Ultrasonic cleaner) 8510 0019 HA118

20 Branson (Ultrasonic cleaner) 1200 0020 HA118

21 Specimen Dryer 452-TD-0781 0021 HA118

22 Isomet 1000 (Precision Saw) 502-IPS-00292 0022 HA118

23 Air compressor for vacuum 1020 0023 HA118




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Line item


Code Location

Bldg. 2291

24 SurfMet I (Belt Grinder) 441-EMD-D1524 0024 HA116

25 SurfMet I (Belt Grinder) 499-EMD-1782 0025 HA116

26 SurfMet I (Belt Grinder) N/A 0026 HA116

27 Simplmet 2000 (Mounting Press) 452-N2S-0336 0027 HA116

28 Simplmet 3 (Mounting Press) 466-N3S-00718 0028 HA116

29 Camera Stand N/A 0029 HA119

30 Camera Stand Minolta N/A 0030 HA119

31 Power Supply for etching E3614A 0031 HA216

32 Portable Band Saw 016878 0032 HA119

33 Sputter Coater EMITECH 675X-059 0033 HA220

34 Vibromet 2 504-V2P-461 0034 HA215

35 Vibromet 2 488-V2P-439 0035 HA215

36 Vibromet 2 462-V2P-324 0036 HA215

37 Digital Balance 14658484 0037 HA215

38 Ultrmet II (Ultrasonic Cleaner) 364-B2C-2219 0038 HA215

39 Digital FARNELL (for etching) LS30-10 0039 HA215

40 FeritScope MP3C 08533298 0040 HA124

41 Portable Brinel Hardness Tester 2761313 0041 HA124

42 Barcp-Impressor (non-metallic) GYZJ934-1 0042 HA124

43 Ultrasonic Thickness Gage (37DL Plus) 091751911 0043 HA124

44 QualiTest (non-metallic) 21807 0044 HA124

45 MIC-10 Hardness Tester 8004 0045 HA124

46 Trans Pol-5 59710072 0046 HA124

47 Trans Pol-5 (Grinder/ Polisher) 59710073 0047 HA122






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Line item


Code Location

Bldg. 2291

50 TAU (Cooperheat) (Welding) 41756/7 0050 HA121

51 Fully Automatic Voltage Regulator SVC-500 VA 0051 HA221

52 P. A. M. S II Charger (Welding) N/A 0052 HA121

53 LN-742- LINCOLN ELECTRIC (Welding) 10240 0053 HA121

54 ROROTEC GUN (Welding) 10011 0054 HA121

55 Simplimet 2 (Mounting Press) 452-N25-0336 0055 HA116

56 Portable Microscope (UNITRON) RMM 1822 0056 HA124

57 Thickness Gage “T-Mike EZ” 701853 0057 HA124

58 DC Air Plasma Cutting System 1250 0058 Shaded Area

59 Air Compressor 60 GAL 0059 Shaded Area

60 Olympus TGHM 100/115 V 238889 0060 HA121

61 Lamp Olympus 300808 0061 HA121

62 Olympus TGHM 200/240 V 240562 0062 HA121

63 Lamp Olympus 298283 0063 HA121

64 Inspector FERRITE 1136915 0064 HA121

65 Thermometer 9010 0065 HA121

66 EZ-Label Printer (CASIO) KL-8200 0066 HA124




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Appendix 3 - Chemicals List

Chemical Name Quantity Location

Hydrochloric Acid 1 HA-118

Nitric Acid 1 HA-118

Sulfuric Acid 5 HA-118

Sodium Arsenite 1 HA-118

Potassium Permanganate 1 HA-118

chloroform 1 HA-118

Glycerin 1 HA-118


Nitric Acid 2 HA216

Hydrochloric Acid 3 HA216

Picric Acid 1 HA216

Oxalic Acid 2 HA216

Acetic Acid 1 HA216

Chromic Acid 2 HA216

Cupric Sulfate 1 HA216

Chromium Oxide 1 HA216

Hydrogen Peroxide 1 HA216

Potassium Hydroxide 1 HA216

Potassium Hydroxide reagent 1 HA216

Potassium Ferrcyanide 1 HA216

Sodium Arsenite 8 HA-219



Phosphoric acid 1 HA-219

Perchloric Acid 1 HA-219

Ammonium Hydroxide 1 HA-219

Chloroform 1 HA-219





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Appendix 4A – Metallurgical Laboratory Safety Manual

This manual highlights the issues specific to the Metallurgical Engineering Laboratory (MEL).

