高择优取向碱性锌酸盐镀锌层的耐蚀性

Corrosion Resistance of a Fully Preferred Orentation Zinc Coating Obtained from Alkaline Zincate Solution

采用盐水浸泡试验,电化学测试和盐雾试验研究了碱性锌酸盐体系中获得的高择优取向镀锌层和随机取向镀锌层的耐蚀性能,对比了不同取向镀锌层三价铬和六价铬钝化膜的耐蚀性;采用盐雾试验对比了两种取向镀锌层和氰化镀锌层的耐蚀性。结果表明,高择优取向镀锌层的耐蚀性优于随机取向镀锌层;两种取向的镀锌层经三价铬钝化比六价铬钝化耐蚀性要好;经三价铬钝化处理后的高择优取向镀锌层耐盐雾时间可达720h。

Fully preferred orientation and random orientation zinc coatings were prepared from alkaline zincate solutions.Salt water immersion experiments,Tafel curves and electrochemical impedance spectroscopy were used to compare the corrosion resistance of fully preferred orientation galvanized zinc coating and random orientation galvanized zinc coating.Fully preferred orientation zinc coating was more resistant to corrosion than random orientation zinc coating.The corrosion resistance of fully preferred orientation zinc layers with trivalent chromium passivation was higher than that of random orientation zinc layers with hexavalent chromium passivation.