碳钢在模拟油田采出液中的缝隙腐蚀行为及机理研究  

Study of Crevice Corrosion Behavior and Its Mechanism of Carbon Steel in Simulated Oilfield Produced Fluid

作　　者：王勤英 吴亚飞 秦淑芝 西宇辰 董立谨 张华礼 李玉飞[3] 张智[2] 张进[1] 曾德智[2] 刘奇林 WANG Qin-ying;WU Ya-fei;QIN Shu-zhi;XI Yu-chen;DONG Li-jin;ZHANG Hua-li;LI Yu-fei;ZHANG Zhi;ZHANG Jin;ZENG De-zhi;LIU Qi-lin(School of New Energy and Materials,Southwest Petroleum University,Chengdu 610500,China;School of Petroleum and Gas Engineering,Southwest Petroleum University,Chengdu 610500,China;Engineering Technology Research Institute,PetroChina Southwest Oil and Gas Field Company,Deyang 618300,China;Sichuan Northwest Mining Area,PetroChina Southwest Oil and Gas Field Company,Mianyang 621000,China)

机构地区：[1]西南石油大学新能源与材料学院,四川成都610500 [2]西南石油大学石油与天然气工程学院,四川成都610500 [3]中国石油西南油气田分公司工程技术研究院,四川德阳618300 [4]中国石油西南油气田分公司川西北矿区,四川绵阳621000

出　　处：《材料保护》2023年第6期97-105,共9页Materials Protection

基　　金：国家自然科学基金(52174007,51801167);四川省科技厅省院省校合作项目(23SYSX0127)资助。

摘　　要：为研究Q235碳钢在不同缝隙宽度和环境温度下的缝隙腐蚀行为和机理,采用丝束电极(WBE)技术和电化学阻抗谱(EIS)技术分别研究了丝束电极的电流密度、极化电阻和腐蚀形貌的差异。结果表明:当缝隙宽度大于0.1 mm时,缝隙腐蚀特征不明显。当缝隙宽度为0.1 mm时,碳钢在25,40,60℃环境下浸泡初期的最大电流密度差值分别为1.24,19.90,7.20μA/cm^(2),浸泡72 h后最大电流密度差值分别仅为浸泡初期的41.9%、4.2%、11.9%。此外缝隙内外均发生电流的极性转换现象,说明Q235碳钢随浸泡时间的延长,逐渐由局部腐蚀向均匀腐蚀转变。升高温度增大了发生缝隙腐蚀的趋势,缝隙外的腐蚀最严重的原因是浸泡时间不够以及溶液电阻降的增加。FeOOH参与阴极反应导致电极由阳极转变为阴极,而金属的溶解反应导致电极阴极向阳极的转换。For studying the crevice corrosion behavior and mechanism of Q235 carbon steel under different crevice widths and environmental temperatures,wire beam electrode(WBE)technology and electrochemical impedance spectroscopy(EIS)technology were used to study the differences in current density,polarization resistance,and corrosion morphology of wire beam electrodes.Results showed that when the crevice width was greater than 0.1 mm,the corrosion characteristics of the crevice were not obvious.When the crevice width was 0.1 mm,the maxi⁃mum current density differences of carbon steel during the initial immersion at 25,40,and 60℃were 1.24,19.90,and 7.20μA/cm^(2),respectively,while the maximum current density differences after 72 h of immersion were only 41.9%,4.2%,and 11.9%of the initial immer⁃sions.In addition,the polarity conversion phenomenon of current occurred both inside and outside the crevice,indicating that Q235 carbon steel gradually transformed from local corrosion to uniform corrosion with the prolongation of immersion time.Moreover,increasing temperature could enhance the trend of crevice corrosion,and the causes of the most serious corrosion outside the crevice were insufficient soaking time and an increase in solution resistance drop.In general,FeOOH participating in the cathodic reaction caused the electrode to change from the anode to the cathode,while the dissolution reaction of the metal caused the electrode properties changing from the cathode to the anode.

关 键 词：Q235碳钢 丝束电极 缝隙宽度 温度 腐蚀机理 

分 类 号：TG172[金属学及工艺—金属表面处理]