冷轧钢表面植酸-硅烷双膜复合层的耐蚀性能

为了研究植酸-硅烷复合膜对冷轧钢腐蚀行为的影响,采用浸泡法在冷轧钢板表面分别制备了植酸化学转化膜、硅烷膜层及植酸-硅烷复合膜层。采用扫描电子显微镜观察冷轧钢板表面经植酸转化膜和植酸-硅烷复合膜层处理之后的形貌;运用红外光谱和X-射线光电子能谱方法研究植酸转化膜及植酸-硅烷复合膜层的化学组成;采用极化曲线、电化学阻抗谱、盐雾试验研究植酸-硅烷复合膜层的耐蚀性能及在3.5%氯化钠腐蚀溶液中的稳定性。结果表明:植酸-硅烷复合膜层的耐腐蚀性能及在氯化钠溶液中的稳定性明显高于单一的硅烷膜层。其作用机理在于植酸转化膜一方面可以提高硅烷膜层与金属基体的结合力,另一方面可以与硅烷膜层协同作用提高复合膜的耐腐蚀性能。

Anti-corrosion Performance of Phytic Acid-Silane Composite Coating on Cold-rolled Steels

To investigate the influence of phytic acid-silane composite coating on the corrosion behavior of cold-rolled steels, phytic acid (PA) conversion coating, silane coating and phytic acid-silane composite coating were fabricated on the cold-rolled steel substrate through a simple immersion method. Scanning electron microscope was used to study the microstructure and surface morphologies of the cold-rolled steel before and after being covered by the phytic acid conversion coating and phytic acid-silane composite coating. Chemical bond and surface functional groups of the phytic acid conversion coating using IR and XPS. The anti-corrosive performance and stability of the phytic acid-silane composite coating were investigated by the polarization curve, electrochemical impedance spectroscopy and salt spray test methods, respectively. The results show that the anti-corrosive performance and stability of phytic acid-silane composite coating are much better than that of the single silane coating. The phytic acid chemical conversion coating one side can improve the adhesion between the silane coating and the steel substrate. On the other hand, it can improve the anti-corrosion performance of the composite coating due to the synergistic effect.