Study on Rapid Tempering Microstructure and Property Evolution of GCr15 Bearing Steel

The rapid tempering and conventional isothermal tempering of GCr15 bearing steel were conducted by using MMC 200 thermal simulation test machine and salt bath furnace, respectively. The microstructure and properties changes of bearing steel under different tempering conditions were studied. Scanning electron microscope and XRD measurements were used to analyze the morphology and phase content of GCr15 bearing steel under different tempering conditions, and the hardness and wear resistance were measured as well. The results show that the rapid tempering refines the size of the GCr15-bearing steel-tempered carbide and inhibits the residual austenitic decomposition. Under the same tempering parameters, when the two microhardness is comparable, the higher wear resistance can be obtained by rapid tempering.