阴极极化对碳钢局部腐蚀闭塞区化学和电化学状态的影响  

EFFECT OF CATHODIC POLARIZATION ON CHEMICAL AND ELECTROCHEMICAL STATES INSIDE OCCLUDED CELLS OF LOCALIZED CORROSION OF A3 STEEL

作　　者：许淳淳[1] 张晓波[1] 李志强 刘幼平[1] 

机构地区：[1]北京化工大学应用化学系

出　　处：《腐蚀科学与防护技术》2000年第5期260-263,共4页Corrosion Science and Protection Technology

基　　金：国家自然科学基金

摘　　要：采用模拟闭塞电池装置研究阴极保护对碳钢局部腐蚀扩展阶段闭塞区化学和电化学状态的影响 .对A3钢 NaCl水溶液体系 (pH =1 0 .0 0 ,t=50℃ )闭塞区进行阴极极化 ,结果表明 :Cl- 由闭塞区内向外电迁移 ,即闭塞区内Cl-浓度下降 ,pH值由 5.6迅速上升至 1 1以上 ,最终可达 1 2 .碳钢表面发生明显钝化 ,闭塞区的自腐蚀电位Ecorr正移 ,自腐蚀电流密度下降 ,局部腐蚀受到抑制 .A simulated galavanstatic occluded cell was used to investigate the effects of cathodic protection on chemical and electrochemical states inside occluded cells of localized corrosion for A3 steel in 0.01 mol/L NaCl solution ( pH=10.00, t =50℃). It was found that Cl - concentration of the occluded solution decreased by electro\|migration, solution pH inside occluded cells increased from 5.6 to above 12, the surface of A3 steel can from passive film, the E corr of the occluded cell did rise, corrosion rate decreased, so the localized corrosion of A3 steel in the solution was retarded.

关 键 词：局部腐蚀 闭塞电池 阴极保护 碳钢 阴极极化 

分 类 号：TG174.41[金属学及工艺—金属表面处理]