Corrosion Behaviors of Ship Structural Steel in Simulated Marine Tidal Environment

The tidal zone is severe marine environment for steel structures due to its wet-dry cyclic corrosion pattern. Regarding a specific application for inner ship hull, ship structural steel is always prone to corrosion dealing with three marine environments, including atmospheric, tidal, and immersion zones. Therefore, the current study aimed to investigate corrosion behaviors of two commercial ship structural steels, i.e. alloys A and B, which were exposed to simulated marine tidal environment. The effects of specimen arrangements designated as the isolated short-scale and vertical long-scale specimens were also determined. Based on weight loss determination, it revealed that the corrosion rates of isolated short steel specimens exposed in the tidal zone were almost two times larger than that of vertical long-scale steel specimen. In the tidal zone, the corrosion rates of isolated short-scale steel obtained from weight loss determination quite agreed with the EIS corrosion sensor results. Based on the corrosion resistance aspects, the alloy A is slightly better than the alloy B.