化学镀镍层的置换法封孔

Effect of Pore-Sealing by Copper Sulfate Displacement on Porosity and Corrosion Resistance of Electroless Nickel Coating on Q235 Steel

孔隙是化学镀镍层防腐蚀应用的制约因素。对Q235钢化学镀镍层采用硫酸铜置换封孔,通过贴滤纸法和盐水浸泡法研究了封孔后镀镍层的孔隙率和耐蚀性能。结果表明:硫酸铜置换可对镀镍层表面的孔隙进行封堵,封孔后化学镀镍层的孔隙率优于相同厚度的镀层,当硫酸铜置换次数达到3次时,孔隙率基本为零,可明显提高化学镀镍件在氯化钠溶液中的耐蚀性能。

The pores of electroless Ni coating on Q235 steel was sealed by copper sulfate displacement.The porosity and corrosion resistance of the electroless Ni coating after pore-sealing treatment were measured by filter-paper sticking method and brine immersion method.Results show that the pores of electroless Ni coating on the steel can be well sealed by making use of copper sulfate displacement,and the porosity of the Ni coating after pore-sealing treatment is greatly reduced.Particularly,after electroless Ni coating is subjected to copper sulfate displacement by three cycles,its porosity is drastically reduced to nearly 0,while its corrosion resistance in 5%NaCl solution is significantly increased.