基于WBE阻抗技术研究缓蚀剂对碳钢管道垢下腐蚀的抑制行为  

Research on the Inhibition Behavior of Inhibitor on Under-Deposit Corrosion of Carbon Steel Based on Synergistic WBE Impedance Method

作　　者：闻小虎 石鑫[1,2] 吴雨乐[3] 蔡光义 董泽华 WEN Xiao-hu;SHI Xin;WU Yu-le;CAI Guang-yi;DONG Ze-hua(SINOPEC,Northwest Company of China Petroleum and Chemical Corporation,Urumqi 830011,China;Key Laboratory of Enhanced Oil Recovery in Carbonate Fractured-vuggy Reservoirs,CNPC,Urumqi 830011,China;School of Chemistry and Chemical Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]中国石油化工股份有限公司西北油田分公司防腐蚀研究所,新疆乌鲁木齐830011 [2]中国石油化工集团公司碳酸盐岩缝洞型油藏提高采收率重点实验室,新疆乌鲁木齐830011 [3]华中科技大学化学与化工学院,湖北武汉430074

出　　处：《材料保护》2021年第12期42-48,58,共8页Materials Protection

基　　金：国家自然科学基金面上项目(51771079);国家青年科学基金(52001127)资助。

摘　　要：基于碳钢丝束电极(WBE)与定频电化学阻抗技术,研究了不同缓蚀剂对碳钢沉积物下腐蚀的抑制机制。研究表明,由于葡萄糖酸锌对沉积物的低渗透性导致其只能在裸电极上形成保护膜,反而强化了沉积物垢内外的电偶效应,使垢下局部腐蚀更为严重;相反,NO_(2)^(-)能够渗透至沉积物内部,从而垢层内外电极均形成了保护。但由于NO_(2)^(-)在沉积物中的扩散速率受限,可能会导致沉积物下的局部浓度不够,在部分丝束电极表面形成了点蚀。基于WBE的定频阻抗、表面电位与电流扫描表明:碳钢丝束电极的腐蚀速率与电位、电流以及阻抗面分布具有较好的一致性,可以准确反映沉积物下的局部腐蚀程度,因此WBE阻抗扫描是一种有效的垢下腐蚀监测方法。Based on the carbon steel coordinated wire beam electrode(WBE)and constant-frequency electrochemical impedance scanning technology(CF-EIS),the inhibition mechanism of different inhibitors on the under-deposit corrosion of carbon steel was studied.Results showed that zinc gluconate could only form a protective film on the bare electrode due to its low permeability to the deposit,which would enhance the galvanic effect inside and outside the deposit and induce more serious localized corrosion under the deposit.NO_(2)^(-) could penetrate into the sediment,so that the electrodes inside and outside the scale layer were protected.However,the pitting corrosion of a few wire beam electrodes emerged,because of the limited diffusion rate of NO_(2)^(-) in the deposit leading the insufficient local concentration under the deposit.Additionally,the results of CF-EIS,surface potential and current scanning based on WBE showed that the corrosion rate of carbon steel wire beam electrode was in good consistency with potential,current and impedance surface distribution,which could accurately reflect the local corrosion degree under the deposit.Hence,the WEB impedance scanning could be considered as an effective method for monitoring corrosion under deposit.

关 键 词：沉积物下腐蚀 缓蚀剂 WBE阻抗技术 协同测试 腐蚀程度 

分 类 号：TG172[金属学及工艺—金属表面处理]