Combined Effects of Micro Shot Peening and Deep Rolling on the Fatigue Life of Thrust Ball Bearings

Author:  Hatsuhiko USAMI, Shinya SATO, Misaki SAITO, Masafumi ANDO
Source:  ICSP-13
Doc ID:  2017116
Year of Publication:  2017
Introduction: Rolling bearings are widely recognized to be one of the most important of all mechanical elements. Size reductions and increased efficiency are demanding the provision of higher fatigue strength and wear resistance for rolling bearings, and micro structure control and surface modifications have been attempted with regard to bearing raceways and rolling elements. It is widely recognized that the application of compressive residual stress is an effective means of improving fatigue strength, since crack growth during rolling contact fatigue usually originates from subsurface regions [1]. Using manufacturing processes based on plastic deformation near the surface, such as a shot peening and deep rolling, it is possible to apply residual stress. Furthermore, shot peening with fine particles as the impact media, i.e. micro shot peening, results in higher residual stress near the surface without impact surface coarsening, and deep rolling is usually applied as the surface finishing process for flattening. Therefore, a combination of micro shot peening and deep rolling is a promising process for the surface modification of bearing elements [2]. The present study examines the applicability of a proposed surface modification process consisting of micro shot peening and deep rolling to the improvement of the fatigue properties of thrust ball bearing raceways. The changes in residual stress during a rolling contact fatigue experiment and the relationships between residual stress distribution and fatigue life were evaluated.

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