This work presents the experimental research carried out to optimize a current computational software “CorOns”, to obtain a better ship hull electrical signature modelling. Middle-term ageing (597 days) of anticorrosion paints, highlights the appearance of additional corrosion processes, despite an absence of visual defects. A specific model is proposed for an aged surface in seawater based on Electrochemical Impedance Spectroscopy (“EIS”) data analysis. We also investigate the impact of the interruption of cathodic protection on the corrosion process, with the objective of modelling the electrical signature in real conditions that could be encountered. These studies’ interruption of the cathodic protection during 24 h, do not seem to have an impact on the current densities. However, EIS studies, highlight that the protection interruptions damage the calcareous deposit, well-known for it is protective effect once formed.

The modelling of corrosion protection systems in seawater is classically based on Boundary Element Method (BEM) and is generally limited to static studies. This paper presents an original transient approach coupling a BEM for the modelling of the seawater and a circuit representation approach in order to introduce nonlinear polarization laws and Impressed Current Cathodic Protection (ICCP) electric system. A special care is taken to the numerical implementation enabling the modelling of complex systems and interface phenomena.