富锌涂料的防腐性能研究

摘要

采用4种市售富锌涂料施涂于钢材基体,经4000h中性盐雾实验后发现产品防腐性能存在显著差异.采用差示扫描量热法(DSC)、X-衍射分析法(XRD)和扫描电镜分析法(SEM)分别测试分析了涂料干膜含锌量、盐雾实验前后的晶体物质组成、腐蚀前后的微观形貌.研究表明4种涂料在盐雾腐蚀过程中的产物和机理相近,而影响其防腐性能的主要因素为干膜中含锌量、腐蚀产物的致密程度和锌粉颗粒在涂料中的分散均匀性.%Four commercial zinc - rich coating products were applied onto the steel substrates, then the specimens were tested by the neutral salt spray for 4 000 h and obvious difference of the anticorrosion performance among the coatings was found. The zinc contents in dry film, crystal material compositions and mi-crostructures of the coatings before and after test were analyzed by differential scanning calorimetry ( DSC ) , X - ray diffraction analysis ( XRD) and scanning electron microscope ( SEM ) . The results showed that there was no difference of the corrosion products and corrosion mechanisms among the four coatings. However, the content of zinc in dry films, the degree of densification of the corrosion products and the dispersion uniformity of the zinc particles in coating might be the critical factors to influence the anticorrosion performance of the zinc - rich coatings.