African Fusion June 2019

AFRICAN JUNE 2019

Journal of the Southern African Institute of Welding

Contents

June 2019 FEATURES 4 SAIW’s 71 st president’s report

Published four times a year and mailed out together with MechChem Africa by: Crown Publications cc Crown House Cnr Theunis and Sovereign Streets Bedford Gardens 2007 PO Box 140

In his president’s address following the SAIW’s 71 st Annual General Meeting. Morris Maroga introduced the new board and outlined progress for the 2018/2019 financial year. 6 Phased-array UT introduced by ESKOM African Fusion talks to Eskom’s Level 3 NDT specialist and chief engineer, Grant Meredith, about research carried out at Eskom and the advantages of moving towards the use of digital phased array UT technology as a replacement for radiography. 12 Cold repair of Inconel 625 clad layers on medium carbon high strength steels This paper, presented at the IIW Annual Assembly in Indonesia (Bali) in 2018, won its principle author, Kristian Kruger, the 2018 Harvey Shacklock Gold Medal Award for the best technical paper presented at an SAIW event. 18 Welding the nickel superalloys Metallurgist Michael Fletcher talks about the requirements forwelding thenewhigh-temperature creep- and corrosion- resistant nickel-based superalloys, such as Inconel 740H, withparticular regard for purgingandgas puritymonitoring. 20 Welding for space travel: the ultimate challenge Quality requirements for equipment and vessel structures for spaceships are exceptionally high with welding technology standards posing particularly arduous challenges. This article from Fronius describes some solutions. 22 Coating specialist adds laser cladding capability Thermaspray has installed a purpose built laser-cladding booth to its coating facility in Olifantsfontein. The company’smanaging director, Jan Lourens, introduces the technology and its advantages. 24 Let’s make welding cool, clever and clean MDof KEMPER, Frederic Lanz, describes his future vision for welded fabrications. 26 HyperFill: SAW deposition rates with GMAW flexibility Lincoln Electric South Africa introduces HyperFill, an innovative twin-wire GMAW welding solution, to maximise productivity from a single power source, wire feeder, welding torch and contact tip. 27 Afrox advances cylinder tracking Leading gas supplier, Afrox, has completed the national roll- out of its state-of-the-art digital cylinder tracking service. REGULARS 3 Morris Maroga’s message 8 SAIW Bulletin board 10 Front cover story: The 3-metre radius welding offering 28 Welding and cutting forum 32 Today’s technology: The OmniScan MX2 Phased Array, ultrasonic flaw detector.

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Bedfordview 2008 Tel: (011) 622 4770 Fax: (011) 615 6108

Editor: Peter Middleton E-mail: peterm@crown.co.za Advertising: Helen Couvaras E-mail: helencou@crown.co.za Publisher: Karen Grant

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Deputy publisher: Wilhelm du Plessis Production & layout: Darryl James Circulation: Brenda Grossmann Printed by: Tandym Print, Cape

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Michael Ashley, Mwali Kawawa and Rolf Schluep, members of the Air Liq- uide marketing team, talk about the development of their new welding and cutting offerings aimed at being the top of mind partner to the Auto- motive and Fabrication industries.

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Publisher of the Year 2018 (Trade Publications)

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www.africanfusionmagazine.co.za

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SAIW: Sean's comment

SAIW and SAIW Certification

SAIW Governing Board President: Morris Maroga – Eskom B Beetge – Sentinel Inspection Services L Breckenridge – CEA J Guild – SAIW G Joubert – SAISI DJ Olivier – Olivier Survey Group A Paterson – University of the Witwatersrand J Pieterse – Afrox T Rice – Personal member J Tarboton – SASSDA JR Williamson – Wilconsult J Zinyana – New Age Welding Solutions SAIW Certification Governing Board Chairperson: G Joubert – ArcelorMittal B Beetge – Sentinel Inspection Services P Bruwer – Sasol Synfuels F Buys – Consultant and SAQCC IPE G Buitenbos – Steinmüller D Olivier – Olivier Survey Group H Potgieter – SAIW Certification P Pistorius – University of Pretoria R Williamson – Wilconsult J Zinyana – New Age Welding Solutions

Morris Maroga’s message A t Eskom, we are busy with a programme to replace traditional radiographic test- ing (RT) with phased-array ultrasonic

