SUP9 스프링강의 쇼트피닝가공에 의한 피로수명향상과 고온환경에서의 압축잔류응력 소멸현상에 관한 연구

A Study of Shot peened Spring Steel for Fatigue Life Improvement and Compressive Residual Stress Disappearance on the High Temperature

The compressive residual stress, which is induced by shot peening process, seems to be an important factor of increasing the fatigue strength. And then it was showed that residual stress was disappearenced at the high temperature. The fatigue characteristic study of a SUP9 spring steel processed shot peening is performed by considering the high temperature service conditions in the range of room temperature through $180^{\circ}C$ in the range of stress ratio of 0.3 by means of opening mode displacement. The fatigue resistance characteristics and fracture strength at high temperature is considerable lower than that of room temperature in the early stage and stable of fatigue crack growth region.