表面硬化对地铁轮轨磨耗性能影响的实验研究

Experimental study on effect of surface hardening on wheel rail wear performance of metro

针对地铁轮轨的表面硬化问题,为了进一步降低轮轨的磨耗,通过对某实际运营线路中的钢轨和两种不同车轮钢的摩擦磨损进行实验研究,探讨了材料表面硬化对轮轨耐磨性的影响规律。首先,采用了赫兹模拟准则,对典型工况下地铁车辆的轮轨接触情况进行了模拟;然后,选取了某地铁线路现役的轮轨材料作为研究对象,并确定了其垂向载荷、运转速度和轮轨试样尺寸等实验参数;最后,采用GPM 60摩擦磨损实验机搭建了测试平台,进行了轮轨接触模拟实验,分析了表面硬化与地铁轮轨磨耗性能之间的规律。研究结果表明:车轮试样的磨耗率随表面硬化程度提高而下降,初始硬度较高的微合金化地铁车轮钢表现出更高的表面硬化程度和更好的耐磨性,相较于CL60钢,其磨耗率可降低35.1%,与其匹配的钢轨磨耗率可提高7.8%,轮轨总磨耗率可降低1.6%;建议在运营初期,对轮轨接触面进行喷丸强化处理,预先提高其表层硬度,以减少轮轨磨合阶段时间和初期磨耗量。

Aiming at the problem of surface hardening of subway wheels and rails,in order to further reduce the wear of wheel and rails,the friction and wear of rails and two different wheel steels in an actual operating line were experimentally studied,and the effect of material surface hardening on the wear resistance of wheel and rails was discussed.First of all,the Hertz simulation criterion was used to simulate the wheel rail contact of metro vehicles under typical working conditions.Secondly,taking wheel steel and rail in service of a subway line as the research objects,parameters such as the vertical load,running speed and wheel rail sample size required for the experiment were determined.Finally,the GPM 60 friction and wear test machine was used to build a test platform,and the wheel-rail contact simulation experiment was carried out.The relationship between surface hardening and metro wheel rail wear performance was analyzed and studied.The results show that the wear rate of wheel samples decreases with the increase of surface hardening.The micro alloyed metro wheel steel with higher initial hardness shows higher surface hardening degree and better wear resistance.Comparing with CL60 steel,its wear rate can reduce by 35.1%,its matching rail wear rate can increase by 7.8%,and the total wear rate of wheel and rail can reduce by 1.6%.It is recommended to perform shot peening treatment on the wheel-rail contact surface in the early stage of operation to increase the surface hardness in advance to reduce the wheel-rail running-in phase and the initial wear.