A numerical framework for the modeling of corrosive dissolution

We present in this work a numerical framework for simulating corrosive dissolution over long periods of time. Our proposed framework consists of three main elements: a novel dilute electrochemical model, a projective integration approach for obtaining the motion of the anodic front, and an adaptive remeshing scheme. One of the main challenges in modeling corrosive dissolution is the vast difference in the time scales involved. That is, ionic transport occurs at time scales that are many orders of magnitude smaller than the time scale at which the motion of dissolving fronts occurs. Based on the disparity of the time scales, we postulate that the evolution of the ionic distribution in the electrolyte as driven by a changing anodic front can be approximated as a sequence of steady states, effectively reducing the problem to a single time scale. With this simplification, we are able to use a simple explicit time integration scheme for determining the evolution of the dissolving anodes. We present demonstrative examples to show the capability of the proposed framework to capture complex electrochemical behavior in corroding systems when the motion of anodic fronts is considered.

► A framework for simulating corrosive dissolution is proposed.
► Combines an ionic transport model, projective integration, and adaptive remeshing.
► Time scale difference between ionic transport and anode front motion is addressed.
► Sensitivity of corrosion current to grain–grain boundary structure is demonstrated.