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.

Deterioration of metals as a result of the metabolic activity of microorganisms.

A chemical compound with one or more carboxyl radicals (COOH) in its structure; examples are butyric acid, CH3(CH2)2COOH; maleic acid, HOOCCH-CHCOOH; and benzoic acid, C6H5COOH.

To coat a metal surface with zinc using any of various processes.

See principal stress (normal).

(1) A molecular structure in which a heterocyclic ring can he formed by the unshared electrons of neighboring atoms. (2) A coordination compound in which a heterocyclic ring is formed by a metal bound to two atoms of the associated ligand. See also comple ...

Tendency of an environment to cause corrosion in a given corrosion system.

An electrode immersed in a suitable electrolyte, designed for measurements of electrode potential; A pure metal in contact with a solution of known concentration of its own ion, at a specific temperature develops a potential which is characteristic and re ...

A reaction in which there is a decrease in valence resulting from a gain in electrons. Contrast with oxidation.

The potential of a reversible oxidation-reduction electrode measured with respect to a reference electrode, corrected to the hydrogen electrode, in a given electrolyte.

The potential of an electrode in an electrolyte as measured against a reference electrode. The electrode potential does not include any resistance losses in potential in either the solution or external circuit. It represents the reversible work to move a ...

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.

Surface discoloration of a metal caused by formation of a thin film of corrosion product.

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 ...

A glass membrane electrode used to measure pH or hydrogen-ion activity.

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.

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.

See salt fog test.

See auxiliary electrode.

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