抄録
Fatigue tests under rotating bending and torsion were conducted in air, in distilled water and in 3 percent saltwater, using smooth specimens of a high strength low alloy steel. In each case, the fatigue crack length distributions were examined at the fixed cycle ratios, and the dependences of a parameter in the distribution function on cycle ratio and stress level were discussed.
It was found that the fatigue crack length distributions under both loading conditions were well approximated by a three-parameter Weibull probability model in all environments, as same as the previous results on low carbon steel. The dependence of shape parameter on cycle ratio was not recognized, but that on stress level was more remarkable in distilled water than in other environments. These trends of the results were approximately in agreement with those of low carbon steel.