There are many hazards that can be avoided through use of proper precautions as detailed in

this manual. Safety is everyone’s responsibility. When in doubt, ask for further clarification or

instruction. Keep in mind that some of the equipment here has the possibility of causing

permanent injury or even death. A moment’s inattention can lead to tragedy. We take safety

seriously. Knowledge is one of the most important factors for safe laboratory work. Protective

clothing and safety shielding are not always adequate. They must be supplemented by

intelligent use and awareness of the specific situation. Many of the projects that the MEL deals

with are related to safety issues. It is imperative to the company objectives that laboratories are

maintained and operated safely. In addition to creating and keeping a safe environment for

employees, the laboratories must be safe for non-technical visitors such as students. Many of

these people may not be aware of the hazards in a lab, especially in the metallurgical

laboratory. A clean and safe lab environment will also help minimize errors. MEL safety

procedures are listed below:

General Safety Rules for CSD LAB

Wear appropriate eye protection whenever working with any potential eye hazards

(safety glasses, chemical goggles and face shields)

Easily accessible fire extinguisher

Limited quantities of hazardous chemistries, such as acids and bases used for etchants,

are stored in cabinets.

Limited quantities of solvents are in bottles marked with the appropriate labeling.

Floor and bench space is free of clutter and inactive samples.

A functioning vent hood is present and ready for use.

Laboratory equipment, such as the polishers and low speed cut-off wheels, are at a safe

shut-off position.

Emergency eyewash is marked and easily accessible.

Additional eyewash solutions (for neutralizing hazardous chemistries) are available.

Location for the acid spill kit is marked.

Location for MSDS information is indicated. It is also important to keep safety and

laboratory equipment updated.

Safety glasses, is required when in any shop area, whether working or not!!

Shoes must be worn in shop area. No one wearing sandals will be allowed to enter the

lab area.

Do not operate any item of equipment unless you are familiar with its operation and have

been authorized to operate it. If you have any question regarding the use of equipment ask

the area supervisor.




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No work may be performed using power tools unless at least two people are in the shop

area and they can see each other.

Do not attempt to remove foreign objects from eye or body. Report to health service

for medical treatment. If chemicals get in eye(s), wash for 15 minutes in an open flow

of water before proceeding for medical treatment.

Think through the entire job before starting.

Before starting a machine, always check it for correct setup and always check to see if

machine is clear by operating it manually, if possible.

Do not rush or take chances, obey all safety rules.

If you have not worked with a particular material before, check the hazardous materials

data sheet book for any specific precautions to be taken while working with the material.

Follow all appropriate precautions when working with solvents, paints, adhesives, or

other chemicals. Use appropriate protective equipment.

Check the power cords and plugs on portable tools for damage before using them.

Use equipment for its intended purpose.

Never leave a machine running unattended.

Do not talk to, or permit anyone to fool around with equipment while you are operating it.

Get help in lifting or moving any heavy tool, attachment, or equipment.

Make sure to wear appropriate clothing for the job (i.e., do not wear short sleeve shirts

or short pants when welding).

Do not work in the shop if you are tired, upset or drugged.

Never indulge in horseplay in the shop areas.

All machines must be operated with all required guards and shields in place.

A brush, hook, or special tool is preferred for removal of cutting chips, shavings, etc.,

from the work area. Never use the hands.

Keep the floor around the machines clean, dry, and free from trip hazards.

Know What to Do in an Emergency

You must be prepared to respond quickly and precisely to an emergency. You must

familiarize yourself with the laboratory you are working in, its exits, and its associated

safety equipment: eyewash stations, showers, sinks, fire extinguishers, and spill kits. Just a

few moments spent learning the locations and use of these pieces of equipment prior to an

emergency could save a life

In case of injury, no matter how slight, report it to the lab supervisor. The emergency

phone number is 110




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Safety Precautions when Working on Machining and Cutting Equipment

Use the appropriate safety equipment for the job. Wear safety glasses with side

shields or goggles. Prescription eye glasses are not substitutes for safety glasses.

Wear appropriate safety footwear.

Wear hearing protection when required. If you have trouble hearing someone

speak from one meter (three feet) away, the noise level from the machine is too

high. Damage to hearing may occur

Do not wear loose clothing, gloves, rings, bracelets or other jewelry that can

become entangled in moving parts.

