Machines. Technologies. Materials.
Vol. 20 (2026), Issue 3, pg(s) 108-110

TECHNOLOGIES

Cathodic Protection Modeling of Steels in Corrosive Chemical Environments Using COMSOL Multiphysics

  • 1 Babeș-Bolyai University, Cluj-Napoca, Romania

Abstract

This study investigates the electrochemical performance of Sacrificial Anode Cathodic Protection (SACP) systems for offshore steel structures using Finite Element Analysis (FEA). Two structural substrates, S235JR carbon steel and S550QL high-strength steel, were modelled in a 3 wt.% NaCl electrolyte. A comparative analysis was performed between two sacrificial anode materials: a conventional Al- 5Mg alloy and a quaternary Al-6Zn-0.2In-1Mg-0.03Ti alloy. The simulations evaluate the influence of anode placement errors by comparing an ideal symmetric distribution (90°) with a clustered configuration (10°). The results show that geometric clustering significantly alters the potential distribution along the structure. For S235JR steel, the clustered configuration produces localized underprotection with potentials reaching −0.78 V (vs. Ag/AgCl). In contrast, for S550QL steel, the same configuration results in localized over-polarization (≈ −0.96 V), thereby increasing the risk of hydrogen-induced stress cracking (HISC). The study demonstrates that improper anode placement may compromise cathodic protection efficiency even when high-performance anode alloys are used. These findings highlight the importance of accurate anode distribution and support the use of numerical simulations in digital twin approaches for offshore corrosion management.

Keywords

References

  1. J. Zhang, X. Wang, Digital Twins for Corrosion Management in Offshore Structures, Journal of Marine Science and Engineering, 10 (2022) 456.
  2. P.R. Roberge, Handbook of Corrosion Engineering, 3rd ed., McGraw-Hill Education, New York, 2019.
  3. DNV-RP-B401, Cathodic Protection Design, Det Norske Veritas (DNV), 2021.
  4. E. Bardal, Corrosion and Protection, Springer Science & Business Media, Trondheim, 2004.
  5. R. Javaherdashti, Corrosion Management in the Chemical Process Industries, CRC Press, 2015.
  6. L. Wright, S. Davidson, How to Tell the Difference Between a Model and a Digital Twin, Advanced Modeling and Simulation in Engineering Sciences, 7 (2020) 13.
  7. M. Sacco, A. Gualtieri, Industry 4.0 and the Digital Twin in Subsea Engineering, Ocean Engineering, 218 (2021) 108214.
  8. COMSOL Multiphysics® v. 6.2, Corrosion Module User's Guide, COMSOL AB, Stockholm, Sweden, 2024.
  9. EN ISO 15589-2:2014, Petroleum, petrochemical and natural gas industries — Cathodic protection of pipeline systems — Part 2: Offshore pipelines, International Organization for Standardization.
  10. ASTM D1141-98, Standard Practice for the Preparation of Substitute Ocean Water, ASTM International, West Conshohocken, PA, 2021.
  11. M.H. Sharqawy, J.H. Lienhard V, S.M. Zubair, The thermophysical properties of seawater: A review of existing correlations and data, Desalination and Water Treatment, 16 (2010) 354-380.
  12. J. Zhang, Z. Zhang, and W. Wu, "Effects of Anode Proximity and Geometric Clustering on CP Interference in Offshore Structures," Ocean Engineering, vol. 245, p. 110482, 2022.
  13. ISO 15589-2:2024, "Petroleum, petrochemical and natural gas industries — Cathodic protection of pipeline systems — Part 2: Offshore pipelines," International Organization for Standardization.
  14. W. H. Hartt and N. K. Lin, "Hydrogen Induced Stress Cracking of Steels with CP in Marine Environments," Corrosion, vol. 63, no. 1, pp. 58–69, 2007.
  15. A. W. Peabody, Peabody's Control of Pipeline Corrosion, 2nd Edition, NACE International, 2001
  16. L. Wang, R. G. Buchheit, "Digital Twins for Corrosion: A Review of the State of the Art and Future Perspectives," Corrosion Science, vol. 189, p. 109591, 2021.
  17. S. Rossi and M. Fedel, "Smart Coatings and Cathodic Protection: Towards Industry 4.0 Digital Twins," Coatings, vol. 10, no. 7, p. 642, 2020.

Article full text

Download PDF