A Study on The Effect of Residual Stress on Fatigue Propagation Behavior of Spring Steel

스프링강의 피로진전거동에 미치는 잔류응력의 영향

  • Park, Keyung-Dong (School of Mechanical Engineering, Pukyang National University) ;
  • Jung, Chan-Gi (Graduate School of Mechanical Engineering, Pukyang National University)
  • 박경동 (부경대학교 기계공학부) ;
  • 정찬기 (부경대학교 대학원 기계공학과)
  • Published : 2002.10.25

Abstract

Recently the steel parts used at automobiles are required to be used under high stress more than ever before in need of the weight down. To achieve this requirement of a high strength steel, it must be necessary to decrease inclusion content and surface deject as like decarburization, surface roughness etc.. In this study, the surface conditions are measured to know tile influence on fatigue properties by two cases of shot peening of two-stage shot peening and single-stage shot peening. And for this study, three kinds of spring steel (JISG4081-SUP7,SAE 9254, DIN 50CrV4, ) are made. This study shows the outstanding improvement of fatigue properties at tire case of two-stage shot peening in the rotary bending fatigue test and this is assumed to be from (1) Decreasing the surface roughness (2) Unchanging the surface hardness (3) Increasing the compressive residual stress But, results also show fatigue failures originated at inclusion near surface, and this inclusion type is turned out to be a alumina of high hardness.

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