X70钢在模拟酸雨溶液中腐蚀行为的研究

Corrosion behaviors of X70 steel in simulated acid rain solution

利用极化曲线技术、电化学阻抗测试技术等方法,研究了X70钢在模拟酸雨溶液中的腐蚀行为.实验结果表明,随着溶液酸度的增加,X70钢的腐蚀电位负移,腐蚀速率增加.在模拟酸雨溶液的pH值为5.0～4.5时,X70钢的阻抗谱为单一的偏心半圆容抗弧;pH值为4.0～2.5时,X70钢的阻抗谱表现为高频的容抗和低频的感抗弧,X70钢在模拟酸雨溶液中的腐蚀受电荷传递过程控制.

The corrosion behaviors of X70 steel in a simulated acid rain solution were studied by using polarization curve technique, electrochemical impedance spectroscopy （EIS）. It was found that the corrosion rate of X70 steel increases and the corrosion potential shifts to negative value with decreasing pH value of solution. Electrochemical impedance diagram has a capacitivearc for the solution of higher pH value（5.0 and 4.5）. EIS consists of a capacitive loop at higher frenquency and an inductive loop at lower frenquency for the solution of higher pH value（4.0--2.5）. The control step for corrosion of X70 steel is charge transfer process.