高温高压CO_(2)环境中超级13Cr不锈钢点蚀有限元模拟

Finite Element Simulation of Pitting Corrosion of Super 13Cr Stainless Steel in High-temperature and High-pressured CO_(2)Containing Artificial Formation Waters

采用腐蚀浸泡实验和有限元模拟研究了超级13Cr不锈钢在高温高压CO_(2)环境中的点蚀行为,重点分析了腐蚀时间、温度和CO_(2)分压对点蚀的影响。结果表明:高温高压腐蚀实验与有限元模拟的点蚀深度较为吻合,且平均点蚀深度随着浸泡时间、温度和CO_(2)分压的增大而增大。有限元模拟可知点蚀坑内部由于阳离子水解使得内部酸化,并且pH随着温度降低和CO_(2)分压的增加而下降。此外,点蚀坑内Fe^(2+)浓度随着腐蚀时间的延长和温度的提高而增加,但CO_(2)分压对其影响不大。

The pitting growth behavior of super 13Cr stainless steel in high-temperature and highpressured CO_(2)containing artificial formation waters was comparatively assessed via immersion corrosion test and finit element simulation,focusing on the effect of corrosion time,temperature and partial pressure of CO_(2)on pitting corrosion.The results show that the pitting depth of super 13Cr stainless steel after high-temperature and high-pressure corrosion tests is consistent with that of finite element simulation,and the average pitting depth increases with the increase of immersion time,temperature and CO_(2)partial pressure.The finite element simulation shows that the interior of the pit is acidified due to cationic hydrolysis,and the pH value decreases with the decrease of temperature and the increase of CO_(2)partial pressure.In addition,Fe^(2+)concentration inside the pit increases with the increase of corrosion time and temperature while the partial pressure of CO_(2)has little effect.