HRH Prince of Wales, Chancellor of the University of Wales, welcomed Prince of Wales Innovation Scholars and their company representatives to his official Welsh residence in Llwynywermod, West Wales, in celebration of the projects success on 2 July 2010.

A Clarence House spokesperson commented: The Prince of Wales was delighted to meet the first group of participants from The Prince of Wales Innovation Scholars programme following the launch of the project last year. His Royal Highness was keen to hear of the scholars progress through their work with the University of Wales Global Academy.

POWIS is a partly EU-funded scholarship project which places a world class scholar in a company for a period of three years, during which time they undertake research and development on any aspect of the companys work; whether that is to improve the companys products and services, their internal processes or the way that they interact with other companies

Sri Naga Pavan Addepalli is our TWI POWIS Scholar under the supervision of Professor Rod Thomas, who is responsible for Thermographic Inspection training at TWI. They are both based at TWI NDT Validation Centre (Wales), Port Talbot.

The TWI project deals with adopting

and developing the latest non-contact infrared thermographic technology to identify various failure modes of complex aerospace composite materials and establish thermography as a new NDT technology. TWI through its Training & Examination service has also developed new Thermographic Inspection Training Courses. One of the advantages of this technology is that it is able to investigate relatively large surface areas quickly and efficiently. This is of particular significance to the aerospace industry where the kissing bond phenomena is of major concern and is a focus of this research.

Issue 167 July/August 2010

Diary events

September 2010

Advanced Structures Technical Group MeetingMilau ViaductThu 9Great Abington

5th Joint TWI/EWI SeminarJoining of Aerospace MaterialsTue 21 Wed 22USA

October 2010

AWFTE ConferenceWorldskills London 2011 the Greatest Skills Event in the WorldFriday 1Rotherham

WJS SeminarStandards for Offshore Power and Low Carbon EnergyTue 12Middlesbrough

Technology Awareness Day (Industrial Members only)Materials Selection and Failure AvoidanceThis event will also be available online via live streamingThu 14Great Abington

Joint Technical Group MeetingOffshore Oil and Gas and Welding ProcessesThu 14Aberdeen

Open DayTWI Technology Centre (Yorkshire)Tue 19Rotherham

Workshops and seminars are recognised

Continuous Professional Development events

T h e m a g a z i n e o f T W I

w w w . t w i . c o . u k e - m a i l : t w i @ t w i . c o . u k

HRH The Prince of Wales celebrates his scholars success

QAJoinIT

register now www.twi.co.uk

What are the residual stresses in a dissimilar metal weld?

Can non-round parts be rotary friction welded?

What protective hardcoats are available for plastics?

HRH Prince of Wales with Sri Naga Pavan Addepalli and Professor Rod Thomas

Phot

o co

urte

sy R

hys W

ebbe

r

2July/August 2010

Connect Ju l y /August 2010 w w w . t w i . c o . u k e - m a i l : t w i @ t w i . c o . u k

Axeon Technologies LtdUKDesign and manufacture of customer battery systems

Citech Energy Recovery Systems UK LtdUKEnergy recovery systems

Cummins Generator TechnologiesUKTurbochargers for commercial diesel engines

Denso Marston LtdUKManufacture of engine cooling components

EUTELSAT SAFranceSatellite communications

Hgans ABSwedenMetal powders

J Ray McDermott IncUSADesign, fabrication, transport and installation of offshore platforms and pipelines

Mecc.AL srl a Socio UnicoItalyHeat sink manufacturer MFE Formwork Technology Sdn Bhd

MalaysiaAluminium formwork

Nabtesco CorporationJapanAerospace equipment and precision machinery

NKT Flexibles I/SDenmarkManufacture of flexible pipe systems

Siemens AG, Energy MuelheimGermanyPower generation R & A Kay Inspection Services Ltd

UKInspection of pressure systems

Texmaco LimitedIndiaManufacturer of railway freight cars, steel castings and hydro mechanical equipment

Vantrunk LtdUKCable management and support systems manufacturer

Zakum Development CompanyUAEOil and gas production

New Members of TWITWI is pleased to welcome the following as Industrial Members

TWI will hold its third Technology Awareness Day on Thursday, 14 October 2010.

We are pleased to welcome Professor John Irven, chairman of TWIs Research Board., as the keynote speaker. This year,the day is dedicated to TWIs Structural Integrity and Materials Departments.

Corrosion and structural integrity management have been an integral part of TWI for more than 60 years and TWI has established a world class reputation for supplying high calibre services to clients across all industry sectors. This event represents a unique

opportunity for TWI members to get an update on the most recent research and advances in this area.

