The Application of Nanocoating and Cold-Dip Galvanization on Mitigating Corrosion for Ship and Offshore Mooring Chains

Abstract

Managing and mitigating corrosion on marine vessels and mooring line is crucial for their safety, operational efficiency and longevity. The study examined and assesed the improvement of the corrosion behavior of mooring chains by the application of mitigation means. The nano-epoxy composite coating, cold-dip galvanizing and bare metal all in fresh and saltwater, were experimentally assessed. The compositions of the water media were studied using Atomic Absorption Spectroscopy (AAS) to determine the concentration of heavy metals. The pH and salinity were checked to ascertain how these parameters affect the corrosion of the metal substrate. The experiment procedure adapted the typical laboratory corrosion experiment, with an exposure period of five weeks. The corrosion rate of each specimen was calculated and on a weekly basis compared to determine the effectiveness on the corrosion mitigation measure applied on the metal substrate. The results shows that, the numerical application of the corrosion equation illustrated significant decrease in the rate of corrosion as demonstrated by the average trendline of each plot. The corrosion rate of the nano-epoxy coating started at 0.13 mm/week and decreased below 0.02 mm/week. The corrosion rate for the cold-dip galvanizing started at the same rate but declined and converged around 0.02 mm/week, while that of the bare metal converged at 0.05 mm/week. These results are indicative that nanocoating effectively reduce corrosion rates much like traditional cold-dip galvanizing. Overall, this study provides valuable insights into the promising role of nano coatings in combating corrosion.