循环压力对环氧涂层在模拟深海环境中失效行为的影响

EFFECT OF CYCLIC PRESSURE ON DEGRADATION BEHAVIOR OF EPOXY COATING IN SIMULATED DEEP OCEAN ENVIRONMENT

在模拟深海环境下,利用电化学阻抗技术并结合重量法,研究了循环压力对纯环氧涂层在3.5mass%NaCl溶液中失效行为的影响。结果表明,循环压力条件下,涂层的阻抗行为呈周期性变化规律:在高压条件下浸泡时,有机涂层电容较高、涂层电阻较低;而常压条件下两者都较高。循环压力增大,腐蚀介质更容易扩散到涂层内部,使得涂层吸水量增加,涂层电阻降低,涂层防护性能恶化。

The effect of cyclic pressure on the degradation behavior of the epoxy coating on carbon steel surface in 3.5% NaCl solution in a simulated deep-ocean environment was studied using electrochemical impedance spectroscopy （EIS） and weight method. The results showed that the EIS characteristics displayed a periodic variation under the cyclic pressure condition. The coating capacitance at high pressure was higher and the coating resistance was lower than that at atmospheric pressure during immersion periods, respectively. With increasing the cyclic pressure, the corrosion medium such as water had diffused to the coating/metal interface more easily. As a result, the increase of the water absorption capacity of the epoxy coating and the decrease of coating resistance were observed. The coating protection properties were obviously deteriorated.