【摘要】 利用20kHz超声疲劳试验方法,研究提速列车50#车轴钢的疲劳性能。超声疲劳试验结果表明,50#车轴钢不存在常规疲劳试验曲线所示的"疲劳极限",其S—N曲线表现出"二次下降型"特征,在超长寿命阶段,S—N曲线继平台之后又出现下降趋势。比较50#车轴钢的超声疲劳性能与常规疲劳性能,疲劳性能受频率影响,超声频率使材料疲劳强度提高。超声疲劳试验结果应用于常规疲劳强度设计时需进行强度修正,给出疲劳强度修正公式及修正系数。更多还原

【Abstract】 The fatigue behavior of 50~# axle steel of speed-increase train is tested with 20 kHz ultrasonic fatigue method. The test shows that the 50~# axle steel has no "fatigue limit" as indicated in the conventional fatigue test curve. The S—N curve indicates a "second order decreasing type" feature. In the ultra-long life period, (after) the platform, the curve has indicated again a decrease trend. The paper compares the ultrasonic fatigue (performance) with that of the conventional fatigue and the comparison indicates that the fatigue performance is subject to the influence of frequency. The ultrasonic frequency enhances the fatigue strength. When the result of the ultrasonic fatigue test is used for conventional fatigue strength design, the strength intensity shall be (corrected). The paper gives the corrected formula and the correction coefficient.更多还原