侵蚀性阴离子对A3钢腐蚀电化学行为的影响

摘要

The corrosion behviors of A3 steel in water with different concentrations of Cl^-, SO4 ^2- and S^2- were studied by electrochemical impedance spectroscopy and polarization curves. The results show that Cl^-, SO4^2- and S^2- impact the corrosion of A3 steel greatly. At the same concentration, the corrosion rate could be ranked in the order of S^2- 〉 Cl^- 〉 SO4^2-. The corrosion potential shifted towards negative direction and the corrosion current increased gradually with the increase of S^2-, Cl^- and SO4^2- concentration. The impedance decreased and the corrosion increased. The corrosion rate of the mixed corrosive anions could be ranked in the order of S^2- ＋ Cl^-〉SO4^2- ＋ S^2-〉 SO4^2- ＋ Cl^-.%利用电化学阻抗谱和极化曲线研究了A3钢在不同浓度的Cl^-、SO4^2-、S^2-溶液中的腐蚀行为。结果表明，阴离子Cl^-、SO4^2-、S^2-对A3钢腐蚀速率影响较大。且在相同浓度下腐蚀速率的排序为：S^2-〉Cl^-〉SO4^2-。随着Cl^-、SO4^2-、S^2-浓度的增加，腐蚀电位负移，腐蚀电流逐渐增大，阻抗弧半径减小，阻抗减小，腐蚀加剧。混合的侵蚀性离子对A3钢腐蚀速率影响依次为：S^2-＋Cl^-〉SO4^2-＋S^2-〉SO4^2-＋Cl^-。