鉄鋼材料の低サイクル疲労強度に及ぼす切削および研削加工の影響

抄録

Surface machined layer may change fatigue strength. In this study, the effect of cutting and grinding on low cycle fatigue strength of steels was investigated. Surface shape was measured using laser micro scope. Microstructure changing was observed by EBSD. There are more scratches and deeper microstructural change on the surface machining under low cutting speed. Fatigue life decreased when specimen was machined under low cutting and grinding speeds. However, fatigue life didn’t change on high speed cutting. From these results, fatigue strength is changed by a scratch configuration including the size, depth and shape under low cycle fatigue condition.Microstructural change has small effect on low cycle fatigue life.