African Fusion March 2019

AFRICAN MARCH 2019

Journal of the Southern African Institute of Welding

ESAB launches EWAC and STOODY for all hardfacing, repair and maintenance requirements

www.esab.co.za

Contents

March 2019

FEATURES 4 SAIW hosts fracture and fatigue seminar AfricanFusion presents someof Professor Adolf Hobbacher’s comments from the opening session of an SAIW-hosted fracture and fatigue seminar. 6 Phased array NDT for rapid detection and repair Following a visit from The German Society for Non- Destructive Testing (DGZfP), SAIW is nowgearing up to offer training in phased array and other advanced NDTmethods to South African plant and fabrication inspectors. African Fusion talks to SAIW’s Mark Digby about the technology. 8 Hlakani: Differentiated by weld-quality management AfricanFusion profilesISO3834-certifiedHlakaniEngineering and talks to sales director Gerhard Holtshauzen about the company’s successes and future outlook. 14 A feasibility study comparing two commercial TIG welding machines for deep penetration Presented by R French, WYeadon, G Kapellmann-Zafra and H Marin-Reyes at the IIW 2018 International Conference in Bali, this paper follows observations of novel weld-pool activity during TIG welding in the 300 to 1 000 A range at the University of Sheffield. 20 Low cost air plasma system transforms steel fabricator African Fusion visits the fabrication facilities of Tsipe Engineering near Rosslyn in Pretoria North and talks to the company’s MD, Martin Krebs, about his investment in a Torchmate 4800 air plasma cutting system from Lincoln Electric distributor Cosmo Automation. 22 Shielding gas: the GMAW solution optimiser African Fusion talks to Afrox’s Johann Pieterse and Arnold Meyer about shielding gas choices: the ultimate differentiator when optimising gas metal arc (GMAW) and flux-cored arc welding (FCAW) processes using Afrox’s 360° welding solutions service. 24 Babcock: fabricating in SA for 25 years November 2018 marked 25 years for Babcock’s fabricating facility as it celebratedproviding fabrication and a full range of specialised support services to Africa’s power generation and metallurgical industries. David Brook, technical director, explains. 26 African Castolin Eutectic licence agreement secured Following the signing of a technology transfer and licence agreement withwear coatings solutions specialist, Castolin Eutectic, Hlakani Engineering is bringing wear plate manufacturing and vertical rolling mill refurbishment capabilities to South Africa. Johan van Niekerk outlines the company’s new offering. REGULARS

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

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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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In light of the global acquisition by ESAB of India-based EWAC Alloys, Chris Eibl talks about the expanded range of preventivemaintenance, re- pair and wear-related solutions now available from ESAB South Africa.

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3 Sean’s comment

12 Front cover story: Hardfacing solutions for maximum uptime and longer equipment life

28 Welding and cutting forum

Publisher of the Year 2018 (Trade Publications)

32 Today’s technology: EXELTOP adds value to Tru-Trac’s welding processes

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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 S Blake – SAIW L Breckenridge – CEA G Joubert – SAISI A Koursaris – Metforensics DJ Olivier – Olivier Survey Group A Paterson – University of the Witwatersrand 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 – TUV S Blake – SAIW G Buitenbos – Steinmüller G Joubert – SAISI A Koursaris – Metforensics D Olivier – Olivier Survey Group H Potgieter – SAIW Certification P Pistorius – University of Pretoria R Williamson – Wilconsult J Zinyana – New Age Welding Solutions M Maroga – Eskom S Moodley – SAPREF

W elding for the future is a key focus for 2019 and we are very proud to have completed the SAIW Future Welding Centre. The Soldamatic Augmented reality machines are in place, along with the Lincoln Realweld, which uses virtual reality to guide trainees while they weld real joints. Our new SAIW Foundation Group, which started towards the end of 2018, will be the first to benefit from the advanced welder training techniques now available through the Future Welding Centre. The group of 15 new students will also be our first to be trained using the newQCTOWelder Programme, which is alignedwith IIW’s Welder Pro- gramme andbeing deliveredby SAIW in partnershipwith ArcelorMittal, which will take responsibility for the workplace experience modules. In addition, based on the IIWRobot Welder curriculum, our Robotic Welder Training course is also going to start this year. With support from Yaskawa, four of our lecturers have already been trained on the use of the new Yaskawa MOTOMAN robot in the Technology Centre and, to take advantage of virtual reality, a Lincoln Electric Classmate virtual and real robot trainer complements the course. We hope to see growing interest in this area for future-minded welders seeking exciting careers in automated and robot welding in sectors such as the automotive industry. Aftermany years of discussion, deliveryof advancedNDT techniques such as phased array, ToFD and digital radiography has now started. Two gentlemen from DGZfP, the German NDT society, have taken our people and some of the industry’smost senior NDT specialists through the new Level 2 Phased Array UT module, which will now be opened to all Level 2 UT professionals wishing to embrace new technology. As well as helping us though the first few phased array courses, the DGZfP will be back later in the year to deliver Level 2 ToFD and digital radiography courses. Adding to the goodnews on theNDT side, our ICNDTMRASchedule 2 certification has been renewed. We have been certified since 2016, and it is still pleasing to note that we continue to meet international standards. This gives our NDT qualifications awarded under the SAIW Certification Scheme full international recognition. ThenewComprehensive Inspector Programmehas alsobeenadded this year, which means we are now able to train welding inspectors at all three competence levels. The IIW Comprehensive Inspection qualification lines up alongside Welding Technologist and Welding Engineer roles in terms of personnel requirements in international standards such as ISO 3834 and ISO 14731 for Welding Co-ordination. We hope to run several of the new courses this year in Johannesburg, Durban, Cape Town and Secunda. Earlier this year we held the SAIWWelding Challenge, in preparation forWorld Skills Africa. More than twenty participants fromevery part of the country participated, drawn fromSAIW, Necsa, ArcelorMittal, Swift Skills Academy and our TVET colleges. Congratulations to our winner, Stefan Lottering. Sincere thanks are due to our sponsors for the 2019 competition: CHIETA, Afrox, AFSA, Air Products, ArcelorMittal, Aveng Grinaker LTA, Columbus Stainless, ESAB, Lincoln Electric and WASA. In these difficult times, we need to keep our eye on the ball with regard to implementing thebest possiblequality standards. Thismakes ourweld inspection; company certification; andpersonnel certification programmesmore important than ever. These programmes all overlap with each other and contribute to the common goal of raising quality standards in South Africa to international benchmarks. It is a goal that drives everything we do. Sean Blake

