Modeling and Simulation of Damage Evolution during Crevice Corrosion

In this paper we report a computational method for determining the spatial and temporal evolution of damage during crevice corrosion. The model uses the potentiodynamic polarization data for nickel (Ni) in sulfuric acid and assumes well-mixed solution chemistry inside and outside the crevice, consistent with a pure IR model. Damage, potential and current profiles as well as other characteristic features of the crevice corrosion process are predicted. We describe for the first time how changing IR inside the crevice results in propagation away from the initiation site both toward the mouth and deeper into the crevice. To validate the model predictions we compare damage profiles from our model for Ni crevice corrosion with published experimental results. Since the model calculates the true crevice gap in real time, the results provide unique insight into the critical length to gap ratio necessary to propagate IR controlled crevice corrosion. (C) 2014 The Electrochemical Society. All rights reserved.