Complete protection against any external factors
Cathodic protection is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. A simple method of protection connects the metal to be protected to a more easily corroded “sacrificial metal” to act as the anode. The sacrificial metal then corrodes instead of the protected metal. For structures such as long pipelines, where passive galvanic cathodic protection is not adequate, an external DC electrical power source is used to provide sufficient current.
conventional methods
Galvanic Cathodic Protection:
In this method, a sacrificial anode made of a more reactive metal (such as zinc or magnesium) is connected to the pipeline. The sacrificial anode corrodes instead of the pipeline, thereby protecting it from corrosion. The sacrificial anode and the pipeline form a galvanic cell, with the sacrificial anode acting as the anode (where oxidation occurs) and the pipeline acting as the cathode (where reduction occurs). This method is simple and cost-effective but requires periodic replacement of sacrificial anodes.
Impressed Current Cathodic Protection:
In this method, an external power source, such as a rectifier, is used to impress an electrical current onto the pipeline. This current opposes the natural flow of electrons in the corrosion process, effectively protecting the pipeline from corrosion. In impressed current cathodic protection, inert anodes, typically made of materials like graphite or mixed metal oxide (MMO), are used instead of sacrificial anodes. This method allows for more precise control of the cathodic protection system and is suitable for larger pipelines or structures.
