Cellular automaton simulations of surface corrosion damage evolution

The evolution of the corrosion damage on the surface of a metal in an aggressive environment is investigated in this article with a simple cellular automaton (CA) model defined at a mesoscopic scale. A diffusion control of the electrolyte species is assumed, and for such elementary physicochemical processes as mass transport, metal dissolution and passivation, simple interaction rules between the cells of the CA are defined. For a single pit, the curves of the equivalent radius via simulation time are obtained, while for multi-pits, the induction time for pit initiation is simulated as Weibull distribution, and the corrosion pits can be created on the metal surface stochastically by using random sampling to produce a number of initiation time samples. The corrosion damage on the surface can be simulated and the law of the surface corrosion damage ratio vs simulation time is investigated. The results show that CA is a feasible approach to model corrosion damage growth, which could be of practical importance in quantifying corrosion damage and predicting structural integrity.