Heat Treatment and Properties of High-Temperature Steels for Rolling Bearings

Abstract It is demonstrated that high speed steels are suitable for manufacturing of heat resistant rolling element bearings especially for applications in aero engines. A detailed analysis of heat treating processes and metallurgical evaluation shows how the properties of these steels grades can be adjusted to meet the specific requirements for engine bearings. Based on results from rig testing it is shown how variations in heat treating parameters can influence the rolling contact fatigue performance. The role of carbides, a typical constituent of high speed steels, on bearing applications is discussed in detail. The high level of heat resistance of high speed steels allows a nitriding in addition to the conventional heat treatment. By nitriding an increase in hardness close to the surface can be achieved which can make bearings more robust against indentation of hard particles. ◼