一种水基无铬达克罗涂层的制备方法及其性能

Preparation Method and Its Properties of a Water-Based Chromium-Free Dacromet Coating

以片状铝粉和锌粉为填料,硅烷偶联剂KH-560和硼酸、复合磷酸二氢盐为成膜物质,在低碳钢工件表面制备了一种水基无铬达克罗涂料。通过扫描电镜(SEM)、能谱仪(EDS)和中性盐雾试验、电化学测试,对涂层的表面形貌、成分、附着力及耐蚀性进行了分析。结果表明:制备的水基无铬达克罗涂层具有良好的稳定性,在60℃、48 h条件下涂层不发生变化;涂装后的无铬水基涂层表面均匀平整,无明显缺陷;在600 h中性盐雾试验后,涂层表面无红锈;水基无铬达克罗涂层的自腐蚀电位负移,腐蚀电流降低一个数量级,说明涂层试样的耐蚀性提高,涂层具有良好的防护性能。

A kind of water-based chromium-free Dacromet coating was prepared on the surface of low carbon steel workpiece by using flake aluminum powder and zinc powder as fillers,silane coupling agent KH-560,boric acid and composite dihydrogen phosphate as film-forming materials.The surface morphology,composition,adhesion and corrosion resistance of the coating were examined by scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),neutral salt spray test and electrochemical test.The results showed that the prepared waterbased chromium-free Dacromet coating had good stability,and the coating did not change under the condition of 60℃and 48h.The surface of the chromium-free water-based coating after coating was uniform and smooth without obvious defects.After 600hneutral salt spray test,there was no red rust on the surface of the coating.The selfcorrosion potential of the water-based chromium-free Dacromet coating was negatively shifted,and the corrosion current was reduced by an order of magnitude,indicating that the corrosion resistance of the coating sample was improved,and the coating had good protective performance.