Modeling and simulation of galvanic corrosion pit as a moving boundary problem

Abstract

In this article, the dynamics of pit formation during galvanic corrosion is modeled and simulated when two dissimilar metal surfaces are in contact forming an 180° joint. As a novel advancement to the analysis of galvanic junction currents, the galvanic corrosion is mathematically modeled as a moving boundary problem represented by Laplace equation for electric potential in the electrolyte and activation driven dissolution of anode surface. In addition to numerically solving for the galvanic current density distribution, we let the anode surface dissolve and perform the calculations in the pitted surface of anode. A linear model of polarization curve or the linear resistance model is applied as the activation boundary condition at the anode and cathode surfaces. The results on progression of pit shape and current density distribution with time are presented.