S112014 ショットピーニング投射材硬度が浸炭硬化鋼の転がり疲労寿命に及ぼす統計的評価([S11201]機械要素の設計・製造・応用技術(1))

Abstract

This study is to investigate the future possibilities of the use of the shot-peening (SP) as the final surface-finishing of carburized rolling contact machine elements. In order to investigate the influence of SP process on the rolling fatigue strength of the carburized steel, 9 kinds of specimens were fatigue tested using a thrust rolling bearing type testing machine. Four kinds of the projection particles were employed for this experiment. It was obvious by means of statistical analyses using Weibull distribution and nonparametric test that the SP process did not bring about longer fatigue life. In view of the properties on the failed surface, there is sufficient evidence to suggest that the fatigue lives of the SPed specimens might be mainly affected not by residual stress but by film thickness ratio and initial surface roughness. Furthermore, the proposed parameter A (Ac / AK) was effective to evaluate the rolling fatigue life.