抄録
Low- and high-cycle fatigue tests were conducted for heats A and B of SUS630 stainless steels. 480℃ (H900) and 580℃ (H1075) aging samples were prepared. In the low-cycle fatigue properties, all samples revealed almost equal fatigue strength under constant strain amplitude tests. Cyclic softening and hardening were small, and cyclic yield stress was higher than conventional steels. In the high-cycle fatigue tests, almost all specimens showed internal fracture in case of H900, while H1075 showed surface and internal fractures in short and long life regions, respectively. In the high-cycle fatigue properties, although the heat A revealed higher fatigue strength than the heat B, the difference was small between the H900 and H1075. The high-cycle fatigue strength of the present materials was lower than that of other high-strength steel in spite of almost equal inclusion sizes.
