关键词: 防护涂层, 电化学阻抗谱, 涂层缺陷, 破损, 剥离

Abstract: An electrochemical technique to detect the defects and detachments of the protective coating on the steel structures with electrochemical impedance spectroscopy (EIS) was offered. A new parameter K,which was defined as the ratio of the electrode resistance amplitude at a certain frequency to that at minimal frequency was obtained in present paper. The results indicated that the change of K at a certain range of frequency reflected the condition of protective coating.The technique was found to be very useful in estimating the different conditions of protective coating after being applied to the carbon steel samples covered with tar asphalt which were buried in soil and subjected to cathodic protection.