采用超音速火焰喷涂技术在Q235结构钢基体上制备了Cr3C2-NiCr复合涂层和镍基合金涂层, 借助扫描电镜分析了两种涂层的微观组织和形貌。采用电化学研究方法研究了两种涂层在质量分数为3.5%的氯化钠溶液中的腐蚀性能。结果表明: Cr3C2-NiCr涂层中碳化物分布均匀, 层状结构明显, 孔隙率为1.6%, 镍基涂层中碳化物颗粒较小, 也呈均匀分布, 孔隙率为1.1%。电化学阻抗谱和极化曲线表明: Cr3C2-NiCr涂层和镍基涂层在3.5%NaCl溶液中的耐蚀性均较好, 镍基涂层的抗腐蚀性能更优。

Cr3C2-NiCr coating and nickel-based coating were prepared on Q235 steel by high velocity oxy-fuel (HVOF) thermal spraying, the microstructures of coatings were analyzed by scanning election microscopy(SEM). The corrosion resistance of the two as-sprayed coatings in the solution of mass fraction of 3.5%NaCl was evaluated by the electrochemical method. The result showed that the Cr3C2-NiCr coating exhibited high consistency and a layered structure, the carbides evenly distributed among the matrix. The carbides in nickel-based coating had smaller particles size and they evenly distributed among the matrix too. The porosity of Cr3C2-NiCr coating and nickel-based coating was 1.6%, 1.1% respectively. The electrochemical impedance spectroscopy (EIS) data and polarization curve indicated both of the two coatings had a quite good corrosion resistance in 3.5%NaCl solution. In comparison of Cr3C2-NiCr coating, nickel-based coating had a better corrosion resistance.