Roller bearing of steel contg. silicon@, manganese@ and chromium@ - includes some residual austenite in the structure to improve working life

摘要

A roller bearing has an outer and inner ring with an intermediate roller body held in a cage. The outer and/or inner and/or roller body has a hardness of 58-64 HRC, and is made of steel contg. (in %): 0.9-1.3C; 0.6-1.2 Si; 1.1-1.6 Mn; 1.3-1.7 Cr; balance Fe and other trace elements. Its structure includes 7-25% stabilised residual austenite. To produce the stabilised residual austenite the parts are isothermally heat treated by heating to 60-120[deg]C directly after quenching. This temp. is held for upto 10 hrs., followed by tempering at 170-230[deg]C without intermediate cooling, followed by cooling to room temp.