At present, China has produced high carbon chromium stainless bearing steel, the main steel number is 9Cr18; carburized bearing steel, the main steel number is G20CrMo; chrome bearing steel, the main steel number is GCr15. Bearing steel is mainly used to manufacture rolling bearing parts. Such as balls, rollers and bearing rings. They are subjected to high concentrated alternating loads during operation. Due to the small contact area between the balls and the bearing rings, there is still sliding at high speeds, which causes a large friction. Therefore, the rolling bearing steel should have high hardness, wear resistance and fatigue strength. The metal lographic structure and chemical composition requirements of the steel are very strict, otherwisethe service life of the bearing will be significantly shortened. Generally, the rolling bearing steel has a high carbon content, ranging from 0.95 to 1.1%, and adding certain alloying elements such as chromium and manganese. It is mostly delivered by spheroidal annealing and requires quenching (about 840 ° C) and low temperature tempering (150 ° C) before use.