镀锌钢板表面混合稀土与三聚磷酸盐复合钝化膜的耐蚀性能

Corrosion Resistance of Mixed Rare Earth-Tripolyphosphate Composite Passivation Coating on the Surface of Galvanized Steel Sheet

对镀锌钢板进行混合稀土和三聚磷酸盐的协同钝化,通过中性盐雾试验、3%CuSO4点滴试验和电化学测试研究了稀土与三聚磷酸盐复合钝化膜的耐蚀性能。结果显示:稀土与三聚磷酸盐复合钝化膜明显提高了镀锌层的自腐蚀电位,大大提高了镀锌钢板的防护性能,且其耐蚀性明显优于低铬酸盐钝化膜。

Galvanized steel was co-passivated with mixed rare earths and tripolyphosphate.The corrosion resistance of as-obtained composite passivation coating of the mixed rare earths-tripolyphosphate was evaluated by neutral salt-spray test,dripping test of 3% CuSO4 and electrochemical test.Results indicate that as-prepared composite passivation coating of the mixed rare earths-tripolyphosphate is able to greatly increase the corrosion potential of the galvanized steel sheet and significantly improve its protective performance as well.Besides,as-obtained composite passivation coating of the mixed rare earths-tripolyphosphate possesses much better corrosion resistance than trivalent chromate conversion coating.