SO_4^(2-)对X80管线钢在酸性红壤模拟溶液中腐蚀行为的影响

Influence of SO_4^(2-)on Corrosion Behavior of X80 Steel in Simulated Acid Red Soil Solution

采用动电位极化曲线、电化学阻抗谱(EIS)及三维视频显微镜技术研究了在酸性红壤模拟溶液中SO_4^(2-)对X80管线钢腐蚀行为的影响。结果表明:随着酸性红壤模拟液中SO_4^(2-)含量的增加,X80钢的腐蚀呈现出先减缓后明显加剧的趋势;在含5%(质量分数,下同)SO_4^(2-)的模拟溶液中,X80钢的腐蚀失重量最低、腐蚀电流密度最小。结合EIS分析表明:SO_4^(2-)的含量会影响X80钢的腐蚀行为,1%~5%SO_4^(2-)会阻碍Cl-在电极表面的吸附,减缓腐蚀;高含量的SO_4^(2-)会破坏电极表面膜的形成,使腐蚀加速。

The influence of SO4^2- on corrosion behavior of X80 pipeline steel in simulated acid red soil solution was investigated by analysis of potentiodynamie polarization curve, electrochemical impedance spectroscopy （EIS） and three-dimensional video microscopy. The results show that the corrosion rate of ）（80 steel firstly deereased and then substantially increased with the increase of SO4^2- concentration; when the mass fraction of SO4^2- was 5%, the weight loss and the corrosion current density of X80 pipeline steel were minimum. EIS results show that the concentration of SO4^2- could affect the corrosion behavior of X80 steel. When the mass fraction of SO4^2- was 1%- 5%, SO4^2- blocked the adsorption of Cl^- on the electrode surface, and slowed down the corrosion; the concentration of SO4^2- could damaged the film forming on the electrode surface, and then accelerated the corrosion rate.