高速铁路轮轨硬度匹配试验研究

摘要

针对我国高速铁路出现车轮磨耗相对较大的问题,对国内外高速铁路轮轨硬度匹配关系的研究及应用现状进行分析,并在实验室进行3种硬度车轮与3种硬度钢轨的对磨试验,对比分析硬度不同的车轮与钢轨对磨时的轮轨磨损、变形和接触疲劳伤损等.结果表明:适当提高车轮的硬度即提高轮轨硬度比以减轻车轮磨耗较大的问题已成为国际上通行的做法;9组轮轨磨损试验中,轮轨硬度比为0.95∶1～1.15∶1时轮轨总磨耗量较小,轮轨硬度比大于1∶1时,轮轨变形和表面接触疲劳伤损较轻,轮轨硬度比为1.15∶1时轮轨总磨耗量最小,且接触疲劳伤损也最轻;随着车轮硬度的提高,不但车轮的磨耗减小,而且其抗变形能力也显著增加.建议动车组车轮与U71MnG钢轨的硬度比控制在1∶1以上,以解决我国高速铁路车轮磨耗较大的问题.%The wheel wear volume is relatively high in China's high-speed railway.To solve this problem,the research and application status of wheel-rail hardness matching relationship of high speed railway at home and abroad was analyzed.Rolling-sliding friction tests of three kinds of wheel samples with different hardness over U74,U71MnG and U75VG rail samples were also done in laboratory.The wheel wear,deformation and contact fatigue damage behavior of wheel/rail samples with various hardness ratios were compared and analyzed.Results show that the appropriate improvement of wheel hardness,that is,the improvement of wheel-to-rail hardness ratio has become an international practice to alleviate the problem of larger wheel wear.In the 9 groups of wheel/rail wear tests,when the wheel-to-rail hardness ratio is in the range of 0.95 ∶ 1～1.15 ∶ 1,the total wear of wheel/rail is relatively low.When the wheel/rail hardness ratio is greater than 1 ∶ 1,the wheel/rail deformation and surface contact fatigue damage are lighter.When the wheel/rail hardness ratio is 1.15 ∶ 1,the total wear amount of wheel-rail is the smallest,and the contact fatigue damage is also the lightest.With the increase of wheel hardness,not only the wheel wear is reduced,but also its resistance to deformation is significantly increased.It is suggested that the hardness ratio of EMU wheel and U71MnG rail should be controlled over 1 ∶ 1 to solve the problem of larger wheel wear of high speed railway in China.