电弧喷涂铝及铝-锌涂层在动态腐蚀介质中的耐蚀性研究

对钢铁基体表面电弧喷涂铝及铝锌涂层进行了动态腐蚀实验 ,以失质量法计算了腐蚀速度 ,并探讨了腐蚀机理。采用SEM对铝及铝锌涂层腐蚀前后的外表形貌进行了观察 ,并对铝及铝锌涂层表面进行了能谱分析 ,采用电化学系统测试了涂层的自腐蚀电位。实验结果表明 ,在 3 %NaCl水溶液中铝涂层的耐蚀性优于铝锌涂层 ;其原因是铝涂层表面上氧化膜的自愈能力及自腐蚀电位高于铝锌涂层。研究还表明 ,铝及铝锌这些阳极涂层不仅能有效地保护它所覆盖的钢铁表面 ,还能保护暴露于腐蚀介质中的钢铁基体表面。在铝、铝锌涂层上刷涂有机涂料 ,有机涂料能渗透到金属涂层的孔隙中 ,将孔隙封闭。同时 ,有机涂层和金属涂层能构成复合涂层 ,其防腐效果更佳

Experiment on corrosion resistance of arc spraying aluminum and aluminum-zinc coatings in dynamic corrosion environment

Arc spraying aluminum and aluminum zinc coatings on steel surface were investigated using dynamic corrosion experiment. The corrosion rate was calculated with weight loss method, and the corrosion mechanism was discussed. The configurations of aluminum and aluminum zinc coatings before and later suffered corrosion were observed with scanning electron microscope, and the coating surfaces were analyzed with energy spectrum. The free corrosion potential of the coatings was tested using the electrochemistry testing system. The results show that the corrosion resistance of aluminum coating in 3 percent sodium chloride solution is more excellent than that of aluminum zinc coating. Aluminum and aluminum zinc coatings can protect the covered steel surface and the steel matrix exposed in the corrosion environment. When aluminum and aluminum zinc coatings sealed with organic coatings have more excellent corrosion resistance.