Investigation on the Fatigue Behaviors of Maraging Steel at Different Stress Ratios

Herein, the high-cycle fatigue behaviors of 18Ni maraging steel with different tensile strength in the stress ratio range from 0.1 to 0.5 are investigated, and compared with those at the stress ratio of -1. It is found that the relationship between the fatigue strength at the stress ratios of -1 and 0.1 and tensile strength is nonmonotonic, while the fatigue strength at the stress ratio of 0.5 improves as the tensile strength heightens. The tensile strength corresponding to the optimal fatigue strength state would change with the variation of the stress ratio, which is related to the alteration of key factors affecting the fatigue damage. Moreover, it is found that the Walker equation: sigma(aR) = sigma (-1) center dot [(1 - R)/2] beta gives reasonable results for the influence of stress ratio on the fatigue strength of 18Ni maraging steel.