通过添加适当的氧化剂和螯合剂,对镀锌层三价铬钝化溶液进行改性,控制溶液的pH,钝化温度和时间,利用对比试验对镀锌层钝化工艺进行研究,通过50g/L的NaCl溶液浸泡试验,探讨三价铬钝化工艺参数对钝化膜耐腐蚀性的影响,通过观察腐蚀面积对钝化膜层的耐腐蚀性能进行初步分析.结果表明:采用改性后三价铬钝化液进行钝化,镀锌层的耐腐蚀性能明显提高,在50g/L的NaCl溶液中浸泡168h无白锈出现,其耐腐蚀性能与传统的Cr(Ⅵ)钝化工艺基本相当.%Zinc coatings were passivated under different pH value, temperature and processing time by using a modified trivalent chromium solution with the addition of oxidant and chelating agent. The effect of processing parameters on the corrosion resistance of passivated zinc coating was determined in 50g/L NaCl solution soaking test. The results show that the corrosion resistance of zinc coating was improved obviously after the modified trivalent chromium solution passivation. There was no white rust on the coating after 168 hours soaking test, which is equivalent with the coating passivated by hexavalent chromium solution.
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