Three dimensional cellular automaton for simulation of the multi-pit corrosion damage evolution

A three-dimensional Cellular Automaton (CA) model is proposed to simulate the evolution of multi-pit corrosion damage on a metal exposed to an aggressive environment. In this model, some simple local rules between the cells of the CA are defined to describe the main elementary physicochemical processes: mass transport, IR drop, metal dissolution and passivation. The proposed model takes into account both pit initiation and growth processes. The pitting corrosion damage at different aggressive environment is obtained by performing the simulation using different simulation parameters. The surface corrosion damage ratio and the maximal depth of corrosion pits are chosen as the corrosion characteristic quantities, and the law of these corrosion characteristic quantities with respect to simulation steps is investigated. The results show that CA can be applied to model the evolution of corrosion damage on a three-dimensional lattice, and prediction of corrosion damage based on the local rules of CA would be of practical importance for the structural integrity evaluation.