A THEORETICAL-STUDY OF AC-INDUCED CORROSION CONSIDERING DIFFUSION PHENOMENA

The effect of AC-induced voltages on corrosion systems was investigate d. Two cases were distinguished: the anodic and cathodic reactions wer e under activation control, the anodic reaction was under activation c ontrol and the cathodic reaction was under mixed control. For the firs t case simple relations could be derived that relate the AC-induced vo ltage with the corrosion potential and corrosion rate. For the second case numerical analysis was necessary to obtain these relations. It wa s shown that the influence of the AC-induced voltages on the corrosion behaviour strongly depended on the Tafel parameters. As the cathodic reaction was under mixed control the increase of the corrosion rate wa s limited to the diffusion-limited current density. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.