A metal having an extremely high melting point, for example, tungsten, molybdenum, tantalum, niobium, chromium, vanadium, and rhenium. In the broad sense, this term refers to metals having melting points above the range for iron, cobalt, and nickel.

A metallurgical term describing the formation of graphite in iron or steel, usually from decomposition of iron carbide at elevated temperatures. Not recommended as a term to describe graphitic corrosion.

An individual crystal in a polycrystalline metal or alloy; it may or may not contain twinned regions and subgrains; a portion of a solid metal (usually a fraction of an inch in size), in which the atoms are arranged in an orderly pattern.

Intergranular fracture of maraging steels with decreased toughness resulting from improper processing after hot working. Thermal embrittlement occurs upon heating above l095

In tensile testing, the ratio of maximum load to original cross-sectional area. Also called ultimate tensile strength.

Substance formed as a result of corrosion

The structure of a prepared surface of a metal as revealed by a microscope at a magnification exceeding 25x.

Corrosion due to the action of "local cells," that is, galvanic cells resulting from inhomogeneities between adjacent areas on a metal surface exposed to an electrolyte.

Spontaneous aging of a supersaturated solid solution at room temperature. See also aging. Compare with artificial aging.

Catastrophic brittle failure of a normally ductile metal when in contact with a liquid metal and subsequently stressed in tension.

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.

Deterioration of wood in contact with iron-based alloys.

Deterioration of gray cast iron in which the metallic constituents are selectively leached or converted to corrosion products leaving the graphite intact. The term graphitization is commonly used to identify this form of corrosion, but is not recommended ...

The reversible interchange of ions between a liquid and solid, with no substantial structural changes in the solid.

A surface-active agent; usually an organic compound whose moleculei contain a hydrophilic group at one end and a lipophilic group at the other.

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.

Corrosion at discrete sites, stress-corrosion cracking.

See transgranular cracking.

Visible at magnifications above 25x.

A form of high-temperature corrosion of chromium-bearing alloys in which green chromium oxide (Cr2O3) forms, but certain other alloy constituents remain metallic; some simultaneous carburization is sometimes observed.