A compound that causes oxidation, thereby itself being reduced.

A visible corrosion product consisting of hydrated oxides of iron. Applied only to ferrous alloys. See also white rust.

(1) Producing a chromate conversion coating on magnesium for temporary protection or for a paint base. (2) The solution that produces the conversion coating.

The maximum compressive stress a material is capable of developing. With a brittle material that fails in compression by fracturing, the compressive strength has a definite value. In the case of ductile, malleable, or semiviscous materials (which do not f ...

Direct current supplied by a device employing a power source external to the electrode system of a cathodic protection installation.

See inhibitor

Corrosion that occurs under some coatings in the form of randomly distributed threadlike filaments.

Corrosion in which cobalt is selectively leached from cobalt-base alloys, such as Stellite

That portion of the base metal that was not melted during brazing, cutting, or welding, but whose microstructure and mechanical properties were altered by the heat; Refers to area adjacent to a weld where the thermal cycle has coused microstructural chang ...

The net transfer of electric charge per unit time. Also called electric current. See also current density.

A decrease in the polarization of an electrode; the elimination or reduction of polarization by physical or chemical means; depolarization results in increased corrosion.

Separation of a solid accompanied by little or no macroscopic plastic deformation. Typically, brittle fracture occurs by rapid crack propagation with less expenditure of energy than for ductile fracture.

A stress that causes an elastic body to deform (shorten) in the direction of the applied load. Contrast with tensile stress.

Numerous, very fine cracks in a coating or at the surface of a metal part. Checks may appear during processing or during service and are most often associated with thermal treatment or thermal cycling. Also called check marks. checking, or heat checks.

Electrochemical system consisting of an anode and a cathode immersed in an electrolyte. The anode and cathode may be separate metals or dissimilar areas on the same metal. The cell includes the external circuit, which permits the flow of electrons from th ...

A chemical process involving formation of a heterocyclic ring compound that contains at least one metal cation or hydrogen ion in the ring.

Plating wherein fine metal powders are peened onto the work by tumbling or other means.

A cell in which chemical change is the source of electrical energy. It usually consists of two dissimilar conductors in contact with each other and with an electrolyte. or of two similar conductors in contact with each other and with dissimilar electrolyt ...

A condition in which a piece of metal, because of an impervious covering of oxide or other compound, has a potential much more positive than that at the metal in the active state.

See principal stress (normal).