testing (PAUT) to validate the quality of the boiler tube welds at our power plants. During shutdowns, we do about 100 000 boiler tube repairs per year and every repair has to be inspected using NDT to ensure that the welding is of an acceptable quality. We have been using radiography for testing welds but, for safety reasons, this involves site clearances and processing delays. Sowe are moving towards phased-array UT, which is far less intrusive and can be done quite quickly after weldingwithout site clearance, helping the repair programme to advance more steadily. The change will also give us better detection sensitivity, which some say will increase weld rejection and repair rates. But we have also implemented an FEA and modelling programme that enables us to much more accurately determine the acceptance criteria for indi- cations. In many cases, we have found that we were repairing tubes unnecessarily, because pore indications on RT film, for example, tend to be larger than they are in real life. Phased-array inspection canmore accurately size a flaw and, with the well-defined acceptance criteria we have now developed, it will help us to avoid wasting money on unnecessary repairs. Many more technicians qualified in phased-array UT are going to be needed, however. We therefore welcome the inclusion of the new Level 2 Phased-ArrayUT course into the SAIWNDT Training programme and look forward to the day when all UT technicians are also able to perform phased-array UT inspections at our plants. SAIWNDTQualifications arewidely respectedand the training team, led by Mark Digby, is among the strongest in the country. The SAIW adopts a code-based training approach based on ISO 9712, which is the standard we use for power generation plant at Eskom, and ASME ASNT, which is preferred by the petrochemical and nuclear industries. This means that SAIW-trained NDT personnel can quickly become qualified to do the work required by industry. Across the country, we are moving towards being more certain that our plants are safe and reliable and that they can operate reli- ably between planned maintenance intervals so that unscheduled shutdowns and outages become a thing of the past. The welding and fabrication industry have a significant role to play in this regard. It is a requirement of all manufacturing codes/health and safety standards that newmaterials andwelded joints are subjected to non-destructive examination (NDE), and this must be carried out by experienced per- sonnel following written procedures. Koeberg nuclear power station has a steam generator replace- ment project coming up, which will require welding, fabrication and NDT skills on nuclear related materials. We will again be calling on our locally skilled people to work on this project. We may need to run special courses to prepare ourselves, however, if we are to avoid having to bring specialists in from overseas, which does nothing to help us to industrialise South Africa. Local welding, inspection and NDT personnel, together with SAIW, may need to refresh and expand their intellectual capacity and prepare themselves so as to be able to deliver the nuclear specific services required. We have seen problems in the large projects we have undertaken in recent years, but the principle of localising those projects and using themto drive up the skills and living standards of South African people remains as important as ever. We have to continue to focus on high level skills to produce quality fabrications, both large and small. South Africa and Africa need the SAIW to help make this happen.

SAIW Foundation Board Chairperson: M Maroga – Eskom J Guild – SAIW P Pistorius – University of Pretoria P Venter – ArcelorMittal J Pieterse – Afrox

SAIW and SAIW Certification representatives

A cting executive director

Training services manager

Jim Guild

Shelton Zichawo Tel: (011) 298 2148

Tel: (011) 298 2101 Jim.guild@saiw.co.za

shelton.zichawo@saiw.co.za

SAIW Certification manager

NDT training manager

Herman Potgieter Tel: (011) 298 2149

Mark Digby

Tel: (011) 298 2169 herman.potgieter@saiw.co.za mark.digby@saiw.co.za

Executive secretary Dimitra Kreouzi Tel: (011) 298 2102 Fax: (011) 836 6014

Technical services manager

Riaan Loots

Tel: (011) 298 2144

riaan.loots@saiw.co.za

dimitra.kreouzi@saiw.co.za

Finance and administration manager Michelle Warmback Tel: (011) 298 2125 michelle.warmbank@saiw.co.za

SAIW regional representatives Cape Town branch manager

KZN branch manager

Liz Berry

George Walker

Tel: (021) 555 2535 liz.berry@saiw.co.za

Tel: (087) 351 6568

george.walker@saiw.co.za

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SAIW president’s report 2019

SAIW’s 71 st president’s report

The SAIW held its 71 st Annual General Meeting at the City West premises in Johannesburg on FridayMay 17, 2019. In his presi- dent’s address, Morris Maroga introduced the new board and outlined progress for the 2018/2019 financial year.

“T he past year has certainly been an interesting and difficult one and it has had an impact on SAIW, began Maroga. “It is increasingly difficult for people to make time for involvement in organisa- tions such as the SAIWandwe therefore appreciate the valuable assistance and contribution of each Board mem- ber,” he added before introducing the 2019/2020 SAIW Board members that had been elected: Johan Pieterse, Robin Williamson, Joseph Zinyana, Gert Jou- bert, Dawie Olivier, Ben Beetge, Paulo Trinchero, John Tarboton, Louis Breck- enridge, Tony Paterson and Tom Rice. “The past 18months have been chal- lenging for SAIW and this has kept the Board very active. Our meetings have beenconstructive throughout theperiod and I would like to thank all Boardmem- bers for the time and expertise, which they contribute to the governance of the Institute,” Maroga said. Moving swiftly onto financial mat- ters, he said that Eric Berman, SAIW’s financial advisor had reported that, for the first time inmany years, SAIWhad re- cordedanoperating loss for the financial year, which amounted to approximately R1.3-million. “Our income was down by around 11.4% compared with 2017, whereas expenses remainedat the same level as 2017. Sponsorship amounted to R1.5-million, which is about 3% of total income. Whilst the Institute is largely self-funding, we have shared a very long relationship with the primary steel pro- ducers andwe hope this will continue in the years to come andwe thank themfor their continued support. “It is not possible to reflect this years’ financial results in a good light and there will certainly be challenges for us in the coming year,” Maroga warned, adding that the Board and the management teamwould be working hard to turn the ship around and get the Institute back to full health. Growing membership, he reported, remains a challenge and a priority, es- pecially during these difficult economic times. “The Institute currently has 222