Presentations will cover corrosion considerations in materials selection, design and fabrication; coatings for corrosion mitigation and corrosion testing. The session on Life Extension will address advances in fatigue life management; Engineering Critical Assessment for life extension and management of ageing assets. For a full programme and registration details please go to: http://www.eventsforce.net/10TAD.

Attendees will have the opportunity

to request one-to-one meetings with our experts on the registration form.

For the first time,we are also offering an interactive online option for members to attend this event. No travelling required! Watch only the topics of interest! There is also a Q&A facility to allow you to ask questions which will be passed on to the speakers in real time. Please register here http://www.eventsforce.net/10LTAD for the online event.

The event is a membership benefit and free for TWI Industrial Members.

For further details please contact: viola.augstein@twi.co.uk

TWI Technology Awareness Day Materials Selection and Failure Avoidance14 October 2010, Cambridge

For further information on TWI, visit the website atwww.twi.co.uk

w w w . t w i . c o . u k e - m a i l : t w i @ t w i . c o . u k Connect Ju l y /August 2010

July/August 2010

3

TWI is pleased to announce

that Christoph Wiesner took

up the reins as the new

Chief Executive on 1 July. He

succeeds Bob John who, for the

past six years, has presided

over the expansion of TWI both

in the UK and overseas.

Christoph joined TWI in 1991 after obtaining his materials engineering degree in Germany and his doctorate at the Swiss Institute of Technology. He worked for twelve years in TWIs Structural Integrity Group, first as Senior Project Leader and later in Section and Group management roles, before being appointed TWI Research & Technology Director in 2003.

Much of his early research and consulting work has been in the application and development of structural assessment and test

methods. More recently his focus has been on people, business and innovation management as a key member of TWIs Executive Board team.

He oversaw the growth in TWIs Technology Programme value through publicly funded programmes, both from the UK and EU and took a leading role in the TWIs externally accredited management systems.

Experiences and networking activities include contributions to, and chairmanship of, BSI and CEN standardisation committees and the UK Technical Advisory Group on the Structural Integrity of High Integrity Plant (TAGSI); membership of the Board of Directors and chairmanship of the Technical Management Board of the International Institute of Welding (IIW).

Responding to the announcement of his appointment, Christoph

commented that he is very much looking forward to the new role as well as the challenges it holds: I feel honoured to have been selected and will do my utmost to lead TWI into a promising future in order to serve the members, customers and staff of this great organisation.

For the third year in a row, TWI is looking forward to running seminars in Japan and China. This years events will take place on Tuesday 23 November 2010 at the Northwestern Polytechnical University in Xian, China, and a week later, on Tuesday 30 November 2010,at the Jidousha Kaikan (Automotive Center) in Tokyo, Japan.

The seminars are whole day events with the morning session being open

to TWI Members and non-Members, the afternoon being for Members only. This years topic is Friction technologies - benefits for manufacturing.

Presentations will cover a broad range of latest advances and future developments in friction technologies including friction stir, rotary and linear friction welding and stationary shoulder friction stir welding.

We believe the variety of this years

programme includes something of interest to everybody and are hoping to see many of our Japanese and Chinese business partners at the seminars. Formal invitations will be sent out in September In the meantime, if you have any questions, please dont hesitate to contact Graham Wylde or Steve Shi at graham.wylde@twi.co.uk or steve.shi@twi.co.uk

TWI seminars in Japan and China Friction technologies - benefits for manufacturing

New Chief Executive

Connect Ju l y /August 2010 w w w . t w i . c o . u k e - m a i l : t w i @ t w i . c o . u k4

Technology Transfer

Nickel is a relatively simple metal. It is face centred cubic and undergoes no phase changes as it cools from melting point to room temperature; similar to a stainless steel. Nickel and its alloys cannot therefore be hardened by quenching so cooling rates are less important than with, say, carbon steel and preheating if the ambient temperature is above 5OC is rarely required. Nickel and its alloys are used in a very wide range of applications from high temperature

oxidation and creep resistance service to aggressive corrosive environments and very low temperature cryogenic applications. Nickel may be used in a commercially pure form but is more often combined with other elements to produce two families of alloys solid solution strengthened alloys and precipitation hardened alloys. Typical

compositions of some of the more common alloys are given in the Table.

All the conventional welding processes can be used to weld nickel and its alloys and matching welding consumables are available. As mentioned above, nickel and its alloys are similar in many respects to the austenitic stainless steels; welding procedures are likewise also similar. Nickel, however, has a coefficient of thermal expansion less than that of stainless steel so distortion and distortion control measures are similar to those of carbon steel.

