Weld Defect 01 New

Defect of Welding Defect of Welding

Ir.Soeweify, M.EngIr.Soeweify, M.EngHead of Strength and Structure Groups Head of Strength and Structure Groups Department of Shipbuilding EngineeringDepartment of Shipbuilding Engineering

Surabaya Institute of TechnologySurabaya Institute of Technology

Welding Engineer 1980 Hiroshima UniversityWelding Engineer 1980 Hiroshima UniversityWelding Inspector 1984 Hamburg UniversityWelding Inspector 1984 Hamburg University

Fracture mechanic sertificate 1990 Bandung Institute of Fracture mechanic sertificate 1990 Bandung Institute of TechnologyTechnology

Welding defectWelding defect

Metallurgical defect Metallurgical defect Melting processMelting process

• Incomplete fusion and incomplete penetrationIncomplete fusion and incomplete penetration Alloying processAlloying process

• Slag inclusion and porousitySlag inclusion and porousity Cristalization processCristalization process

• Cold crack and hot crackCold crack and hot crack

Dimensional defectDimensional defect Tranversal shrinkageTranversal shrinkage

• Angular distortionAngular distortion Longitudinal shrinkageLongitudinal shrinkage

• Longitudinal distortionLongitudinal distortion

Weld defectWeld defect

CrackCrack Incomplete fusionIncomplete fusion Incompl. penetrationIncompl. penetration Slag inclusionSlag inclusion PorosityPorosity Under cutUnder cut UnderfillUnderfill Over lapOver lap

CovexityCovexity Weld reinforcementWeld reinforcement Arc strikeArc strike Tungten InclusionTungten Inclusion SpatterSpatter DelaminationDelamination Lamelar tearLamelar tear Seams/lapSeams/lap Dimensional Dimensional

Defect of WeldingDefect of Welding

Metallurgical defectMetallurgical defect

Crack of weldingCrack of welding

Hot crack, Cold crackHot crack, Cold crack Longitudinal crack, Longitudinal crack,

Transversal crack Transversal crack Base metal ,Weld Base metal ,Weld

metal ,HAZ crackmetal ,HAZ crack Throat, root, toe, Throat, root, toe,

under bead, crater under bead, crater crack crack

Lamelar tearingLamelar tearing

Hot CrackHot Crack

Just start for cristalizationJust start for cristalization Segregeration between cristalSegregeration between cristal Weld metal crackWeld metal crack Crack of the first layerCrack of the first layer Creater crackCreater crack Micro crackMicro crack Transversal and logitudinal crackTransversal and logitudinal crack

The influence of hot crackingThe influence of hot cracking

Name of Name of crackcrack

Form of crackForm of crack Influence factor for cold Influence factor for cold crackingcracking

WWcondcond CChemhem RsRs BBformform

Crack on Crack on the first the first layerlayer

V V VV V V V V V V V V V V V VV V

Dendrite Dendrite crackcrack

V V VV V V V V V V V VV V V V VV V V

Crater crackCrater crack V V VV V V V V V V VV

VV VV

Hot CrackHot Crack

Welding conditionWelding condition Chemical Chemical

compositioncomposition Shrinking load of weld Shrinking load of weld

pointpoint Form of beadForm of bead

Crater crackCrater crack

Crater crack occour in the end of weld couse of wrong welding electrode manipulation, Filler metal have flow characteristiecs with produce concave profile when solidification

Hot crack start from crater crack of fillet weld in pipe welding, E 308 -16, E 309-16, E 316 -16, The welder must take care the end of welding to full fill the crater

Crater crack is one of dangerous hot crack

Preventive Methode of the Hot cracking for each material

Sensitivity Preventive Methods

Crack of Weld Metal For Material

For Prose dur

For De sign

Kind of Material First Layer

Crack Dendrit Crack

Micro Crack HAZ

Other Crack

Crack

In the

HAZ

40 Kg/mm2

Midle sensitive necc to care


Low sensitive No Problem



50 Kg/mm2

Midle sensitive necc care

Midle sensitive necc Care




60 Kg/mm2






70 Kg/mm2






C A R B O N S T E E L

80 Kg/mm2






Reduce of P.S Increase of Mn examine of the elememt

Examine weld condition examine format weld bead.