personal member and 173 corporate members, which is stable and similar to previous year. Wewill be redoubling our efforts to grow the membership, how- ever, through some specific initiatives, but please remember everymember can help in this respect so I encourage you all to invite your contacts to come along and join us. SAIW is a prestigious and respected Institute and being amember is something to be proud of. SAIW activities and events The 2018 annual dinner was awonderful celebration of 70 years of the Institute’s existence. The function was held at Em- perors Palace inSeptember andwewere joined by several former SAIW stalwarts and well-known people from industry who have played a part in the history of the Institute. We were also able to celebrate our award winners for their achievements. The SAIW Gold Medal was awarded posthumously to Philip Doubel for his dedication to welding engineering and inspiring and developing welding technologies, which made a significant contribution to the industry at large. The medal was collected by his wife ac- companied by their son and daughter. The Harvey Shacklock Gold Medal Award, made to the author of the best technical paper presented at an Institute or IIW event, was awarded to Kristian Kruger, who received the award for his presentation ‘Cold repair of Inconel 625 clad layer on medium carbon high strength steel’ . The paper was co-authored by Frederic Laurent of 3C Metal and Pieter Pistorius from the University of Pretoria and presented at the International Institute of Welding Annual Assembly Commission 2 in Bali, Indonesia, in 2018. The 2018 Phil Santilhano Memorial Award, for the best student on theWeld- ing Co-ordination or Welding Inspectors training courses was won by Chane Marais, who achieved the highest mark for the SAIW Welding Inspectors Level 2 programme. The SAIW Presidents’ Award for the

SAIW president Morris Maroga presents Lorien Chettiar of Aveng Grinaker LTA with the Best Responsible Welding Co-ordinator Award for 2018. best NDT student was made to two stu- dents.BronwynNadeneGeelwasreward- ed for achieving distinctions in Magnetic Testing Levels 1 and 2; Penetrant Testing Levels 1 and 2; Visual Testing Level 1; Ultrasonic Wall thickness Testing, Ultra- sonic Testing Level 1 and Radiographic Interpreters Level 2. The second winner was Collen Morithinyana Tseke, who achieveddistinctions inMagneticTesting Levels 1 and2; Penetrant Testing Levels 1 and 2; Visual Testing Level 1; Ultrasonic Wall thickness Testing, UltrasonicTesting Level 1 and Radiographic Interpreters Level 2. Congratulations to both these winners for scoring outstanding marks in these difficult exams. The Best IIWManufacturing Certifica- tion Company Awardwas introduced for the first time in 2018 andmade in recog- nition of a company that has excelled in the ISO3834CertificationManufacturing scheme. Kelvion Thermal Solutions (represented by Angel Krustev and his team) received this award. Also new is the Best Responsible Welding Co-ordinator Award, made in recognition of an exceptional welding co-ordinator on the IIW Manufactur- ing Scheme. Lorien Chettiar of Aveng Grinaker LTA was the worthy recipient of this award. The 2019 annual dinner is scheduled for the 11 th of October when we will be celebrating the 71 st birthday of SAIW. SAIW Welder Challenge The 2019 biennial SAIW Young Welder Challenge competitionwas held inJanu- arywith 20 participants frommany parts of the country taking part. The standard of competitors continues to improve

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SAIW president’s report 2019

South Africa will host the 30 th AFRA Technical Working Group Meeting later in the year. This will be an opportunity for SAIW to showcase the achievements that have been made in NDT projects funded by AFRA/IAEA. University Relationships SAIW continues its close relationship with both Wits and Pretoria Universities whereeachUniversity continues tomake good progress on their respective weld- ing engineer and research and develop- ment programmes in the fieldofwelding. SAIW Foundation The SAIW Foundation has granted two more bursaries to IWT students, Landi Vincent Ndlovu Xaba and Mmaphete Boipelo Robin Phete. We wish them success with their studies. The SAIW Foundation has two exist- ing industrial partnerships for training welders. These are with Afrox (the LIV Project) andArcelorMittal. 15 Apprentice welders are currently receiving training in the Practical Welding School. Both projects are making good progress. Staff During the year Gideon Harris, a Practi- cal Welding instructor, passed away after a short illness and Surekha Krish- nan emigrated. SAIW has also parted company with Sean Blake and is in the process of recruiting a replacement Executive Director. “I would personally like to thank all SAIW staff members for their hard work and contributions. The coming year will certainly bedifficult, but the Institute has faceddifficultiesinthepastandovercome them. That is certainly what we aim to do. Our caretaker executive director, Jim Guild, tellsme we are receivingmany en- quiries from countries throughout Africa and he believes that taking advantage of these opportunities is an important way forward for SAIW,” said Maroga. “We need every single member of staff to do their utmost to ensure that SAIW is seen to be a competent and professional organisation and the ser- vice provider of choice. People should want to come here knowing they are getting the best training possible and the best support and consultancy ser- vices available. “Lastly, I would like to once again thankmy fellowSAIWBoardmembers for their contribution and support tomyself and to the Institute,” he concluded.

The Harvey Shacklock Gold Medal Award, was awarded to Kristian Kruger (centre), who received the award for his presentation ‘Cold repair of Inconel 625 clad layer on medium carbon high strength steel’.

ratory solution, which nowalso includes diffusible hydrogen testing.

and 2019 was the highest standard yet. The overall winner of the competition was Stefan Lottering fromArcelorMittal. Stefan will go on to participate in the national WorldSkills competition. Local SAIW activities Training The training figures for 2018 showed a decline in students attending SAIW courses in all categories. The reasons for this are complex but the general low level of industrial activity andabsence of national projects are important factors. We may have also contributed to the declineby favouring the IIW IWIP courses over the SAIW Level 1 and 2 inspection courses. This however has changed and we have re-introduced the SAIW Level 1 and 2 inspection courses starting from the second half of this year. The purchase of the NASA NDT busi- ness in Cape Town has also not yet resulted in any significant benefit to our business. The factors we have control over are currently being addressed by themanagement team, but it is unlikely we will see a significant benefit until 2020. In total, 1 399 students were trained by SAIW in 2018/2019, compared to 1 960 in the2017/2018period, adeclineof 29% – and the decline is mirrored across the course range. Technical Services Consulting has also suffered at the hands of low-level industrial activity, but every effort is and will be expended by Riaan Loots and his teamto grow this very important part of the SAIW busi- ness. Good progress has been made in the field of Welding Consumable testing andwe are able to offer a one-stop labo-

