3D Cellular Automata–Based Numerical Simulation of Atmospheric Corrosion Process on Weathering Steel

In order to reproduce the atmospheric corrosion process of weathering steel (WS), a three-dimensional (3D) cellular automata (CA) based method is proposed. Firstly, the atmospheric corrosion mechanism of WS is described. Basic assumptions are made with the purpose of simplifying the complicated corrosion process. The evolution rules of atmospheric corrosion are then proposed and the software program is developed. Secondly, the results obtained from the CA model are compared with the basic corrosion laws verified by several experiments. Results show that the basic hypotheses and evolution rules are reasonable and the model is reliable, and thus can be used to describe and to identify the corrosion kinetics, corrosion morphology, and distribution characteristics of pits for WS in atmosphere. Finally, the parameter analysis is performed and the relationship between CA model and atmospheric exposure test is established to achieve the model application. Based on the relationship, the CA model can be used to continuously predict the corrosion behaviors of WS in the long-term atmospheric corrosion process. Good agreement is obtained between the experimental and numerical results.