Microstructure and wear properties of high-speed steel with high molybdenum content under rolling-sliding wear

This paper focuses on the microstructures and frictional wear behaviors of high-speed steel (HSS) with high molybdenum content under different rolling-sliding conditions using self-made wear tester. Results showed that the molybdenum element in HSS mainly formed M2C-type carbide ((Fe27.42Mo48.26Cr24.32)2C). M2C (21-1) is coherent with α-Fe (110). The sliding ratio has a significant influence on frictional wear behaviors. As sliding ratio increases from approximately 1%-10%, the frictional coefficient rises and then decreases, and the wear weight loss rises obviously because the wear mode varies from fatigue to sliding wear. The high stress rolling-sliding contact can cause not only fracture and desquamating of M2C, but also martensitic transformation in subsurface. The martensitic transformation contributes in improving hardness and wear resistance.