A physically based model for endurance limit of bearing steels

Available models are not suitable for calculating the load rating of bearings when an infinite life is required. This paper presents a new model that has been developed from a detailed analysis of the damage mechanism responsible for failure of bearings operating under EHD pure rolling conditions. It is based on the comparison between the local shear stress concentration built up around inhomogeneities present in steels and the microyield stress of the martensitic matrix. The predictions of this model are in good agreement with some literature data concerning the fatigue limit of bearing steels. Finally, the influence of material parameters and operating conditions on the endurance limit of bearings is investigatedAvailable models are not suitable for calculating the load rating of bearings when an infinite life is required. This paper presents a new model that has been developed from a detailed analysis of the damage mechanism responsible for failure of bearings operating under EHD pure rolling conditions. It is based on the comparison between the local shear stress concentration built up around inhomogeneities present in steels and the microyield stress of the martensitic matrix. The predictions of this model are in good agreement with some literature data concerning the fatigue limit of bearing steels. Finally, the influence of material parameters and operating conditions on the endurance limit of bearings is investigated.