N80钢在CO_(2)、H_(2)S及其混合介质环境中的腐蚀行为研究  

Study on Corrosion Behavior of N80 Steel in CO_(2), H_(2)S and Mixed Medium Environment

作　　者：赵国仙[1] 张思琦 王映超 宋洋 郭梦龙 ZHAO Guoxian;ZHANG Siqi;WANG Yingchao;SONG Yang;GUO Menglong(School of Materials Science and Engineering,Xi’an Shiyou University,Xi’an 710065,China;Xi’an Maurer Petroleum Engineering Laboratory Co.,Ltd.,Xi’an 710065,China)

机构地区：[1]西安石油大学材料科学与工程学院,西安710065 [2]西安摩尔石油工程实验室股份有限公司,西安710065

出　　处：《焊管》2022年第3期7-12,共6页Welded Pipe and Tube

摘　　要：针对N80钢油套管在CO_(2)/H_(2)S共存环境中的腐蚀问题,利用失重法与电化学测试方法作对比分析,并利用扫描电子显微镜以及X射线衍射仪对浸泡腐蚀试验后的N80钢试样进行研究。结果显示,浸泡腐蚀试验结果与电化学测试结果一致,在单独CO_(2)环境中,N80钢的自腐蚀电流与平均腐蚀速率最大,腐蚀最严重;在单独H_(2)S环境中,N80钢试样腐蚀速率最小,自腐蚀电流最小;在P_(CO_(2))/P_(H_(2)S)=1∶0.3时,主要以H_(2)S腐蚀为主,但在表面发生局部产物膜剥落,此时的腐蚀速率高于纯H_(2)S条件下的腐蚀速率。研究表明,在单独CO_(2)环境中,腐蚀以阴极反应过程控制为主;在单独H_(2)S环境中,腐蚀以阳极反应过程控制为主;在P_(CO_(2))/P_(H_(2)S)=1∶0.3时,腐蚀以阴极反应过程控制为主。Aiming at the corrosion problem of N80 steel oil casing in CO_(2)/H_(2)S coexistence environment,the weight loss method and electrochemical test method are compared and analyzed,and the N80 steel samples after immersion corrosion test are studied by scanning electron microscope and X-ray diffraction.The results show that the immersion corrosion test results are consistent with the electrochemical test results.In the CO_(2) environment,the self corrosion current and average corrosion rate of N80 steel is the largest and the corrosion is the most serious.In H_(2)S environment,N80 steel sample has the lowest corrosion rate and the lowest self corrosion current.When P_(CO_(2))/P_(H_(2)S)=1∶0.3,it is mainly H_(2)S corrosion,but local product film peeling occurs on the surface.At this time,the corrosion rate is lower than that under H_(2)S.This shows that in the CO_(2) environment,the corrosion is mainly controlled by the cathode reaction process;In H_(2)S environment,the corrosion is mainly controlled by cathode reaction process;When P_(CO_(2))/P_(H_(2)S)=1∶0.3,the corrosion is mainly controlled by cathode reaction process.

关 键 词：油套管 CO_(2)腐蚀 H_(2)S腐蚀 N80钢 腐蚀速率 孔蚀 

分 类 号：TG174.3[金属学及工艺—金属表面处理]