열처리에 의한 탄소강(SM45C)의 피로강도 향상에 관한 연구

A Study on the Fatigue Strength Improvement by Surface Heat Treatment of Carbon Steel(SM45C)

The strengthening method of materials is very important because high strenth material can reduce the weight of automobile parts and should be studied. High strength, high power, and hight demand necessarily hight fatigue strength. To increase fatigue strength, there should be nonmetallic inclusions and no defects on the surface. Especially, the notched part which increase the local stress on the material surface is fatal. Shot-peening can be used to increase the fatigue strength of materials having defects on there surface Thus, it can increase the fatigue strength of automobiles parts Shot-peening is applied to notched specimen of carbon steel for machine structure use (SM45C) for automobiles in this study. Mechanicl properties, fatigue behavior, fatigue fracture surface, notch factor, endurance ratio, and nonmetal are examined in the study.