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

SAIW and SAIW Certification representatives

Executive director Sean Blake Tel: (011) 298 2101 sean.blake@saiw.co.za

Training services manager Shelton Zichawo Tel: (011) 298 2148 shelton.zichawo@saiw.co.za

SAIW Certification manager Herman Potgieter Tel: (011) 298 2149 herman.potgieter@saiw.co.za

NDT training manager Mark Digby Tel: (011) 298 2169 mark.digby@saiw.co.za

Executive secretary Dimitra Kreouzi

Technical services manager Riaan Loots Tel: (011) 298 2144 riaan.loots@saiw.co.za

Tel: (011) 298 2102 Fax: (011) 836 6014 dimitra.kreouzi@saiw.co.za Finance and administration manager Michelle Warmback Tel: (011) 298 2125 michelle.warmbank@saiw.co.za Cape Town branch manager Liz Berry Tel: (021) 555 2535 liz.berry@saiw.co.za SAIW regional representatives

KZN branch manager George Walker Tel: (087) 351 6568 george.walker@saiw.co.za

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SAIW-hosted fracture and fatigue seminar

SAIW-hosted fracture and fatigue seminar

Professor Adolf Hobbacher from the University of Applied Sciences in Wilhelmshaven, Germany presented a series of SAIW-hosted fracture and fatigue seminars during February 2019. African Fusion presents some of his comments from the opening session. SAIW hosts fracture and fatigue seminar

A dolf Hobbacher is a one of the world’s leading experts in frac- ture mechanics and fatigue fail- ure. He was instrumental in identifying how cracks propagate and developing the formulae for predicating the critical crack length leading to brittle fracture in welds (Hobbacher: Engineering Fracture Mechanics, 1993). “For those of you needing a refer- ence to ensure your welds joint designs are resistant to fatigue, I highly recom- mend Professor Hobbacher’s booklet: Recommendations for Fatigue Design of Welded Joints and Components , which is IIWendorsed and published by Springer,” says SAIW executive director Sean Blake in introducing Professor Hobbacher. Hobbacher opens his seminar with a summary of what engineering is about. “The professional work of an engineer must meet the following requirements: It has to represent the state-of-the art and to be technically sound; it must be economical, sincemoney is not infinitely available; and, third, it is very important

that the design is defendable before a court of law in the case of any litigation that arises after an accident or incident,” he notes. Immediately relating this to welding technology, he says that welding is very complex, involving getting everything right in three competing areas:materials and welding metallurgy; manufacture and the welding procedures; and the structural design of the welded com- ponents. “From a structural design per- spective, engineers try to specify joint detail using simple formulae derived from the mechanics of rigid bodies. But welding completely changes the condi- tions of the materials and the design assumptions. “When welding, the materials used must be suitable for welding. Cast iron, for example, is not. Then in the design, we need to make sure that it is possible tomanufacture the structureusingavail- ablewelding processes and equipment. We cannot have submerged arc welding in position, for example. “And we have to make sure that the

structure we design will be safe after manufacture. Therefore there are many additional aspects that must be consid- ered if the structure is to be welded,” he points out. He says that all aspects need to be considered at the same time in order to ensure safe in-service use, whichmakes for a bigger design task. “This leads to the slogan for welding technology as a general denominator for engineer- ing – all engineering aspects must be included. The other comparable field is medicine, which also involves every aspect of science, chemistry, biology, mechanics, psychology and a host of other knowledge disciplines,” Hob- bacher says. “Some might look at this in fear, but we shouldn’t. It is like amedical student who learns early on that aperson candie of some 700 different diseases and finds it difficult to believe how anyone is still alive. But people carry on living and, while structures can fail for numerous different reasons, it is possible to design and build ones that don’t,” he assures. Showing a slide of a heavy gundating back to 1342, he says that humankind has been joining metals such a copper, tin and iron for centuries; by forging, soldering or welding, “and it is fascinat- ing to see how this was done”. The development of steel, how- ever, significantly enhancedweldability, which enabled the design and use of heavier and bigger structures. Hob- bacher displays a slide of the minimum yield strength of structural steels start- ing back in the late 19 th century with S235, one of the early low-carbon steels. “In the 1950s, carbonmanganese steels arrived and steel strength increased steadily toover 500MPa. Thenquenched andquench and tempered (QT) varieties

SAIW hosted a series of fracture and fatigue seminars by world-leading specialist Professor Adolf Hobbacher in Johannesburg, Cape Town and Durban during February 2019.

