The state of the surface of a metal or alloy susceptible to corrosion where its electrochemical behaviour becomes that of less reactive metal and its corrosion rate is reduced.
NOTE: This is generally the result of protective film formation.
A logarithmic index for the concentration of hydrogen ions in an electrolyte.
NOTE: See A.1.
Containing an excess of hydrogen ions over hydroxyl ions.
Containing an excess of hydroxyl ions over hydrogen ions.
Containing equal concentrations of hydrogen ions and hydroxyl ions
A non-uniform corrosion of a metal whereby a number of cavities, not in the form of cracks, are formed in the surface.
Change in the potential of an electrode as the result flow.
A device inserted in the earth of a structure that drains only a small current from the source used to provide cathodic protection for the structure, but provides a low resistance path to currents from high d.c. voltages and all a.c. voltages carried by the structure.
The current made to flow into a metallic structure from its electrolytic environment in order to effect cathodic protection of the structure.
The more negative level to which the potential of a metallic structure, with respect to a specified reference electrode in an electrolytic environment, has to be depressed in order to effect cathodic protection of the structure.
A dielectric material adhering to or bonded to a structure to separate it from its environment in order to prevent corrosion.