Influence of pH on Electrochemical Behavior of X120 Steel in Simulated Yingtan Acidic Soil Solution

The influence of pH value and applied potential on the electrochemical behavior of X120 steel in Yingtan simulated soil solution was investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The results showed that the Ecorr decreased with the increase of pH value, except at pH=5.5. The electrode reaction resistance Rt at high pH values was higher than that at low pH values, indicating that the higher the pH value the greater the resistance to electrode corrosion. At the same pH value, Rt increased firstly and then decreased with decieasing the applied potential, reached the maximum at about -0.75 V. In addition, the influence of pH value on the electrochemical behavior, determined by either measuring the potentiodynamic polarization curves with fast and slow scan rates or EIS, was the same.