Corrosion refers to the chemical reaction between a metal and its surrounding environment. Or, in other words, it could be defined as the oxidation of metal.
Corrosion inhibiting products could be used for the purpose of protecting metals from getting corroded.
Methods of protection from corrosion
Applied coatings on galvanized surfaces & Reactive coatings
Some of the most common anti-corrosion treatment includes plating, painting, and the application of enamel. Chemicals that restrict or rather inhibit corrosion include certain salts in hard water, chromates, phosphates, and a wide variety of specifically-designed chemicals.
Anodization
Quite often, aluminium alloys undergo surface treatment. Electrochemical conditions in the bath are cautiously adjusted so that uniform pores, which are several nanometers wide, appear in the metal's oxide film. As a result of these pores, the oxide grows significantly thicker. Finally, when the treatment ends, the pores are allowed to seal, thus forming a harder and thicker surface layer. If this coating is scratched, the normal passivation processes tends to operate upon the area which was destroyed or damaged, thus trying to protect it.
Controlled permeability formwork
Controlled permeability formwork (CPF) refers to a method of preventing the corrosion caused by carbonation, chlorides, frost and abrasion.
Cathodic protection
Cathodic protection (CP) is a technique used to control metal corrosion by making the surface of the metal, the cathode of an electrochemical cell.
Anode protection
For the technique of cathodic protection to take place efficiently, the potential of the steel surface is negatively polarized until the metal surface has equal potential. As a result of the uniform potential, the strength of the corrosion reaction as well as the factors which trigger corrosion is halted. In the case of galvanic CP systems, the anode material corrodes under the impact of steel. Finally, it needs to be replaced. The polarization reaction is caused by the flow of current from anode to cathode.
Impressed Current Cathodic Protection
Impressed
Current Cathodic Protection systems makes use of anodes connected to a DC power source. Anodes for ICCP systems mostly include high silicon cast iron, graphite, platinum coated titanium or niobium coated rod and wires.
