S45C고주파 표면경화재의 인공결함에 따른 피로한도 예측에 관한 연구

The effects of small hole defect size and effecttive case depth(ECD) on the four point bending fatigue limit of induction surface hardened S45C steel were investigated. the fatigue limit evalation of case of hardened materials is very difficult because of relations of the hardness gradient and residual stress. In this study it is possible to characterize fatigue limit and fatigue life of induction surface hardened S45C steel interms of the hole defect size and effective case depth(ECD) and quanfitative evalation 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.