An electrolytic cell, the electromotive force of which is caused by a difference in concentration of some component in the electrolyte. This difference leads to the formation of discrete cathode and anode regions.

Pertaining to the current resulting from the coupling of dissimilar electrodes in an electrolyte

Localized corrosion frequently observed in oilwell tubing in which a circumfrential attack is observed near a region of metal "upset".

The electromotive force generated in a circuit containing two dissimilar metals when one junction is at a temperature different from that of the other. see also thermocouple.

An obsolete historical term usually applied to stress-corrosion crackling of brass.

A galvanic cell resulting from inhomogeneities between areas on a metal surface in an electrolyte. The inhomogeneities may be of physical or chemical nature in either the metal or its environment.

The force or load that produces elongation.

See embrittlement.

An alloy of lead containing 3 to l5% Sn, used as a hot dip coating for steel sheet or plate. Terne coatings, which are smooth and dull in appearance, give the steel better corrosion resistance and enhance its ability to be formed, soldered, or painted.

Any of several processes in which both nitrogen and carbon are absorbed into the surface layers of a ferrous material at temperatures below the lower critical temperature and, by diffusion, create a concenteration gradient. Nitrocarburizing is performed p ...

The maximum stress that a material can withstand for an infinitely large number of fatigue cycles. See also fatigue strength.

A potential more cathodic (positive) than the standard hydrogen potential.

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

The ratio, expressed as a percentage, of the amount of water vapor present in a given volume of air at a given temperature to the amount required to saturate the air at that temperature.

A metal which because of its relative position in the galvanic series, provides sacrificial protection to metals that are more noble in the series, when coupled in an electrolyte.

A protective or decorative nonmetallic coating produced in silo by chemical reaction of a metal with a chosen environment. It is often used to prepare the surface prior to the application of an organic coating.

A compound that causes reduction, thereby itself becoming oxidized.

The slope (dE/di) at the corrosion potential of a potential (E)/current density (i) curve. Also used to describe the method of measuring corrosion rates using this slope.

(1) The formation at high temperatures of thick corrosion product layers on a metal surface. (2) The deposition of water-insoluble constituents on a metal surface.

A metal that readily combines with oxygen at elevated temperatures to form very stable oxides, for example, titanium, zirconium, and beryllium. Reactive metals may also become embrittled by the interstitial absorption of oxygen, hydrogen, and nitrogen.