机械镀锌镀层钝化与耐蚀性能研究

    对机械镀锌层分别用三价铬、稀土和六价铬进行了钝化处理,利用盐雾试验和电化学测试对不同钝化膜的耐蚀性与电化学行为进行了比较研究.盐雾试验结果表明,稀土与三价铬钝化处理的效果均已超过传统的六价铬钝化,比六价铬钝化膜的耐蚀性提高了一倍以上；稀土钝化膜的耐蚀性最好,三价铬钝化膜的耐蚀性仅次于稀土钝化膜的.电化学测试表明,三价铬、稀土和六价铬钝化膜都能够不同程度地抑制腐蚀的阴极电极反应,抑制阴极反应程度最大的是稀土钝化膜,其次是三价铬钝化膜,最小的是六价铬钝化膜.三价铬与稀土钝化工艺的环保和良好的防腐效果使其具有良好的应用前景.

PASSIVATION AND CORROSION RESISTANCE OF MECHANICALLY PLATED ZINC COATING

    The mechanically plated zinc coating was passivated with chemicals containing trivalent chromium,rare earth metal and hexavalent chromium respectively.Then the corrosion resistance and electrochemical behavior of the passivated coatings were compared by salt spay test and electrochemical test.The result of salt spay test showed that the coatings passivated with trivalent chromium and rare earth metal are superior to that with hexavalent chromium by one fold in corrosion resistance.The coating passivated with rare earth metal was the best in corrosion resistance and that with trivalent chromium was the next.The electrochemical test showed that all the passivation treatments with trivalent chromium,rare earth metal and hexavalent chromium could suppress the cathode reactions to some extent.The effectiveness of passivation chemicals in suppression of the cathodic reaction might be ranking as follows: rare earth metal,trivalent chromium,and hexavalent chromium.Therefore,chemicals containing trivalent chromium and rare earth metal had good application foreground for their good corrosion resistance and environmental friendly.