Qualification and Certification Whilst these activities fall within the remit of SAIW Certification, it is pleas- ing to report that the ISO 3834 scheme continues to grow with 179 companies and 42 sites currently certified. Progress is also being achievedwith the EN 15085 Railway certificationprogramme. A total of 623 persons received qualifications in 2018 and the total number of certified persons is 5 501, a figure that includes people with multiple certifications. International Affairs IIW The next IIW Annual Assembly will be held in Bratislava in July of this year. Our attendancewill be severely curtailed because of the financial circumstances in which we find ourselves, but we will continue to play our part in the boards and committees of both IIW and the International Authorisation Board. ICNDT SAIW Certification has successfully renewed its ICNDT MRA Schedule 2 Registration, which gives international recognition to the SAQCC NDT certifica- tion system. The Institute is active in the meetings and committees of ICNDT and HaroldJansen remains chairpersonof IC- NDT Certification Executive Committee. AFRA/IAEA AFRA/IAEA has funded a contract be- tween SAIW and Hydrac (Cameroon) for establishing a certification scheme in Cameroon and an Approved Train- ing Body. The project also incorporates training of eight Level 3 personnel.

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Eskom to introduce PAUT

Following five years of comparative research on radiography versus phased-array ultrasonic testing (UT) for tube inspection at EskomPower Plant, the power utility ismoving towards the use of this digital UT technology as a replacement for radio­ graphy. African Fusion talks to Eskom’s Level 3 NDT specialist and chief engineer, Grant Meredith, about the research and the advantages of the move. Phased-array UT introduced by ESKOM

“ A t Eskom we have been do- ing ongoing research on the feasibility of replacing radiographic testing (RT) in our boilers with phased-array UT,” begins Meredith. “Radiography iswritten into thePres- sure Equipment Requirements (PER) and it has its own acceptance criteria in the testing codes for boiler tubing. ASME has been pioneering, by way of code cases, the replacement of radiographic NDT results with ultrasound –more spe- cifically, recordedUT – but therewere no acceptance criteria that couldbedirectly applied to recorded phased-array UT,” he continues. “For piping with wall thicknesses greater than 8.0 mm, we found that

we had to prove that we could see an isolated volumetric pore as acceptable/ rejectable at¼of thewall thickness if us- ing the ASME Code or ⅓of the thickness to complywith the ISOCode. Thismeant that, for a 6.0mmwall thickness, we had to be able to reliably see a pore with a diameter of 1.5mm,” Meredith explains. Radiography is very sensitive to volu- metric indications suchas these, but less sowithplanar indications such as cracks or lack of fusion defects. The detection capability of the phased-array process, however, was found to be less adequate on the volumetric sidewhilebeingbetter at detecting planar flaws such as cracks or lack of fusion defects,” he says. “A C-scan on a modern phased ar-

phased-array acceptance criteria were relatively easy to establish, but then came the harder task of evaluating pipe in the 4.0 to 6.0 mm range, for which UT criteria were not yet incorporated into any of the codes. So, about five years ago, we began an investigation at Kendal Power Station to put together comparisons of phased-array UT results with radiographic imagery. “Although becoming an acceptable replacement, in principle, we had to demonstrate that there was sensitivity compatibility between the radiographic films widely used at power stations and the new phased-array NDT data. In accordance with the criteria for radi- ography, when using phased-array UT,

ray UT system gives a com- parable visual result to a radiographic film. In addi- tion, however, built-in digital techniques enable accurate sizing of both pores and crack-lengths from phased- array NDT data, which al- lowed us to directly compare radiographic and phased array results and detection sensitivities,” he explains. A related part of the re- search was to use finite ele- ment analysis (FEA) andmod- elling to show the maximum pore size that would still be safe and fit for service if not detected. “Our task was to determine whether the limit of detectability for phased- array UT was acceptable for Eskom plant. We found, for example, that code re- quirements were oversensi- tive in their rejection criteria on volumetric indications, which was leading to us hav-

A direct comparison between a pore found using phased-array UT (PAUT) and radiography. At a raised sensitivity, the PAUT equipment was found to be able to detect a real 1.5 mm flaw, with the measured size being more accurate than the size of the same indication measured off the radiograph.

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Eskom to introduce PAUT

ing to repair pores that posed no risk.” Explaining how a radio- graphic image is generated, Meredith says that the source radiation is usually posi- tioned slightly to the side of the weld being examined, with the film placed behind the tube. “When you look at the exposed film, you see the whole weld as an ellipse, with one half showing the front of the weld and the other half showing the back. The divergence of the gamma rays fromthe source creates a penumbra effect, so that the size of a pore on a film will look bigger than it actually is. For a pore sized on a film at 1.5 mm, when we cut that sample, we found that its actual pore size was nearer to 1.0 mm, hence our view that the radiography process

Through a five year comparative study, Eskom has demonstrated that there is sensitivity compatibility between the radiographic films widely used at power stations and the new phased-array NDT data.

