Simulation of Metallic Soil Corrosion Behavior and Corrosion Product Layer Based on Cellular Automata

Abstract

As the oil and gas pipelines are mostly laid underground, the pipeline metals are easy to be corroded due to its contact with the soil. For solving this problem, the cellular automata method was applied to construct a dynamic model of metallic soil corrosion, which took into account the key influencing factors such as soil water content, oxygen content and resistivity. With the help of this model, the soil corrosion behavior was simulated for the conditions with different water contents (C), corrosion dissolution probabilities (Pw) and diffusion probabilities (Pd). Results showed that with the increase of soil moisture, the metallic soil corrosion rate increased first and then decreased. With the increase of diffusion probability (Pd), the critical water content corresponding to the highest corrosion rate (Ct) decreased, indicating that the diffusion of water and oxygen dominated the corrosion rate. This was consistent with the actual process of soil corrosion, so it proved that the proposed model could provide a relatively accurate simulation of the soil corrosion behavior.

Keywords

• metallic soil corrosion|cellular automata|corrosion product layer|water content|corrosion rate