The most serious cracking problem

with nickel alloys is hot cracking in either the weld metal or close to the fusion line in the HAZ with the latter being the more frequent. The main source of this problem is sulphur but phosphorus, lead, bismuth and boron also contribute. Both weld metal and HAZ cracking are generally the result of contamination by grease, oil, dirt,

etc left behind following inadequate cleaning; excess sulphur in the parent or weld filler metals causing a problem is a rare event. Machining or vigorous stainless steel wire brushing followed by thorough degreasing with a suitable solvent is necessary prior to welding, with the welding taking place within about eight hours to reduce the risk of contamination. Any heat treatment must be carried out using sulphur-free fuel or by using electric furnaces. Components that have been in service and require weld repair may need to be ground or machined prior to degreasing to remove any contaminants that have

become embedded in the surface in or adjacent to the weld repair area. Remember that if mechanical wire brushing is carried out AFTER the degreasing operation or during welding the compressed air from air powered tools contains both moisture and oil and the cleaned surfaces may be therefore be re-contaminated.

Job Knowledge107 Welding of nickel alloys Part 1

Alloy designation

Alloy type

Typical chemical composition % Mechanical properties

Ni Cr Mo Fe Nb Al Ti Others

0.2% proof, MPa

UTS,MPa

El,%

Alloy 200 CP 99.2 - - 0.2 - - - Mn 0.3 148 452 45

Monel 400 SS 68 - - 1.75 - - - Cu 33 235 562 38

Monel K500 PH 65 - - 1.25 - 2.95 0.55 Cu 32 795 1100 18Alloy 600 SS 75 15.5 - 8.5 - - - 305 670 40

Alloy 617 SS 46 22 9 0.75 - 1.25 0.45Co 12.5 B 0.004

345 725 60

Alloy 625 SS 64 22 8 2.75 3.65 0.25 0.25 - 472 920 45Alloy 718 PH 52 19 3 Rem 5.2 0.5 0.95 - 1100 1420 18Alloy 800 SS 32 22 - 42 - 0.45 0.45 - 290 605 42Alloy 825 SS 42 21.5 3 38 - 0.1 0.9 Cu 2.25 330 715 39Alloy C276 SS 55 15.5 16 5.5 - - - W 3.75 345 795 60

Nimonic PE16 PH 44 16.7 3.3 29 - 1.2 1.2B 0.004Zr 0.03

450 825 28

Table. Typical composition and properties of some of the more common alloys

ComputerHighlight

ComputerHighlight

ComputerHighlight

ComputerHighlight

ComputerHighlightprecipitation hardened,

ComputerHighlightsolid solution

ComputerHighlight

w w w . t w i . c o . u k e - m a i l : t w i @ t w i . c o . u k Connect Ju l y /August 2010

Technology Transfer

5

Porosity can be a problem with the nickel alloys, the main culprit being nitrogen. As little as 0.025% nitrogen will form pores in the solidifying weld metal. Quite light draughts are capable of disrupting the gas shield and atmospheric contamination will occur resulting in porosity. Care must be taken to ensure that the weld area is sufficiently protected and this is particularly relevant in site welding applications. With the gas shielded processes, gas purity and the efficiency of the gas shield must be as good as possible. Gas hoses should be checked for damage and leaks at regular intervals and, with the TIG process, as large a ceramic shroud as possible should be used together with a gas lens. It goes without saying that gas purging of the root is essential when depositing a TIG root pass.

A small amount of hydrogen (up to 10%) added to the argon shield gas has been found to reduce the problem. Start and finish porosity is a problem when MMA welding. The weld start should be carried out by welding back over the arc strike position, remelting any porosity that has formed due to the poor gas shielding at the start of the weld. Care also needs to be taken at the weld end, with the arc length reduced and travel speed increased slightly to reduce weld pool size.

Oxygen is also a cause of porosity in certain circumstances when it combines with carbon in the weld pool to form carbon monoxide. Consumable manufacturers generally overcome this problem by ensuring that sufficient deoxidants (primarily manganese, aluminium and titanium) are present in the filler metal.

One feature of nickel alloys that is

often encountered is the formation on the surface of the weld pool of a viscous and adherent scum. This can be difficult to remove and can result in inclusions and lack of inter-run fusion if not removed prior to depositing the next pass. Wire brushing is frequently not sufficient to remove this layer and it then becomes necessary to grind the weld surface.

