Corrosion and Degradation of Materials in Marine Environments: Implications for Coastal and Offshore Infrastructure

Marine infrastructure, including offshore platforms, pipelines, and subsea cables, operates under the simultaneous influence of cyclic hydrodynamic loads and a corrosive marine environment, leading to complex material degradation and reduced structural reliability. In this study, material corrosion and degradation are examined not as isolated processes, but as key factors governing the fatigue behavior, crack initiation, and limit states of marine structures. It is demonstrated that localized forms of corrosion (pitting, crevice corrosion, and subsurface coating degradation) act as critical initiators of structural failure; indeed, even defects with a depth of merely 0.5–2 mm can significantly amplify stress concentration factors and reduce fatigue life by an order of magnitude. In the most aggressive zones of the marine environment (specifically the splash and tidal zones), corrosion rates can reach 0.5–1.5 mm/year, resulting in an accelerated transition from latent degradation to active structural failure. An integrated failure evolution framework is proposed, linking environmental conditions, corrosion mechanisms, and damage morphologies to their impact on structural response and failure probability. Unlike traditional approaches, which rely on averaged corrosion rates, this study emphasizes the critical role of localized defects as triggers for fatigue failure under cyclic loading conditions. Furthermore, a decision‐oriented approach is proposed for selecting protection and operational strategies; this approach integrates coating degradation analysis, cathodic protection, monitoring techniques, and residual life assessment. It is demonstrated that relying solely on a “corrosion allowance” is insufficient to ensure the reliability of structures susceptible to localized degradation. The obtained results establish an engineering foundation for integrating corrosion processes into tasks related to structural strength analysis, fatigue assessment, and the lifecycle management of offshore structures, including the optimization of inspections and service life extension.