Glossary CorrosionRSS

Glossary Corrosion

A network of checks or cracks appearing on the surface.

Time-dependent strain occurring under stress. The creep strain occurring at a diminishing rate is called primary creep; that occurring at a minimum and almost constant rate, secondary creep; and that occurring at an accelerating rate, tertiary creep.

Embrittlement under creep conditions of, for example, aluminum alloys and steels that results in abnormally low rupture ductility. In aluminum alloys, iron in amounts above the solubility limit is known to cause such embrittlement; in steels, the phenomen ...

The stress that will cause fracture in a creep test at a given time in a specified constant environment. Also called stress-rupture strength.

Localized corrosion of a metal surface at, or immediately adjacent to, an area that is shielded from full exposure to the environment because of close proximity between the metal and the surface of another material.

The maximum anodic current density observed in the active region for a metal or alloy electrode that exhibits active-passive behavior in an environment.

The size of a flaw (defect) in a structure that will cause failure at a particular stress level.

The relative humidity above which the atmospheric corrosion rate of some metals increases sharply.

The lowest value of oxidizing potential at which pits nucleate and grow. It is dependent on the test method used.

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

The current flowing to or from a unit area of an electrode surface, generally expressed as amps per sq ft or milliamperes per sq ft (also milliamps per sq cm, etc).

The ratio of the electrochemical equivalent current density for a specific reaction to the total applied current density.

See ferrite.

Removal of dissolved mineral matter, generally from water.

A crystal that has a treelike branching pattern, being most evident in cast metals, slowly cooled through the solidification range.

Corrosion in which nickel is selectively leached from nickel-containing alloys. Most commonly observed in copper-nickel alloys after extended service in fresh water. See also dealloying, and selective Ieaching.

The mass of a unit volume of a gas at a stated temperature and pressure.

The mass of unit volume of a material at a specified temperature.

(1) The removal of oxygen from molten metals by use of suitable deoxidixers. (2) Sometimes refers to the removal of undesirable elements other than oxygen by the introduction of elements or compounds that readily react with them. (3) In metal finishing, t ...

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