抄録
Recently, fatigue limit estimation based on the dissipated energy measurement using infrared thermography has attracted attention in various industries. In this study, fatigue limit estimation based on dissipated energy measurement was applied to the evaluation of shot peening treatment. Shot peening treatment is used for fatigue limit improvement by applying work hardening layer and compressive residual stress. The strength of material is affected strongly by shot peening treatment condition. Therefore, it is useful to evaluate the effect of shot peening condition by fatigue limit estimation. The fatigue limit estimation by energy dissipation was applied to shot peened 316L stainless steel specimen. It is found that estimated fatigue limit of the shot peened material obtained by dissipated energy is conservative value compared with that obtained by conventional fatigue test. After the fatigue test, micro cracks were observed in the unbroken specimen of shot peened materials. Therefore, dissipated energy for shot peened materials subjected to the stress amplitude below fatigue limit was affected by non-propagation cracks. It was considered that the estimated fatigue limit indicated crack initiation stress level.
