Corrosion and Fatigue in Marine Welds

This chapter delves into the degradation mechanisms that threaten the durability of welded joints in marine environments. It begins with an overview of the types of corrosion general, galvanic, crevice, pitting, and stress corrosion cracking (SCC) that occur due to seawater exposure and dissimilar metal contact. The discussion extends to fatigue behavior, describing how cyclic loading and stress concentrations at weld toes and roots lead to crack initiation and propagation. Analytical approaches such as the S – N curve method and fracture mechanics are presented for fatigue life assessment. The chapter further explores corrosion prevention techniques, including material selection, protective coatings, cathodic protection (CP), and post-weld treatments. Standards and testing methodologies are reviewed, with references to American Bureau of Shipping (ABS), Det Norske Veritas (DNV), ISO, and American Petroleum Institute (API) guidelines. The final sections address emerging strategies like nanomaterial-based coatings, artificial intelligence (AI)-driven predictive maintenance, and digital twins for weld life prediction. This chapter equips readers with a deep understanding of how to design, evaluate, and maintain welded structures against long-term degradation in marine conditions.