Effect of alternating voltage on corrosion of X80 and X100 steels in a chloride containing solution - Investigated by AC voltammetry technique

AC corrosion of the X80 and X100 steels in 0.1 M NaCl solution were studied by the AC voltammetry technique. Corrosion electrochemical kinetics and solid/solution interface structure changes under the influence of AC voltage were characterized. Results illustrate that corrosion potential of the two steels shift negatively with the increase of AC amplitude and decrease of AC frequency. The anodic processes are under charge-transfer control and the anodic Tafel slopes increase with the increase of AC magnitude. The cathodic processes are under diffusion control at low AC amplitudes, while they become increasingly under charge-transfer control with higher AC amplitudes.