沿海干湿交替环境中氯化橡胶涂层失效过程分析

Corrosion Process of Chlorinated Rubber Coating in Dry-wet Environment

针对常用的氯化橡胶防腐蚀涂层在沿海潮差区干湿交替环境使用中的腐蚀问题,采用电化学阻抗谱(EIS)技术、数值分析技术进行了研究,探讨了该环境下涂层内水分的扩散过程。结果表明,干湿交替环境下涂层老化过程中涂层电阻lgRc随时间t的变化关系均可通过分段函数y=a+bx表示。从电容-时间曲线(lnCc-t1/2)中,氯化橡胶涂层内水分的扩散过程可分为两个阶段:线性增加阶段和缓慢增加阶段,根据第一阶段计算得到涂层中水分的扩散系数D为1.5941×10-9 cm2/s。

The degradation of wildly used chlorinated rubber coating under cyclic wet-dry condition and the water diffusion process during coating＇s aging process were studied by EIS and numerical value analysis techniques. The results indicated that the evolution of coating resistance with the experimental time under cyclic wet-dry condition could be described by the equation y=a＋bx. The lnCc -t^1/2 curve for chlorinated rubber coating indicated that the coating capacitance （lnCo） presented two typical stages as the immersion time （t^1/2） increasesd, the coating capacitance increased rapidly in the beginning time of immersion （0- 12 h）, and then tended to be a slow growth stage after 12 h. According to the linear part of lnCc - t1/2 in the early immersion period, the water diffusion coefficient D was obtained and the value was 1. 5941 × 10^-9 cm2/s.