在锌铝涂层表面喷涂HD590富铝涂液形成复合涂层,对比了锌铝涂层与复合涂层的附着强度、耐磨性、微观形貌,并通过中性盐雾试验、海洋平台棚下大气暴露试验和海水周期喷淋试验,对比研究了二者的耐蚀性。结果表明:复合涂层的附着强度比锌铝涂层提高了30%,耐磨性好,涂层厚度满足紧固件工件的配合精度要求;复合涂层的抗盐雾腐蚀性能和耐海洋环境腐蚀性能优于锌铝涂层,其防腐机理为屏蔽作用、钝化作用和阴极保护相结合;防腐过程中,富铝层发生活化反应,产生一定的牺牲阳极保护作用,同时使涂层腐蚀电位负移,提高了其阴极保护作用。

Composite coating was prepared by spraying the HD590 rich-Al dope on Zn-Al coating. Comparing the adhesion intensity, abrasion resistance, micro-morphology of composite coating with Zn-Al coating, and their anticorrosion performance were studied by salt spray test, marine platform outdoor exposure and seawater periodic spraying test. The results show that the adhesion intensity of composite coating is improved 30% than Zn-Al coating, the abrasion resistance is excellent and the thickness settles for precision of fasteners; The composite coating exhibits obviously better anticorrosion performance than Zn-Al coating in salt spray and marine environment. The corrosion mechanism is that composite coating protects substrate steel by combining action of sheet shield, passivating and cathodal protection; In the anticorrosive process, the rich-Al coating activating dissolves and exerts sacrificial anode effects, also it enhances the cathodal protection by change the corrosion potential of composite coating to more negative.