Corrosion is the chemical or electrochemical reaction between a material and its environment. This results in the deterioration of the material and its properties. The arrangements of metals determine what metal will be the anode and cathode when the two are put in the electrolytic cell.
There are different forms of corrosions and these are classified as follows:
- General : Uniform formation of corrosion products that cause even thinning of steel
- Localised : Caused by the difference in chemical and physical conditions between adjoining steel
- Bacterial : Caused by formation of bacteria with an affinity for materials on the surface of the steel
- Galvanic/dissimilar Metal : Cause when dissimilar metal come in contact. The difference in electrical potential creates a corrosion cell or a bimetallic couple
The methods of corrosion protection systems we adopt are:
- Barrier protection : This provide a protective coating that acts as a barrier between corrosion elements and the material substance
- Cathodic Protection : Employs protecting one metal by connecting it to another metal that is more anodic according to galvanic series. This is achieved by installing sacrificial anodes, impressed current or galvanic zinc application
- Corrosion resistant material : Material inherently resistant to corrosion in certain environments
- Migrating corrosion inhibitors in reinforced concrete structures to prevent/reduce corrosion of embedded reinforcing steel and the formation of incipient anodes