中文摘要：

利用高温高压模拟实验、微观形貌观察和电化学测试研究了介质中Cl^-含量对J55钢CO2腐蚀行为的影响。结果表明，在研究范围内（Cl^-含量为0-200g／L），随Cl^-含量的增加，J55钢均匀腐蚀速率减小，腐蚀产物膜变得更加致密，对基体保护能力增强，且无明显局部腐蚀。Cl^-含量的变化没有改变电极反应活化控制步骤，但随含量增加，溶液的pH值降低，同时更多Cl^-占据阴极活性点，阻滞了阴极反应，提高了腐蚀电位。Cl^-含量较低时电化学阻抗谱呈现三个时间常数，随Cl^-含量增加，中低频区感抗弧逐渐消失，金属表面被完整的腐蚀产物膜覆盖。

英文摘要：

High temperature high pressure corrosion tests, microstructure observation and electrochemical tests were used to analyze the effects of Cl^- content on the CO2 corrosion of J55 steel. With Cl^- content increased up to 200 g/L in the solution, CO2 corrosion rate of J55 steel decreased, corrosion scale became much compact and localized corrosion not obvious. The primary rules of anodic and cathodic reactions do not change with the increase of Cl^- content, although the pH of the solution and the cathode reaction rate decreased. The electrochemical impedance spectroscopy characters have three time-loops in dilute Cl^- solutions, but the inductive arc disappeared in high Cl^-content solutions.