Material removal and chip formation mechanisms of UHC-steel during grinding

The grinding process is still an important manufacturing process for the machining of automotive components. For power train components, ultra-high carbon steel (UHC-steel) is a promising new innovative alloy because of its low specific density. Results from turning of UHC-steel showed that the texture of UHC-steel significantly differs from conventional steels. Furthermore, extremely hard carbides, which are embedded into a soft ferrite matrix, result in a UHC-steel specific machining behavior and a high tool wear rate. Therefore, UHC-steel is marked as a difficult-to-cut material. So far, there are no research results available for the grinding of UHC-steel. Therefore, fundamental investigations were conducted in order to analyze the material removal and chip formation mechanisms. Scratching tests with a geometrically defined cubic boron nitride cutting edge showed ductile material removal mechanisms for a single grain chip thickness variation from h(cu) = 1.5 up to 14 mu m. Analysis of the contact zone by means of an innovative quick stop device confirms these results.