Have you ever marveled how sea vessels that are continuously submerged in the sea and ocean protected from rust? It is widely known that steel is not immune from oxidation that leads to rust. Over time, and in the event of corrosion, the metal structure will weaken. The shipping industry in particularly has benefited from cathodic protection. Cathodic protection is the means by which the hulls of cruise liners, oil tankers, aircraft carriers and other sea vessels are protected from corrosion.
One of the advanced and definitive forms of cathodic protection is the ICCP system. ICCP stands for Impressed Current Cathodic Protection. Ship owners now regard the system as the long-term solution to corrosion problems.
The Older Form of Cathodic Protection
The other form of cathodic protection is what is known as the galvanic method. It is an older system but basically performs the same function. With the galvanic system, the metal at risk of corrosion is protected through a complicated metal-to-metal process. It involves the use of another metal (aluminum, magnesium, or zinc) that is then connected to the structure that needs protection through an insulated wire.
The connection forms a sacrificial anode. The cell of electricity produced with a current then flows from the structure to the anode. This is called a cathode, and it acts to protect the metal from corrosion. Instead of the metal structure being corroded, the anode is eaten away by corrosion or rust over time.
What gave rise to the ICCP system is a flaw in the galvanic system. However, the galvanic system has significant shortcomings. After the anode is fully corroded, the metal structure loses its protection. You will need to replace the anode with a new one.
The New and Superior Alternative
The fundamental difference with the galvanic system is the power source used to produce the current. Alternating current (AC) is used to generate the electric current in the In an ICCP system; a rectifier is used to convert AC power to DC (Direct Current)
Because of the switch, the current that powers the reaction is supplied externally and distant from the anode. The anode is protected in a way that corrosion takes considerably slower. Given this rectification of the galvanic method, the anode will last longer, and replacement is less frequent.
More ship owners are shifting to the ICCP system because this advanced system not only reduces maintenance cost but extends the economic life of vital parts like propellers, rudders, and shafts as well as other underwater parts affected by oxidation. The system is not limited to the shipping industry but in other industries where metal needs to be protected from corrosion.