Modeling the Current Distribution in Thin Electrolyte Films with Applications to Crevice Corrosion

The current distribution on an electrode covered by a thin electrolyte layer, where the current is fed from one edge, is analytically modeled. Separate solutions are presented for the Tafel and linear kinetics regimes. The model is applied to the cathodic region in crevice corrosion and provides the current density profiles and the total current capacity of the cathode in terms of the system parameters. The results agree well with numerical simulations. The conditions for the saturation of the cathodic current as well the trends in the variation of the cathode capacity as a function of electrode length are identified.