samplestotestbeforepresentingareport on the findings, which need to closely align with what we know about the qualification samples. If successful, they will be qualified to do phased array in- spection on our sites, but requalification will become necessary if their system; equipment; procedure; or personnel are changedinanyway,”Meredithpointsout. With respect to qualified companies with this capability and phased array personnel, he says that there are per- haps only 20 or so companies with this capability and, with only one or two qualified personnel in each company, far too few people with these skills are available. Hence capacity for these in- spections is a limiting factor. “We have an outage coming up now and we are looking at doing a complete radiography inspection with phased- array comparisons and we need 10 or so teams of 2 or 3 technicians to do this work. “Ultimately, we believe that rather than being a ‘special’ process, phased- array UT will replace conventional UT as a mainstream inspection technique. We are therefore very pleased to see new Level 2 phased-array courses being introduced by training service providers suchas theSAIW. In thenear future, how- ever, we also want to see phased-array technology becoming an integral part of all UT training courses and qualification programmes,” Meredith concludes.

the orientation that they lie. “Our findings in this regard are in agreement with research from The Electric Power Research Institute (EPRI) in the USA, which began to do some similar research some years back. Our recent research has gone a little further, however, and we have now published specific accept/reject criteria of our own that we can use alongside criteria being developedby the ISOCode. We intend to use these to produce an internal Eskom Standard, so that when we contract phased-array NDT service providers, we can give them clear and precise requirements about what is acceptable to Eskom,” he notes. Eskom is also now in the process of drafting a phased-array inspection pro- cedure for tube thicknesses of between 3.2 and 3.8 mm which, when complete, it intends to incorporate into qualifica- tion procedures for using phased-array UT during most of its scheduled boiler plant shutdowns. “To properly qualify an NDT proce- dure, contractors need to do a perfor- mance demonstration that qualifies their system; their equipment; the procedure and their personnel, and this qualification standard is also now drafted. Phased-array practitioners first need to demonstrate that they can detect known sized defects in manufactured samples. “We then give them blind trial

overestimates pore size,” he explains. “In addition to rejecting these welds because they measure outside of maxi- mum code requirement on the ra- diograph, modelling by FEA analysis showed that, from a fitness for purpose point of view, actual pore sizes reject- able by code would have been accept- able to Eskom,” he adds. By beefing up the sensitivity of the phased array UT equipment to detect a real 1.5 mm flaw, however, the correla- tion between the detected size and the measured size was found to be more accurate. The bigger issue, however, is that cracks and lack-of-fusion defects can be missed by radiography and these pose a far greater rupture risk. This is because of the uncertainty and vari- ability in terms of the plane alongwhich these indications lie with respect to the radiation direction. Planar flaws beyond 15° of being in line with the source rays cannot be seen at all on an X-ray film, and these flaws are more serious than a 1.5 mm pore, Meredith says, noting that phased array UT offers far better sensitivity at detecting such flaws. “The chances ofmissing aplanar flaw that is outside a 30° cone on either side of the exposure direction is very high,” he reiterates. With semi-automated phased array, however, it is possible to detect a crack length and a through wall dimension of a planar flaw in

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SAIW bulletin board

Improvement to flagship SAIW Welding Inspector Programmes old Jansen, says that while the outstanding quality of the IWIP courses is not doubted by the local industry, it is abundantly clear that industry wants the SAIW courses to once again play a major part in the SAIW Inspectors programme. “We have heard them and it makes absolute sense. After all, these are courses that were developed in conjunction with local industry with content that is absolutely pertinent to South African conditions and local industry characteristics.”

F ollowing a decision to focus more on the internationally recognised Inter- national Institute of Welding’s (IIW) IWIP Basic, Standard and Comprehensive pro- grammes, SAIW Inspectors Level 1 course were removed from the curriculum, while SAIW Inspectors Level 2 took a back seat. “In retrospect, we see that this has not worked out in the way it was planned and we will, with immediate effect, be bring- ing back a new version of the Inspectors programme which includes both the SAIW Inspectors courses and the IIW courses,” says Jim Guild, SAIW’s caretaker execu- tive director. He adds that for more than 40 years the SAIW Welding Inspector programmes (Level 1 and Level 2) were the backbone of the South African welding industry and by far the most popular courses at the SAIW. These courses have been specifically tai- lored to meet local industry requirements and, since inception, theyhavebeen thepre- ferred education and training choice of the largeend-user organisationsand fabricators in the local welding industry. “It’s time to refocus on these iconic courses,” says Guild. SAIWsystems andqualitymanager, Har- SAIW Open Days A s part of its strategy to promote weld- ing as a career to the youth of South Africa, the Southern African Institute of Welding (SAIW) has put into motion a se- ries of Open Days to enable young people who are in the process of deciding what to do with their lives to see what weld- ing and its related technologies can offer