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SAIW-hosted fracture and fatigue seminar

were developed and, in the early 2000s, thermo-mechanically treated steels ar- rived,” he says, adding that today there are QT steels with tensile strengths of 1 200 MPa that are widely used for rail- ways, for example. Introducing the possible failure models for welded structures, he says that the first cause of structural failure is static overload, and codes such as Euro- code, DNV-GL, AASHTOandBS standards are in place to help designers prevent this from happening. “The problem is that while these codes deal well with the resistance side of the structures, designs depend on load assumptions and if these are wrong or change due to circumstances, failures will occur. Eurocode, therefore, embeds a margin of safety into its requirements to ensure that the structural resistance is always higher than the predicted maximum loads, but this may be set to only 10%, which is acceptable if we are able to predict the loads accurately. But uncer- tainty always exists!” he warns. With respect to fatigue, Hobbacher says that codes exist here too, butwarns: “You cannot learn about technology by reading codes. They only tell youwhat to do but not why,” before citing Eurocode, DNV-GL, IIWPressure vessel codes along with API for pipelines and ASME codes, which all present requirements for pre- venting fatigue failures. Fatigue failure risks may arise from the structural design detail, which can embed unintended shapes that impair the fatigue resistance, while manufac- turing imperfections such as undercut in aweldwill also have a negative effect. “Generally speaking, the metallurgy is secondary. One cannot prevent fatigue by selecting a stronger material,” says Hobbacher. Another common failure mode for structures is brittle fracture and codes such as Eurocode 1-10 specifyminimum fracture toughness or Charpy-V-notch values in mitigation. “But if toughness is not present or has been degraded in service or the service temperature becomes lower than the values used in thedesign, thenbrittle fracturebecomes a very real risk,” he advises. Describing a recent bridge collapse in Genoa, Italy, he suggests the causewas a question of design. “There was a single steel rope hanger with no redundancy and this was embedded in concrete, so it could not be inspected. This should not be done. Ropes such as these must

A 1934 image of a bridge collapse in Belgium that occurred while unloaded in the middle of a very cold night. “… if toughness is not present or has been degraded in service or the service temperature becomes lower than the values used in the design, then brittle fracture becomes a very real risk,” Hobbacher advises.

be able to be inspected, because, like an Irish harp, if onebreaks, then load transfers to the others. This brings into sharp focus the need for redundancy in support structures. “As an engineer, I cannot understandhow any engineer would have taken this risk. In Germany some 200 bridges will have to be replaced for fatigue reasons. “Civil engineers in Germany are required to comply with huge numbers of codes, so

The Wöhler S-N curve was developed in 1860 following an investigation into the failure of railcar axles. The curve describes three distinct fatigue regimes: low cycle (LC) fatigue at high plastic strain; finite life (FL) fatigue where the number of lifecycles (N) is inversely related to the stress range (N=C/Δ σ m ); and an infinite life (IL) regime at stress range levels below the fatigue limit.

For conveyors, fatigue is also a big is- sue (31.5%), along with static strength (36%) because conveyors are also often overloaded. Hobbacher’s seminar went on to detail failure mechanisms for brittle fracture, crack propagation and fatigue as well as to highlight the code require- ments and his own engineering insight into how such failures can be best prevented. Especially relevant to professionals in steel construction, design, fabrication andmaintenance,ProfessorHobbacher’s seminarwaspresented inJohannesburg, Cape Town and Durban.

they sometimes see only the legal im- plications and follow what is allowed instead of what is reasonable. But this is not what engineering is about. Safety is an engineering responsibility not just a legal one,” he says. Citing some relatively recent failure statistics for buildings, bridges and con- veyors, Hobbacher says that overloading failures are the cause of about 29% of the failures, but this mostly applies to buildings and conveyors. “With respect to bridges, static overload is seldom the cause. Fatigue accounts for nearly 40% of recorded bridge failures, with corrosion accounting for another 32%.

Prof Adolf Hobbacher Prof Hobbacher, one of the world’s leading fatigue experts, has an extensive background in engineering as a designer, researcher and educator. His experience includes chemical plant equipment, heavy machinery, pressure vessels/pipes and structural steelwork. Hobbacher’s research activities are mainly on the fatigue of welded structures and he was instrumental in establishing the new fatigue design recommendations of the Interna- tional Institute of Welding (IIW) through Commission XIII: Fatigue of welded components and structures; and Commission XV: Design, analysis and fabrication of welded structures.

