Effect of Shot Peening on Fatigue Life of Heat Treated Spring Steel

열처리된 스프링강의 피로수명 개선을 위한 쇼트피닝 가공 효과

  • Lee, Seung-Ho (Department of Automobile, Kyonggi Institute of Technology) ;
  • Shim, Dong-Suk (Department of Automobile, Kyonggi Institute of Technology)
  • 이승호 (경기공업대학 자동차과) ;
  • 심동석 (경기공업대학 자동차과)
  • Received : 2004.08.26
  • Accepted : 2004.10.13
  • Published : 2004.11.30

Abstract

The effect of shot peening conditions on the fatigue properties of heat-treated spring steel has been investigated by using residual stress measurement and metallography. The mechanical properties of material did not change so much by shot peening. However, the fatigue strength and fatigue life increased about 20% to 40% by 1-step and 2-step shot peening process. The fatigue strength and life were closely related to the value and position of maximum compressive residual stress by shot peening process. In the case of warm shot peening, compressive residual stress of specimens shot peening processed at $200^{\circ}C$ was higher than those of specimens shot peening processed at room temperature, $100^{\circ}C$ and $300^{\circ}C$.

Keywords

References

  1. Lee J. K. and Kim J. K., 'Influence of Residual Stress Due to Shot Peening on Fatigue Strength and Life,' Transaction of KSME A, Vol. 21, No. 9, pp. 1498~1506, 1997
  2. Lee S. H. and Kim H. S., 'The Effect of 2-Step Shot Peening on the Fatigue Behavior of Spring Steel,' Transaction of KSME A, Vol. 23, No. 1, pp. 140~147, 1999
  3. Yozo, K., Shinzaburo, T. and Masaki, K., 'Effect of Shot Peening on Fatigue Strength of Ti-6Al-4V Alloy at Elevated Temperatures,' Journal of The Society of Materials Science in Japanese, Vol. 45, No. 1, pp. 43~47, 1996
  4. Natto, K., Ochi, T., Takahashi, T. and Suzuki, T., 'Effect of Shot Peening on the Fatigue Strength of Carburized Steels,' Proc. The 4th International Conference on Shot Peening, Tokyo, pp. 519~526, 1990
  5. Lyu, S. K., Inoue, K. and Kato, M., 'Effect of Surface Treatment on the Strength of Carburized Gear,' Proc. International Gearing Conference, London, pp. 183~188, 1994
  6. Tange, A. and Takamura, N., 'Relation between Shot-peening Residual Stress Distribution and Fatigue Crack Propagation life in Spring steel,' Proc. The 4th International Conference on Shot Peening, Tokyo, pp. 243~253, 1990