CATHODIC PROTECTION

Cathodic protection is a fundamental electrochemical technique used to prevent corrosion of metal structures exposed to aggressive environments such as soil and water. This method is based on the principle of transforming the metal surface from an anode (which corrodes) to a cathode (which is protected), halting or significantly slowing the corrosion process.

The two main methods for achieving cathodic protection are:

• Sacrificial anode protection: this “passive” method uses blocks of less noble metals (such as zinc, aluminum, or magnesium) that, immersed in the conductive environment and connected to the structure to be protected, corrode in place, sacrificing themselves over time. Ideal for smaller structures or in moderately aggressive environments.
• Impressed current protection: this “active” method uses an external energy source (such as a cathode power supply) to provide a forced direct current between an inert anode (such as graphite, titanium) and the structure to be protected. Suitable for large structures where precise potential control is required.