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SAIW’s new phased array course

Following a visit fromTheGermanSociety for Non-Destructive Testing (DGZfP), the body that coordinates NDT activities in Germany, SAIW is now gearing up to offer training in phased array and other advanced NDT methods to South African plant and fabrication inspectors. African Fusion talks to SAIW’s Mark Digby about the technology. Phased array NDT for rapid detection and repair

F rom February 4 to February 13, 2019, two German phased array UT specialists, Wolfgang Kotter and Michael Berke of the DGZfP, the equivalent of the SAQCC in South Africa, visited SAIW to deliver the Institute’s first-ever PhasedArrayUTLevel 2 course.

qualified at Level 2 in ultrasonic testing (UT). “Of the total, six of us are already Level 3 NDT professionals, four of whom are from Steinmuller, Rotek, Sasol and Eskom. Of the remaining candidates (Level 2), three were from TÜV SÜD in Middleburg, and we had one indepen- dent NDT technician,” he adds. “The International Institute of Weld- ing-aligned phase array NDT course will get us to the point where our SAIW NDT lecturers are able todeliver local courses at this level. In the interim, though, DGZfP has agreed to support us with respect to technical guidance for the first course and to advise about additional equipment we may need. The course is an add-on method to our traditional UT course and candidates are therefore required to have qualified at Level 2 in UT before enrolling,” he explains. “It was an intensive 7-day course that included an exam on the last day – and we all spent the weekend at SAIW preparing for it. Wolfgang and Michael were fantastic lecturers, and we hope to have them back to do Time of Flight Diffraction (ToFD) UT training sometime later this year,” Digby notes. Advantages of phased-array UT LikemanyNDT techniques, phasedarray made its first appearance in themedical industry. When pregnant women go for their routine scans, a probe is put onto their bellies and, using a C-section scan, they can instantly see the unborn baby’s limbs andheartbeat – and they can even determine the baby’s sex. “As usual, industrywas a little slower on the uptake and it took them a few years to realise that phased array could also be used to inspect the integrity of manufacturedor in-service components and weldments,” Digby tells African Fusion . Phased array enables inspections to be completed significantly faster than traditional UT, while at the same time

“They came to present to a selected few inspection specialists in South Africa, including myself and Absolom Chiswo, andwewill be taking the course further into South Africa,” says Digby. In total, 10 inspection professionals participated, all of whom were already

As well as SAIW’s Mark Digby and Absolom Chiswo, 10 of South Africa’s Inspection professionals participated in the first-ever SAIW Phased Array UT Level 2 course, which was delivered by two German UT specialists, Wolfgang Kotter and Michael Berke of the DGZfP.

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SAIW’s new phased array course

substantially more information can be collected and stored. “For instance, if scanning a weld using traditional UT-technology, then several different probes –with 0°, 45°, 60° and sometimes 70° angles – have to be used to cover the entireweld volume. One probewill scan the bottom of the weld, another the fu- sion zone and a third probe for the top edges, for example. “In addition, each probe has to be moved backwards and forwards next to the weld – a process known as raster- ing – to ensure that the ultrasonicwaves are directed towards every possible flaw location,” Digby explains. “With phased arrayUT, a single probe can cover all these angles and many more without having to do rastering. Now an entire weld can be inspected by sliding the probe laterally along the length of the joint,” he says. SAIW is currently working with OmniScan MX2 phased-array equip- ment from Olympus for its training. “These machines are fully digital and incorporate many features to make the inspection tasks easier. Based in plate thickness and weld configuration, for example, the OmniScan will work out the optimum scanning position along- side the weld. Simply put, it will tell you where to place the probe.” Digby adds. Explaining the difference between phased array and traditional UT, he says a traditional UT probe consists of a crystal, which generates the ultrasonic wave, and a casing, which holds the crystal at the steering angleof theprobe. “Sodifferent probes are needed for each angle. Typically, three or four have to be systematically used to ensure that the full weld volume is inspected.” Phased array technology replaces one crystal with an array of crystal ele- ments in a single casing. Probes can have 8, 16, 32, 64 or even 128 individual ultrasound generating elements. “Our OnmiScan probes, for example, have 64 elements. Combinations of these can be made to fire at various angles, which means that, collectively, one phased array probe can scan an entire weld from a single position,” Digby informs African Fusion . The elements can be split up into ar- rays of 16, for example, so that each set of element arrays creates an ultrasonic wave-front in a different direction. If us- ing a 64-element system, this will create four different angles that fire from the same probe position.

SAIW is currently working with OmniScan MX2 phased-array equipment from Olympus for its training. “These machines are fully digital and incorporate many features to make the inspection tasks easier. Multiple views of the results are displayed at the same time on the monitor. A-scans (top left) show only the position of a potential defect or reflecting surface, while the B- and C-scan images (bottom and top right, respectively) show different 2D views of the relative position and size of the indications.

