铁路货车轴承套圈滚道表面应力状态分析

Analysis of Surface Stress State of the Bearing Ring Raceway for Railway Truck

铁路轴承套圈表面层残余应力分为拉应力和压应力。列车运行时,残余拉应力作用下,轴承套圈易萌生裂纹并加速扩展,而残余压应力能够部分地抵消工作载荷施加的拉应力,抑制裂纹萌生及扩展,从而延长轴承套圈的接触疲劳寿命。因此,生产轴承套圈时希望产品保持残余压应力状态。通过安排合理的制造工艺、选择合适的工艺参数、提高磨削液冷却效果等措施,可以将套圈表面层残余压应力控制在合理范围内。在热处理、初磨、附加回火和未附加回火、终磨、超精后,通过试验检测轴承套圈表面层残余应力,验证了过程控制能使套圈表面层残余压应力在预期结果内。

The residual stress on the surface layer of railway bearing rings is divided into tensile stress and compressive stress.During train operation,under the action of residual tensile stress,the bearing rings are prone to crack initiation and accelerated propagation,while residual compressive stress can partially offset the tensile stress applied by the working load,which can suppress crack initiation and propagation so that the contact fatigue life of the bearing rings is extended.Therefore,when producing bearing rings,it is hoped that the product maintains a residual compressive stress state.By arranging reasonable manufacturing processes,selecting appropriate process parameters,and improving the cooling effect of grinding fluid,the residual compressive stress on the surface layer of the ring can be controlled within a reasonable range.After heat treatment,initial grinding,additional tempering,and no additional tempering,final grinding,and ultra precision,residual stresses on the surface layer of the bearing ring were tested.It is verified that process control can keep the residual compressive stresses on the surface layer of the ring within the expected results.