Simulation research on near-neutral electrochemical corrosion of ferrite–pearlite pipeline steel

Abstract

The problem of electrochemical corrosion of buried pipelines in near-neutral electrolytes leads to defects in or even fracture of oil and gas pipelines and the leakage of natural gas. Based on the principle of material diffusion and migration, the research object established an electrochemical corrosion model under the metallographic structure of pipes with ferritic–pearlitic pipeline steel. The results show that the most severe corrosion occurs at the center of the corrosion on the surface of the pipeline steel in a near-neutral corrosive environment. In addition, due to corrosion product accumulation, the material corrosion rate increased by about 38%. The electrolyte potential near the corrosion electrode is smaller, the ion concentration near the electrode is the highest, and the mass transfer phenomenon around the corrosion electrode is obvious. When the material undergoes metallographic corrosion, the corrosion is more severe. This research method can be used to predict the electrochemical corrosion occurring in the metal structure of buried pipelines and has some guidance for the assessment of the integrity of the external surface of buried pipes.