Effect of Aggressive Anions on Corrision Behavior of A3 Steel

The corrosion behviors of A3 steel in water with different concentrations of Cl-, SO42-and S2-were studied by electrochemical impedance spectroscopy and polarization curves. The results show that Cl-, SO42-and S2-impact the corrosion of A3 steel greatly. At the same concentration, the corrosion rate could be ranked in the order of S2-> Cl-> SO42-. The corrosion potential shifted towards negative direction and the corrosion current increased gradually with the increase of S2-, Cl-and SO42-concentration. The impedance decreased and the corrosion increased. The corrosion rate of the mixed corrosive anions could be ranked in the order of S2-+ Cl-> SO42-+ S2-> SO42-+ Cl-.