Numerical Simulation and Prediction of Corrosion Behavior of Low-Carbon Steel Under Different Salt Spray Concentrations Based on Cellular Automata

The rate of corrosion weight loss of low-carbon steel under different salt spray concentrations was analyzed by salt spray tests. It was observed that the solubility of O₂ in the salt spray initially increased, followed by a decrease, as the concentration of salt spray increased. The highest solubility of O₂ was observed at 5% NaCl salt spray concentration. Specifically, in the initial stages of corrosion, a higher salt spray concentration led to a faster weight loss rate of low-carbon steel, the corrosion rate being primarily controlled by the Cl⁻ concentration. During the later stages of corrosion, a higher O₂ concentration led to a faster rate of corrosion weight loss, the corrosion rate being primarily controlled by the diffusion rate O₂. These experimental results were compared to simulations using the cellular automata (CA) method including the mechanism of oxide film shedding, mechanism of pit evolution, and mechanism of rust layer shedding, leading to the prediction of the corrosion life of low-carbon steel under various salt spray concentrations. This method not only effectively simulated and verified the corrosion behavior of low-carbon steel but also offers an effective approach for the prediction of the service life of low-carbon steel.