The Use of Finite Element Methods (FEM) in the Modeling of Localized Corrosion

Abstract

. Typical forms of localized corrosion include crevice corrosion, pitting, stress corrosion cracking, and intergranular corrosion. 1 Localized corrosion represents the primary corrosion failure mode for passive/corrosion resistant materials. There has been extensive experimental characterization of the dependence of the susceptibility to corrosion on alloy and solution composition, temperature, and other variables. Computational modeling can play an important role in improving the understanding of localized corrosion processes, in particular when it is coupled with experimental research that accurately quantifies the important characteristics that control corrosion rate and resultant morphology. There are many modeling methods that can be applied, with the choice of method driven by the goal of the modeling exercise. Empirical models 2 can be used to predict performance within the parameter space for which they are created. Such models can provide insight into what kinds of processes might be dominating the corrosion process, but further dissection of controlling factors is more difficult. Numerical modeling, in which the concentration, potential, and current distributions are calculated, plays a role in helping to understand controlling factors. There are several numerical methods that have been implemented by corrosion scientists and engineers. Among these, the finite element method (FEM) has been the most widely used to investigate transport phenomena in systems undergoing. The finite element method (FEM) is a numerical technique used to obtain approximate solutions to the differential equations that describe a wide variety of physical phenomena, ranging from electrical and mechanical systems to chemical and fluid flow problems. Generally, FEM establishes credible stability criteria and provides more flexibility (e.g., in handling inhomogeneity and complex geometries) compared to other numerical modeling methods such as the finite difference method (FDM). The finite element approach in corrosion study was introduced in the early 1980s by Alkire, Forrest, and Fu. 3-5 The FEM approach has demonstrated an ability to predict electrochemical parameters such as potential and current distributions for localized corrosion.