Open Day Initiative The first ‘experimental’ OpenDay in Johan- nesburg was a rip-roaring success with nearly 50 young people attending. “The response was better than we expected, pointing to the need for young people to gain first-hand experience of what the welding industry can offer in terms of a career,” says Guild. He adds that experiencing at close quar- ters thewide range of career possibilities in welding helps to counter the stigma that welding is a low-paying ‘backyard’ activity for fixing gates and burglar bars. “Nothing could be further fromthe truth,” Guild says. “In the three broad categories of Welding Inspection and Technology, Non-Destruc- tive Testing, and Practical Welding there are a host of different complex, high-end specialities to choose fromenabling young people to find a career in something that suits their individual interest and tempera- ment … and make a good living!” All participants were given a chance to, inter alia , make a weld, see a robotic weld- ing machine in action, see the processes involved in a host of non-destructive test- ing techniques and to witness some of the activities in the SAIW’s state-of-the-art Materials Testing Laboratory. The response fromthe participantswas, as expected, enthusiastic. focusedprogrammewithan internationally recognised programme, the SAIWwill offer the best of both worlds. In order to ensure the best possible standards, the SAIW has taken cognisance of the latest industry feed-back and has refined the courses to ensure they are completely up to date with the pertinent technology. “By amalgamating parts of the IWIP programmes with SAIW programmes we have created a world-class product to the satisfaction of the local industry. From the students’ perspective they obtain two diplomas simultaneously at each level – one South Africa focused and one interna- tionally focused,” Zichawo says. Upon successful completion of the SAIW Inspectors Level 1 examination, students will not only be issued with an SAIW In- spectors Level 1 qualification, providing access to the South African industry, but alsowith an IWI Basic Diploma, which gives individuals access to the global market with an internationally recognised and respected International InstituteofWelding (IIW) qualification. Should students want to go to the next level, they will no longer be required to

them. The first Open Day was recently held to great success in Johannesburg with Cape Town and Durban to follow in the near future. According to the SAIW caretaker ex- ecutive director, Jim Guild, there is little doubt that one of themost pressing global issues for young people is finding a solid, fulfilling and financially rewarding career. “In a country like South Africa, where the unemployment rate is amongst the highest in theworld and job opportunities increas- ingly hard to come by, this issue is perhaps the most urgent of all,” he says. But, he adds, all is not lost! “Welding, being the foundation of almost everything that ismanufactured, constructed or built, constantly requires welding professionals to operate in a vast range of industries including the construction, automotive, oil and gas, aeronautical, shipping, power generation and more. In fact, the welding industry is pretty much the perfect hedge against recessionary economies in terms of its ability to provide employment. “We have called welding the ‘miracle career’ because of its ability to provide employment both locally and abroad with recent surveys showing, for example, that most of the people who successfully complete an SAIW course get employed in a stable job,” Guild says. After deep analysis and research, and taking into account the needs and desires of the local industry, the SAIWhas launched a new, improved Inspectors programme, which incorporates SAIW Levels 1 and 2 with the IIW programmes. Shelton Zichawo, SAIW training services manager says that froma local perspective, the advantages of the new arrangement is that it focuses squarely on national requirements in the development of local competence, while directly addressing the local needs for national skills development. “And, perhaps most importantly, it’s what our industry wants,” he says. He adds that by combining the locally

The first ‘experimental’ Open Day in Johannesburg was a rip-roaring success with nearly 50 young people attending.

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SAIW bulletin board

Welder Challenge standard the highest ever

obtain two years’ experience as Welding Inspectors before enrolling for the SAIW Level 2 course. The two years’ experience will only come into play should a qualified Senior Welding and Fabrication Inspector (Level 2) wish to obtain the IWIP Standard qualification. “This enables the students to get into the market two years earlier with a higher qualification, making them that much more marketable in the industry andmore likely to get a higher paying job,” says Zichawo. He adds that the IWIP Comprehensive course, the highest level in the Inspectors programme will remain a stand alone course in the future. “A very small number of people may be caught at a crossroad in the progression path,” says Zichawo, “and each person will be treated sympathetically and with support from SAIW to ensure they achieve the best outcome for their future.” Anyone uncertain about how they are affected by the changes that are being introduced is invited to speak with any of the lecturing staff or any of the follow- ing members of the SAIW staff – Shelton Zichawo, Nico Fourie, Laetitia Dormehl or Michelle Warmback. sheldon.zichawo@saiw.co.za

T he 2019 SAIW Welder Challenge com- petition was held recently with more than twenty participants frommany parts of the country displaying skills levels un- precedented in this competition. “It once again proved to be the foremost skills test for young welders in South Africa,” says SAIW caretaker executive director Jim Guild. The overall winner, Stefan Lottering, won a cashprize of R15 000 and joined an il- lustrious list of winners of this competition, including Thembinkosi Matyeka, Houston Isaacs and Jaco van Deventer, who have all gone on to stellar careers in the weld- ing industry. Guild says that Stefan’s effort is a credit to all the youth of South Africa who are involved in the welding industry. “Like Thembi, Houston, Jaco and many others, Stefan is an example of the wonderful opportunities that welding offers young people who are looking for an exciting and rewarding career. The reason we hold this competition is to encourage young people from all over the country to demonstrate their skill levels in welding and to compete against the best the country has to offer. It

gives all participants a view of their skill level and motivates everyone to improve,” says Guild. He adds that the SAIWWelder Challenge competition is an industry initiative and would not survive without its sponsors. “We are all grateful that the sponsors understand the continued importance of this competition in terms of encouraging welding as a career for our youth,” he says. The sponsors for the 2019 competition were: CHIETA (main sponsor), Afrox, AFSA, Air Products, ArcelorMittal, Aveng Grinaker LTA, Columbus, ESAB, Lincoln and WASA. The overall winner of the SAIW Welder Challenge competition, Stefan Lottering (centre) with equipment sponsor, Lincoln Electric’s Benoit Lamotte (left) and SAIW president, Morris Maroga (right).

