Influence of Steel Making and Further Processing on the Distortion of Bearing Steel Components

Distortion of bearing steel components after hardening has a major influence on the total manufacturing cost of bearings. This publication presents results and experiences of recent investigations regarding possible causes for the distortion of bearing rings. It does not consider the influence of the soft machining and of the hardening process itself but concentrates on the contribution of the steel grade as such, the casting conditions, and the further processing. Based on a systematic approach, it will be shown how such parameters influence both the dimensional variations (like ovality or conicity of the rings) and the dimensional changes (such as mean diameter) after the hardening operation. Such results can help to minimize distortion by selection of suitable steel making and further processing routes and, thus, to reduce manufacturing cost of bearing steel rings.