目的 研究 Q420 钢表面热镀锌工艺中,Zn 和 Zn-Al-Ni-RE 合金镀层在酸性铜离子加速盐雾试验条件下的耐蚀性能。 方法 Q420 钢表面预处理后进行热镀锌, 根据 GB 6460—1986 进行铜加速醋酸盐雾腐蚀试验,对比纯 Zn 镀层与 Zn-Al-Ni-RE 合金镀层的耐蚀性。 结果 Ni, RE 等元素的加入使镀层表面光亮,组织更加细密。 在酸性铜离子加速实验进行到 192 h 时,纯锌镀层的腐蚀质量损失是合金镀层的 2. 7 倍; 72 h 后纯锌镀层出现红锈, 120 h 后合金镀层出现红锈,说明 Zn-Al-Ni-RE 合金镀层比纯 Zn镀层更耐腐蚀。 结论 通过适量添加 Al,Ni 与稀土元素, 能使 Q420 钢合金镀层的耐蚀性能大幅度提高。

Objective To study the corrosion resistance of hot dip galvanized pure Zn and Zn-Al-Ni-RE alloy coatings of highstrength steel Q420 under the acidic and copper accelerated salt spray corrosion condition. Methods On the basis of surface pretreatment, the Q420 steel was treated by hot dip galvanizing. Copper accelerated acetic acid salt spray corrosion test was carried out according to GB 6460—1986, and the corrosion resistance of the pure Zn coating and Zn-Al-Ni-RE coating was compared. Results With the addition of Ni, RE and other elements, the coating surface was bright and the microstructure became finer. After 192 h, the corrosion weight loss of pure zinc coating was 2. 7 times higher than the corrosion weight loss of Zn-Al-Ni-RE alloy coatings under the acidic and copper accelerated salt spray corrosion condition. Pure zinc coating showed red rust after 72 h, while Zn-Al-Ni-RE alloy coating showed red rust after 120 h, so Zn-Al-Ni-RE alloy coating was more corrosion resistant than the pure Zn coating. Conclusion By means of adding nickel aluminum elements and rare earth elements, the corrosion resistance of alloy coating was greatly improved.