本文在应用Ramberg-Osgood模型拟合U71Mn轨钢拉伸应力应变曲线过程中,选取了六组不同的拟合参数组合。对由此得到的各种拟合结果与实验曲线进行了对比分析,提出了σ_(p2)和σ(0.1)两个拟合参数适用于U71Mn轨钢的拟合方程.从而为钢轨的应力计算、强度分析、寿命估算、低周疲劳的数值方法解以及研究轨钢的力学行为提供了基本资料。 In this paper, the Ramberg-Osgood model fitting U71Mn rail tensile stress-strain curve process, selected six different combinations of fitting parameters. The results of fitting and experiment are compared with each other, and the fitting equations of σ_ (p2) and σ (0.1) for the U71Mn rail steel are proposed, and the stress of the rail is calculated , Strength analysis, life estimation, numerical solution of low cycle fatigue and the mechanical behavior of rail steel.