基于电化学阻抗谱技术建立了实验室检测钢铁表面防护层破损与剥离的电化学方法．提出了在一定频率范围内以电极阻抗幅值比Ｋ的变化关系作为防护层缺陷状态的表征．用此方法测定了土壤中阴极保护的表面涂覆不同状态石油沥青防护层的Ａ３钢模拟试片，得到了较为满意的结果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.作者联系地址：天津大学,中国石油天然气管道科学研究院Author's Address: Tianjin UniversityTianjin300072 Liao YupingLai GuangsenLiu Lingli China Oil & Gas Pipeline Scientific Research InstituteLangfang06500
