二相ステンレス鋼SUS329J3Lの低・ギガサイクル疲労特性

抄録

Low- and rgiga-cycle fatigue tests were conducted for heats A and B of SUS329J3L duplex stainless steels. 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 revealed to be almost equal to that of conventional steels. In the giga-cycle fatigue tests, almost all specimens showed surface fracture in case of Heat A, while Heat B showed surface and internal fractures. In the giga-cycle fatigue properties, the difference was small between the Heat A and Heat B. In this case, the rotating bending tests revealed higher fatigue strength than uniaxial loading tests.