许多铁路车辆构件,如车轴、齿轮、销、套等是经感应硬化的,其中,车轴更是最重要的一种构件。今后随着车辆速度的提高,车轴将承受更高的可变载荷,为此希望进一步改善车轴的机械性能。感应硬化是热处理的一种,它能改进钢材的机械性能,并且普遍认为,由于迅速加热和淬火而产生的表面残余压应力能显著改进钢件的疲劳强度。然而,残余应力对疲劳强度影响的许多研究局限在较小的零件上,如汽车零件,象铁路车轴那样大件还不多。目前,车轴感应硬化采用的电流频率是10千赫,根据其频率特性,硬化深度是很浅的, Many railway vehicle components, such as axles, gears, pins, sleeves and the like, are inductively hardened, with axles being the most important component. In the future, as the speed of the vehicle increases, the axle will undergo a higher variable load, in the hope of further improving the axle’s mechanical properties. Induction hardening is a form of heat treatment that improves the mechanical properties of steels and generally believes that residual compressive stress on the surface due to rapid heating and quenching can significantly improve the fatigue strength of the steel. However, many studies on the effect of residual stresses on fatigue strength have been limited to smaller parts such as automotive parts, which are not as bulky as railway axles. At present, the current frequency used for axle hardening is 10 kHz. According to its frequency characteristics, the depth of hardening is very shallow,