Low Shrink age Pre vent Stress

Cr- ½ Mo






1Cr – ½ Mo






1 ¼ Cr – ½ Mo






2 ¼ Cr – ½ Mo






3 Cr – ½ Mo






5 – 9 Cr – ½ Mo






L O W A L L O Y S T E E L

Mn - Mo Midle sensitive necc care





Reduc of P.S Increase of Mn Examined of the elememt

Examine weld codition Examine format weld bead. Clean Keep enough Slag

Low Shrink age Pre vent SC



Austenit Midle sensitive necc to care


High sensitive Must care



Martensit Midle sensitive necc care





S T A I N L E E S

Ferrit Midle sensitive necc care


Midle sensitive not care

High Sensitive Must care


Reduc of P.S Increase of Mn Examin of the element Reduced Harmful element Pb,B,O Keep delts ferrite

Examine weld codition Take of crater Examine format weld bead. Clean Keep enough Slag

Low Shrink age Prevent Stress Concent

Pure Nikkel






Inconnel High sensitive Must care





Hactelloy High sensitive Must care





N I

B A S E

Monel High sensitive Must care





Reduce PS Increase Mn Reduce Harmful elemen, Pb,B,O Add little element Ti,Nb.Al,Ni Examine element comp

Examine weld codition Examine format weld bead. Clean Keep enough Slag Apply peening

Low Shrink age Prevent Stress

Cold crackCold crack

Process of crackProcess of crack Finish cristalizationFinish cristalization Hydrogen diffusibleHydrogen diffusible Stress at the weld Stress at the weld

metalmetal HAZ and base metal HAZ and base metal

crackcrack Root crackRoot crack Toe crackToe crack Under bead crackUnder bead crack

Caused of crackCaused of crack Chemical composition Chemical composition Welding heat inputWelding heat input Hydrogen diffusibleHydrogen diffusible Restraint of jointRestraint of joint Residual stressResidual stress Diforation anggleDiforation anggle

The influence of cold crackingThe influence of cold cracking

Name Name of of

crackcrack

Form of crackForm of crack Influence factor for cold Influence factor for cold crackingcracking

WhWh HHdiffdiff PPcmcm RR AA RsRs

Root Root crackcrack

V VV V V V V V VV

V V V V VV

V V V V VV

V V V V VV

V VV V V V V V VV

V VV V VV V V V V VV


Name Name of of

crackcrackForm of crackForm of crack

Influence factor for cold Influence factor for cold crackingcracking

WhWh HdHd PPcmcm RR AA RsRs

Toe Toe crackcrack

V VV V V V V V VV

V V V V VV

VV V V V V VV

V VV V V V V V VV

VV VV VV


Name Name of of

crackcrackForm of crackForm of crack

Influence factor for cold Influence factor for cold crackingcracking

WhWh HdHd PPcmcm RR AA RsRs

UnderUnder

bead bead crackcrack

V VV V V V V V VV

V VV V V VV V V V V V VV

LameLame

lar lar teartear

inging

VV V VV V VV V V V V VV

V V V V VV

Longitudinal and transversal crackLongitudinal and transversal crack

Longitudinal crack start from the weld toe in the HAZ

Transvers crack start from the stop and run of weld

Longitudinal and transversal crackLongitudinal and transversal crack

Under bead crackUnder bead crack

Under bead crack

Some kind of cold

crack

Start from the toe of

weld in HAZ

Mainly caused by

Hydrogen diffusible

Effect of pre heating on root crakingEffect of pre heating on root craking

Experimental resultsExperimental results

Hydrogen CrackingHydrogen Cracking Hydrogen cracking, also called Hydrogen cracking, also called

cold cracking, requires all three cold cracking, requires all three of these factorsof these factors HydrogenHydrogen StressStress Susceptible microstructure (high Susceptible microstructure (high

hardness)hardness) Occurs below 300°COccurs below 300°C Prevention by Prevention by

Preheat slows down the cooling Preheat slows down the cooling rate; this can help avoid martensite rate; this can help avoid martensite formation and supplies heat to formation and supplies heat to diffuse hydrogen out of the materialdiffuse hydrogen out of the material

