SAIW’s first graduation dinner for 2016 was held in the Crown Reef Room at Gold Reef City in Johannesburg on March 12, at which 124 graduates on SAIW courses received diplomas. African Fusion reports and summarises the motivational talk by Gert Joubert.
At the top of the list of graduates that completed SAIW courses during 2015 are those on SAIW’s IIW welding co-ordination programmes. SAIW offers IIW Welding Practitioner, Welding Specialist, Welding Technologist and IIW Welding Engineer qualifications and five IIW welding technologists, including two women, along with two welding specialists graduated at the March dinner.
These qualifications are required by schemes such as ISO 3834 and EN 15085 for people responsible for managing welding processes within fabrication environments. They require specialist knowledge of welding engineering and the control of welding processes – and when things go wrong, these specialists have the knowledge to rectify issues and resolve problems.
In addition, 49 Level 2 Inspectors, 17 of which also received standard level IIW Inspector certificates, while 68 people graduated as Level 1 Inspectors, five of them with distinction.
ArcelorMittal’s Gert Joubert targeted his address for the evening at spouses and those less familiar with the daily responsibilities of weld Inspection personnel. “The welding world is about building structures, pressure vessels, boilers and pipelines. To build these structures we need good engineers to design structures that don’t fall down. They establish the integrity and the safety of the design. Then you need fabricators to build the structure, construction or vessel – the boilermakers and welders – and the inspectors to ensure that the work has no flaws and that it is done according to the design, at the required quality and to the relevant construction codes,” he explains.
Joubert recalls seeing a student welding inspectors carrying an ASME code with yellow post-it notes sticking out from every second page. “He was about to write an open book exam on this code. It’s not easy, but inspectors need to learn these standards so that they know exactly what the requirements are,” he points out.
Describing the processes involved in producing a simple weld, he says that a boilermaker prepares the joint. “A butt joint, for example, is two pieces of metal that are aligned side by side, typically with a V-preparation on thicker sections. When the V is filled with metal, we call the joint a butt joint.
“The weld fabrication inspector first comes into play to inspect the joint design. After the boilermaker has tacked the joint together, the inspector will check the dimensions – the V-angles, root gaps, and so on.
“This is to make sure that the welder has the best possible chance of making a good weld,” Joubert tells us. “Because if he or she cannot produce a good weld, we could have an in-service failure, and on products such as pressure vessels or boilers, this could be disastrous. So the inspectors job is extremely important!” he exclaims.
“Once the joint is inspected, the welder will strike the arc and begin to weld the root run,” Joubert continues. “And magic happens. As soon as the arc is struck, plasma is created, which is an intense hot channel of conductive gas that carries the arc current to the workpiece. I wish I could make myself small enough to see what is happening here: how the metal droplets are melted and transferred across from the consumable and into the joint; and how the welder manipulates the placement of these droplets.
“Welders are called artisans because they are really are artists. They deposit molten metal so that when it solidifies it is exactly where it is needed. I have huge respect for welders and the work they do,” Joubert says.
Continuing, he says that plasma melts the metal and forms a molten weld pool, almost like casting hot metal into the butt joint – and the solidification of the metal starts immediately “with the purest metal in the coldest part of the weld and moving towards the hottest parts in middle and at the top – and all of the impurities are pushed along the solidification line.
“The combination of these impurities with shrinkage forces can lead to a hot crack in the centre of the weld. To avoid this, the welding inspector needs to know exactly what might happen to the weld the instant it solidifies,” he advises the new graduates.
“Shrinkage also causes stress, which remains in the weld. And if there are any hydrogen atoms in the weld, which are the tiniest of all atoms, these can migrate through the metal atoms and accumulate in the heat-affected zone, eventually, along with the stress, causing a hydrogen crack or a cold crack. This needs to be anticipated and, if it happens, seen by the welding inspector. That is why the inspector needs to have – and to understand – the welding procedure, because to prevent hydrogen cracking, for example, you may need to pre-heat the materials at exact levels depending on the material, thickness and consumables being used.
“When the joint is complete, the inspector needs to have look at the weld profile, to make sure that it has the correct sizes, is properly filled and that there is no undercut. When part of a structure is exposed to fluctuating stresses or fatigue, any small crack or shape deviation can cause a failure, even after several years of service,” Joubert warns.
“The people graduating today, those that you have supported during their studies, have learned about all of these matters. By doing these courses, they can relate to metallurgy, hot cracking, cold cracking and embrittlement. They have studied and sweated,” he says, adding that an inspector’s job is not just about codes and standards. “It’s about understanding the world of welding.
“You cannot put up a structure such as a pressure vessel without a welding engineer signing it off. In welding, design-engineering qualifications are defined properly; welder-qualifications are defined properly; and all of you graduates, as weld fabrication inspection personnel, your qualifications are all defined properly. Not all disciplines have standards that say that companies shall have in their employment people with your qualifications. Yours are sought after qualifications with many avenues available to you. If you have a mind to become a higher-level inspector, a weld fabrication inspector or a non-destructive testing inspector, go ahead, Do it! You can do whatever you want to. I urge you not to stop studying. Pursue your career,” Joubert advises.
“Our job is all about quality assurance. It’s about making sure that the bridge, which millions of people are going to travel on and under, does not ever fall down,” Joubert concludes, before congratulating the SAIW graduates and wishing them well in their careers.