The weld pool, in addition to this surface film, is also sluggish and does not flow freely as with a carbon or stainless steel. This may result in a lumpy and very convex weld bead and a poor toe blend unless the welder manipulates the weld pool to avoid such defects. Although stringer beads may be used, a slight weave to assist the weld metal to wet the side walls of the preparation is beneficial. In addition, weld preparations must be sufficiently wide to enable the welder to control and direct the weld pool; an included angle of 70 to 800

is recommended for V butt welds. A U preparation included angle of 30 to 400 is acceptable and, though more expensive to machine than a V preparation, may be cheaper overall as the amount of filler wire required can be reduced, depending on material thickness. Addition of hydrogen to the shield gas (up to 10%H in argon) in TIG welding also has been found to be beneficial in reducing the weld pool surface tension.

A further characteristic of nickel alloys is that the amount of penetration is less than with a carbon or stainless steel. Increasing the welding current will not increase penetration. The implication of this is that the root face thickness in single sided full penetration welds should be less than with a stainless steel. It is recommended that the thickness of

the root face should not be greater than 1.5mm in a zero gap TIG butt weld. Removable backing strips are very useful to control root bead shape. These can be made from copper, stainless steel or a nickel alloy. Carbon or low alloy steel backing strips should be avoided.

Although weldability of nickel and its alloys is generally good the composition, metallurgical structure and its heat treatment and/or service history all affect its response to welding. Wrought, fine grained components have better weldability than cast items as these often have significant amounts of segregation. Coarse grains may lead to micro-fissuring in the HAZ thus high heat input is best avoided. All the alloys are best welded in the annealed or solution treated condition and this applies particularly to the precipitation hardenable alloys such as Inconel 718.

Further precautions to be taken with the commoner welding processes and recommendations on the welding of specific alloys will be covered in Part 2.

This article was written by Gene Mathers

ComputerHighlight

ComputerHighlight

ComputerHighlight

ComputerHighlight

ComputerHighlight

ComputerHighlight

ComputerHighlight

ComputerHighlight

ComputerHighlight

ComputerHighlight

Connect Ju l y /August 2010 w w w . t w i . c o . u k e - m a i l : t w i @ t w i . c o . u k6

July/August 2010

CSWIP Welding Quality Control Co-ordinator scheme launched

The first CSWIP Welding Quality Control Co-ordinator course will take place in Abington, UK on 23 - 27 August (4 days training and 1 day examination). The next course has been scheduled for 27 Sept 1 October in Middlesbrough. It will be followed by a November course (venue to be dependent on student location demand).

The qualification is a natural career progression for experienced inspection personnel who wish to demonstrate their level of competence in the field of Quality Control Management.

The programme covers:

Planning

Inspection test plans (quality plans)

Review and acceptance of: material certification, mechanical testing reports, welding procedures qualifications, welder qualifications, PWHT reports and procedures, pressure testing reports, NDT reports, as-built drawings, engineering query, non-conformance reports, final certification.

The requirements for candidates to be able to take the examination are, as a minimum:

A current valid CSWIP 3.2 Senior Welding Inspector certification plus three years documented experience related to the duties and responsibilities or an International equivalent.

OR

A current valid CSWIP 3.1 Welding Inspector with 10 years documented experience related to the duties and responsibilities or an International equivalent.

OR

When the above requirements are not met, candidates can be assessed on an individual case by case basis for entry. (The candidate must show competence and knowledge of subjects covered as detailed below.)

Below is a list of typical prior knowledge requirements:

Application of the requirements of codes and standards.

Use and application of inspection quality test plans/written schemes of examination.

Knowledge of quality related procedures and associated practices.

Identification of relevant material, components and associated certification.

Awareness of associated manufacturing processes and operations.

Knowledge of heat treatment procedures, recording systems and reports.

Awareness of hydrostatic test methods, safety and best practice and pneumatic testing.

Knowledge of non-destructive testing and destructive mechanical testing.

Health and safety requirements and practices.

For more information or to enrol, please contact Customer Services on +44 (1223) 899500 or e-mail trainexam@twi.co.uk

7 w w w . t w i . c o . u k e - m a i l : t w i @ t w i . c o . u k Connect Ju l y /August 2010

July/August 2010

WJS/DVS Conference on Joining PlasticsInternational Conference on the latest developments in joining plastics in mass production and fabrication 2 November 2010 Handwerkskammer, Dsseldorf, Germany This event, which will be conducted in English, is organised jointly by the WJS of The Welding Institute and the German Welding Society (DVS) and will provide a unique opportunity for fabricators, processors, manufacturers, design engineers and product developers to discover the latest technical developments from industrial and academic experts from Europe and North America.