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Cover story: Air Liquide

The 3-metre radius welding

Michael Ashley, Mwali Kawawa and Rolf Schluep, mem- bers of the Air Liquide Marketing Team, talk about the development of their new Welding and Cutting offering aimed at being the topofmindpartner to the Automotive and Fabrication industries.

products. We have now introduced the offering to all our main-hub offices across the country, which all stock gas, filler materials and our full range of welding and cutting equipment. This en- ables customers to get everything they need to set up awelding operation from any Air Liquide branch,” Ashley assures. “As well as offering a wide range of filler materials for all welding applica- tions, the equipment range, torches, regulators, nozzles and brazing rods which have enjoyed notable growth, we still experience significant demand for various types of electrodes and the intro- ductionof Hyperthermplasmamachines hasbeenwellreceived”Ashleycontinues. “To meet the needs of the premium customer, the company has chosen to partner with several premiumsuppliers. “For filler materials and equipment, we have chosen as a partner ESAB, which is a global provider of innovative welding

Air Liquide nowhas the ability tooffer a completeweldingandcutting solution. Aholistic offeringprovidingwelding filler materials, welding and cutting equip- ment – alongside the traditional Air Liquidegas offering. “Our offering relates directly to the welders’ needs within a 3 metre radius as most welding cells will requiremore thanoneprocess tobeused to complete a fabrication task,” Ashley tells African Fusion . “We have long seen the potential of hard goods being sup- plied in conjunction with our gas,” he says, adding that this strategy was per- ceived well before Weld-Cut equipment was fully integrated into Air Liquide. “With the 3 metre radius in mind, we began to look for extended opportuni- ties to support our customers’ needs, with a firm goal in mind of providing a one-stop-shop for everything a welder needs to productively, efficiently and successfully produce quality welded

“ I n today’smanufacturingenviron- ment, customers are expecting their supply partners to become more integrated into their eco-systems, be more agile as well as being able to provide unique andglobally competitive solutions for their operations. Within this context, “Air liquide has further evolved a number of its offers which aim to provide its customers with world class solutions” begins Schluep. “The first of these solutions is the Air Liquide hardgoods offeringwhich encompasses a 3 metre radius around the welder and aims to support our customers with a fully inclusive solution”. From left: Michael Ashley, Mwali Kawawa, Rolf Schluep.

“To facilitate traceability, all the delivery, stocking, purchasing, material certificate records and environmental data is stored in the Cloud. This enables supervisors and managers to monitor acquisition activity via their computers, smartphones or tablet devices,” explains Schluep.

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offering and cutting solutions” he adds.

“For cutting and brazing, we offer Harris Gas Equipment. Harris is currently one of the most consistently requested product lines from customers, while for automated plasma cutting, we have formed a strong relationship with Hy- pertherm” Ashley elaborates. “Inaddition,weoffermoreaffordable house brands for welding applications where product certification is relaxed. These include Gemini electrodes for which we are the sole supplier, and Ultra-Arc ER70S-6wire aswell as various grades of stainless steel and aluminium wires,” Ashley informs African Fusion . “As for the torches, we continueour relation- ship with TBi” he adds. New partners to further support Air Liquide’s 3 metre radius offer are constantly being sought. “We recently identified Tyrolit as our supply partner for grinding and cutting discs, this after having identified the ongoing require- ment for these products by our custom- ers,” Ashley notes Demonstration and testing facilities are now available at Air Liquide’ Alrode plant. “We have a ‘welding demonstra- tions and development room’, which is also being used as both an internal and external training facility for all ap- plications. The offering is not only about the products, however. “Our in-house tech- nical support forms a cornerstone of the approach. By taking control of thewhole welding process, any problem that arises on site canbe dealt withby Air Liq- uide. We often get called out to resolve problems supposedly linked with gas, for example, only to find that the gas is not the actual problem. Nowwe are able to resolve any issue, without the need for the client to call in another Original Equipment Manufacturer (OEM). Inter- nally, we have the local expertise and

The Connected Store is compliant to the ISO 3834 requirements with respect to the storage and handling of consumables.

the recently launchedWelding Efficiency Analysis. Over many years, Air Liquide Worldwide has developed a substantial database that is able to benchmark lo- cal customers against global players. The analysis enables optimal use of hardgoods, gases, labour and energy for Gas Metal Arc Welding (GMAW) and cutting related processes. This helps lo- cal operations to becomemore globally competitivewhile keeping their costs to aminimum,” he adds. “We can nowoffer this service to clients in South Africa to enable themtobenchmark theirwelding costs to operations across the globe” Kawawa tells African Fusion . “Subsequent to gathering a holistic view of the current welding and cutting consumable consumption data, we can develop and implement a customised improvement plan to achieve improved results. By best utilising the informa- tion, Air Liquide products and expertise, the customer can realise productivity improvements that are benchmarked globally. The process minimises rework and wastage thereby enabling the cus- tomer to focus on growing their business through enhanced efficiencies. “In summary, these ever-evolving offerings aim to provide our custom- ers with unique solutions making their operations ever more competitive in a global context,” Schluep concludes.

should we encounter an unusual, dif- ficult issue, we have the support of our global technical experts too.” “In order to support the use and distribution of gases and hardgoods, Air Liquide has developed a deployable store coupled toadigitisedprocurement process. More and more customers want to control spend, have informa- tion available in realtime and be able to remotely manage their operations. The Connected Store is an ‘as andwhen’ needed solution which is on offer to all Automotive and Fabrication customers” explains Schluep. “The Connected Store is compliant to ISO 3834 requirements with respect to the storage and handling of consum- ables. To facilitate traceability, all the delivery, stocking, purchasing, material certificate records and environmental data is stored in the Cloud. This enables supervisors and managers to monitor acquisition activity via their computers, smartphones or tablet devices – added to that, a fully stocked Connected Store is now ready and available for de- ployment” explains Schluep further. “To optimise site welding works and complement the hardgoods offer, the Exeltop coupled to Arcal New Genera- tion shielding gases are available at the Connected Store,” adds Kawawa. “The newest part of our offering is

