Improvement of Surface Durability of Case-Carburized and Hardened Gear by Shot Peening and Barrelling Processes

Author:  Munetoh Hashimoto, Sigeru Hoyashita
Source:  Conf Proc: ICSP-6, (p. 34-43)
Doc ID:  1996049
Year of Publication:  1996
Abstract:  
In this investigation, a surface durability (pitting limit) of the case-carburized steel rollers with surface hardness of 750 Hv is examined under rolling/sliding conditions using a rolling contact fatigue testing machine. Two kinds of rollers which are finished to a surface roughness of abut 0.2 umRmax or about 3 umRmax by a cylindrical grinding machine are used. To improve the surface durability, the shot peening and the barrelling processes are employed and they are compared to the non-treated surface. The processes of shot peening and barrelling can be applied to surfaces with complex configurations, such as gear. Each surface roughness of rollers finished by above machining methods is measured before/after load running and residual stresses are also detected by an x-ray diffration method. Consequently, it is clarified that the surface durability of rollers whose surfaces are subjected to the barrelling process after the shot peening process is improved.