“Phased array UT is being usedmore and more, sometimes to replace tradi- tional UT inspections but, increasingly, as an alternative to radiographic inspec- tion (RT). Inside a boiler, for example, boiler tubes were historically X-rayed. Due to safety concerns, it meant all the welders, grinders andworkers anywhere in the vicinity of the inspection area had to stop and move away. “Using phased array UT, an inspector and a welder can work side by side. As soon as theweld cools down sufficiently tobe touched, aphasedarray inspection can be completed. The results can be viewed online by the welder, who can see exactly what is going wrong and, if allowed, theproblemcanbe fixed imme- diately and thewelds retested,” he says. “If using X-ray technology, the entire area would have to be cleared before X- ray exposure. The films would then be taken away for processing, which could take days. If there was a problem, the maintenance team would have to be informed to reschedule the repair and the repaired weld would have to be re- radiographed. In terms of the possibility of detec- tion, Digby says phased array offers better reliability and sensitivity. “We are now finding things that have been invisible in the past, such as fine cracks and small areas of lack of fusion. Phased array has been found to be excellent in exposing such imperfections,” he concludes.

How is the firing angle varied? “The software in the machine sequences the firing times so that the individual waves interfere with each other, creating new wave fronts at different angles. It’s all basedon the science of constructive and destructive interference,” he responds. In addition, phased array probes can be mounted on angled wedges, which can be used to create shear waves in ad- dition to longitudinal ultrasonic waves. Shear waves tend to travel a lot slower, so they deliver better sensitivity and resolution. Very fine defects such as fa- tigue cracks canbe reliably detectedand monitoredusing this technique,” he says. Multiple views of the results are dis- played at the same time on themonitor. “A-scans show only the position of a potential indication or reflecting sur- face, while the B- and C-scan images show different 2D views of the relative position and size of the indications,” Digby explains. Being digital, phased array UT ma- chines can store large amounts of in- spection data and they embed software that enables inspection reports to be generated quickly and immediately after an inspection is completed. Where required, images of the inspected com- ponent can also be embedded into the reports. “The data collected can be copied onto memory cards for upload- ing onto computer systems, emailing to clients or archiving for long term trace- ability,” notes Digby.

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SAIW Member profile: Hlakani Engineering

African Fusion profiles ISO 3834-certified Hlakani Engineering, and talks to sales director Gerhard Holtshauzen about the company’s successes and future outlook. Hlakani: Differentiated by weld-quality management

G erhard Holtshauzen was an Eskom employee at the turn of the century. “I leftEskomback in 2003 andwent towork for one of the util- ity’s key service providers, Steinmüller. Then in 2009, I decided to form a weld fabrication and repair company, Hlakani Engineering, to service some of the key needs we were seeing at our Power Sta- tions. In 2010, Hermann Brümmer and Quereshini Naidoo joined me in team Hlakani,” he tells African Fusion . Initially operating out of a barn in the Arnot district, Hlakani soon won its first Eskom contract, the fabrication of riffle plates for splitter boxes at Duvha Power Station. “These plates are an essential part of the pulverised fuel (PF) burner inlet systems. “Flowsplitting is necessary todistrib- ute even amounts of pulverized coal into each of the burners and the riffle plates help to prevent particle roping, which is when more densely packed areas of fuel collect in the inlet stream. PF Rop- ing causes excess localised erosion and an uneven distribution of fuel between

the burners, which increases the level of unburned carbon and raises NOx emis- sions,” Holtshauzen explains. Contracts for manufacturing PF burner spares for the Kendal, Lethabo and Duvha PF burners followed. Then, in late 2013, Hlakani Engineering was awarded a breakthrough project for the supply of 164 low-NOx burners for the Camden Power station. “This was a complex fabrication task, that involved welding three different steels: chrome- moly (16Mo3) steel; 314 stainless steels; and Integra 100 and Integra 300 hardfac- ing deposits,” he tells African Fusion . All 164 of these burners were suc- cessfully fabricated and delivered and four of the boiler units at Camden are still running with these burners. Also noteworthy is that this is an Eskom- owned design that is contributing to a relatively reliable boiler performance at Camden, which is now nearing the end of its second life. “The acceptance criteria by Eskom in terms of the tolerances they wanted were very tight for a welded construc-

Hlakani Engineering’s fabrication team poses in front of the last of 164 low-Nox PF burners the teammanufactured for Eskom’s Camden Power Station. tion – ovality acceptance criteria for the 1 000 mm OD, 10 mm wall thick- ness welded cylinders were limited to ±2.0 mm in eight places around the circumference,” he continues. “In addition, the Outokumpu SS 314 material is very difficult to work with, particularly with regard to hot cracking. Distortion and shrinkage problemswere also encountered, making it difficult to achieve the required tolerances, he adds. The design was therefore reviewed, specifically with regard to welding re- quirements, and several measures put in place. First, the boilermakers had to work on circumference dimensions and not on diameters to have any chance of achieving the tolerance requirements. They also had to apply careful sequenc- ing andheat input control to limit distor- tion and weld shrinkage. “The welders had to be specifically trained for the stainless steel sections. They were required to manage cleanli- ness, low interpass temperatures, se- quencing and stop and start placement due to the intricacy of the components. This helped to overcome the high sus- ceptibility to hot cracking of 314 stain- less as well as other challenges. “Each welder was given his own summarised weld procedure specifica- tion, together with the consumables including the consumable batch num- ber. This allowed for easy recording of weld details by the inspector for the data books. They were also trained to do their own dye penetrant testing after cleaning to ensure sound welds

Hlakani engineering was adjudged the winner in the Afrox-sponsored Welding category at the 2018 Sassda Columbus Stainless Awards. From left are: Nocwaka Ntshangase, Sassda; Dillan Fernando, Afrox; Gerhard Holtshauzen, Que Naidoo and Hermann Brümmer from Hlakani Engineering; Afrox’s Hennie van Rhyn; and Sassda’s John Tarboton.

