利用6kW横流CO2激光器在1Cr18Ni9Ti不锈钢表面进行了不同工艺参数下单道Ni25WC35合金粉末熔覆.分析了熔覆层的物相组成,研究了不同工艺参数对熔覆层耐腐蚀性能的影响.结果表明:熔覆层主要由(Fe,Ni)固溶体和WC原位自生成的W2C组成,同时含有CrNiFeC,Cu3.8Ni化合物和FeW3C,Ni2Si,Fe3Ni3B等硬质相.光学显微观察显示熔覆层组织均匀、致密,与基体结合良好.在5.0％NaCl饱和溶液中电化学腐蚀测量分析结果得出,随着激光功率的增加,熔覆层的耐腐蚀性能降低；随着扫描速率增加,耐腐蚀性能先增加,后降低.最高自腐蚀电位为-554.70mY,最低腐蚀电流密度为0.55μA·cm-2.综合得出,P=3.0kW,ν=500mm·min-1的试样熔覆层耐腐蚀性能最好.%A 6kW CO2 laser apparatus was used for cladding Ni25WC35 alloy powder on lCrl8Ni9Ti stainless steel surface by different technological parameters to obtain single-pass cladding coating. The phase composition of cladding layer and effects of technological parameters on corrosion resistance of coating were studied. The results show that the coating mainly consists of(Fe,Ni)solid solution, W2C by WC irrsitu reaction, and contains CrNiFeC, Cu3.8 Ni compounds and some hard-phase such as FeW3C,Ni2Si,Fe3Ni3B. Optical microscope analysis results indicated that microstructure of cladding coating was homogeneous, dense, forming a good metallurgical bonding layer. Electrochemical corrosion measurements in 5. 0%NaCl saturated solution results show that, with increasing laser power, the corrosion resistance presents a trend of decrease; with increasing scanning speed, the corrosion resistance presents firstly increasing, and then a trend of decrease. The maximum self-corrosion potential of cladding coating was -554. 70mV, the lower corrosion current density was 0. 55jnA · cm~2. As a result, the process parameter of the best corrosion resistance was P=3. OkW and v=500mm · min"1.
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