MechChem Africa March-April 2021

⎪ Products and industry news ⎪

NFTN intervention helps lift SA foundry to global standards

MechChem Africa talks to Manini Phokwane Ramagaga, technical advisor for the National Foundry Technology Network (NFTN), an initiative of the Department of Trade, Industry and Competition (the dtic) about an intervention completed at Steelbest foundry that secured the future of 130 jobs.

automotive sector, which assembles basedon just-in-time principles; where every compo- nent has to be delivered on time for vehicles to be produced efficiently,” she adds. The high scrap rate was leading to poor productivity levels of acceptable quality, which was compromising the completion of orders due for delivery, she explains. If the foundry could not keep up with stock levels, this could have caused another SouthAfrican foundry to close. “I was initially asked to do a metallurgical assessment, but it became apparent from a gap analysis that this was a multi-facetted challenge, which could be attributed to process, die design and metallurgical skills shortcomings. First off, a professional metallurgical skill set was required to meet the automotive requirements. “Having worked in the sector myself, I knew that an in-house metallurgist was going to be required and would be ben- eficial for the foundry for long-term success. TheNFTNpartnerswithacademia, science councils and government agencieswho assist with human capital development within the SA foundry industry. This includes assistance with the development of artisanal, profes- sional and specialised skills. “Through our NFTN collaboration with Mintek, one of the three (3) Science Councils in the country with a skills development pro- gramme, for training and placing engineering personnel into South African industry, a metallurgical engineer was seconded, who has since been permanently employed as a metallurgist at Steelbest.We are hopeful that the young people we place will rise up the ranks and pass on their skills to more young

people in the sector,” she notes. The second intervention involved the simulation of the die component itself from eastern Asia. The die was optimised through simulation of the solidification rate so as to reduce the defects that occurred. “Thediewasmodifiedusing the results of the simulation to regulate the so- lidification rate and to keep the temperatures even in all areas,” Ramagaga tells MechChem Africa. “This led to a further research and development collaboration between the foundry and a leading European Simulation Research Science Council, playing a key role in the automotive sector. “To get the benefit of the upgraded die de - sign, we then had to optimise the process and productionoutput efficiencies,whichwas also at the coreof resolving the challenge. That led toprocess operators being trainedon thenew improved process, and five additional opera - torswere found to be needed,” she continues. These multi-faceted interventions sig- nificantly reduced the pinhole-porosity scrap challenge and raised the quality of the end products. They also generated a high degree of confidence in the capacityof the foundry to deliver to the automotive original equipment manufacturer (OEM). When the original modified die design needed tobe replaced, thenewandoptimised die was ordered, which further improved product quality and productivity. With the optimised die , the newmetallurgist, the new process, the newly trained die operators, and all of the required quality checks, the scrap rate decreased to below 2.0 % – from nearly 25%. This resulted in the global order being renewed for a further nine years, securing work for the foundry up to 2028. “Retention of jobs was key for the NFTN and the dtic and theway todo that is todevel- opa strong and sustainableorder book, which for a global automotive OEM, means that high quality standards have to be achieved and maintained. “This success proves that the SA Foundry Sector can do it. With a bit of effort and cooperation and by going back to fundamental metallurgical principles, the South African foundry sector can produce high quality castings that can compete on a global scale,” Ramagaga concludes. q

“S teelbest, formerly known as Zealous foundry, specialises in high pressure die casting, most- ly of aluminium components for the automotive industry,” begins Manini Phokwane Ramagaga, who has a metallurgi- cal engineering degree from the University of Johannesburg and over 20 years of experi- ence in the South African Foundry industry, most notably in the automotive and jobbing casting sectors. “The companymakes cast components for cam-carriers, water pump housings, engine and axle components, housings, street lights, general engineeringproducts and castings for the food industry,” she adds. “With the NFTN, my current role is to give technical support to the South African foundry industry, at large. I also contribute to the technical support of the existing South African steel andmetal casting sector through research, development and productivity growth topromote local andexport consump- tion i.e. to improve the casting industry’s global competitiveness and its technical and regulatory compliance. It was in this capacity that I was first introduced to Steelbest, who had approached the NFTN to investigate a quality related challenge with regards to pinhole-porosity that was causing an ex- ceptionally high scrap rate on an aluminium casting for a key automotive client,” she tells MechChem Africa. “This challenge was preventing the com - pany from meeting the client’s turnaround times for quality cast products; critical in the

The optimised die, shown here undergoing its final spray cooling cycle.

38 ¦ MechChem Africa • March-April 2021

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