新型活化环氧富锌涂层的耐腐蚀性研究

Corrosion Resistance Property of the Advance Activated Zinc-Rich Epoxy Coatings

富锌涂料在防腐蚀领域具有广泛应用,然而其长效防护性能却受到锌粉活性影响。本文以冷涂锌涂层、传统环氧富锌涂层作为对照,研究了新型具有电化学活性的环氧富锌涂层在盐雾加速腐蚀试验后的耐腐蚀性。宏观形貌分析表明:盐雾加速腐蚀1800 h后,活化环氧富锌涂层表面并未出现锈点;采用扫描电子显微镜、维体式显微镜观察试验后涂层的表面形貌和涂层结构,发现活化环氧富锌涂层微观表面更加平滑,锌粉并未出现大面积的氧化,涂层内部大小锌粉颗粒均匀排列;通过电化学方法研究涂层的耐蚀机理与防护性,发现活化富锌涂层具有更持久的低防护电位。以上研究结果表明,较冷涂锌及传统环氧富锌涂层而言,新型活化环氧富锌涂层具有优异的长期防护性能,是值得关注和研究的一种新型技术。

The zinc-rich epoxy coatings has been widely used in anticorrosion field,but its long-term protection performance was limited by the activity of zinc powder filler.In this work,the anticorrosion properties in salt spray test of the advance activated zinc-rich epoxy coatings were studied with comparison to the cold application zinc coatings and the traditional zinc-rich epoxy coatings.The macroscopic analysis of the surface morphology showed that no rust spots were found on the surfaces of advance activated zinc-rich epoxy coatings after 1800 h’s salt spray test.Scanning electron microscopy(SEM)and three-dimensional stereomicroscope were used to observe the surface morphology and coatings layer structure,after salt spray accelerating corrosion test.Results showed the advance activated zinc-rich epoxy coatings indicated a smooth surface while the other two coatings were covered with rust.The zinc powders inside the advance activated coatings were arranged evenly in the polymer film and had not been oxidized in large areas.The electrochemical behaviors of the three coatings were studied by the OCP and EIS to reveal their long-term protection mechanism.The results showed that the advance activated zinc-rich epoxy coatings showed lower long-lasting protective potential compared with that of the cold application zinc coatings and traditional zinc-rich epoxy coating.The excellent long-term protection performance of the advance activated zinc-rich epoxy coatings would be worthy of business attention and technological research.