Combined ZEISS Microscopy for materials testing.

Thomas Schaupp is laboratory manager at SPC. He, too, knows the pain of the steel industry all too well: “A very high percentage of crude steel came from Russia until two years ago, and it was very high quality”. He says the replacement steel from other sources is now of poorer quality, and the same is true of scrap, which is always added proportionately to steel products.
This often has serious consequences for the resulting components, as in the case of a pinion shaft that a steel trader submitted to SPC for testing. Thomas Schaupp explains: “The manufacturer of the pinion shaft complained to our customer after a complete batch of pinion shafts cracked lengthwise in the manufacturing process. He commissioned us to investigate the cause.”

A visual inspection suggested that the crack was caused by damage to the surface of the raw part during hardening process. But analysis with the ZEISS Smartzoom 5 digital microscope suggested a different conclusion, says Thomas Schaupp: “Around the central axis, ‘scaling’, i.e. oxidation of the steel, was visible. The fracture therefore originated from the inside.”

To identify what materials the contamination consisted of, the staff examined a metallographic section from the pinion shaft with the ZEISS EVO scanning electron microscope. The result: there were non-metallic inclusions with high concentrations of manganese and sulfur, as well as segregations of sulfur and phosphorus, in the steel of the pinion shaft near the axle. “Normally, these impurities would still be tolerable,” says Thomas Schaupp, “but a hole was drilled at precisely this point, which put particular strain on the material, and fracture occurred.”

For the laboratory manager, there is therefore no alternative to ZEISS: “Hardware and software are optimally matched. Everything works intuitively and easily, as well as quickly and efficiently thanks to the automation functions. This allows reproducible results, regardless of the user. Without ZEISS, our processes would certainly take 30 percent longer.”