热浸镀锌铝镁镀层钢板硅烷涂装性能评价

Evaluation of silanization and e-coating performance of hot-dip Zn-Al-Mg alloy coated steel sheet

以热浸镀纯Zn镀层板为对比,对具有不同表面状态(涂油或钝化)的热浸镀锌铝镁(ZM)镀层平板及双拉变形板在汽车主机厂进行了硅烷电泳处理,随后对其硅烷膜和电泳漆膜的品质进行了评价。结果表明:ZM镀层板的硅烷涂装性能优于纯Zn镀层板;变形对纯Zn镀层和ZM镀层的涂装性能无明显影响,但表面钝化会明显降低电泳漆膜的附着力和耐蚀性。

As compared with hot-dip pure Zn coated steel sheets,the flat and double-drawn Zn-Al-Mg alloy(ZM)coated steel sheets with different surface states(oiled or passivated)were treated by silanization and e-coating in an automobile manufacturer,and then the quality of silanization film and e-coating film were evaluated.The results showed that the silanization and e-coating performance of ZM coated steel sheet was better than that of pure Zn-coated one.Deformation had no obvious effect on the e-coating performance of pure Zn-and ZM-coated steel sheets.Surface passivation resulted in a great reduction of the adhesion strength and corrosion resistance of e-coating film.