2830/140V油套管钢的电偶腐蚀行为  

Galvanic Corrosion Behavior of 2830/140V Oil Casing Steel

作　　者：赵国仙[1] 高明忍 ZHAO Guoxian;GAO Mingren(School of Materials Science and Engineering,Xi'an Shiyou University,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

出　　处：《焊管》2020年第10期8-16,共9页Welded Pipe and Tube

摘　　要：为研究140V碳钢和2830镍铬合金钢之间的电偶腐蚀行为,通过模拟150℃、H2S分压1.5 MPa、CO2分压4.5 MPa、Cl-浓度90000 mg/L的地层水井下环境,采用浸泡腐蚀模拟试验,并利用XRD结合SEM、EDS观察分析腐蚀产物膜特征,研究了2830镍铬合金钢与140V碳钢在模拟地层水环境中偶接前后的电偶腐蚀行为。结果表明:在模拟地层水腐蚀环境下,2830镍铬合金钢与140V碳钢偶接后,发生了明显的电偶腐蚀,其中碳钢140V作为偶对体系的阳极,平均腐蚀速率明显增长,而镍铬合金钢2830作为阴极,平均腐蚀速率有所减缓。XRD检测结果表明,2830钢试样表面生成主要是内部基体的Fe-Ni固溶体、Cr-Ni固溶体、Fe及Ni的腐蚀产物膜,140V钢试样表面则主要是FeS、FeS2、FeCO3及Fe3O4的腐蚀产物膜。电偶腐蚀评价研究表明镍铬合金钢+碳钢组合电偶腐蚀较严重,在油套管应用中应避免直接接触使用。In order to study the galvanic corrosion between140 V carbon steel and 2830 Ni-Cr alloy steel,by simulating formation water subsurface environment with 150℃,H2 S partial pressure 1.5 MPa,CO2 partial pressure 4.5 MPa and Clconcentration 90000 mg/L,the immersion corrosion simulation test was carried out,and the characteristics of the corrosion products were observed and analyzed by XRD,SEM and EDS,the galvanic corrosion behavior of 2830 Ni-Cr alloy steel and140 V carbon steel before and after coupling in simulated formation water environment was studied.The results show that under the simulated formation water corrosion environment,the galvanic corrosion of 2830 Ni-Cr alloy steel and 140 V Carbon steel occurs obviously,in which the average corrosion rate of carbon steel 140 V as the anode of the coupling system increases obviously,while that of 2830 Ni-Cr alloy as the cathode decreases somewhat.XRD test results show that Fe-Ni solid solution,Cr-Ni solid solution,the corrosion product film with internal matrix are mainly generated on the surface of 2830 sample,while the corrosion product film of FeS,FeS2,FeCO3 and Fe3O4 are mainly used on the surface of 140 V sample.The galvanic corrosion evaluation shows that the galvanic corrosion of Ni-Cr alloy steel and carbon steel is serious,so direct contact should be avoided in oil casing application.

关 键 词：电偶腐蚀 镍铬合金钢 碳钢 地层水环境 

分 类 号：TG174.36[金属学及工艺—金属表面处理]