在CO₂饱和水溶液中对X70、X80和X90管线钢进行电化学试验。使用COMSOL Multiphysics软件建立三电极体系的简化模型, 基于试验数据验证了模拟方法的适用性。最后建立X80管线钢弯管的几何模型, 对其进行电化学腐蚀模拟, 分析弯管表面电位和腐蚀电流密度分布, 及弯管不同部位的电流密度。结果表明: 弯管表面电位分布存在细微的差别, 弯管内弯侧比外弯侧电位更负, 电流密度更大, 更易遭到腐蚀破坏; 沿着流体流动方向, 弯管腐蚀速率先增大后减少, 弯管中后段腐蚀速率最大。

Electrochemical tests were carried out on X70, X80 and X90 pipeline steels in CO₂ saturated solution. A simplified model of three-electrode system was established using COMSOL Multiphysics software, and the applicability of the simulation method was verified based on experimental data. Finally, the geometric model of X80 pipeline steel elbow was established to simulate its electrochemical corrosion process, and the distributions of potential and corrosion current density on elbow surface were analyzed, as well as the current density on different parts of the elbow. The results show that there was a slight difference in the potential distribution on elbow surface. The inner side of the elbow had more negative potential and greater current density than the outer side of the elbow, and was more likely to be damaged by corrosion. Along the direction of fluid flow, the corrosion rate of the elbow increased first and then decreased, and the corrosion rate of the middle and later sections of the elbow was the largest.