交流杂散电流对埋地Q235钢腐蚀行为的影响  

Influence of Stray Alternating Current on Corrosion Behavior of Q235 Steel in Soil

作　　者：李晓[1,2] 李言涛[1] 蒋泓松[3] 刘建国[4] 侯保荣[1] 

机构地区：[1]中国科学院海洋研究所,山东青岛266071 [2]中国科学院研究生院,北京100049 [3]空军第六空防工程处,湖南衡阳421001 [4]中国石油大学(华东)储运与建筑工程学院,山东青岛266555

出　　处：《材料保护》2012年第5期28-31,86,共4页Materials Protection

基　　金：山东省优秀中青年科学家科研奖励基金计划(2008BS06011)

摘　　要：土壤腐蚀中的交流杂散电流对管线钢腐蚀严重,为了弄清其影响规律,在室内模拟埋地Q235管线钢所处环境及受交流杂散电流腐蚀状况,通过调节交流电压改变交流信号的强度,利用失重试验和电化学技术研究了交流杂散电流强度对Q235钢腐蚀行为的影响。结果表明:Q235钢在土壤中的腐蚀同时存在交流杂散电流腐蚀和电化学腐蚀,其中交流杂散电流腐蚀可加剧电化学腐蚀过程;随着杂散电流强度的增大,腐蚀程度大大增加;在交流杂散电流存在的情况下,随着所施加交流电压的增大,Q235钢腐蚀电位负移,腐蚀电流密度增大,塔菲尔斜率r(βa/βc)相应减小,易发生阳极反应;随着埋地时间的增加,Q235钢在土壤中的腐蚀速率先增大后减小,逐渐趋于稳定。The corrosion of Q235 pipeline steel in soil in the presence of stray alternating current(AC) was simulated indoor to investigate the effect of stray AC on the corrosion behavior of the steel by weight loss analysis and electrochemical measurement.It was found that the corrosion of Q235 steel in soil involved stray AC-induced corrosion and electrochemical corrosion,and the former could enhance the latter.The corrosion was greatly extended with increasing stray AC.In the presence of stray AC,the corrosion potential of Q235 steel shifted negatively and the corrosion current density rose with increasing AC.Relevant Tafel slope was reduced therewith,and the steel was liable to anodic reaction.Moreover,with extending time of burying in soil,the corrosion rate of Q235 steel initially rose but later declined and tended to stabilize.

关 键 词：土壤腐蚀 腐蚀速率 Q235钢 交流杂散电流 

分 类 号：TG172.4[金属学及工艺—金属表面处理]