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SAIW Member profile: Hlakani Engineering

throughout the process. This helped to ensure that, on X-ray testing, a failure rate of below 1.0%was achieved for the entire project – and some of our welders did not have a single X-ray failure for the duration of the three year project,” says Holtshauzen proudly. He adds that, for the overall success of the project, collaboration between the client and the fabricator was criti- cal. “Dimensions coming from burner functionality requirementswere defined and used to monitor actual single com- ponent dimensions and to optimise the sub-assemblies and final assembly to fit the critical dimensions,” he explains. This required all components to be tracked individually throughout the fabrication process and relevant docu- mentation to be maintained. At the 2018 Sassda Columbus Stain- less Awards, this project was adjudged the winner in the welding category for its “local fabrication standard for these high tolerance burners, overcoming significant welding challenge such as distortion and hot cracking on theway.” WithbothHoltshauzenandBrümmer having a quality management back- ground, Hlakani Engineering was quick to adopt ISO 3834: Part 2-certification according to the SAIW Welding Fabrica- tor certification scheme. “People in the fabrication industry are underestimating the new SANS 347 Pressure Equipment Regulations (PER), particularly with respect to the Hazard categories. We find that clients are unin- formed about what is legally allowable and what is not. “We feel our ISO 3834 certification along with unbelievably good welders andour systemic approach toweldqual- ity places us in an excellent position to

Above: A pulverised coal burner assembly for the Lethabo Power Station. Right: Coal nozzle assemblies manufactured in 310 stainless steel for burners at Eskom’s Kendal Power Station. take onwork in the high hazard classes,” Holtshauzen informs African Fusion . He cites a the recent replacement of an acid line in thewater plant at Lethabo Power station as an example, where stainless steel and rubber-lined carbon steel piping was fabricated to a high hazard category level. “ISO3834 certification is a key indica- tor to clients that we can deliver quality welded products and it is fast becom- ing the gatekeeper welding standard for company’s such as Sasol and Anglo American. “Producingwelded constructions ac- cording toworld-class standards suchas ISO 3834 sometimes makes a job seem more costly. But years of experience tell us that taking short cuts can have disas- trous and very expensive consequences. “By delivering a superior product

at the outset, clients can rest assured that their components will be safe and reliable in service, and reliable products require less maintenance and plant downtime. This is of huge financial ben- efit with respect to productivity levels and to the lifecycle costs of the plant,” argues Holtshauzen. “We believe ISO 3834 is a must for any credible fabricator of critical plant equipment,” he says, adding that Hlakani is also a B-BBEE Level 2 con- tributor; has as CIDB Level 7 rating; and an ISO 9001: 2015 certificate. “In addition, we have some wonder- ful welding talent and a very effective internal training system in place to de- velop new talent,” he concludes.

Hlakani Engineering Shop 1 Fabrication workshop Covered workshop area 1 914 m 2 Storage area 5 902 m 2 Total area 7 816 m 2 Max structure size 66×29×7 m Lifting capacity 1×30 t; 3×10 t; 1×7 t Materials handled

Carbon steel, alloyed steel, stainless steel, aluminum

GMAW/FCAW welding

CEA Maxi 505s

SMAWmachines Thermamax TSA Other notable equipment Baking and holding ovens, hotboxes, mobile submerged arc welding systems, CEA Plasma Plus cutting systems. Adendorff pipe bender, Mac Africa pipe threading machines, and more…

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SAIW bulletin board

SAIW 2019 Welding Challenge standard the highest ever

T he 2019 SAIWWelder Challenge compe- tition, whichwas held from14‑18 Janu- ary 2019, went off with a bang with more than twenty participants from many parts of the country displaying a level of skill unprecedented in this competition. “It once again proved to be the foremost skills test for young welders in South Africa,” says SAIW executive director Sean Blake. 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 gone on to stellar careers in the welding industry. Blake 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 andmany others, Stefan is an example of thewonder- ful 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 investigate Become an International Welding Technologist at SAIW what welding has to offer with respect to their futures,” Blake says. He adds that the SAIWWelder Challenge

According to Etienne Nell, the 2019 group of SAIW Welding Challenge competitors was the best yet. “It’s very exciting that the standard of welding among our youth improves every year”, he said.

competition is an industry initiative and would not survive without its sponsors. “We are all grateful that the sponsors

