1绪言铁道车辆在制造时．其零部件因使用条件的不同．有时需要进行淬火、回山等热处理，有时则不需要上述热处理。车轮与钢轨接触面（轮辋都位的踏面）的残余应力在周向是压缩应力，而在轴向几乎等于零。这种情况说明，在这种状态下，轮辋部位即使发生了裂纹，也不致于扩展到轮 1 Introduction Railway vehicles at the time of manufacture. The parts due to the different conditions of use. Sometimes need to be quenched, back to the mountains and other heat treatment, and sometimes do not need the heat treatment. The residual stress at the wheel-rail interface (rim-bit tread) is compressive in the circumferential direction and nearly zero in the axial direction. This situation shows that in this state, even if the rims have cracks, it will not extend to the wheel