An overview of recent progresses in probing and understanding corrosion under disbonded coatings

• Published in: Corrosion Engineering, Science and Technology Vol. 58; no. 4; pp. 323 - 332
• Main Authors: Tan, Mike YJ, Bob Varela, Facundo, Huo, Ying
• Format: Journal Article Book Review
• Language: English
• Published: London, England Taylor & Francis 19.05.2023; SAGE Publications
• Subjects: cathodic protection; corrosion monitoring; corrosion under disbonded coatings; electrochemical probe; Localised corrosion; pipeline corrosion; Localised corrosion; corrosion monitoring; electrochemical probe; pipeline corrosion; cathodic protection; corrosion under disbonded coatings
• ISSN: 1478-422X; 1743-2782
• DOI: 10.1080/1478422X.2023.2182458

Corrosion under disbonded coatings (CUDC) remains a major unsolved issue and a prime risk to underground steel structures such as buried gas pipelines. CUDC could not be effectively mitigated by conventional cathodic protection (CP) or be detected through usual inspection and survey technologies due to CP shielding. This article provides a brief review of recent progresses made through laboratory and field probing of CUDC and its influence factors. Discussions on CUDC processes and mechanisms are made based on results from an extensive laboratory and field-testing program using electrode array-based corrosion probes. It is shown that CUDC is affected not only by well-known factors such as the CP level, but also by coating disbondment geometry and soil conditions especially the seasonal dry-wet changes in soil saturation status. These findings have led to improved understanding of CUDC, and could lead to the development of better CUDC mitigation and control methods.