Do not remove cuttings by hand. Wait until the machine has stopped running to

clear cuttings with a brush or rake.

Do not leave machines running unattended. Turn power off.

Do not free a stalled cutter without turning the power off first.

Do not clean hands with cutting fluids.

Do not use rags near moving parts of machines.

Do not use compressed air to blow debris from machines or to clean dirt from

clothes.

Ensure that the machining equipment have a start/stop button within easy reach of

the operator.

Ensure that the work piece and cutter are mounted securely before taking a cut.

Mount work in a vise that is bolted or held magnetically to the table. Use proper

hand tools to make adjustments.

Change cutting coolants periodically.

Keep working surface clear of scraps, tools and materials.

Keep floor around the machine equipment free of oil and grease.

Use lifting equipment when appropriate to move heavy work to or from machines.

Make sure the power is off before changing cutting blades.

Always stay at the machine when it is in operation.

Consult with an expert if necessary

Notes:

o Read the equipment owner's manual carefully before operating.

o Make sure you understand instructions and are properly trained before operating machining and cutting equipment.




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Things you should avoid doing during machining and cutting:

Do not wear gloves, rings, watches or loose clothing.

Do not attempt to mount measure or adjust work piece until cutting or machining

equipment is completely stopped.

Do not use an excessively heavy cut or feed as it can cause the cutter to break.

The flying pieces could cause serious injury.

Do not lean or rest hands on a moving table.

Do not make any adjustments while the machine is running.

Safety Precautions when Working on Tensile Testing Machine

General Process Description:

This piece of equipment works using a hydraulic system and applies a load to stress a sample

until failure to a maximum load of 600KN. Users MUST have the required training prior to

working in the tensile testing machine.

The major risks of this equipment are:

1. Pinch area between the platens.

2. Flying material from failed samples.

Personal Protective Equipment (PPE)

Before using the Tensile Tester, ensure that you will at least meet the following protective

requirements:

o Safety Glasses

o Safety shoes with socks

o Long pants (no shorts!)

o Lab coat (optional)

o Safety Shield (optional)

o When placing the sample in between the platens MAKE sure that the valve for the Load

is completely closed.

o Make sure that there are no apparent leaks from the hydraulic system

Note:

o Before proceeding you must have read and are familiar with the safe operations of the Tensile Testing machine.




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o Although not required having a second person working with you would be better if an

injury was to occur.

o If working after hours you have to ask for approval from your Supervisor and the

Person In-charge

Health Threatening Situation - In the event of an imminent or actual health-threatening emergency:

1. CALL 110 FOR THE EMERGENCY RESPONSE

REMAIN IN THE AREA TO ADVISE RESPONDERS IF YOU CAN.

2. ACTIVATE LOCAL ALARM SYSTEMS

Safety Precautions when Working on Hardness Testing Machines

General Process Description

This piece of equipment is used to perform hardness test on different kinds of materials.

Users MUST have the required training prior to working in the hardness testing machine by a

technical staff.

Hazards of Rockwell Hardness Tester/ Class of Hazard:

The major risk of this equipment is the pinch area between the indenter and anvil.


Before using the Rockwell Hardness Tester, ensure that you will at least meet the following

protective requirements:

1. Safety Glasses

2. Closed-toe shoes with socks

3. Lab coat (Optional)

4. Ensure that your hands are not in the pinch area when load is being applied. The anvil

should be placed in the storage container, and the indenter placed into the appropriate

storage case.

When finished using the Rockwell Hardness Tester clean the immediate area,

and return the indenter and anvil back to the storage container.

Note:

Before proceeding you must have read and are familiar with the safe operations of the Rockwell Hardness Tester.




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Safety Precautions when Working on Impact Testing Machine


The Model 84 impact test machine is used to test the impact characteristics of an extensive

variety of materials and components over a wide range of impact velocities. Data from these

tests can then be used in the evaluation of material or component performance.

Hazards of Impact Tester/ Class of Hazard:

Materials testing involve inherent hazards from high forces, rapid motions and stored energy.

You must be aware of all moving and operating components which are potentially hazardous,

particularly the moving crosshead or pendulum in an impact tester.


Before using the impact tester, ensure that you will at least meet the following protective

requirements:

1. Safety Glasses



4. Ensure that your hands are not in the pinch area when load is being applied. The anvil

should be placed in the storage container, and the indenter placed into the appropriate

storage case.

Wear protective clothing when handling equipment at extremes of temperature.

