钢轨轨底残余应力测量与研究

Measurement and Study of Residual in Rail Foot

钢轨轨底残余应力是影响钢轨行车安全的一个重要指标,由钢轨轧制、冷却和矫直过程中不均匀变形引起。钢轨轨底残余应力的测量是利用应变片和静态电阻应变仪,通过机械量(应变)→电量(电阻、电压)→机械量(应变)方式测出。通过对60 kg/m规格的U75V进行测量分析,结果表明矫直是残余应力增加的主要工序,钢轨通长轨底残余应力波动在15 MPa范围内。降低钢轨残余应力的重点,是对预弯和矫直压下规程进行优化。

The residual stress in rail foot is an important technical index affecting the train running safety,which is caused by the inhomogeneous deformation in the process of rail rolling,cooling and straightening.The residual stress in rail foot is measured in the form of mechanical parameter(strain)-electric parameters(resistance,voltage)-mechanical parameter(strain)by means of strain gauge and static resistance strain instrument.Measuring and analyzing of 60kg/m U75V show that straightening is the main process for the increase of residual stress,and the difference of residual stress along rail foot fluctuates in the range of 15MPa.The reduction of rail residual stress should focus on the optimization of prebending and straightening procedures.