Case Depth and Static Capacity of Surface Induction-Hardened Rings

Abstract

Abstract Large-size slewing bearings are usually surface hardened by means of induction heating. The load-carrying capacity of the bearing is dependent on, among others, the depth of the hardened layer, i.e., case depth (CD). It is of crucial importance for bearing manufacturers to ensure that sufficient CD is produced to meet the required bearing capacity for the applications. Compared to through-hardened bearings, the calculation method for the load-carrying capacity of surface-hardened bearings, especially the induction-hardened bearings, is not well established. This paper reports on a new calculation method for the static capacity of induction-hardened rings. The method is based on consideration of both the plastic indentation on the raceway and the damage tolerance in the subsurface region. The models for evaluating plastic indentation and subsurface damage have been validated with the standing contact fatigue testing.