车轮轮辐钢S500LF的疲劳性能

采用PX-100高频疲劳试验机，采用升降法在振动频率为100~120Hz、拉-压对称应力的条件下测定车轮轮辐钢S500LF的疲劳极限，并用数理统计方法分析确认疲劳极限为291MPa.此值作为母体50%存活率下的疲劳极限估计量时，以95%的置信度，相对误差不超过±5%.在测定的疲劳极限基础上，采用多试样法测得不同应力水平下的疲劳寿命，据此绘制出应力-寿命关系曲线，通过回归得到应力-寿命曲线方程.对试样断口进行了理论分析，结果表明试验钢韧性良好.

Fatigue Property of Spoke Steel S500LF

An experiment was carried out on the high frequency fatigue testing machine PX-100 and with the method of progressively increasing/decreasing stress to determine the fatigue limit of wheel spoke steel S500LF on the condition that the vibration frequency was 100~120Hz and the tensile-compressive stress was symmetrical. The fatigue limit was 291MPa by the mathematical statistical analysis. When this value was used as an estimator of the maternal 50% survival rate， the relative error was no more than ±5% with a confidence level of 95%. The fatigue life at different stress levels was measured by the multi-sample method according to the measured fatigue limit. Based on this， the S-N relation curve was drawn and the S-N curve equation was regressed. Besides， the fracture of the samples was analyzed theoretically， and the result shows the good toughness of the test steel.