缺陷缠带防护层下碳钢的电化学行为

ELECTROCHEMICAL BEHAVIOR OF CARBON STEEL COATED WITH DEFECTIVE TAPE COATING

采用电流阶跃技术和电化学阻抗谱 (EIS)方法研究聚烯烃缠带防护层 (PolyolefinTapePro tectiveCoating)的破损以及其与基体金属粘结力 .提出用阻值比系数K判断防护层缺陷状况 .结果表明在破损孔存在条件下 ,防护层很容易从金属基体剥落 。

Both the holidays crossing through the polyolefin tape coating and the loss of adhesion of polyolefin tape result in poor protective capabilities of coating.Galvanostatic step technique and electrochemical impedance spectroscopy were used to investigate the electrochemical behavior of carbon steel with coating of different failure.The difference of the voltage response curves for the samples with different coating failures was observed and the ratio of the coating resistance to the gross resistance was proposed to determine the coating condition.The degrading process of polyolefin tape immersed into tap water was studied and it was found that the adhesion of coating degraded quickly for tape coating having holidays.The study demonstrated that in addition to EIS technique,galvanostatic step technique is another suitable method in studying coating-metal system.