Cl^-浓度对X80管线钢在CO_3^(2-)-HCO_3^-溶液中电化学腐蚀行为的影响  

Effect of Concentrations of Cl^- on Corrosion Behavior of X80 Pipeline Steel in the CO_3^(2-)-HCO_3^- Solutions

作　　者：肖辉宗 谢飞[1] 吴明[1] 王丹[1] 赵威 郭大成 吴蒙 XIAO Hui-zong;XIE Fei;WU Ming;WANG Dan;ZHAO Wei;GUO Da-cheng;WU Meng(College of Petroleum Engineering, Liaoning Shihua University, Fushun 113001, China;Liaoning Haitai Science and Technology Development Company Limited, Fushun 113001, China;China Petroleum Liaohe Oilfield Gathering Technology Company, Panjin 124010, China;PetroChina Fushun Petrochemical Company, Fushun 113001, China)

机构地区：[1]辽宁石油化工大学石油天然气工程学院,辽宁抚顺113001 [2]辽宁海泰科技发展有限公司,辽宁抚顺113001 [3]中国石油辽河油田集输技术公司,辽宁盘锦124010 [4]中国石油抚顺石化公司,辽宁抚顺113001

出　　处：《材料保护》2018年第3期56-60,共5页Materials Protection

基　　金：国家自然科学基金资助项目(51574147;51604150)

摘　　要：随着高强度管线钢广泛应用于油气管道输送领域,长距离埋地管道腐蚀现象越发明显。为了探究Cl^-与CO_3^(2-)-HCO_3^-共同作用下高强度钢的腐蚀行为,利用动电位极化及交流阻抗技术研究X80钢在不同浓度Cl^-的0.05 mol/L Na_2CO_3+0.10 mol/L NaHCO_3溶液中的电化学特征,并结合金相显微镜对X80钢的腐蚀形貌进行表征。结果表明:X80管线钢在不同浓度Cl^-的0.05 mol/L Na_2CO_3+0.10 mol/L NaHCO_3溶液中,其极化曲线呈现典型的活化-钝化-再活化特征;当Cl^-浓度由0 mol/L增大至0.09 mol/L时,X80钢的腐蚀速率呈现逐渐增大的趋势;当Cl^-浓度为0 mol/L时,试样表面腐蚀反应受阻,腐蚀现象较弱,只有几个小的腐蚀坑存在;当Cl^-浓度为0.09 mol/L时,极化电阻Rp出现最小值,此时X80管线钢的腐蚀现象最严重;溶液中的Cl^-吸附在X80钢表面会加速金属腐蚀反应的进行。In order to study the corrosion behaviors of high strength pipeline steel under combination effect of Cl-, CO3^2- and HCO3^-, the elec- trochemical characteristics of X80 steel were evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy in 0.05 mol/L Na2CO3＋ 0.10 mol/L NaHCO3 solution with various C1- concentrations, and the corrosion morphologies were observed by metallographic microscope. Results showed that the polarization curves of XS0 pipeline steel had typical activatiun-passivation-reactivation features in 0.05 mol/L Na2CO3＋0.10 mol/L NaHCO3 solution. As Cl- concentration increased, the corrosion rate of X80 steel increased gradually. When Cl^- concentration increased from 0 mol/L to 0.09 mol/L, the corrosion rate of X80 steel was on an ascending trend. When Cl- concentration was 0 mol/L, the surface corrosion reaction on steel surface was blocked, and the corrosion phenomenon was very slight, observing only several tiny corrosion pits. When Cl- concentration was 0.09 mol/L, the polarization resistance （Rp） was the minimum, and the corrosion phenomenon of XS0 was the most serious. Therefore, the solution containing Cl- ions that was adsorbed on the surface of X80 steel could accelerate the metal corrosion process.

关 键 词：X80管线钢 腐蚀行为 电化学 高pH值模拟溶液 CL^-浓度 

分 类 号：TG174.4[金属学及工艺—金属表面处理]