Effect of Fine Particle Bombarding on Rolling Fatigue Strength of Carburized Steel

This study is to pilot the future possibilities of the use of the fine particle bombarding (FPB) as the final finishing of the carburized sliding-rolling contact machine elements. In order to evaluate the influence of FPB process on the surface strength of the carburized steel, four kinds of test specimens, which are as-carburized, ground and FPBed ones, were fatigue tested using a thrust rolling bearing type testing machine under a constant loading. The results of the fatigue tests were discussed using the statistic analysis and the observations on the surface properties after the fatigue tests. From the results of both the Weibull plot and the nonparametric test, there was a good possibility that the FPB process after carburizing will be available for the purpose to increase the fatigue life by the improvement of the abnormal layer. The formation of the wear trace of the FPBed disk during fatigue process was different from that of the as-carburized and ground disks, and the FPB process might control the propagation of the fatigue crack due to flaking.