Impact testing is often carried out at non-ambient temperatures using cryogenic chambers

(Temperature controller). Extreme temperature means an operating temperature below 0°C

(32°F). You must use protective clothing, such as gloves, when handling equipment at these

temperatures. Display a warning notice concerning low temperature operation whenever

temperature control equipment is in use. You should note that the hazard from extreme

temperature can extend beyond the immediate area of the test.

Notes:

o Before proceeding you must have read and are familiar with the safe operations of Impact Tester

o The best safety precautions are to gain a thorough understanding of the equipment by reading your instruction manuals and to always use good judgment




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Safety Precautions when Working on Analytical Equipment


This unit analyzes and identifies metals. Only such metals may be analyzed for which the unit

has been calibrated by the manufacture or by qualified technical personnel.

Hazards of Analytical equipment/ Class of Hazard:

This unit has been manufactured in accordance with the state of art. Nevertheless, a residual

risk cannot be completely excluded.


Before using the analytical equipment, ensure that you will at least meet the following

protective requirements:

1. Safety Glasses



User Information:

o Absolutely comply with all safety regulations

o Observe all safety and accident prevention regulations at all times while operating,

maintaining and repairing the unit.

o Maintenance and repairing may only be carried out by qualified personal

o Check if the safety devices work properly after every maintenance or repair

o Never tamper with the safety devices’ if you feel that a safety device does not work

properly , shut down the unit immediately

o The unit may be operated only in a dry environment

o Disconnect the mains power plug before opening the unit for servicing

Every user of the unit must have understood the present Operation Instructions. This applies in particular to the safety regulations.

Before proceeding you must have read and are familiar with the safe operations of the analytical equipment.




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Prohibited Operating Conditions:

Operating the unit is not allowed if one of the following conditions applies:

o If the unit is faulty or damaged

o If the unit is not subject to regular maintenance

o If the ambient conditions do not comply with the specifications

Warning ǃ Danger or injury:

When the unit is switched on, there is a risk of suffering an electric shock when the electrode is

touched or when the sample is removed during a measurement.

Never touch the sample while a measurement in progress

Avoid any contact with electrode when the unit is switched on.

Safety Associated with Preparation of Samples for Microscopy:

Mounting, Grinding, Polishing, and Etching

For polishing and grinding, safety glasses are required with a recommendation that long

sleeves, gloves, long pants and closed shoes be worn. The compounds used for polishing and

grinding grit may cause skin irritation thus, covering exposed skin is highly recommended.

If you have skin that is easily irritated or known allergies to silica, alumina, silicon carbide, or

other polishing materials, then gloves, long sleeves, long pants, and closed shoes are required.

When etching samples, safety glasses or face shield, gloves appropriate for the chemical

etchant, lab coat with long sleeves, long pants, and closed shoes are required.




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Appendix 4B - Quarterly Safety Inspection Checklist

Consulting Services Department

Quarterly Safety Inspection Checklist Date

Areas Inspected Adequate? Actions taken with responsible

person and dates listed Yes No

I. Office Areas

- Floor clear of obstruction

-No high storage of boxes, materials

- Electrical devices, cords in good condition

-Lighting

II. Hallways

- Clear means of egress

-Lighting

-Exit lights working

III. Common Areas

-Floors clear of tripping areas

- Proper office tools available; in good condition

- Safety equipment and extinguishers clear

IV. Lab Shaded Area

- Entrances, clearances, obstructions

- level walking surfaces

- Material storage

V. Lab Areas

- Chemical storage, handling, spent chemicals

- compressed gas cylinders storage

- Personal Protective Equipment use

- Fire extinguishers, testing

-First Aid, Eye Wash Stations, Safety Showers

- Lab equipment condition, calibration

-Overhead 3 Tons, overdue

- Fume hood condition, air velocity

- House keeping

QSI Completed by:

Reviewed by:




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Appendix 5 - MSDS for Picric Acid




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Appendix 6 - Materials Laboratory Technician CMap




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Appendix 7 – Prepamatic-2 (Automatic Sample Preparation) Procedure




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Describing the Buttons of Operation Board




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1-Open the valve of the water No. 1 and air No. 2 and turn power on No. 3 the machine.

2-Check all DP-suspension and lubricants bottles are full.

1

2

3




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3-Clamp the specimens samples in the specimen clamed holder of the sample.

4-Fix the specimen holder of the sample in the machine.




