表面性状および圧縮残留応力解放を考慮した浸炭焼入れ鋼の疲労限度推定

抄録

In order to estimate the fatigue limit of carburized steels having surface compressive residual stress and surface texture generated by peening, we investigated the effect of surface texture and residual stress relaxation on the fatigue limit of carburized steels. In this study, rotating bending fatigue tests were conducted for the carburized steels treated with electrochemically polishing, fine particle peening and shot peening prior to gas carburizing. In the proposed fatigue limit estimation method for carburized steels, the surface texture formed by peening and the sum of mean stress and compressive residual stress experiencing relaxation are considered. The method shows that the maximum value of fatigue limit of carburized steels increased with decreasing the waviness in the surface. Additionally, the lower the waviness in the surface, the lower the maximum value of compressive residual stress contributing to the increased fatigue limit of carburized steel. These results indicate that fatigue limit of the carburized steel depends on the surface texture formed by peening.