摘要
模拟高温高压CO2腐蚀实验,通过失重法,结合扫描电镜(SEM)、能谱分析(EDS)和X射线衍射(XRD)等分析技术,研究了原油含水率对N80油套管钢和D级抽油杆(25Cr Mn VA)钢的超临界CO2腐蚀形态、腐蚀速率和腐蚀产物膜特征的影响规律。结果表明:在超临界CO2腐蚀环境中,材质对腐蚀速率具有重要影响。平均腐蚀速率转变的临界含水率,N80钢为75%,25Cr Mn VA钢为50%。腐蚀形态由全面腐蚀向局部腐蚀转变的临界含水率为50%,含水率在50%~75%范围内发生点蚀,含水率高于75%,主要发生台地腐蚀。
Effect of water content of crude oil on CO2 induced corrosion behavior of N80 steel and25 Cr Mn VA steel was investigated in a simulated high temperature and high pressured oil field environment. The corrosion rates of the steels were measured by mass loss method. SEM, EDS and XRD were employed to analyze the morphologies and characteristics of corrosion scales on the steels. The results indicate that the critical water content 75% corresponds to the abrupt change of average corrosion rate of N80 steel, but 50% to that of 25 Cr Mn VA steel. The critical water content50% may correspond to the transformation from uniform corrosion into local corrosion for the two steels. When the water content within a range 50%~75% pitting corrosion is the dominant mechanism of corrosion for the steels. However, the steels are suffered from the mesa-type localized attack when the water content higher than 75%.
出处
《腐蚀科学与防护技术》
CAS
CSCD
北大核心
2015年第1期73-77,共5页
Corrosion Science and Protection Technology
基金
十二五国家科技支撑计划项目(2012BAC24B03)资助