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5-look to the main screen of the machine, select the struers method and click to the enter by

using the button

6-Select the metalog method D.

7- NOT: Make shore the disc of the polishing machine are wit for the first time use the machine

you have to make it wit by using the forward and backward botme and pressing the lubricant

button.




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8- Make shore the door closed and check disc name and the Dp-suspension in the screen are

matched with the disc and bottles in the machine.

9-Run the machine by pressing the button start or F2.




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10- Remove the specimen holder after completed the all process and inspect the metallographic

samples.

11- Don’t forget to clean the Op-x by returning to the main menu and select the manual

function.

12-Follow the instruction in the screen to clean the tube.




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Appendix 8 - SpectroMAX Procedure

Starting up the Instrument

1. Open the argon gas from the cylinder nozzle using the key provided.

2. Switch ON the power supply for both instrument and computer.

3. Switch ON the POWER switch on the back side (top) of the instrument.

4. Switch ON the SOURCE switch on the back side (Bottom) of the instrument.

5. Switch ON the computer and start SPARK ANALYZER SOFTWARE.

6. As soon as the communication starts between the PC and the instrument, you should here a

noise of the argon gas solenoid valve opening. THAT MEANS COMMUNICATION

ESTABLISHED BETWEEN PC AND INSTRUMENT.

7. Always place some sample in the spark stand. It should not be kept open.

8. You should see argon bubbles coming out in the bottles even in standby mode (without

sparking)

9. Flush some argon by pressing CTRL+F or by going to “instrument” and “argon flush”.

10. Spark any sample to check whether spark is coming OK or not.

Performing Analysis

1. Sample polishing should be very fine without any dents or any irregularities in the surface

of the sample that we are going to SPARK.

2. Select the base you want to analyze (i.e., Fe, Al, Ni or Cu) by pressing F10.

3. Enter the sample ID thru the “SAMPLE MANAGER” in “FILE”.

4. Place the sample in the spark stand and check whether argon bubbles are coming slowly

even when no spark. This will give you a idea of the sample finishing.

5. Now press F2 for Sparking.

6. If the sparking is ok, the results will come on the screen. Otherwise, an error message

“REFERENCE INTENSITY BELOW LIMIT FOR FE....” will come on the screen.

7. Spark at least 3 times for a sample and take average of the three sparks.

8. The results will be automatically stored once you select the menu for sample ID for next

sample.




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Performing ICAL (INTELLIGENT CALIBRATION)

1. Polish the RH 18 sample for ICAL.

2. Clean the spark stand.

3. Check with any sample for good spark before starting calibration.

4. Select F8 in the screen for ICAL.

5. A message will come on the screen with last calibration performed date. Press OK.

6. Place the sample in spark stand and press F2 or press OK.

7. Spark the sample for 5 times. You should select the good repeatable results of intensity.

8. After 5 good sparks instrument will automatically start calculating the new calibration.

At last of the process, it will show “STANDARDIZATION WAS SUCCESSFUL”.

Entering New Grades

1. Select the method for which you want to enter new grades.

2. Go to “Program development”

3. Go to “Extra”.

4. Go to “Alloy grade library”.

5. Select any one of the sample and press “COPY”.

6. Enter the name of the grade you want to enter without modifying any data and press “OK”.

7. Now you have to enter the grade values. This can be done by selecting the grade name and

just press “EDIT”.

8. Now you can modify the values according to your interests.

9. Then press “OK” and close this window.

10. Now you have to save this modified data. For this go to “File” and press “save”.

11. Now close the “program development” window.

Using DIA 2000 Software

1. Open the DIA software in DESKTOP screen.

2. Enter password: supervisor.

3. Press ok.

4. All the measurement that we did would be saved automatically in this software.




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Appendix 9 - Tensile Machine Operating Procedure

Equipment Description

This piece of equipment works using a hydraulic system and applies a load to pull a sample

until failure. Users must be properly trained on this piece of equipment before use.


Before using the Tensile Tester, ensure that you will at least meet the following protective

requirements:

1. Safety Glasses


3. Long pants (no shorts!)

4. Lab coat (optional)

Although not required, having a second person working with you would be better if an injury

was to occur.

Before proceeding you must have read and are familiar with the safe operations of this Tensile Tester.

Tensile Test Procedure

1. Before starting, make sure you are wearing all Personal Protective Equipment.

2. Log on to the computer, if locked, using the following password: aramco.1

3. Click on the “Bluehill 3” shortcut found on the desktop ( ).

4. Wait for the program to load then switch on the hydraulic motor (green button) from the

control panel (see Fig. 1-H).

