Protective current

The protective current in cathodic corrosion protection is used to protect metallic structures from the damaging effects of corrosion. This process is based on the principle of the electrochemical reactions that occur during corrosion. Essentially, in cathodic corrosion protection, an external current is applied to cathodically polarize the metal to be protected. This protective current causes a reversal of the electrochemical reactions that would normally lead to corrosion.

The implementation of the protective current requires the placement of anode materials, typically made of less noble metals such as zinc or aluminum, near the metallic structure to be protected. These anodes serve as victims for the corrosion and provide electrons that flow through the electrolyte to the protected metal. The external power source used to generate the protective current is connected to the anodes and the metallic structure to be protected. Applying the current cathodically polarizes the protected metal, which means that it absorbs electrons and is thus protected from oxidation.

The effectiveness of cathodic protection depends on various factors, including the current density, the composition of the electrolyte, the surface condition of the metal and the environmental conditions. Thorough planning and installation are crucial to achieve effective corrosion protection.

This process is used in various industries and applications, including the oil and gas industry, shipping, construction and water and wastewater treatment. Cathodic corrosion protection offers a reliable and cost-effective way to extend the life of metallic structures and reduce maintenance costs by minimizing corrosion damage.