Corrosion Inhibitor Coatings and Durability Improvement in Offshore Steel Structures

Abstract

The structural integrity and operational longevity of offshore steel platforms are perpetually threatened by severe marine corrosion, necessitating advanced mitigation strategies. While corrosion inhibitor coatings have demonstrated substantial efficacy in mitigating electrochemical degradation at the microscale, their macroscopic impact on long-term structural durability remains challenging to quantify through empirical observation alone. This paper investigates the explicit linkage between the application of advanced corrosion inhibitor coatings and the consequent improvement in the load-bearing durability of offshore steel structures using comprehensive Finite Element Modeling. By coupling mass transport phenomena with elastoplastic structural mechanics, a high-fidelity numerical framework is developed to simulate the time-dependent degradation of offshore tubular joints over a projected quarter-century operational lifespan. The simulation models the barrier properties and active inhibition mechanisms of the coatings against aggressive chloride ingress and subsequent localized pitting. Comparative analyses between uncoated, conventionally coated, and inhibitor-enhanced models reveal that the presence of active inhibitors drastically alters the spatiotemporal evolution of stress concentrations at critical weld toes. The numerical evidence indicates a significant delay in the onset of critical micro-crack formation and a remarkable retention of ultimate structural capacity. The findings provide a rigorous theoretical and computational validation for the integration of active corrosion inhibitors into lifecycle management strategies for marine infrastructure.