采用电化学阻抗谱技术(EIS)研究了环氧铝粉涂层和FEVE氟碳涂层/碳钢体系在天然海水介质中的电化学腐蚀行为,通过对两涂层的涂层电容分析及腐蚀后表面形貌的观察,评价了两种有机涂层的防腐蚀性能.结果表明,随着浸泡时间的延长,两种有机涂层体系的保护作用都有所降低.环氧铝粉涂层在浸泡初期呈现单容抗弧特征,浸泡57天时出现了双容抗弧.氟碳涂层在浸泡周期内EIS曲线均呈现单容抗弧特征,浸泡110天时低频阻抗模值仍高于108 Ω·cm2.在整个浸泡周期内,氟碳涂层的涂层电容基本维持在1.6×10-10～1.8×10-10 F·cm-2,约为环氧铝粉涂层电容的1/20,表现出低渗水性.%Electrochemical corrosion behavior of epoxy aluminum coating and FEVE fluorocarbon coating on carbon steel was investigated by electrochemical impedance spectroscopy (EIS) in natural sea water. The capacitances of the two coatings were analyzed and the corrosion morphologies of the coatings were observed by scanning electron microscope (SEM). The results indicate that the protective effect of the two coatings are both decrease with the immersion time. After 57 d of immersion in seawater, the EIS plots of epoxy aluminum coating change from single capacitance arc to double capacitance arcs. For fluorocarbon coating, during all the stage of immersion, plots of EIS retaine single capacitance arc with impedance values at low frequency higher than 108 Ω ? Cm2 even after immersed for 110 d. The capacitance of the fluorocarbon coating is steady at 1. 6×10-10~1. 8×10- 10 F ? Cm-2 , only about 1/20 of the capacitance of the epoxy aluminum coating which imply low rate of water penetration in the fluorocarbon coating.
展开▼
