The electrochemical characteristics of corrosion scale on P110 carbon steel

The properties of corrosion scale on P110 carbon steel in the saltwater solution containing CO2 have been examined by electrochemical impedance spectroscope (EIS). The change of electrode reaction process on the corrosion scale has been discussed in the present work. It is found that the corrosion rate decreases with the increasing of the experimental time, and the reducing tendency of corrosion rate becomes low as the experimental time was 72 hours, EIS results indicate that the polarization resistance increases gradually and the electrode reaction is controlled by both diffusion and activation in comparison with activation only at the beginning.