不同地区大气曝晒对涂层耐蚀性能的影响 Ⅱ.氟碳涂层

ANTI-CORROSION BEHAVIOR OF COATING EXPOSED IN DIFFERENT REGIONS Ⅱ.FLUOROCARBON COATING

通过检测在拉萨和武汉地区户外曝晒的氟碳涂层的界面电化学腐蚀特征、吸水率和耐盐雾腐蚀性,研究不同大气环境对涂层的耐蚀性能的影响。研究表明,氟碳涂层的电化学阻抗性能在拉萨大气环境中下降较为严重,在两地区经过6个月曝晒的涂层的界面电极反应由电化学步骤控制,而经过12个月曝晒的由扩散步骤控制;在拉萨地区曝晒的涂层的孔隙率较武汉地区的大,且随曝晒时间的延长两者的差值也增大;在拉萨地区曝晒后,涂层内部产生相对较多的缺陷,因此涂层阻挡腐蚀性介质(H2O、Cl-)的性能下降较为明显。

Effect of different climates on anti-corrosion of fluorocarbon coating have been studied in this paper, which were exposed in plateau climate with amounts of ultraviolet radiation at Western China and in subtropical climate with high humidity at central of China. Anti-corrosion of the coating after exposure in Lasa and Wuhan was evaluated by EIS, water absorption rate, and salt spray test. The results showed that electrochemical resistance of fluorocarbon coating exposed in Lasa lost more badly than that in Wuhan.The electrochemical reaction rate, produced on the interface of coating and metal, was controlled by electrochemical step after coating was exposed in Lasa and Wuhan for 6 months, however, the electrochemical reaction rate was controlled by diffusion step after coating exposed for 12 months. Compared with coating exposed in Wuhan, there have been more porosity in coating exposed in Lasa, and with exposure time prolonging in Lasa, more porosity showed in coating, accordingly, the capability of coating to prohibit corrosive media （H2O、Cl^-） such as through coating lost more badly.