目的 针对热采过程中生产阶段和焖井阶段的典型温度工况条件，研究80 ℃与140 ℃温度下N80套管钢在不同CO2分压下的腐蚀电化学行为。方法 利用高温高压电化学设备，采用三电极体系进行动电位极化曲线和电化学阻抗谱（EIS）的测试，并采用ZSIMPWIN软件对电化学阻抗谱测试结果进行拟合分析。利用高温高压反应釜进行腐蚀模拟实验，并使用扫描电子显微镜（SEM）进行腐蚀产物微观形貌观察。结果 在80 ℃与140 ℃条件下，N80钢在CO2分压0.5~4.0 MPa条件下的腐蚀均为阴极控制，随CO2分压的增大，腐蚀电位Ecorr正移，腐蚀电流密度Jcorr增大。80 ℃下N80钢的电化学阻抗谱呈现3个时间常数，为高频容抗弧、中低频感抗弧和低频容抗弧；温度升至140 ℃后，N80钢电化学阻抗谱中感抗弧消失，呈现2个时间常数，为高频容抗弧与低频容抗弧。结论 通过阻抗谱拟合结果对比及对浸泡实验试样腐蚀产物的微观形貌观察发现，温度升高后，腐蚀产物膜电阻Rc与电荷传递电阻Rt增大，孔隙率降低，对基体的保护性增强。

The work aims to study the corrosion electrochemical characteristics of N80 casing steel under different CO2 partial pressures at 80 ℃ and 140 ℃ for the typical temperatures in the recovery stage and sock stage in thermal recovery process. Potentiodynamic polarization curves and electrochemical impendence spectroscopy (EIS) were tested by high temperature and high pressure electrochemical autoclave with three-electrode system. The results of the electrochemical impedance spectroscopy were fitted and analyzed with ZSIMPWIN. Corrosion simulation test was conducted by high temperature and high pressure autoclaves, and the microstructure of corrosion scale was observed by scanning electron microscope (SEM). At 80 ℃ and 140 ℃, the corrosion of N80 steel under CO2 partial pressure 0.5~4.0 MPa was controlled by cathode. As CO2 partial pressure increased, the corrosion potential shifted positively and the corrosion current density increased. The EIS plots of N80 steel at 80 ℃ presented three time constants, capacitance loop in high frequency, inductance loops in mid-low frequency, and capacitance loops in low frequency. However, the inductance loops in mid-low frequency disappeared when the temperature reached 140 ℃ and only two time constants existed, capacitance loop in high frequency and capacitance loop in low frequency. Through the comparison of fitting results in EIS and the microstructure of corrosion product in immersed experimental sample, the corrosion scale resistance Rc and the charge transfer resistance Rt increases as the temperature rises, the porosity of corrosion scale decreases and the corrosion scale enhances the protection to the substrate.