Overview
A voiding corrosion in a harsh ocean environment often requires the use of cathodic protection methods. These utilize different tools, such as sacrificial anodes or impressed currents, to help maritime-based industries stay afloat.
One such system, impressed current cathodic protection (ICCP), mitigates corrosion by applying an external current to a ship hull. The efficiency of this method depends on factors such as the use of a coated propeller.
Sitting on the deck of a ship, you may be unaware of everything occurring underneath you. But if you were to dive beneath the waves, you might observe one of the biggest problems ships face: corrosion.
The corrosion you see on a ship’s hull occurs when there are areas with different potentials within an electrolyte — ocean water, in this case. Put simply, the ocean is an electrolyte that facilitates a flow of electrons from an anode with a higher electrolyte potential to a cathode with a lower electrolyte potential. This causes oxidation and corrosion in the anodic areas.
Corrosion causes structures like ships, jackets, floatings and oil platforms to deteriorate and weaken. This may result in leakages and unsafe working conditions. Instead of trying to fix these issues after the fact, which can be costly, you can focus on avoiding corrosion before it happens with protection methods, such as ICCP.
Operation
A
lthough modern hull coatings provide some protection against corrosion they do not offer a complete solution.
For this reason, most operators choose to protect their vessels with a purpose designed impressed current cathodic protection system.
Using an arrangement of hull mounted anodes and reference cells connected to a CPUs, the system produces a more powerful external current to suppress the natural electro-chemical activity on the wetted surface of the hull.
This eliminates the formation of aggressive corrosion cells on the surface of plates and avoids the problems which can exist where dissimilar metals are introduced through welding or brought into proximity by other components such as propellers.