Twenty papers will be presented in

two parallel sessions, one dealing with mass production welding and the other concentrating on fabrication welding. Areas covered will include new developments in laser welding, infrared welding, ultrasonic welding, and adhesive bonding; welding of thermoplastic tanks and pipes; joining of composites; testing of welded joints; and qualification of plastics welders.

For further information please contact simone.mahlstedt@dvs-hg.de or visit the website www.dvs-ev.de/joiningplastics2010.

One day seminar TWI Technology Centre (Yorkshire), Rotherham 19-20 October 2010 The seminar will include presentations and demonstrations held at TWIs

Technology Centre in Rotherham on the 19 October 2010, with the option of further one-to-one discussions on the 20 October with TWI engineers.

The day will provide overview of the technology and highlight recent technological advances, giving companies the chance to see the benefits from early industrial adoption of the process.

Friction stir welding of steel has been in development for over a decade, but only in recent years have the strength and wear characteristics of the tool materials improved extensively.

For more information, contact jonathan.martin@twi.co.uk or jonathan.perrett@twi.co.uk

UK and China co-operate in steel research The 1st UK-China Steel

Research Forum was held at

the University of Leicester

19-20 July 2010

Seventy-five people attended the forum, representing 20 universities and 15 research and industrial companies from both the UK and China.

The forum was sponsored by the Chinese Embassy in the UK, IOM3, East Midland Materials Society and other industry companies and Universities, including TWI.

As an invited speaker, Dr Paul Woollin gave a presentation on Hydrogen

embrittlement of welded subsea oil and gas transport systems - remaining technology gaps.

Dr Lijuan Zhang also presented results of research work related to the weldment properties of duplex stainless steel and 9-12%Cr steels.

The organising committee has provisionally agreed that the 2nd UK-China Steel Research Forum will be held in 2012 in Wuhan, China, and will be jointly organised

by Wuhan University of Science and Technology and Wuhan Iron and Steel (Group) Corporation.

Dr Paul Woollin and Dr Lijuan Zhang of TWI at the Research Forum in Leicester.

News in brief

TWI played a major part in the

gold medal winning garden at

Sandringham in July.

Designed by Giles Landscapes, the gardens theme was a nostalgic look back to the industrial revolution.

TWIs contribution was an artificially aged steel water feature which carried a steady flow of water, at exactly the right height, falling vertically from the end of a trough to form a water curtain.

Quite a challenge!

Many visitors on the day, including the Prince of Wales and the Duchess of Cornwall, complimented the designers on the award winning garden.

8

TWI contributes towards Royal flower show gold

Connect is the bi-monthly magazine of TWI

Editor Penny Edmundson

Photography Simon Condie

Production Penny Edmundson

Copyright TWI Ltd 2010

Articles may be reprinted with permission from TWI. Storage in electronic media is not permitted.

Articles in this publication are for information only. TWI does not accept responsibility for the consequences of actions taken by others after reading this information.

Published by TWI Ltd, Granta Park, Great Abington, Cambridge CB21 6AL, UK Tel: +44 (0)1223 899000 Fax: +44 (0)1223 892588 E-mail: twi@twi.co.uk www.twi.co.uk

TWI Technology Centre (North East) Tel: +44 (0)1642 216 320 Fax: +44 (0)1642 252 218

TWI Technology Centre (Yorkshire) Tel: +44 (0)114 269 9046 Fax: +44 (0)114 269 9781

TWI NDT Validation Centre (Wales) Tel: +44 (0)1639 873 100 Fax: +44 (0)1639 864 679

TWI AberdeenTel: + 44(0)1224 691222

w w w . t w i . c o . u k e - m a i l : t w i @ t w i . c o . u k

Issue 167 July/August 2010

Join TWIs new group in LinkedIn! Over 70 million professionals use the LinkedIn social networking website to exchange information, business ideas and opportunities.TWI has created a group in LinkedIn so that you can stay informed about our news, events, services, technologies and jobs.

We also aim to divert visitors to different subgroups (also managed by TWI) for more focused areas for discussion and news sharing.

Find the people and knowledge you need to achieve your goals. The TWI group is composed of people with similar industry interests.

The Welding Engineering Network subgroup, which is up and running, is managed by Sayee Raghunathan, one of TWIs Technology Group Managers.

There you will be able to participate in discussions, find out about specific events and news related to this area, and more.

Already in LinkedIn?

Join our TWI - Technology Engineering group: www.linkedin.com/groupRegistration?gid=2888580

Join our Welding Engineering Network subgroup: www.linkedin.com/groupRegistration?gid=2948627

Not yet on LinkedIn?

Get the most from your professional network

Join LinkedIn today: www.linkedin.com

If you have any queries, please contact the Marketing Department on +44 (0)1223 899000