Nonlocal modelling of temperature-dependent electrochemical corrosion using peridynamic operator method

A nonlocal nonlinear temperature-dependent electrochemical corrosion model is proposed in this paper. The corrosion process is described by the concentration of ions controlled by diffusion and electromigration, and the influence of temperature is taken into consideration as well. The weak form of governing equations is obtained by using the weighted residual method which is then reformulated in their nonlocal form by using the peridynamic operator method. Numerical examples of galvanic corrosion and pitting corrosion illustrate that the model is capable of determining the corrosion rate quantitatively and capturing the moving interface of corrosion naturally. The influence of temperature and inert inclusions on diffusivity and electrical conductivity are discussed as well, leveraging the advantages of peridynamics in directly solving discontinuous problems. The 2D and 3D simulation results both indicate that an elevated temperature accelerates corrosion, and the non-uniform temperature distributions lead to the formation of different pitting corrosion morphologies.