Evaluation of Rolling Contact Fatigue Crack of Train Wheels

Rolling contact fatigue of the wheel tread, which affects the safety and comfort of train, is the key scientific issue. Standard rolling contact fatigue test was carried out for a common wheel material and the damage behaviors of the standard rolling contact fatigue sample and the service wheel were compared using metallographic microscope, scanning electron microscope, transmission electron microscope and microhardness tester. The rolling contact fatigue crack evaluation method of the train wheel were studied. The results show that the rolling contact fatigue cracking is the result of cumulative plastic deformation damage of the surface metal. The depth of the spalling pit of the standard rolling contact fatigue sample is exactly equal to the depth of the hardened layer. The depth of the spalling pit of the service wheel is less than the depth of the hardening layer. The rolling contact fatigue crack on the wheel surface is designated as “triangular directional crack. Quantitative evaluation method for rolling contact fatigue damage degree of wheel surface was proposed.