New phase field model for simulating galvanic and pitting corrosion processes

This manuscript presents a new phase field model for simulating galvanic and pitting corrosion phenomena in metallic materials. The Laplace equation is employed to approximate the electric potential distribution, which determines the phase evolution by relating the anodic current density to the interface kinetics parameter. While the anode is assumed to be nonpolarizable, the nonlinear polarization behavior including the diffusion-limited kinetics is considered as boundary condition on the cathode. Several numerical examples are presented to verify the accuracy of the proposed model. We also demonstrate the application of this model for simulating coupled galvanic-pitting corrosion processes in a hybrid joint and an aluminum composite material under varying environmental conditions. The last example simulates the corrosion of a steel wire, which shows the feasibility of incorporating homogeneous chemical reactions and polarization behavior on the anode into the proposed model. (c) 2017 Elsevier Ltd. All rights reserved.