S45C강의 고주파 열처리 표면경화재 피로한도 예측에 관한 연구

The effects of small hole defect size and effective case depth(ECD) on the four point bending falimit of induction surface hardened S45C steel were investigated. the fatigue limit evaluation of hardened materials is very difficult because of relations of the hardness gradient and residual stress. In this study, it was possible to characterize fatigue limit and fatigue life of induction sur. face hardened S45C steel in terms of the hole defect size and effective case depth(ECD) and quan-evaluation of the fatigue limit with hole defects use Murakami's evaluation method and the range of evaluated values is a good accuracy compared with results.