A substance that produces depolarization.

Foreign substance which comes from the environment, adhering to a surface of a material

Pitting corrosion resulting from deposits on a metal surface which cause concentration cells.

Corrosion occurring under or around a discontinuous deposit on a metallic surface. Also called poultice corrosion.

Removing the thick layer of oxides formed on some metals at elevated temperatures.

Corrosion in which zinc is selectively leached from zinc-containing alloys. Most commonly found in copper-zinc alloys containing less than 83% copper after extended service in water containing dissolved oxygen; the parting of zinc from an alloy (in some b ...

A chromate conversion coating produced on magnesium alloys in a boiling solution of sodium dichromate.

In a cathodic protection system, in electrically nonconductive material, such as a coating, plastic sheet or pipe that is placed between an anode and an adjacent cathode to avoid current wastage and to improve current distribution, usually on the cathode.

An electrolytic cell, the electromotive force of which is due to a difference in air (oxygen) concentration at one electrode as compared with that at another electrode of the same material; an oxygen concentration cell (a cell resulting from a potential d ...

Any process whereby a base metal or alloy is either (1) coated with another metal or alloy and heated to a sufficient temperature in a suitable environment or (2) exposed to a gaseous or liquid medium containing the other metal or alloy, thus causing diff ...

A factor of proportionality representing the amount of substance diffusing across a unit area through a unit concentration gradient in unit time.

The current density, often referred to as limiting current density, that corresponds to the maximum transfer rate that a particular species can sustain because of the limitation of diffusion.

A fractographic term describing ductile fracture that occurs through the formation and coalescence of microvoids along the fracture path. The fracture surface of such a ductile fracture appears dimpled when observed at high magnification and usually is mo ...

The destruction of adhesion between a coating and the surface coated.

Any interruption in the normal physical structure or configuration of a part, such as cracks, laps, seams, inclusions, or porosity. A discontinuity may or may not affect the usefulness of the part.

A linear imperfection in a crystalline array of atoms. Two basic types are recognized: (1) an edge dislocation corresponds to the row of mismatched atoms along the edge formed by an extra, partial plane of atoms within the body of a crystal; (2) a screw d ...

The range of the stress-intensity factor during a fatigue cycle.

The interface between an eletrode or a suspended particle and an electrolyte created by charge-charge interaction (charge separation) leading to an alignment of oppositely charged ions at the surface of the electrode or particle. The simplest model is rep ...

Conduction of electric current from an underground metallic structure by means of a metallic conductor. Forced drainage is that applied to underground metallic structures by means of an applied electromotive force or sacrificial anode. Natural drainage is ...

See gaseous corrosion.