5. Move the upper crosshead using the “JOG UP” button on the control panel (see Fig. 1-E)

until the “Extension” reading on the program screen is between 5.000 mm and 10.000 mm.

6. Wait 15 minutes for the machine to warm-up.

7. Click on “Test” on the program Home screen.

8. Select the Test Method you need from the available list:

a. ASTM A370 Flat Sample

b. ASTM A370 Round Sample




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c. API 5L Flat Sample

d. API 5L Round Sample

e. ASTM A370 Flat Sample without Extensometer

f. ASTM A370 Round Sample without Extensometer

g. API 5L Flat Sample without Extensometer

h. API 5L Round Sample without Extensometer

9. Insert the sample name on the given field then click “Next.”

10. Take initial specimen measurements; Gauge length, width, and thickness for a flat

sample or diameter for a round sample.

11. Enter the test information and specimen measurements into the appropriate fields then

click “Next.”

12. Move the lower crosshead up or down (see Fig. 1-F, Fig. 1-G) to create appropriate

space between the two crossheads to install the specimen.

13. Install the specimen into the upper grip only (make sure it is strait).

14. Click on “SPECIMEN PROTECT” on the control panel (see Fig. 1-A) then close the

lower grip immediately.

15. Wait until the “Load” reading on the program screen stabilizes.

16. Install the extensometer on the specimen, make sure it fits properly (see Fig. 2).

17. Click on the “Reset gauge length” button on the program screen (see Fig. 3-J).

18. Start the test by pressing the “START TEST” button on the control panel (see Fig. 1-B)

or click the “Start” button on the program screen (see Fig. 3-K).

Note: If you need to stop the test before it completes, press the “STOP TEST” button on the

control panel (see Fig. 1-C) or click the “Stop” button in the program screen (see Fig. 3-L).

Caution

If during the test a condition develops that could affect the safety of an operator or

could damage the specimen or test equipment, press the “Emergency Stop” button on

the control panel (see Fig. 1-I).

Do not release the grips after using the “Emergency Stop” button.

The specimen may be under load after an emergency stop. The high energies involved

can cause the broken parts to be projected forcefully from the test area upon releasing

the grips. First, investigate and resolve the situation that caused the use of the

“Emergency Stop” button, reset the system and then move the crosshead to relieve any

load on the specimen. Only then should the grips be released.




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19. Upon reaching the yield point, the computer will ask you to remove the extensometer.

Remove the extensometer then click “Enter” on the keyboard.

20. Wait until final rupture occurs.

Note: The program will stop capturing data at this point, if not, then press the “STOP

TEST” button on the control panel (see Fig. 1-C) or click the “Stop” button on the

program screen (see Fig. 3-L).

21. Remove the broken specimen by first releasing the upper grip followed by the lower

grip.

22. Bring the crosshead back to gauge length by pressing the “RETURN” button on the

control panel (see Fig. 1-D) or by clicking the “Return” button in the program screen

(see Fig. 3-M).

23. Take final specimen measurements; Gauge length, width, and thickness for a flat

sample or diameter for a round sample.

24. Enter the final measurements on the appropriate fields then click “Next.”

25. Click on “Finish” then “Finish Sample” on the program screen.

26. A dialog appears asking to start a new sample. Click “No.”

27. Go to the computer desktop and click on the “Instron Test Results” shortcut ( ).

28. Open the “pdf” file with your sample name to show your test results.

29. Print the results.

30. Turn off the tensile machine if you are done testing by closing the program window.

Modifying an Existing Test Results

Follow this procedure if you need to either modify an existing test results or apply a different

test method to an existing sample:

1. Click on the “Bluehill 3” shortcut found on the desktop ( ).

2. Click on “Analysis” on the program Home screen.

3. Click “Browse”… A standard Open File dialog box displays.

4. Select the results you need to modify and click “Open.”

5. Select the Test Method you want to apply to the sample.

Note: Before modifying, click on the results to highlight the results table. Otherwise, any modification to the specimen measurements will not take effect.




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6. Enter the correct specimen measurement values (length, width, and thickness for a flat

sample or diameter for a round sample) in the “Operator inputs” area.

7. If you need to change the unit of a particular result, right-click on that result and select

“Column properties” from the context menu.

