An aggregate of iron or alloy carbides of essentially spherical shape dispersed throughout a matrix of ferrite.

A specimen that is notched and subjected to alternating stresses until a crack has developed at the root of the notch.

See intergranular corrosion.

A metal whose luster has been reduced because of a surface film, usually a corrosion product layer.

See hydrogenembriltlement.

Embrittlement of iron-chromium alloys (most notably austenitic stainless steels) caused by precipitation at grain boundaries of the hard, brittle intermetallic sigma phase during long periods of exposure to temperatures between approximately 560 and 980

The component of either a liquid or solid solution that is present to a greater or major extent; the component that dissolves the solute.

Resin formed by condensation of polybasic and monobasic acids with polyhydric alcohols.

The technique for maintaining a constant electrode potential.

In fatigue, the variation in the stress-intensity factor in cycle, that is, Kmax-Kmin.

The formation of isolated particles of corrosion products beneath the metal surface. This occurs as the result of preferential oxidation of certain alloy constituents by inward diffusion of oxygen, nitrogen, sulfur, and so forth.

An atom, or group of atoms, that has gained or lost one or more outer electrons and thus carries an electric charge. Positive ions, or cations, are deficient in outer electrons. Negative ions, or anions, have an excess of outer electrons.

Corrosion that proceeds laterally from the sites of initiation along planes parallel to the surface, generally at grain boundaries, forming corrosion products that force metal away from the body of the material, giving rise to a layered appearance.

The liquor resulting from dissolving molten melt irom the kraft recovery furnace in water. See also kraft process and smelt.

A gaseous environment containing hydrogen sulfide and carbon dioxide in hydrocarbon reservoirs. Prolonged exposure to sour gas can lead to hydrogen damage, sulfide-stress cracking, and/or stress-corrosion cracking in ferrous alloys.

Electrode potential where half-cell reaction involves only the metal electrode and its ion.

Corrosive attack that progresses preferentially along interdendritic paths. This type of attack results from local differences in composition, such as coring commonly encountered in alloy castings.

Between crystals or grains. Also called intercrystalline. Contrast with transgranular.

The swelling or bubbling of a coating usually because of heating (term currently used in space and fire protection applications).

A plot of r urrent density versus electrode potential for a specific electrode-electrolyte combination.