目的 研究耐蚀轨道钢U68CuCr的磨损性能及损伤机理。方法 利用M200型摩擦磨损实验机进行轨道钢U68CuCr和U75V与车轮钢滚动对磨实验。运用电子分析天平测量轮轨失重，来研究轮轨磨损随时间的变化规律。通过扫描电子显微镜、超景深显微镜观察轮轨表面损伤形貌。结果 磨损初始的15 h， U68CuCr磨损量大于U75V。磨损40 h时，U68CuCr与U75V的磨损量基本相同，但随时间增加，U68CuCr的磨损量将低于U75V钢。在干态实验下磨损，钢轨表面存在未剥落的片状氧化物以及其剥落后留下的凹坑和划痕，并伴有塑性变形，而车轮表面没有残留的片状氧化物。磨损过程中，钢轨亚表层为塑性变形区，珠光体发生变形，产生加工硬化，使塑性变形层的硬度高于基体。结论 U68CuCr既具有良好的耐磨性，又有高的耐腐蚀性，能改善钢轨使用性能。氧化磨损是钢轨表面损伤的主要方式，磨损是氧化与剥落交错重复出现的过程。

The work aims to study wear resistance and damage mechanism of corrosion resistant U68CuCr railway steel. M200 friction and wear tester was used to conduct rolling grinding experiment between U68CuCr/U75V railway steel and wheel steel. The pattern in which wheel rail wear varied from time was studied by measuring weight loss of wheel-rail with electronic analytical balance. Surface damage morphology of the wheel-rail was observed by using scanning electron microscope and super depth-of-field microscope. The abrasion loss of U68CuCr exceeded that of U75V during the first 15 h of wear, basically equal to the latter after 40 h, and lower than the latter as wear time prolonged. There were unpeeled flaky oxides as well as dents and scratches left after peeling, accompanied with plastic deformation on the steel rail surface worn in dry-state experiment. However, there was no flaky oxide on wheel surface. Rail subsurface was plastic deformation area during wear process. Hardness of plastic deformation area was higher than that of the substrate due to pearlite deformation and work hardening. U68CuCr exhibits good wear resistance and high corrosion resistance, which can improve the usability of steel rail. Surface damage of steel rail is mainly oxidation wear, accompanied with ridge oxide. Wear is the process in which oxidation and peeling alternate repeatedly.