Effect of Shot-peening on Fatigue Crack Growth

J. Ocean Eng. Technol. 2004;18(6):91-95.

SHIM DONG-SUK;LEE SEUNG-HO;LEE MYUNG-HO;

Department of Automobile, Kyonggi Institute of Technology;Department of Automobile, Kyonggi Institute of Technology;Department of Mechanical Eng, Seoul National Polytechnic University Siheung;

균열진전에 대한 쇼트피닝 효과

심동석;이승호;이명호;

경기공업대학 자동차과;경기공업대학 자동차과;서울산업대학교 기계공학부;

Keywords: Two-Step Shot-peening, Compressive Residual Stress, Fatigue Crack Growth, Initial Stress Intensity Factor Range, Fracture Toughness

핵심용어: 2단쇼트피닝, 압축잔류응력, 피로균열진전, 초기응력확대계수범위, 파괴인성

Abstract

In this study, to investigate the effects of shot peening on crack growth behavior, crack growth tests are conducted on spring steels and shot peened cracks. The probabilistic crack growth equation, which can represemt the sigmoidal crack growth behavior as recently reported by Kim and Shim, is used to evaluate the experimental results. The results show that fatigue cracks grows slower in the shot peened specimen than in the unpeened and, due to the compressive residual stress occurring on the specimen surface. In the case of the shot peened specimen, the initial stress intensity factor range and the fracture toughness is higher than the non-peened specimen because the compressive residual stress affects crack growth and fracture of the specimen.