Surface Nanocrystalline of Martensite Steel Induced by Sandblasting at High Temperature

The mechanical and tribological properties were conducted to investigate surface nanocrystalline of martensite steel with hardness of 5 GPa by using sandblasting technique at 500 °C. The average grain size of surface is 30 nm. In contrast, the average grain size of the martensite steel surface, which processed by sandblasting at room temperature and post‐annealing at 500 °C, is 112 nm. Fine grains and Fe₃C phase in situ form during sandblasting at 500 °C that is favor for producing nanoscale structure of the martensite steel. The nanostructure surface of the martensite steel has higher hardness and better wear resistance.