Low-hydrogen welding procedureLow-hydrogen welding procedure

Cracking in Welds

0.1.1.5.2.T12.95.12

Couse and Prevention Cracks on Couse and Prevention Cracks on the HAZ the HAZ

CouseCouse Base metal have high Base metal have high

hardenabilityhardenability High C ek and P cm High C ek and P cm C, Mn,Cr conten to C, Mn,Cr conten to

highhigh Hidrogen diffusibleHidrogen diffusible Hidrogen Hidrogen

EmbrittlemenEmbrittlemen High restrain joint High restrain joint

PreventivePreventive Chose the lower Cek Chose the lower Cek

and Pcm and Pcm Elec. Low hydrogenElec. Low hydrogen Dry Filler metal Dry Filler metal Clean edge Clean edge

preparationpreparation Moderate high restrainModerate high restrain Good weatherGood weather Pre heating and post Pre heating and post

heatingheating

Lamelar tearingLamelar tearingThick material only

Delamination first

High Stress through the thickness

Fillet weld only

Degree of constraint

High inclusion of base metal

Low transverse ductility

High residual stress

Lamellar tearing

Lamelar tearingLamelar tearing

Lamelar tearingLamelar tearing Lamelar tearingLamelar tearing Lamellar tearingLamellar tearing

Lamellar TearingLamellar Tearing Occurs in thick plate subjected to high Occurs in thick plate subjected to high

transverse welding stresstransverse welding stress Related to elongated non-metallic inclusions, Related to elongated non-metallic inclusions,

sulfides and silicates, lying parallel to plate sulfides and silicates, lying parallel to plate surface and producing regions of reduced surface and producing regions of reduced ductilityductility

Prevention byPrevention by Low sulfur steelLow sulfur steel Specify minimum ductility levels in transverse Specify minimum ductility levels in transverse

directiondirection Avoid designs with heavy through-thickness Avoid designs with heavy through-thickness

direction stressdirection stress

Cracking in Welds

0.1.1.5.2.T14.95.12

Improve CleanlinessImprove through thickness properties

Buttering

Reheat CrackingReheat Cracking Mo-V and Mo-B steels susceptibleMo-V and Mo-B steels susceptible Due to high temperature embrittlement of the heat-Due to high temperature embrittlement of the heat-

affected zone and the presence of residual stressaffected zone and the presence of residual stress Coarse-grained region near fusion line most Coarse-grained region near fusion line most

susceptiblesusceptible Prevention byPrevention by

Low heat input weldingLow heat input welding Intermediate stress relief of partially completed weldsIntermediate stress relief of partially completed welds Design to avoid high restraintDesign to avoid high restraint Restrict vanadium additions to 0.1% in steelsRestrict vanadium additions to 0.1% in steels Dress the weld toe region to remove possible areas of Dress the weld toe region to remove possible areas of

stress concentrationstress concentration

Cracking in Welds

0.1.1.5.2.T15.95.12

Knife-Line Attack in the HAZKnife-Line Attack in the HAZ CrCr2323CC66 precipitate in precipitate in

HAZHAZ Band where peak Band where peak

temperature is 800-temperature is 800-1600°F1600°F

Can occur even in Can occur even in stabilized gradesstabilized grades Peak temperature Peak temperature

dissolves titanium dissolves titanium carbidescarbides

Cooling rate doesn’t Cooling rate doesn’t allow them to form againallow them to form again

Weld

HAZ

Knife-line attack

Stainless Steel

Lamellar TearingLamellar Tearing Occurs in thick plate subjected to high Occurs in thick plate subjected to high

transverse welding stresstransverse welding stress Related to elongated non-metallic inclusions, Related to elongated non-metallic inclusions,

sulfides and silicates, lying parallel to plate sulfides and silicates, lying parallel to plate surface and producing regions of reduced surface and producing regions of reduced ductilityductility

