为了提高缸套内表面磨损均匀性、改善与环的配副性，制备了等离子束淬火和等离子束淬火/渗硫两种工艺下的缸套试样，并借助OM、SEM、XRD和硬度计等比较研究了其内表面的组织性能。结果表明：淬火层组织由隐针马氏体+残余奥氏体组成，淬火/渗硫复合层组织由α-Fe+FeS+FeS₂组成；随扫描速度逐渐降低，自下而上，淬火层的硬度逐渐提高，淬火/渗硫复合层的硬度、厚度和FeS含量逐渐增加；淬火缸套试样磨损量基本为0.009 mm，淬火/渗硫缸套试样磨损量基本为0.003 mm，相对淬火缸套减少了66.7%，配副环的开口间隙相对减小了65.3%。淬火缸套内表面强化效果自下而上逐渐提高，其对FeS支撑作用逐渐增强，与缸套不同部位实际工作条件的变化对耐磨性的要求基本一致，是两种缸套试样具有“等耐磨性”的主要机理所在。

In order to improve the wear uniformity of inner surface and the mating with ring for cylinder liner, the cylinder liner samples were prepared under the two processes of plasma beam quenching/sulfurization. The microstructure and properties of inner surface were studied by OM, SEM, XRD and hardness tester. The results show that the quenched layer is composed of martensite and residual austenite and the quenched/sulfurized composite layer is composed of α-Fe+FeS+FeS₂. As the scanning speed gradually decreases, the hardness of quenched layer gradually increases and the hardness, thickness and FeS content of quenched/sulfurized composite layer gradually increase from bottom to top. Compared with the quenched cylinder liner sample, the wear of quenched/sulfurized cylinder liner sample is 0.003 mm and reduces by 66.7%, and the opening clearance of auxiliary ring reduces by 65.3%. The hardening effect for the inner surface of quenched cylinder liner gradually increases from bottom to top and its supporting effect on FeS gradually enhances, which is basically consistent with the requirements of wear resistance from the changes of actual working conditions in different parts of cylinder liner and the main mechanism of uniform wearability for the two cylinder liner specimens.