Distortion of conical formed bearing rings made of SAE 52100

Abstract

Abstract In general, causes for distortion phenomena during heat treatment e.g. are in general inhomogeneities or asymmetries of the distributions of mass, alloying elements, microstructure and residual stresses. Recently published papers with cylindrical shaped bearing rings clearly pointed out the influence of residual stresses and their spatial distribution within a work piece on distortion [1]. In this contribution the influence of mass distribution will be investigated by means of conical bearing rings. The investigations of conical shaped bearing rings show in comparison to cylindrical shaped bearing rings an additional distortion even though the cooling is homogeneous over the whole surface of the work pieces. The asymmetric mass distribution leads in comparison to cylindrical rings to higher thermal stresses during the quenching process and therefore to a change of the conical angle of the work piece. The behavior of the conical bearings was investigated by means of cooling in gas nozzle fields and in a one chamber vacuum furnace with high pressure gas quenching. Additional to the investigations of different quenching processes, geometry variations were investigated. The experimental investigations of the considered processes were supplemented by computer simulation.