AbstractThe objective of this study is to investigate fatigue life and fatigue crack propagation behavior in the reduced activation ferritic steel JLF-1. The experiment of fatigue life for JLF-1 steel have been carried out for the stress ratio R=0 at room temperature and 400 °C. The fatigue crack propagation behavior of the JLF-1 steel was investigated by the constant amplitude loading test for the stress ratios R=0.1, 0.3 and 0.5, respectively. The effects of stress ratios and specimen size on the fatigue crack growth behaviors for JLF-1 steel were discussed within the Paris law. The fatigue life test performed under the room temperature and 400 °C. At room temperature, the fatigue limits of longitudinal and transverse direction to the rolling direction were 480 and 490 MPa at 1×107 cycles, respectively. Also, at 400 °C, the fatigue limits of longitudinal and transverse direction to the rolling direction were 400, 416 MPa at 1×107 cycles, respectively. The base material of JLF-1 steel showed the isotropic behavior in fatigue properties of the rolling direction and the test temperature. The fatigue crack propagation rate of a half size specimen was similar to that of a full size specimen at the stress ratios of 0.1, 0.3 and 0.5, respectively. The fatigue crack propagation behavior of this material can be evaluated by using half size specimens.
Fatigue life and cyclic softening behavior of JLF-1 steel