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利用6 kW多模横流CO2激光器在45钢表面熔覆了Ni60CuMoW合金粉末,并对熔覆涂层进行了回火处理。通过OM、XRD、SEM、EDS和电化学综合测试系统等手段分析了激光功率和回火复合处理对熔覆层组织和耐蚀性能的影响。结果表明:熔覆层与基体呈良好的冶金结合,熔覆层组织致密。熔覆层主要由富含Ni的基体相γ(Ni,Fe)、固溶体(Ni,Cu)、化合物Ni31Si12、BCr、Cr5 B3、BNi3、FeNi3和M23 C6(M=Cr、Ni、Fe)等组成。随着激光功率的增加,熔覆层与基体间的过渡区域更加平滑。试样耐蚀性随激光功率的降低而增强,腐蚀电位明显正移,腐蚀电流密度降低近2个数量级。对单道涂层试样,回火处理后的耐蚀性好于回火前,而多道熔覆层的耐腐蚀性又优于单道。
The 6 kW multi-mode cross-flow CO2 laser cladding Ni60CuMoW alloy powder on the surface of 45 steel and tempering the cladding coating. The effects of laser power and tempering on the microstructure and corrosion resistance of the coatings were analyzed by means of OM, XRD, SEM, EDS and electrochemical integrated testing system. The results show that the cladding layer has a good metallurgical bond with the substrate and the cladding layer is dense. The cladding layer is mainly composed of the Ni-rich phase γ (Ni, Fe), solid solution (Ni, Cu), compounds Ni31Si12, BCr, Cr5 B3, BNi3, FeNi3 and M23 C6 (M = Cr, Ni, Fe) . As the laser power increases, the transition area between the cladding and the substrate is smoother. The corrosion resistance of the samples increases with the decrease of the laser power, the corrosion potential is obviously positive and the corrosion current density is reduced by nearly 2 orders of magnitude. For single-coated samples, the corrosion resistance after tempering is better than that before tempering, and the corrosion resistance of multi-pass cladding is better than that of single pass.