Abstract: Microstructure change of Fe-based hot spray-welding layers remelted by different laser power under same process conditions was studied by optical microscope and XRD. The results show that the microstructure of Fe-based hot sprayed-welding layer is coarse. After laser remelting at different laser powers, the microstructure of hot sprayed-welding layers is refined to some extent. By comparison, the quicker the laser power, the finer the microstructure of remelted sprayed-welding layers. The microstructure of Fe-based remelted hot sprayed-welding layer is composed of matrix phase of g-(Fe,Ni) solid solution and precipitate phases of Cr7C3, Cr23C6 and Cr2B, etc. Hardness and wear resistance of hot sprayed-welding layers are improved greatly after laser remelting at different laser powers, and the higher the laser power, the more prefect the remelted sprayed-welding layers become. The hardness and wear resistance are increased almost by 16% and 55% respectively compared with unremelted hot sprayed-welding layer.

Key words: Fe-based alloy, hot sprayed-welding layer, laser remelting, microstructure, wear resistance

摘要： 利用金相显微镜和X射线衍射仪等分析手段，研究了Fe基合金热喷焊层在其他工艺参数相同的条件下，经不同激光功率重熔处理后组织结构的变化，并对其硬度和耐磨性进行了测定比较. 结果表明，Fe基合金热喷焊层的组织较粗大，经不同激光功率重熔处理后有不同程度的细化，激光功率越小，重熔热喷焊层组织越细小. Fe基合金重熔热喷焊层组织主要由g-(Fe,Ni)固溶体基体相和Cr7C3, Cr23C6及Cr2B等强化相组成，硬度和耐磨性较原始热喷焊层均有较大幅度提高，激光功率越大硬度和耐磨性越好，硬度提高约16%，耐磨性提高约55%.

关键词: Fe基合金, 热喷焊层, 激光重熔, 组织, 耐磨性