Three dimensional discrete stochastic model of occluded corrosion cell

•Quantitative modeling of occluded corrosion using stochastic discrete model.•Special emphasis given to the connection between anodic and cathodic reactions.•Two regimes are evidenced and controlled by diffusion.

We present a stochastic three dimensional (3D) model for corrosion at a mesoscopic scale. The competition between uniform and localized corrosion is studied, with special emphasis given to the connection between the anodic and cathodic reactions. Even if the reactions happen at different places, they are linked and occur simultaneously, maintaining an electric balance. We focused on the particular case of an occluded corrosion on a metal covered by a non reactive layer, where two growth regimes are evidenced and controlled by the diffusion of species in the electrolyte.