Influence of a simulated deep sea condition on the cathodic protection and electric field of an underwater vehicle

To investigate the effect of the deep sea condition on the corrosion behavior, cathodic protection and electric field of underwater vehicles, potentiodynamic polarization tests were carried out under a simulated deep sea condition. A 3-D boundary element method (BEM) was used for an underwater vehicle with and without sacrificial anode cathodic protection (SACP). The simulated deep sea condition influenced the cathodic polarization curves due to the difference between the cathodic reactions. Under the deep sea condition, the cathodic protection potential criterion was more easily satisfied as the protection current density of SACP was decreased. The electric field underneath the underwater vehicle showed that the deep sea condition decreased the electric field due to the lower current density and the shape of the electric field distribution changed from one dipole to two dipoles.