Abstract: Effects of cleaning process after oil quenching, subzero treatment process and interval between cleaning and subzero treatment on the final retained austenite content of 9Cr18 steel bearing ring were analyzed in view of the same quenching and tempering conditions. The results show that the higher the cleaning temperature after oil quenching, and the longer the interval between cleaning and subzero treatment, the higher the retained austenite content. However, the content of retained austenite increases when the temperature of subzero treatment is much too low, so the recommended subzero treatment temperature should be between －70 ℃ and －80 ℃.

Key words: high carbon chromium stainless bearing steel 9Cr18, bearing ring, retained austenite, cleaning method, subzero treatment