土壤含水率和氯离子含量对最佳 保护电位的影响.PDF

第24 卷 第3 期 腐蚀科学与防护技术腐蚀科学与防护技术 Vol. 24 No. 3 2012 年5 月 CORROSION SCIENCE AND PROTECTION TECHNOLOGY May 2012 土壤含水率和氯离子含量对最佳 保护电位的影响 李自力 王太源 郝宏娜 杜松林 崔 淦 中国石油大学(华东)储运工程系 青岛 266555 摘要 : 利用电化学阻抗谱技术, 研究X70 钢的最佳阴极保护电位随土壤中Cl－和含水率的变化. 结果表明: 在Cl－含量 10 mmol/kg 时最佳保护电位随着含水率的增加先升高后降低, 变化幅度在150 mV 左右; Cl－含 量≥10 mmol/kg 时, 最佳保护电位随着含水率增加呈现降低的趋势; Cl－含量为20 mmol/kg 时的不同含水率的 － 土壤中最佳保护电位均达到最小值; 随着含水率的升高Cl 对最佳保护电位的影响逐渐减小. 关键词 : 电化学阻抗谱 最佳保护电位 阴极保护参数 含水率 氯离子 中图分类号: TE988 文献标识码: A 文章编号: 1002-6495(2012)03-0232-04 Influence of Moisture and Chloride Ion Content in Soil on Optimal Cathodic Protection Potential for X70 Steel LI Zili, WANG Taiyuan, HAO Hongna, DU Songlin, CUI Gan Oil and Gas Storage and Transportation Engineering Department of China University of Petroleum, Qingdao 266555 Abstract : The relationship of moisture and chloride ion content in Qingdao soil with the opti- mum cathodic protection potential for X70 steel was studied by electrochemical impedance spec- troscopy (EIS)in a laboratory test set. The results revealed that the optimum cathodic protection potential increased firstly, then reduced with the increase of moisture content when chloride ion was less than 10 mmol/kg with a potential fluctuation about 150 mV. When the chloride ion is greater than 10 mmol/kg, the optimal protection potential showed a trend of reducing with increas- ing moisture content. The optimal cathodic protection potential in soil with various moisture con- tents reached a minimum for chloride ion conte