目的 通过添加超细VC颗粒改善Q235合金表面激光熔覆H13涂层的显微组织，并提高其耐磨性。方法 利用激光熔覆技术在Q235表面制备了H13/VC复合涂层，利用光学显微镜、扫描电镜、显微硬度仪以及摩擦磨损试验仪，研究了超细VC颗粒不同添加量对涂层微观结构、显微硬度和摩擦磨损性能的影响。结果 激光熔覆H13/VC复合涂层与基体呈冶金结合，无明显气孔和裂纹等缺陷。超细VC颗粒在激光熔覆过程中全部熔解，显著改变了涂层的微观特征。V元素没有明显的元素偏析现象，但是随着超细VC含量的增加，枝晶干和枝晶间内的V元素含量呈现增加的趋势。超细VC颗粒起到了固溶强化的作用，促使熔覆层的显微硬度随着超细VC含量的增加而增加。H13熔覆层的平均显微硬度为504.21HV0.3，随着超细VC含量的增加，复合涂层的显微硬度逐渐增加(608.21、658.24、680.41HV0.3)。H13熔覆层的磨损体积为3.97×10^?2 mm³，当VC添加量为2%时，复合涂层的耐磨性较H13合金有所提高，摩擦因数保持在较小的范围内，主要以磨粒磨损和氧化磨损为主，粘着磨损为辅。随着超细VC含量的增加，复合涂层的磨损体积逐渐减少，当VC添加量为10%时，复合涂层的磨损体积为2.69×10^?2 mm³，约为未添加超细VC颗粒涂层的2/3。结论 超细VC的添加有助于改善合金的显微组织和耐磨性。

The work aims to improve the microstructure and wear resistance of laser cladded H13 coating on Q235 alloy by adding ultrafine VC particles. H13/VC composite coating was prepared on Q235 surface by laser cladding. The effects of different amount of ultrafine VC particles on microstructure, microhardness and wear properties of the coating were studied by optical microscope (OM), scanning electron microscope (SEM), microhardness tester and friction tester. The results show that the laser cladded H13/VC composite coatings were metallurgically bonded to the substrate, without obvious pores and cracks. The ultra-fine VC particles were completely dissolved in the laser cladding process, which significantly changed the micro characteristics of the coating. There was no obvious segregation of V element, but with the increase of ultra-fine VC content, the content of V element in dendrite stem and inter dendrite showed an increasing trend. The ultra-fine VC particles play the role of solution strengthening, and the microhardness of the cladding layer increased with the increase of VC content. The average microhardness of H13 cladding layer is 504.21HV0.3, with the increase of ultra-fine VC content, the microhardness of the composite coating increases gradually (608.21, 658.24, 680.41HV0.3). The wear volume of H13 cladding layer is 3.97×10?2 mm3. When the VC content is 2%, the wear resistance of H13 alloy is higher that H13 alloy, and the friction coefficient is kept in a small range. The main wear mechanisms are abrasive wear and oxidation wear, and adhesive wear is secondary. With the increase of ultra-fine VC content, the wear volume of the composite coating decreases gradually, When the VC content is 10%, the wear volume of the composite coating is 2.69×10?2 m3, which is about 2/3 of that of the coating without the addition of ultrafine VC particles. This shows that the addition of ultrafine VC particles can help to improve the microstructure and wear resistance of the composite coating.