OS0603 低合金鋼SFVQ1Aの高サイクル疲労における繰返し速度効果(OS6-1 基礎疲労特性と試験法・評価法,OS-6 金属材料の超高サイクル疲労と信頼性評価)

抄録

To investigate effects of cyclic frequency on high cycle fatigue properties of SFVQ1A, uni-axial fatigue tests were conducted under several stress ratios and cyclic frequencies. In the case of stress ratio of R = -1, longer fatigue lives and higher fatigue strength were observed under higher frequency condition in comparison to those under lower frequency condition. Strain ranges during the fatigue tests were measured, and the difference of range was not observed at the same stress amplitude in both cyclic frequency conditions. The result indicated that the strain rate can affect fatigue properties. However, the difference of fatigue lives and strength did not appear under R = 0.1. The strain ranges were relatively small, and the effects of strain rate probably became smaller than those under R = -1. Effects of strain rate were observed under R = 0.5, and strength in the cyclic loading condition became higher than that in the static loading condition. Strain rate should play an important role in the fatigue properties of the material.