History of Cathodic Protection

History of cathodic protection & factors determining current requirement in Oil & Gas, Chemicals, Fertilizers, Petrochemicals, Power Plants, Infrastructure, etc.
Cathodic protection was first described by Sir Humphry Davy in a series of papers presented to the Royal Society in London in 1824. Sir Humphrey Davy’s work on protecting the copper sheathing on wooden hulls in the British Navy by sacrificial zinc or iron anodes is generally considered to be the earliest example of practical cathodic protection.
Thomas Edison experimented with impressed current cathodic protection on ships in 1890 but was unsuccessful due to the lack of a suitable current source and anode materials.
In the USA by 1945, the use of CP was commonly applied to the rapidly expanding oil and natural gas industry. In the UK, CP was applied from the 1950s onwards and Cathodic Protection Company Limited was established in this period, pioneering its use in the UK.
CP is now well established on a large variety of immersed and buried metallic structures as well as reinforced concrete structures and provides effective corrosion control.
Important cathodic protection standards and guidelines
history of cathodic protection
Concept of cathodic protectionr
Cathodic protection is an electrochemical means of corrosion control.
The objective of cathodic protection is to ensure that the metal surface becomes cathodic (Electronegative) of an electrochemical cell.
The potential difference between anode and cathode that causes corrosion current to flow is neutralized by exte
al current which eliminates the potential difference between anode and cathode and corrosion current ceases to flow.
The oxidation reaction at anode that releases electrons are consumed at cathode to produce hydrogen and OH-.Corrosion current is reduced as exte
al current polarizes cathode in electronegative direction and as cathode potential becomes equal to or more of anode open circuit potential, the corrosion stops.
Oxidation reaction at anode: Fe â Fe +++ 2e-
Reduction reaction at cathode: 2e-+ 2H+â2HâH2âor H2O +2e-+½ O2â2(OH-)
Cathodic protection provides current through exte
al anode to polarize the structure in electronegative direction. Thus exte
al anode is consumed to protect the structure