Protection of metal and steel parts of vessels and other submerged structure from corrosion is important as it may cause serious damages to the entire structure. Corrosion of metal parts is a very common phenomenon and must be taken care of to prevent the structure from dying.
How to prevent corrosion?
Cathodic protection method can be used to prevent corrosion. It is a proven method that is used worldwide to prevent and control corrosion of parts that are buried, partially buried and submerged in the water. A well designed and installed cathodic protection system effectively eliminates corrosion by passing direct current to the metal parts. This can be achieved by using sacrificial galvanic anodes.
Among the various materials and marine anodes that are being used for cathodic protection, Zinc plates and anodes are of prime importance. The fitting of
in the immersed metal parts is a common practice.
Some of the important applications of zinc plates include:
Protect the surface of underground or underwater pipe
Care for the interiors of pipe handling corrosive waters and effluents
Keep lead sheathed electric cable in vessels unaffected from corrosion
Protect the other important metal-sheathed electric cable found in vessels and other submerged structures
Control corrosion of induce AC on underground pipe
Control and prevent the oxidization of gap between outer steel casing and inner pipe of deep wells
Protect the narrow interior bottoms of oil storage tanks
Prevent rusting of double bottom areas of ship ballast tanks
Protect the underneath areas of cargo/ballast tanks of cargo carriers.
Zinc Plating for Effective Cathodic Protection
Zinc plating is a commonly used technique used for corrosion protection by many industries for many reasons. This method is done by coating Zinc at a thickness varying from 5 to over 25 µm depending on the applications on the intended steel parts. Zinc plated coatings are usually dipped in a Chromate solution to enhance the resistance power.
The three popular types of Zinc plating methods are:
Acid chloride zinc
Alkaline cyanide-free zinc
It is crucial to choose one among these types of coating method after understanding the processes involved, advantages, disadvantages and durability of the method.
Corrosion resistance of zinc coated plates mainly depends on factors like coating thickness, environmental exposure and post-plate treatments. Like any other sacrificial marine anodes, zinc plates corrode first and then sacrifice itself for the protection of steel. As Zinc plating is cost-effective solution for corrosion, it is fast becoming an alternative for other expensive coating solutions.
Zinc Plating Ensures Cathodic Protection