采用脉冲单电源等离子渗金属技术在Q195钢表面进行铬镍共渗。利用X射线衍射仪、扫描电子显微镜(SEM)及能谱仪(EDS)对渗层的表面形貌、相结构及铬镍含量进行分析。用电化学测量仪测定铬镍共渗层在3.5% NaCl、1 mol/L HNO3溶液中的极化曲线, 研究其腐蚀形貌。结果表明, 铬镍共渗层的主要相成分为Fe-Cr-Ni固溶体。铬镍共渗层的表面呈上凸的胞状组织, 排列致密。表面成分的质量分数为: Cr 16.9%、Ni 48.16%, 其余铁。在NaCl溶液中, 未处理Q195钢表面腐蚀严重产生蚀坑, 而铬镍共渗层表面只有轻微局部腐蚀蚀斑。在HNO3溶液中, 未处理Q195钢表面为严重的面腐蚀, 铬镍共渗层表面几乎未被腐蚀, 后者的耐腐蚀性比前者极大提高。

A nickel-chromizing layer was formed on the surface of Q195 steel by pulse single power plasma. The surface morphology, phase composition and Cr-Ni content of nickel-chromizing layer were analyzed by XRD, SEM and EDS. The polarization curves of nickel-chromizing layer in 3.5% NaCl solution and 1 mol/L HNO3 solution were measured by electrochemical tests. The corrosion morphology was investigated and compared that of unprocessed samples of Q195 steel. The results show that the main phase composition of nickel-chromizing layer was Fe-Cr-Ni solid solution. The surface convex cellular organizations of nickel-chromizing layer were dense. The composition of the surface was Cr 16.9%, Ni 48.16%, and iron remaining. In NaCl solution, the surface of unprocessed sample of Q195 steel was corroded seriously resulted in holes, but the surface of nickel-chromizing layer only showed minor localized corrosion and produced some plaques. In HNO3 solution, the unprocessed sample of Q195 steel showed serious surface corrosion, but it was almost not corrode in the nickel-chromizing layer, i, e., the corrosion resistance of the latter was much higher than that of the former.