1. n. [Enhanced Oil Recovery]

A technique used to minimize the rate of corrosion of a structure. Cathodic protection does not eliminate corrosion; it transfers corrosion from the structure under protection to a known location where artificial anodes (plates or metal bars) are placed and could be replaced easily. Cathodic protection is used for floating vessels, platforms, storage tanks, and pipelines.

The cathodic protection principle is based on the electrochemical nature of the corrosion phenomena; the anodic area corrodes (current is discharged) and the cathodic area does not corrode (current is received). Cathodic protection overrides the naturally occurring anodic areas inside a structure, thus turning the structure under protection completely cathodic, which means it receives current from the surrounding electrolyte (for example, soils, water) and does not corrode. Cathodic protection is achieved by passing enough direct current electricity from an external source (a more powerful anode), which could be a galvanic anode or an impressed current anode.

See: corrosion,  corrosion control,  galvanic anodes,  impressed current anodes