8. Select the desired unit from the dialog window then click “Close.”

9. Click “Save As”… a dialog window displays.

10. Provide the name that you want to save the results with then click “Enter” on the

keyboard.

11. Click “Finish” from the program screen.

12. Go to the computer desktop and click on the “Instron Test Results” shortcut ( ).

13. Open the “pdf” file with your new sample name to show your modified test results.

14. Print the results.




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Figure 1 - Control Panel

A

B

C

D

E

F

I

H

G




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Figure 2 - Extensometer Installed onto a Sample

Figure 3 - Tensile Program Workspace Screen

J

K

L

M




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Appendix 10 – Scanning Electron Microscope Procedure

Equipment Descript

The scanning electron microscope (SEM) uses a focused beam of high-energy electrons to

generate a variety of signals at the surface of solid specimens. The signals that derive from

electron-sample interactions reveal information about the sample including external

morphology (texture), chemical composition, and crystalline structure and orientation of

materials making up the sample. In most applications, data are collected over a selected area of

the surface of the sample, and a 2-dimensional image is generated that displays spatial

variations in these properties. Areas ranging from approximately 1 cm to 5 microns in width

can be imaged in a scanning mode using conventional SEM techniques (magnification ranging

from 5X to approximately 30,000X, spatial resolution of 50 to 100 nm). The SEM is also

capable of performing analyses of selected point locations on the sample; this approach is

especially useful in qualitatively or semi-quantitatively determining chemical compositions

(using Energy Dispersive Spectrometer (EDS).

Scanning Electron Microscope 6490LA (SEM) Basic operation

Starting the Instrument:

Turn on the main power supply

Turn on the water chiller wait for 15 min then Turn the keys-witch to START

Wait for 10 second, switch on the personal computer

Start JOEL SEM Program wait until the evacuation completed and the EVC turn to

green.

Sample Exchange:

Press the Vent Key (wait until the vent key stop from flashing).

Open the specimen chamber door and insert the sample.

Press EVAC key (wait until the EVAC key stop from flashing). The system now is

ready for observation.

Gun Alignment:

Click the { Gun} icon the Gun alignment will appear

Turn ON the Emp ( emission pattern)

Open valve VT3

http://serc.carleton.edu/research_education/geochemsheets/electroninteractions.html

http://serc.carleton.edu/research_education/geochemsheets/eds.html




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Turn [ON] the HT

Turn [OFF] the beam blanking

Set the spot size to [30], and set the Alignment – Tilt- Shift [X, Y] slide to near the

center.

Press the per heat then drag the filament heating slider slowly to the right until you

reached the saturation point

If the L.C value shows 20µA over or below the following value, adjust the L.C value by

performing bias adjustment

High Acc voltage (5.0-30kv): 60-80µA

Low Acc voltage (0.3-4.0 kv): 40-60µA

Turn [OFF] the Emp ( emission pattern) to bring the image into focus

Energy Dispersive Spectrometer (EDS)

EDS Basic Operation

Liquid Nitrogen Filling Procedure

Note: Before you use the EDS you have to filling the mini-cup tank with Liquid Nitrogen, to do so, please follow the following procedure:

1. Confirm the “ Power” lights

2. Confirm the “EVAC” lights

3. Press the “ start “ at the Detector controller you will hear Beep after 15 minutes`

4. “ EVAC” to lit continuously from blinking (Pour LN2 within 10 minutes)

5. “COOL” to be lit continuously from blinking (Beep will stop) the system will be ready

after 50 minutes approx.

Gun Alignment:

HT must be ready

Switch on the HT

Conduct a filament saturation (get the first and the second beaks)

Tilt Adjustment: set the spot size to 20 and below, adjust the tilt X, Y until you get the

max brightness.

Shift adjustment: set the spot size50 and above, adjust the tilt X, Y until you get the

max brightness.




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Adjust stigmatisms and Wobblers (Wobblers should be carried out at high mag.5000 and

above). EDS analysis:

Filling the liquid nitrogen tank with liquid nitrogen, make sure the EDS ready before start the

analysis.

Performing EDS Analysis:

1. Make sure that the WD is 10 mm and the KV at least 15 KV or higher.

2. Get an image from the SEM and freeze it

3. Send the image to the EDS, system will ask you to create and project no. for this take,

Please does so.

4. Set the analysis conditions (CPS should be between 1500-5000)-blue and green color

are acceptable. If the CPS is not foiling in this range you need to adjust WD/SS and

filament saturation.

