摘要
采用模拟闭塞电池恒电流实验研究了 30 4不锈钢在 0 .5mol/LNaCl(pH =7)溶液中及在该溶液中添加不同浓度十二烷基硫酸钠 (C12 H2 5SO4Na)后局部腐蚀闭塞区内化学状态的变化 .结果表明 ,对内试件通入阳极电流后 ,随着时间的延长 ,闭塞区内的pH值下降 ,C12 H2 5SO-4离子基本上不影响闭塞区溶液pH值的变化 ,C12 H2 5SO-4离子与Cl-离子向闭塞区内竞争迁移 .当在主体溶液中添加 0 .0 1mol/LC12 H2 5SO4Na时 ,C12 H2 5SO-4离子能有效地阻止Cl-离子向闭塞区的迁移 ,闭塞区内Cl-离子增浓倍数降低 .闭塞区内C12 H2 5SO-4浓度随主体溶液中C12 H2 5SO-4离子浓度的增加而增大 .对含一定浓度C12 H2 5SO-4的主体溶液 ,C12 H2 5SO-4离子向闭塞区的迁移量随时间延长而增大 ,而迁移速率则随时间的延长而降低 .极化曲线测试结果表明十二烷基硫酸钠为阴极型缓蚀剂 。
Simulated occluded corrosion cell(OCC) was used to study the changes of chemical state within the OCC of 304 stainless steel in neutral solution of 0.5 mol/L NaCl containing various SDS(sodium dodecyl sulphate) ion concentration at 50℃.Anodic polarizing occluded specimen to simulate reaction current between outer and inter of OCC.It was found that,when C 12 H 25 SO - 4 anion added into the bulk solution,it migrated into OCC,and the migration quantity increased with the concentration and the time,the migration rate decreased with the length of the time.C 12 H 25 SO - 4 was in competition with Cl - on migration,It can retard the migration of Cl - effectively above a certain concentration,The higher the concentration,the more the efficiency.C 12 H 25 SO - 4 can not retard pH fall but fell multiples of Cl - enrichment effectively above a certain concentration.SDS was anioning inhibitor, E b and E p were shifted towards positive potentials by the addition of C 12 H 25 SO - 4,indicating suppression of pit propagation.
出处
《中国腐蚀与防护学报》
CAS
CSCD
2002年第3期129-132,共4页
Journal of Chinese Society For Corrosion and Protection
基金
国家自然科学基金项目 (No .5 970 10 0 9)
国家重点基础研究发展规划项目 (No .19990 65 0)
关键词
闭塞电池
不锈钢
局部腐蚀
十二烷基硫酸根
occluded corrosion cell,304 stainless steel,localized corrosion,SDS
