The threshold value of the corrosion potential that has to be reached to enter a protective potential range. The term used in cathodic protection to refer to the minimum potential required to supress corrosion.

The potential of a specimen (or specimens in a galvanic couple) when two or more electrochemical reactions are occurring. Also called galvanic couple potential.

The property that enables a material to undergo permanent deformation without rupture.

A corrosion test involving exposureof specimens at controlled levels of humidity and temperature. Contrast with salt-fog test.

Artificial aging in which a constituent precipitated from a supersaturated solid solution.

The stress required to produce fracture in the plane of cross section, the conditions of loading being such that the directions of force and of resistance are parallel and opposite although their paths are offset a specified minimum amount. The maximum lo ...

Brittle failure by cracking under the combined action of tensile stress and corrosion in the presence of water and hydrogen sulfide. See also environmental cracking.

Coating metal with a very thin layer of molten solder or brazing filler metal.

(1) State of anodically passivated metal characterized by a considerable increase of the corrosion current, in the; absence of pitting, when the potential is increased. (2) The noble region of potential where an electrode exhibits at higher than passive c ...

Destruction of metals or other materials by the abrasive action of moving fluids, usually accelerated by the presence of solid particles or matter in suspension. When corrosion occurs simultaneously, the term erosion-corrosion is often used.

The rate of charge transfer per unit area when an electrode reaches dynamic equilibrium (at its reversible potential) in a solution; that is, the rate of anodic charge transfer (oxidation) balances the rate of cathodic charge transfer (reduction).

A cracking process that requires the simultaneous action of a corrodent and sustained tensile stress. This excludes corrosion-reduced sections that fail by fast fracture. It also excludes intercrystalline or transcrystalline corrosion, which can disintegr ...

The formation of blisters on or below a metal surface from excessive internal hydrogen pressure; Formation of blister-like bulges on a ductile metal surface caused by internal hydrogen pressures. Hydrogen may beformed during cleaning, plating, corrosion, ...

The reversible potential for an electrode process when all products and reactions are at unit activity on a scale in which the potential for the standard hydrogen half-cell is zero.

Lacking an affinity for, repelling, orfailing to absorb or adsorb water. Contrast with hydrophilic.

A single, solid, homogeneous crystalline phase containing two or more chemical species.

A conjoint action involving corrosion and erosion in the presence of a moving corrosive fluid, leading to the accelerated loss of material.

The part of the total carbon in steel or cast iron that is present in elemental form as graphite or temper carbon. Contrast with combined carbon.

An instrument for automatically maintaining an electrode in an electrolyte at a constant potential or controlled potentials with respect to a suitable reference electrode.

The first coat of paint applied to a surface. Formulated to have good bonding and wetting characteristics; may or may not contain inhibiting pigments.