T he welding technologist course is aimed at equipping personnel with the necessary skills and technical knowledge for the planning, executing, supervising and testing of the tasks and responsi- bilities involved inwelding fabrication and construction. Engineering personnel with a National Diploma in engineering, or equivalent

qualification, who intend to pursue ca- reers in welding fabrication should apply for this course. It is suitable for engineers working on site and in fabrication work- shops, inmanufacturing, EPCMcompanies and for end-users of fabricated vessels or structures. The qualification is referenced as suit- able for employees with welding coordi-

nation responsibilities in ISO 3834 and ISO 14731 standards that address welding quality systems. It is also an excellent qualification for Welding Coordination Personnel with the responsibility for confirming the ac- ceptability of welding procedures used in welded fabrications. Module 1 of the SAIW’s International Welding Technologist coursewill run from1 to12April 2019at SAIW’sWesternBoulevard premises in Johannesburg. This Welding Process and Equipment module is the first of four two-weekmodules thatmakeup the course, with Module 2: Materials and their behaviour during welding, running from 6 to 22 May; Module 3: Construction and Design from 24 to 28 June; and Module 4: Fabrication, Applications and Engineering from 22 July to 02 August. In addition, a Practical Modulewill need to be completed to ensure knowledge on the control of the different welding pro- cesses and to familiarise candidates with the problems and typical defects associ- atedwith incorrect use of different welding processes. Exemption from the practical training module is available on application with a suitable CV showing welding experience in all the processes. confidence.lekoane@saiw.co.za

The internationally recognised IIW International Welding Technologist (IWT) qualification is suitable for employees with welding coordination responsibilities in ISO 3834 and ISO 14731 standards that address welding quality systems.

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SAIW bulletin board

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. SAIW’s Samuel Mnguni, the head judge for the competition, said that the standard of the rather competition was so high that the results were a close call. “Fortunately, we utilise an objective rather than a sub- jective marking technique, which means we are able to very accurately discern the ultimate winners,” Mnguni said. He added that the increased involve- ment of those who are teaching the youth welding skills is most encouraging and with their support, the SAIW will continue to extend the footprint of the competition throughout the country. “We are par- ticularly pleased with the participation of TVET colleges and hope towork evenmore closely with them in the future.” SAIW’s Etienne Nell who has been central to the growth of the SAIW Welding Challenge over the years was also ebullient about this year’s competition: “The SAIW biennial Welding Challenge has certainly

Chief Judge Samuel Mnguni (centre) with his judging panel.

along the standards and protocols of the WorldSkills competition, aimed to find the most proficient welder in three material categories: carbon steel, stainless steel and aluminium using four welding processes: SMAW, GTAW, GMAWandFCAW. Therewas a prize in each category as well as the overall winner and overall runner-up.

become one of the premier technical com- petitions in the country. The standard is always high and the enthusiasm electric – and this year was no different. The 2019 group of competitors was the best yet. It’s very exciting that the standard of welding among our youth improves every year.” The competition, which was run strictly

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Cover story: ESAB South Africa

In light of the global acquisition by ESAB of India-based EWAC Alloys, Chris Eibl talks about the expanded range of preventive maintenance, repair andwear-related solutions nowavailable from ESAB South Africa. Hardfacing solutions for maximum

ment life, as well as adding to the life of new replacement components such as buckets and shovels. “EWAC also manufactures a range of wear plates and we are now making these available to local industry,” he continues. “Whena companybuys anew dump truck or front-end loader, ideally they should add wear plates to protect the equipment’s contact surfaces from wearing through. Replacing an entire bucket costs a lot of money, but by us- ing replaceable wear plates to protect the substructure, the life of the original bucket can be extended by three or four times,” he suggests. Changing the wear plates instead of buying new buckets offers massive savings. The useful life of the asset is prolonged so more production can be extracted, which significantly reduces the total costs of using the machine,” he says. EWAC manufactures its wear plates using a three-axis robot welding tech- nique and a welding process with con- trolled cooling. This ensures a coating with low dilution, uniform hardness and exceptional wear properties. The fast, controlled cooling creates an overlay with a dense, extremely tough microstructure that is consistent across the plate. Features of ESAB’s EWAC wear plate manufacturing process include: • Robot manufacturing to achieve highly consistent overlay quality and thickness. • Precise control of the consumables ensures consistent metallurgical properties and high quality plates. • Low dilution with a uniform micro- structure and an optimisedmatrix to carbides ratio is achieved. • Special E-Wave weld bead patterns better resist severe abrasive wear. • Special alloyedwear plates are avail- able for high impact applications. • A wide range of wear plates meets- customer cost-to-performance re- quirements. Controlled cooling also promotes low stress – surface relief cracks that form

at right angles to the welding direction do not propagate into the base metal. Plates of up to30mmcanalsobe formed using a three-roller hydraulically oper- ated bending machine. Stoody hardfacing and high-alloy joining ESAB South Africa is also introducing the Stoody hardfacing range, which is a world-leading producer of welding wires, electrodes, and powders for combating various types of wear and corrosion. “Stoody became an ESAB- ownedbrandas part of theacquisitionof the Victor Group about six years ago and we have now decided to begin actively marketing these alloys here in South Africa,” says Eibl. Ideal for applications such as mill- roll reclamation, Stoody alloys are engineered to withstand the demands of high impact and/or high abrasion conditions found in metal-to-metal or metal-to-earth applications, including those that are subjected to high tem- peratures or corrosion. The extensive Stoody family of weld- ing products for hardfacing includes iron, nickel, cobalt, titanium, tungsten, chromium, niobium and vanadium bearing alloys. “The company offers purpose-designed products for a vast number of specific applications in every industry,” says Eibl, citing mill rolls and continuous casters in the steel industry; dragline bucket and shovel tips for min- ing; roller crushers and coal grinding rings in the power generation industry; pump housings, seals and impellers for dredging applications; and, for the cement industry, high-pressure clinker rolls – to name a few. “There is an automated sugar roll rebuilding system in the Stoody range, for example, which is a whole solution that includes matching consumables and the manipulators to do this very

