利用交流阻抗和动电位极化技术，在碱性硫化物溶液中，分别研究了阳极极化电位下Cl-对低碳钢钝化过程阻抗行为的影响，钝化膜临界孔蚀电位Eb与Cl-浓度的关系以及临界Cl-浓度随温度的变化。结果表明，在除氧的碱性硫化物溶液中，阳极极化的初期阻抗具有两个时间常驻数，随极化电位的升高，钝化膜逐步趋于完整；在点蚀的形成过程中，容抗弧半径逐渐变小，当极化电位为-600mV时容抗弧半径大幅度下降，并出现低频实部电感性收缩现象；在点蚀形成后的发展阶段，容Cl-浓度增加，电极表面的钝化颁向降低，临界孔蚀电位随Cl-浓度增加而线性正移。
The effects of Cl- on the AC impedance features of carbon steel under anodic polarization conditions, and the critical pitting potential (Eb) at different temperature have been investigated respectively by EIS and potentiodynamic polarizaton in alkaline solutions containing H2S.The results indicate that the carbon steel gets into stage of passivity with increasing of polarization potential at the initial stage of anodic polarization During the pitting initiation, the Nyquist diagram has a shrinkage of real part at low frequency and the polarization resistance sharply decreases.The Nyquist diagram is composed of two capacitive loops during the pits propagation.With increasing of polarization potential, the capacitive loop of high frequency disappwars.With increasing of Cl- concentration at different temperature, the passivity trend of mild steel decreases.The relationship beetween Eb and Cl- concentration at different temperature follows the Eb=a + blnCcl-
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