Diffusional Effects in Simulated Localized Corrosion

The importance of diffusion was investigated under potentiostatic dissolution conditions with wire electrodes contained in inert supports. The artificial cavities created simulated localized corrosion conditions. Current‐time behavior at voltages in excess of the critical pitting potential [>0.5V (SCE)] was examined for nickel and stainless steel specimens in concentrated chloride solutions. The effect of changing the concentration or activity gradient of the dissolving metal cations within the artificial cavity was studied by altering the composition of the bulk solution. Solutions of , , , , , , and ranging from 0.5 to 10M were used. Mass transfer models were developed for the observed transient and quasi steady‐state periods of dissolution.