Understanding and probing progression of localized corrosion on inner walls of steel pipelines: an overview

Corrosion poses a major threat to the safety of transportation pipelines. Therefore, it is crucial to have an in-depth understanding of corrosion mechanisms in pipeline steels for the effective management of pipeline integrity. Conducting research on corrosion mechanisms relies on the use of efficient and reliable corrosion monitoring and analysis techniques. The advancements in corrosion monitoring techniques specifically designed for the localized corrosion monitoring were aimed to be introduced, and a comprehensive overview of recent progress in understanding the localized corrosion mechanisms in pipeline steels was provided. Based on the different corrosive environments encountered, the localized corrosion issues inside pipelines are classified into two categories: localized corrosion primarily influenced by electrochemical processes and localized corrosion controlled by both electrochemical and mechanical factors. Additionally, a thorough analysis of the synergistic effects between micro-cell and macro-cell currents, as well as the interplay of mechanics and electrochemistry is presented. Finally, recommendations for future research on the mechanisms of internal localized corrosion in pipelines are provided.