O_2对CO_2环境中P110钢应力腐蚀开裂的影响  

Effect of O_2 on Stress Corrosion of P110 Steel in CO_2 Environment

作　　者：胡静思[1] 任呈强[1] 鲍明昱 雷梦莺 刘丽[1] 王丰[1] 王书亮[1] HU Jingsi;REN Chengqiang;BAO Mingyu;LEI Mengying;LIU Li;WANG Feng;WANG Shuliang(School of Materials and Engineering,Southwest Petroleum University,Chengdu 610500)

机构地区：[1]西南石油大学材料科学与工程学院,成都610500

出　　处：《材料导报》2017年第A01期506-509,513,共5页Materials Reports

基　　金：国家自然科学基金(51374180);能源材料电化学科研创新团队(2015CXTD04)

摘　　要：近年来某些油田采用注N2提高采收率技术,由于现场制N2不纯,溶入大量的O_2,给油管套钢造成严重腐蚀,其中又以应力腐蚀开裂(SCC)危害最为严重。采用慢应变速率拉伸(SSRT)试验和扫描电镜(SEM)分析方法,研究了在3.5%NaCl溶液中充入纯CO_2、10%O_2+90%CO_2、50%O_2+50%CO_2、纯O_2条件下P110钢SCC的行为和特征。通过应力-应变曲线计算SCC的综合敏感性指数(ISSRT),发现CO_2环境中P110钢SCC敏感性指数最小,随着O_2含量的增加,SCC敏感性指数增大,表明SCC的程度逐渐严重。随着O_2含量的增大,P110钢断口准解理脆性特征愈加明显。由此可知,O_2促进了CO_2环境中P110钢SCC断裂的发生。In recent years,oil recovery technology was improved by injection of N2.However,large amount of O2 generated in the in-situ(or on-site)preparation of N2 causes serious corrosion of the tubing steel,among which stress corrosion cracking(SCC)is most damaging.In the present work,we studied and evaluated the behavior and characteristic of the corrosion process in a simulated environment.Particularly,SCC of P110 steel in a 3.5%NaCl solution filled with pure O2,50%O2+50%CO2,10%O2+90%CO2 and pure CO2 were respectively studied by slow strain rate test(SSRT)and scanning electron microscopy(SEM).The SCC sensitivity index(I SSRT)of P110 steel was obtained from stress-strain curve.It was found that the SCC sensitivity index of P110 steel is the smallest in CO2 environment,whereas it increased with increasing amount of O2,indicating a growing extend(or degree)of SCC.As the content of O2 increasing,the typical characteristics of the quasi-cleavage brittle fracture for P110 steel became more and more obvious.It can be concluded that the stress corrosion cracking of P110 steel in CO2 environment was accelerated by O2.

关 键 词：P110钢 氧气 二氧化碳 慢应变速率拉伸 

分 类 号：TG115.7[金属学及工艺—物理冶金] TG172.3[金属学及工艺—金属学]