Numerical evaluation of subsurface stress field under elastohydrodynamic line contact for AISI 52100 bearing steel with retained austenite

In rolling contact bearings, contact occurs between the rolling surfaces over a small region. Hence, high contact stresses are induced in the region even under a small load. These stresses are cyclic in nature. Over a long period of time, the surface gets fatigued and surface fatigue wear ensues. The experimental investigation carried out in the laboratory earlier consumed a long time. Therefore, a numerical approach is resorted to in this paper. To study this aspect, the stress field in the contact surface region is analyzed under elastohydrodynamic lubrication with line contact considering the friction effect. The bearing steel microstructure is considered as a mixture of martensite and retained austenite having entirely different mechanical properties and yield behavior. Using finite element analysis, the stress field has been evaluated taking into account two volumetric fractions (8% and 20%) of retained austenite in heat treated AISI 52100 bearing steel. A simplified approach neglecting the effect of strain induced transformation of austenite is attempted in the first phase. The depth at which the failure is expected to occur is compared with the experimental values of earlier investigation. The predicted values are marginally higher than the experimental values.