General Information:

Right click on the mouse for course adjustment, Lift click on the mouse for fine

adjustment.

If the specimen has different level, set up the aperture at No. 1.

To see two different images (SE-BE) at the same screen (center of the screen) click on

Tool-Mulilive image- Flexible window image.

For higher resolution, you need to set the aperture at position no. 1.

The aperture should be set on position 2 or 3 for analysis purpose

Aperture sizes:

1-20 micron higher resolution

2-30 micron general purposes

3-100microm when you have difficulty in getting higher CPS, it is recommended to set

the aperture at position 3.

WD is related to the KV

Low Vacuum Mode:

After the evacuation completed, set up the pressure at 10 PA and click on start (you will find

the low vacuum control key at the right side on the screen).




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Note-1

If the sample gets charging, increase the pressure until you get red out the charging.

At low vacuum mode, if we conducted an analysis on low vacuum mode and noticed that the

CPS is low (less than 1500 CPS) then you need to increase the spot size.

Increase the spot size, if the image becomes so dark and CPS is not increasing then adjusts the

contrast and brightness using the course knob (backscatter). Then, adjust the gun alignment

shift.

Recipe Icon: This is to save all conditions for certain project, after you are done with all

adjustments and freeze the photo. Press the Recipe icon and add the name for your sample

press OK. Then, all condition will be saving for you, and you can come back again and use

same condition for smaller samples.

If you missed one of the imaging icons from the main screen, go to the setup and select

icon setup- select the missing icon and apply.(1)

Note-2

The accuracy of the EDS analysis is 0.01% for all elements except the light elements, so

any element is greater than the 0.01% should be detected by the EDS.

The quantitative analysis results should show the mass % is greater than the error%, If

the error % is greater than the mass % for certain element, that element is not exist.

VID (visual identification) technique used to determine the present of an element or not.

Press the VID icon you will see two lines, one is yellow and the other one is black, the

yellow is the back ground and the black is the compare generator spectrum , if the back

ground is filling the black line profile, the element is exist.

If you want to add an element to the analysis list click on the “Ptbl” (Periodic table)

icon and the element and press play which is located under tool.

To change the color of the mapping screen go Tool-Edit Element Palette –Rest –select

Mono color –OK-Auto- Apply Now- OK.

To report mapping:

After saving the mapping data, click on OVER icon –select the element you want to be

shown on the report and drag it to the right side of the screen-Press analysis- show

spectra –Press Quantify – Previews- Export to word.

Measurements:

To do measurement, first you have to freeze the image-select image-select Texl/Scaler-

select ruler and do your measurements.




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SRT (scan rotation)

If you want to rotate the live image-Press SRT icon and adjust the sliding bar between -

180+180. (This icon is located at the top tool bar, if it not there you can add) see Note (1).

At any spectrum you can change the color, font, and lines of spectrum by clicking on

the Tool-Setup.

To know the energy level of any elements go to the Predict table and select the element

and Press Label icon at the same menu.

Multiview Sequential analysis:

The Multiview sequential analysis use to analyze different areas in sequins, if you want

to conduct a sequential analysis first get images from all areas of inters, and send to the

EDS. Press the SEQ (sequential analysis) icon- set the conditions at the SEQ window as

shown below:

® ZAF ® Standard less ® Pure ® HT turn off HT when analysis finish

Then Press Start and wait until the analysis completed

Highlighted all images

On the analysis station window Press file-Page setup- Map/Thumbnail—OK

Press File—Print Preview.

To remove JEOL Logo- Select Hand Icon- Right Click on the logo then Delete

To report the data, highlights the EDS results-Right click-Show compare

SIP Procedure:

Switch on the machine

Open VT1 &VT3 and press EVAC

Before you turn on the SIP leave the system for 2 hours to be stabilized.

After that close VT1&VT3 and wait until the SIP Lab become orange.

Press SIP power and wait until the system reached 10 -5

Pa. When the Machine reaches

10 -5

Pa, the system is ready.




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Appendix 11 - Contributors

This manual was developed by the following CSD staff.

Name Login ID Tel.

Kermad, Abdelhak kermadax 880-9529

Ghamdi, Khalid S. ghamks0k 880-9536

Kawaie, Ali Y. kawaieay 872-3676

Gurusamy, Ramesh gurusarx 880-9537

Otabi, Waleed O. otaibiwl 880-9531

Saab, Mishal S. saabms 880-9530

Manual Materials Laboratory

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