目的 研究30CrMnSiNi2A滑靴在不同火箭橇轨道上运行时的摩擦磨损特性。方法 在U71Mn火箭橇轨道和贝氏体火箭橇轨道上，各开展1发工况一致的超声速单轨火箭橇试验，将每发试验后的30CrMnSiNi2A前滑靴作为研究对象，采用共聚焦显微镜、扫描电子显微镜、能谱仪、X射线衍射分析仪和维氏硬度计对2个滑靴磨损表面的形貌、成分、相组成和截面的硬度、组织结构进行对比分析。结果 不管30CrMnSiNiA滑靴是在U71Mn轨道上运行，还是在贝氏体轨道上运行，均会发生晶粒细化，出现加工硬化现象，使得滑靴局部区域的硬度增大。在贝氏体轨道上运行后，滑靴的表面硬度由390HV提高到795HV，在U71Mn轨道上运行后，滑靴的表面硬度由390HV提高到720HV。在滑靴的磨损表面可以观察到犁沟、凹坑、剥落坑和微裂纹等特征，磨损形式以磨粒磨损为主，伴随着黏着磨损、疲劳磨损和氧化磨损。在U71Mn轨道上运行时，滑靴的磨损表面粗糙度更大，其值为1.90，约是贝氏体轨道上运行时滑靴的2倍，剥落坑更多且磨痕更深，并且在其磨损横截面的变形层更厚，约为12 μm。同时，在变形层中能够观察到更多的富含氧、硅等元素的孔洞。结论 30CrMnSiNi2A滑靴在贝氏体轨道上运行时，其抵抗磨损的性能更优，使用30CrMnSiNi2A滑靴的橇车应优先考虑在贝氏体轨道上开展试验。

During the high-speed operation of the rocket sled, the friction pair composed of the slipper and the track continuously experiences friction. Due to the lack of effective lubrication measures between the slipper and track, the surface of slipper is severely worn. In order to make the sled pass smoothly on the track, there is usually a certain gap left between the slipper and the track. As the surface of the slipper wears down, the gap between the slipper and the track continues to increase, changing the operating state of the sled. When the slipper is severely worn, it can even disrupt the operation stability of the sled and pose a threat to test safety. In order to control the wear of the slipper, it is necessary to understand the wear behavior of the slipper during the track operation of the rocket sled. The work aims to conduct a single track rocket sled test with consistent operating conditions based on U71Mn steel rails and bainitic steel rails. In the test, the maximum speed is 900 m/s, and the sled slides 6.4 km along the track. After the experiment, the sled will be recycled and the 30CrMnSiNi2A front sliding shoes will be taken as the research object. Two front slippers are analyzed separately and the friction and wear characteristics of 30CrMnSiNi2A slipper-U71Mn rail friction pair and 30CrMnSiNi2A slipper-bainitic rail friction pair are studied. The three- dimensional morphology and two-dimensional contour features of the worn surface of the slipper are analyzed with confocal microscopy. The microstructure and elemental distribution of the worn surface of the slipper are investigated through scanning electron microscopy and energy dispersive spectroscopy. The phase composition of slipper materials subject to friction and wear is explored with an X-ray diffraction analyzer. The cross-sectional hardness and microstructure of the sliding shoe are analyzed with a Vickers hardness tester and scanning electron microscope. The wear mechanism of 30CrMnSiNiA slipper, whether running on U71Mn rail or bainitic rail, is mainly abrasive wear, accompanied by slight adhesive wear, fatigue wear, and oxidative wear. After running on U71Mn and bainite rails, the local hardness of the worn surface of the 30CrMnSiNiA slipper increases. The highest hardness of the worn surface of the slipper paired with U71Mn rail is 720HV, and the highest hardness of the worn surface of the slipper paired with bainite rail is 795HV. However, as the depth increases, the hardness gradually decreases to the hardness level of the substrate material. Grain refinement is the main reason for the increase in the hardness of the slipper, which is related to material work hardening caused by high friction heat and high normal load. The 30CrMnSiNiA slipper running on the U71Mn rail has a larger wear surface roughness, more peeling pits, and deeper wear marks compared to the 30CrMnSiNiA slipper running on the bainitic rail. It also exhibits thicker deformation layers and more pores rich in oxygen, silicon, and other elements on its wear cross-section. This means that the 30CrMnSiNiA slipper has better wear performance when running on the bainitic rail. The 30CrMnSiNi2A slipper has better wear resistance performance when running on the bainitic rail. Therefore, sled rockets with30CrMnSiNi2A slippers should be tested on bainitic rails first.