E WAC, with more than 50 years of experience in preventive main- tenance and repair of industrial machinery, offers a wide range of cost effective solutions for wear-related problems. The company manufactures special welding electrodes, gas brazing rods and fluxes, welding torches and accessories, metal alloy powders, flux- cored wires and wire feeders, polymer compounds and wear resistant plates. “EWAC’s original focus was the re- pair and maintenance sector in India and it has become a market leader in hardfacing, providing products and solutions that maximise uptime, extend lifecycles and reduce operating costs. The addition of EWAC’s hardfacing and consumable technologies to ESAB’s portfolio neatly complements our range of high-end welding and cutting prod- ucts,” begins Eibl. “Right now in South Africa’s mining, petrochemical, power generation and industrial sectors, operators are more inclined to repair existing assets than to invest innewcapital goods,” he explains. “They are striving tokeep the equipment they have operating productively for as long as possible,” he tells African Fusion . “The only way to do this is to imple- ment repair andmaintenance processes far more effectively,” he advises. “What EWACoffers is a complete range of repair and maintenance consumables and hardfacing solutions that can be used easily and directly to prolong equip-

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uptime and longer equipment life

EWAC offers a complete range of repair and maintenance consumables and hardfacing solutions that can be used easily and directly to prolong equipment life. unpleasant task faster, more safely and more cost effectively,” he adds. “In addition to hardfacing products, ESAB can now also offer Stoody’s full line of high-alloy stainless and nickel- based joining and cladding wires and electrodes that are designed to the suit major industries such as power gen- eration, mining, construction, railroads, steel mills, steel foundries, oil and gas production and exploration as well as the pulp and paper industry,” Eibl in- forms African Fusion . Credited with its invention Stoody continues to lead innovation in hardfac- ing alloys and, from its Bowling Green premises in Kentucky, USA, offers com- plete engineering and laboratory ser- vices to ensure high standards of quality control aswell as custommetallurgy and product development. Cutting solutions for maintenance and repair “Another novel solution for onsitemain- tenance work is the ESAB ArcAir Slice Pack, which is an exothermic cutting system that can cut steel and a host of other materials very quickly and easily,” continues Eibl. Working off a 220 V or a 12-volt battery, the Slice torch combines oxy- gen and electrical power to produce exothermic cutting via a carbon steel consumable rod. A supply of oxygen is fed through the rod and, after touching it against a grounded workpiece or a striker plate, the rod ignites creating a very high temperature flame. The process can be used to cut virtually any metallic, non-metallic or composite material and, when cutting steel, the Arcair Slice system needs no pre-heat. Compared to oxyacetylene

Stoody manufactures products such as the Stoody 1102 solid core electrode, which has an all weld metal composition and physical properties similar to those of H-12 tool steel. This makes it ideal for repair welding of components such as bearing housings.

In South Africa’s mining, petrochemical, power generation and industrial sectors, operators are more inclined to repair existing assets than to invest in new capital goods, says Eibl. cutting, it cuts 75 mm mild steel three times faster and is twice as fast on 3.0 mm steel, with similar results on other commonmetals. “The systemcan also cut aluminium, stainless steel, cast iron and cement, which can’t be done by oxy-acetylene systems,” Eibl notes. The ArcAir Slice Pack is deliveredwith all thebasic items needed for cutting ina rugged toolbox. “Also included is a collet extension and shield for added protec- tion when piercing,” Eibl notes, adding that the system is ideal for peoplework- ing regularly onsite and the product will be launched into South Africa in the next few months. On the other end of the cutting spectrum, ESAB is introducing its latest state-of-the-art high-precision plasma cutting system, the Suprarex™HDX. This is ESAB’s latest global machine design, offering outstanding performance from a heavy-duty large gantry, resulting in reliable productivity and a machine customised to exact needs. “This high precision automated plasma profiling machine gives laser-like cut quality on thinner materials and next-generation torches and nozzles give longer con- sumable life and lower cut costs – way cheaper than any laser cutting system can achieve,” he says. “ESAB South Africa has an extensive range of hi-precision plasma cutting systems that we have been making available to the service industries for many years. These businesses are ide-

The ArcAir Slice Pack is delivered with all the basic items needed for cutting in a rugged toolbox. ally placed to produce profiled products such as cut-to-size wear plates for end- users. Also, operations with large fleets of equipmentmay find it cost effective to purchase their ownESABplasma cutting system to meet their wear plate cutting needs,” Eibl suggests. From a repair perspective, as well as multiple ranges of hardfacing and joining consumables, ESAB now has access to a host of welding and cutting equipment solutions to enable difficult- to-weld surfacing and hardfacingmate- rials to be repaired at local workshops, mines, cement plants and materials handling equipment repair facilities. “We have solutions that are ideal for the places we are used to seeing in Africa,” Eibl concludes.

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