超声弯曲疲劳试验方法及其应用

在三点弯曲超声疲劳试验方法的基础上开发了对称弯曲超声疲劳试验系 统. 介绍了对称弯曲超声疲劳试样的设计及其加工误差的影响，并利用对称弯曲超声疲劳系 统(20\,KHz)测定了50$^{\#}$车轴钢的$S$-$N$曲线. 结果表明，50$^{\#}$车轴 钢的$S$-$N$曲线是一条连续下降型曲线. 与对称拉压加载下50$^{\# }$车轴钢的$S$-$N$曲线对比结果表明，在高周阶段，加载方式对疲劳性能有明显 影响，而在超高周阶段，加载方式无明显影响.

METHOD OF ULTRASONIC BENDING FATIGUE AND APPLICATIONS

The paper discusses the development of an ultrasonic symmetric bending fatigue system on the basis of the three-point bending method,including the design of ultrasonic symmetric bending samples and the influence of processing errors.The S-N curve of 50~# axle steel is determined by the ultrasonic symmetric bending fatigue system(20 KHz).The results show that the S-N curve of 50~# axle steel is a continuously declining curve.Compared to the S-N curve of 50~# axle steel under the symmetric tension and compression loading,it is shown that in the high-cycle stage,the loading method has a significant effect on fatigue properties, and in the ultra-high-cycle stage,the loading method has no significant impact on fatigue properties.