含Cr钢筋在水泥萃取液中的电化学腐蚀行为

Electrochemical Corrosion Behavior of Cr Modified Steel Rebars in Cement Extract Solution

利用极化曲线和交流阻抗谱研究比较了基材HRB400及添加不同Cr含量的3种钢筋在氯离子浓度不同的水泥萃取液中的腐蚀行为;利用Mott-Schottky理论研究了4种钢筋钝化膜的半导体特性.结果表明:在同一腐蚀溶液中,随着钢筋中Cr含量的增加,钢筋腐蚀电流密度减小、钝化区间和极化电阻增大、钝化膜稳定性增强,钢筋耐腐蚀性能提高;随着溶液中氯离子浓度增大,钢筋腐蚀电流密度增大、钝化区间和极化电阻减小、载流子密度增大,钢筋耐腐蚀性能降低;Cr合金化的钢筋具有相对较好的耐蚀性.

Electrochemical corrosion behavior of HR]3400 and three Cr modified steel rebars in cement ex- tract solution with different chloride concentrations were estimated by potentiodynamic polarization curves and electrochemical impedance spectroscopy（EIS） ; semiconductor properties of passivation film of the four steel rebars were studied by Mott-Schottky（M-S） theory. The results show that with the increasing of Cr in the steel rebar, the corrosion current density decreases, passivation interval and polarization resistance increase, and the passivation film stability is enhanced, which indicates that the corrosion resistance of steel rebar is improved. In addition, increase of chloride concentration in cement extract solution leads to increase of the corrosion current density, decrease of the passivation interval and polarization resistance, and significant increase of the carrier density, while the corrosion resistance of steel rebar is decreased. Cr modified steel rebars have higher corrosion resistance than HRB400.