超高サイクル域を含む冷間工具鋼の回転曲げ疲労特性

抄録

In order to investigate very high cycle fatigue properties of improved cold work steels, rotating bending fatigue tests were conducted at room temperature. Two types of fatigue specimens were provided to examine the effect of extracted direction to rolled direction of the material on fatigue strength. Time strength distributions at N=5×10⁶ cycles are estimated by the corresponding values along regression lines. In addition, fracture surfaces were observed by scanning electronic microscope (SEM).