无铬钝化热浸镀铝钢板涂装前处理工艺研究

STUDY ON PRETREATMENT TREATMENT OF CHROMIUM-FREE PASSIVATION HOT DIP ALUMINIZED STEEL SHEET

通过对无铬钝化热浸镀铝钢板进行涂装前处理工艺研究,发现在脱脂工艺为弱碱环境时,表面钝化皮膜较为完整。中碱环境进行脱脂时,钢板表面钝化皮膜发生脱落。单一的脱脂温度对表面钝化皮膜影响较小。磷化时间≤120s、磷化温度≤45℃时,磷化后表面钝化皮膜较为均匀,继续提高温度和时间导致表面钝化皮膜磷化结晶增加。

Through the pre-coating treatment of chromium-free passivated hot-dip aluminized steel sheets, it was found that the surface passivation film was relatively complete when the degreasing process was a weak alkaline environment. When the medium alkali environment is degreased, the passivation film on the surface of the steel sheet is peeled off. A single degreasing temperature has less effect on the surface passivation film. When the phosphating time is less than or equal to 120s and the phosphating temperature is less than or equal to 45 ° C, the surface passivation film is more uniform after phosphating, and the increase of temperature and time leads to an increase in the surface passivation film phosphating crystal.