Journal of the Korean Society for Railway (한국철도학회논문집)

The Korean Society for Railway (한국철도학회)
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Effect of Shot Peening on the Fatigue of SS400 Weldments

SS400 용접부의 피로강도에 미치는 쇼트 피닝의 영향

  • 김진헌 (서울메트로, 군자차량사무소) ;
  • 구병춘 (한국철도기술연구원, 철도구조연구실) ;
  • 김현규 (서울산업대학교, 기계공학과) ;
  • 정성균 (서울산업대학교, 기계공학과)
  • Published : 2009.12.30
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Abstract

Fatigue fracture of the welded joints of bogie frames is one of unsolved problems. To improve the fatigue strength of the welded joints, various techniques have been applied. In this study, we have investigated the effect of shot peening on the fatigue characteristics of SS400 welded specimens. The fatigue lives of four kinds of welded specimens were examined; welded, PWHT, shot peened, and shot peened after PWHT. The results of the fatigue tests show that the fatigue limit of the shot-peened specimens is higher than that of the welded specimens, and the PWHT specimens have a lower fatigue limit than the welded specimens. It was found that shot peening is a very effective method to improve the fatigue strength of SS400 welded joints.

철도 차량 대차 프레임은 주로 용접을 이용하여 제작되고 있는데 용접부에서의 피로파괴는 늘 문제가 되어왔다. 용접부의 피로강도를 향상시키기 위한 여러 방법 중 본 연구에서는 쇼트 피닝을 적용하였다. 철도 구조물에 많이 사용되는 소재의 하나인 SS400 판재를 이용하여 용접시편을 만들어 쇼트 피닝과 후열처리 유무에 따른 피로특성을 분석하였다. 피로시험결과에 의하면 쇼트 피닝은 피로강도를 향상시키는데 매우 효과적이었고 후열처리는 피로강도를 도리어 저하시키는 것으로 나타났다.

Keywords

References

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