State of the art testing laboratory available to all industry members

The new metallurgical testing laboratory is based at the SAIW head office in Johannesburg and is open for research and development and material testing services such as mechanical testing and failure analysis. Services will also include welding consumable evaluation, weld procedure qualification, welder qualification, post-weld heat treatment and positive material identification.

Equipment is state of the art and the newest technology is available. The tensile testing machine is a 300KN machine which can also do bend testing. Tensile testing is a fundamental materials science test in which a sample is subjected to a tensile force until failure. The test is commonly used to select a material for an application, for quality control or to predict how a material will react under other types of forces. Properties that are directly measured via a tensile test are ultimate tensile strength, yield strength, maximum elongation and reduction in area. The former two are measures of the strength of the material whilst the latter two measurements are measures of the ductility of the material.

Other equipment includes a 450 Joule Charpy impact machine for impact strength of materials, a spectrometer for chemical analysis, an XRF analyser for material sorting and chemical analysis as well as a micro hardness tester for hardness testing and hardness traverses. There is also a hydrogen analyser for testing diffusible hydrogen in weld metal, a Nikon optical microscope, various sample preparation and machining equipment for preparation of test specimens, an impact specimen preparation machine and now a diffusible hydrogen analyser. The Bruker G4 Phoenix Diffusible hydrogen analyser allows for measurement of the quantity of hydrogen in welds as well as evaluation of the hydrogen content of welding consumables. ISO 3690 compliant testing protocols are being developed and experience is gained on testing techniques of this complex test. Sample preparation is a key factor in obtaining reliable test results which requires welding a test piece on a precise assembly where after the sample is quenched and stored at cryogenic temperatures.

To date the team of qualified metallurgists led by Sean Blake have undertaken 61 jobs in the laboratory. These jobs included procedure and welder qualifications which were previously outsourced to a third party laboratory, evaluation of welds, failure analysis of welds as well as the evaluation of welding consumables. “An interesting job that we undertook was the evaluation of copper welds, most of the jobs we do involve either steel or stainless steel,” says Blake. “The copper samples provided us with a different engineering material, which although well established in industry, does pose some interesting weldability issues”.

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Industry members in need of the services offered at the Testing Laboratory can contact Sean Blake at blakes@saiw.co.za.