4 The key innovations built into Air Liquide’s EXELTOP solution include: 1: A quick connector to couple the gas hose to the EXELTOP gas cylinder; 2: Easy dial setting to set the initial flow to zero. 3: A pull up lever to open the cylinder. 4: Easy flow adjustment on the graduated hand wheel. 1 3 2

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Cold repair of 625 HSS

This paper, presented at the IIW Annual Assembly Commission 2 in Indonesia (Bali) in 2018, won its principle author, Kristian Kruger, the 2018 Harvey Shacklock Gold Medal Award for the best technical paper presented at an SAIWevent. The paper was co-authored by Frederic Laurent and Pieter Pistorius. Cold repair of Inconel 625 clad layers on medium carbon high strength steels KJ Kruger, F Laurent and PGH Pistorius

M edium carbon steel ASTM A519 Gr 4130 pipes and forgings are often clad with Inconel 625 before being placed in service in the subsea oil and gas industry. Due to the service conditions, itmay be necessary to repair the Inconel cladding without subjecting the underlying alloy to a second post weld heat treatment (PWHT) cycle. A ‘cold repair’ technique was developed with the intention of removing cladding such that a standard amount of the clad thickness remains, followed by a weld build up. The new build up requires low heat input such that a new HAZ does not form in the medium carbon steel and PWHT is not neces- sary to temper the heat affected zone. The effect of changes in welding parameters, specifically the welding speed, on the dimensions of the repair weld bead was estimated using the thick-plate Rosenthal equation. The study showed that it is possible to repair weld remain- ing Inconel cladding with a minimum 1.5 mm clad thickness using pulsed gas metal arc welding (GMAW-P). The results of the study showed no visible new HAZ in the medium carbon steel, no increase in medium carbon steel HAZ hardness, as well as sufficient fusion at the Inconel-Inconel interface. 276 MPa 30% Table 2: Minimum tensile properties of solution-annealed Inconel 625 plate as per SB-443 Gr 2. Introduction Inconel 625 is a solution strengthenednickel-basedalloy that is well known for its high tensile strength, impact toughness and corrosion resistance in chloride and acid containing environ- ments at a range of temperatures. Table 1 and Table 2 show the typical chemical composition andmechanical properties of In- conel 625plate [1]. The combinationof corrosion resistanceand mechanical properties makes Inconel 625 an ideal candidate formarine applications. Inconel 625 is often used as a cladding material to impart these beneficial properties to the surface of other materials in order to reduce the cost of fabrication. Initial fabrication During fabrication of components intended for use in the ma- rine industry, several factorsmust come into balance, namely: material requirements such as tensile strength, corrosion 690 MPa %Cr %Mo %Nb+Ta %Fe 8-10 3.15-4.15 <5.0 %Co <1.0 %S 20-23 0.015 %P %C 0.1 %Al %Si %Mn %Ni 0.015 Bal Table 1: Chemical composition of Inconel 625 plate as per SB-443 [1]. 0.4 0.5 0.5 Yield strength Tensile strength Elongation

resistance, hardness, and impact toughness; fabrication lead time or availability; and cost. While inmany cases Inconel 625 would conform to or exceed design requirements, in general the feasibility in terms of lead time and cost to produce large complicated components out of the alloy makes this option entirely unfeasible. For this reason, Inconel 625 (ERNiCrMo-3) cladding is often applied, typically to a layer thickness rang- ing from 3.0 to 5.0 mm onto a selected surface of a more affordable material such as ASTM A519 Grade 4130. Table 3 and Table 4 show the chemical composition and mechanical properties of 4130. Themost common claddingmethod is through arcwelding followed by a post weld heat treatment (PWHT) of the clad components.

%C

%Cr

%Mo

%Mn

0.28-0.33

0.9-1.1

0.15-0.25

0.4-0.6

%Si

%S

%P

%Fe

0.10-0.35

0.04

0.035

Bal

Table 3: Chemical composition of ASTM A519 Gr 4130 [1].

Yield Strength Tensile Strength

585 MPa 725 MPa

Elongation

10 %

Hardness (HRB) 95 Table 4: Typical mechanical properties of ASTM A519 Gr 4130 in the stress relieved condition [2]. Repair of worn cladding During service of larger moving parts that have been clad, the Inconel cladding experiences degradation that affects the performance of the component. In these cases, it is necessary either to repair the cladding or to scrap the component. Scrapping and replacing large components is extremely costly and not the preferred route. Should the component undergo conventional repair, the route would be to remove and re-apply the cladding. This would be followed by a PWHT identical to that specified in the initial cladding application. However, it is often the case that if the steel is exposed to an additional welding cycle and subsequent PWHT, the base metal mechanical properties could fall below theminimumre- quirements for the component. In order to avoid this scenario, a technique that does not expose the medium carbon steel to a weld thermal cycle that results in austenitisation must be employed to repair the damaged cladding and to obviate the need to perform a PWHT. This technique is referred to as a cold repair and this paper sets out the results of such a cold repair on ASTMA519 Gr 4130 clad with Inconel 625.

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