A fracture, usually of' polycrystalline metal, in which most of the grains have failed by cleavage, resulting in bright reflecting facets. It is associated with low-energy brittle fracture.

Interfacial reaction equivalent to a transfer of charge between electronic and ionic conductors. See also anodic reaction and cathodic reaction.

See exfoliation corrosion.

Introducing nitrogen into the surface layer of a solid ferrous alloy by holding at a suitable temperature (below Ac1 for ferritic steels) in contact with a nitrogenous material, usually ammonia or molten cyanide of appropriate composition. Quenching is no ...

A type of weld cracking that usually occurs below 203

See cathodic protection.

Electroplating tin on an object.

Aging under conditions of time and temperature greater than those required to obtain maximum change in a certain property, so that the property is altered in the direction of the initial value.,/dd>

The electric current that flows between metals or conductive nonmetal in a galvanic couple.

The severe loss of ductility of a metal resulting from corrosive attack, usually inter,granular and often not visually apparent.

Particles of foreign material in a metallic matrix. The particles are usually compounds (such as oxides, sulfides, or silicates), but may be of any substance that is foreign to (and essentially insoluble in) the matrix.

A measure of the acidity or alkalinity of a solution; The negative logarithm of the hydrogen-ion activity; it denotes the degree of acidity or basicity of a solution. At 25

See mixed potential.

Forming an adherent phosphate coating on a metal by immersion in a suitable aqueous phosphate solution. Also called phosphatizing. See also conversion coating.

A reference electrode composed of mercury, mercurous chloride (calomel), and a saturated aqueous chloride solution.

That portion of the polarization of a cell produced by concentration changes resulting from passage of' current through the electrolyte.

Modification of a corrosion system so that corrosion damage is mitigated.

Chromium plated for engineering rather than decorative applicactions.

Accelerated corrosion of a metal because of an electrical contact with a more noble metal or nonmetallic conductor in a corrosive electrolyte.

Deterioration of metals as a result of the metabolic activity of microorganisms.