为细化高碳高铬合金堆焊层中粗大初生碳化物, 提高堆焊层耐磨性能。以Q235为基材, 高碳高铬合金选取D632A焊条, 对比研究激光电弧复合堆焊试样与电弧堆焊试样。通过显微硬度测试和摩擦磨损试验, 分别评价堆焊层的硬度和耐磨性, 并通过光学显微镜对磨损前堆焊层显微组织进行观察和扫描电子显微镜对磨损形貌进行分析, 分析总结了高碳高铬合金激光电弧复合堆焊试样与电弧堆焊试样摩擦磨损性能差异的原因。在激光电弧复合热源作用下, 堆焊层显微组织中的M7C3初生碳化物由粗大条块状细化为细粒状,且均匀弥散分布。相对于电弧堆焊层, 激光电弧复合堆焊层平均显微硬度提高了约12.5%, 最大显微硬度达到了1 064 HV。激光电弧复合堆焊层的耐磨性较好, 相同条件下磨损质量为5 mg, 摩擦系数为0.38; 电弧堆焊层的耐磨性较差, 相同条件下磨损质量为7 mg, 摩擦系数为0.43。两种堆焊层磨损破坏的机制主要为疲劳破坏。激光电弧复合堆焊通过激光干扰熔池, 细化堆焊层中初生碳化物, 有效提高了高碳高铬合金堆焊层的硬度和耐磨性。

To refine the coarse primary carbides in the high carbon and high chromium alloy hardfacing layer and improve the wear resistance of the surfacing layer. D632A welding rods were selected for hardfacing on Q235 steel plates, and the laser-arc hybrid hardfacing sample and the arc hardfacing sample were compared. Microhardness test and friction and wear test were taken to value the hardness and wear resistance. Their microstructure of the hardfacing layer before wear was observed by Optical microscopy (OM) and their morphologies were studied by SEM. The reasons for the difference in friction and wear properties between laser-arc hybrid hardfacing samples and arc hardfacing samples. Under the action of laser-arc hybrid heat source, the M7C3 primary carbides in the hardfacing layer are refined into fine granular from coarse strip. Theses granular carbides were evenly distributed. Compared with arc hardfacing layer, the average microhardness of the laser-arc hybrid hardfacing layer was increased by about 12.5%, and the maximum microhardness was 1064 HV. The wear resistance of the laser-arc hybrid hardfacing layer was better. The wear quality was 5 mg and the friction coefficient was 0.38 under the same conditions. The wear resistance of the arc hardfacing layer was poor. The wear quality was 7 mg and the friction coefficient was 0.43 under the same conditions. The mainly wear failure mechanism of the two hardfacing layer was fatigue failure. Laser-arc hybrid hardfacing can effectively improve the hardness and wear resistance of the high carbon and high chromium alloy hardfacing layer by refining the primary carbide in the hardfacing layer.