Prevention byPrevention by Low sulfur steelLow sulfur steel Specify minimum ductility levels in transverse Specify minimum ductility levels in transverse

directiondirection Avoid designs with heavy through-thickness Avoid designs with heavy through-thickness

direction stressdirection stress

Cracking in Welds

0.1.1.5.2.T14.95.12

Improve CleanlinessImprove through thickness properties

Buttering

Reheat CrackingReheat Cracking Mo-V and Mo-B steels susceptibleMo-V and Mo-B steels susceptible Due to high temperature embrittlement of the heat-Due to high temperature embrittlement of the heat-

affected zone and the presence of residual stressaffected zone and the presence of residual stress Coarse-grained region near fusion line most Coarse-grained region near fusion line most

susceptiblesusceptible Prevention byPrevention by

Low heat input weldingLow heat input welding Intermediate stress relief of partially completed weldsIntermediate stress relief of partially completed welds Design to avoid high restraintDesign to avoid high restraint Restrict vanadium additions to 0.1% in steelsRestrict vanadium additions to 0.1% in steels Dress the weld toe region to remove possible areas of Dress the weld toe region to remove possible areas of

stress concentrationstress concentration

Cracking in Welds

0.1.1.5.2.T15.95.12

Knife-Line Attack in the HAZKnife-Line Attack in the HAZ CrCr2323CC66 precipitate in precipitate in

HAZHAZ Band where peak Band where peak

temperature is 800-temperature is 800-1600°F1600°F

Can occur even in Can occur even in stabilized gradesstabilized grades Peak temperature Peak temperature

dissolves titanium dissolves titanium carbidescarbides

Cooling rate doesn’t Cooling rate doesn’t allow them to form againallow them to form again

Weld

HAZ

Knife-line attack

Stainless Steel

Incomplete fusionIncomplete fusion

Low heat inputLow heat input Travel speed to highTravel speed to high Amperage to lowAmperage to low Wrong electrode Wrong electrode

positionposition Weld metal to weld Weld metal to weld

metal metal Weld metal to base Weld metal to base

metalmetal

Incomplete fusionIncomplete fusion

Typical side wall incomplete fusion

Incomplete penetration Incomplete penetration

Couse of Incomlete penetrationDiameter electrode to bigGroove angle to smallAmperage to lowWrong electrode not deep penetration Weld metal does not extend entirelyWeld metal does not extend entirely

Incomplete penetration Incomplete penetration

Incomplete penetration on radiography

Incomplete penetration in root of weld

Incomplete fusion

Incompete Penetration

Slag inclusionSlag inclusion

Incorrect welding Incorrect welding parameterparameter

Difficult to clean slackDifficult to clean slack Molten slack to thickMolten slack to thick Oxidation and Oxidation and

deoxidation processdeoxidation process Unadequate weld Unadequate weld

preparationpreparation Iregular visual in X RayIregular visual in X Ray Black vision on DTBlack vision on DT

PorosityPorosity

Gas entrapment Gas entrapment during solidificationduring solidification

The least dangerousThe least dangerous HH22S, CO, NOS, CO, NO22

Uniformly scatteredUniformly scattered Clustered porosityClustered porosity Piping porosityPiping porosity Linear porositLinear porosit Dirty base metalDirty base metal

Under cut Under cut Under CutUnder Cut

Amperage to highAmperage to high The wrong welding The wrong welding

techniquetechnique Angle of electrode Angle of electrode

during weldingduring welding Initial crack start from Initial crack start from

this defectthis defect Maximum 0.5 mmMaximum 0.5 mm

Under fillUnder fill

Over lapOver lap

Over lapOver lap Protrusion of weld Protrusion of weld

metal beyond the metal beyond the

weld toeweld toe Wrong electrode Wrong electrode

positionposition Burn torchBurn torch

UNDERCUTUNDERCUT

POROSITYPOROSITY

INCOMPLETE FUSIONINCOMPLETE FUSION

OVERLAPOVERLAP

UNDERFILLUNDERFILL

SPATTERSPATTER

EXCESSIVE CONVEXITYEXCESSIVE CONVEXITY

EXCESSIVE CONCAVITYEXCESSIVE CONCAVITY

EXCESSIVE WELD EXCESSIVE WELD REINFORCEMENTREINFORCEMENT

INCOMPLETE PENETRATIONINCOMPLETE PENETRATION&&

EXCESSIVE PENETRATIONEXCESSIVE PENETRATION

UNACCEPTABLEUNACCEPTABLEWELD PROFILESWELD PROFILES

Weld Defect 01 New

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