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.

A loss ofstrength and ductility of .steel by high-temperature reaction of absorhcd hydrogen with carbides in the steel resulting in dec arbwri:.alien and internal fissuring.

The stress condition in linear elastic fracture mechanics in which the stress in the thickness direction is zero; most nearly achieved in loading very thin sheet along a direction parallel to the surface of the sheet. Under plane-stress conditions, the pl ...

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

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.

The surroundings or conditions (physical, chemical, mechanical) in which a material exists.

That type of force that causes or tends to cause two contiguous parts of the same body to slide relative to each other in a direction parallel to their plane of contact.

(1) The change from the open-circuit electrode potential as the result of the passage of current. (2) A change in the potential of an electrode during electrolysis, such that the potential of an anode becomes more noble, and that of a cathode more active, ...

Resin formed by the reaction of bisphenol and epichlorohydrin.

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 algebraic ratio of two specified stress values in a stress cycle. Two commonly used stress ratios are: (1) the ratio of the alternating stress amplitude to the mean stress. A = Sa/Sm and (2) the ratio of the minimum stress to the maximum stress. R =Sm ...

A twisting deformation of a solid body about an axis in which lines that were initially parallel to the axis become helices.

Fracture through or across the crystals or grains of a metal. Also called transcrystalline fracture or intracrystalline fracture. Contrast with intergranular fracture.

An accelerated corrosion of' metal surfaces that results from the combined elTect of oxidation and reactions with sulfur compounds and other contaminunts, such us chlorides, to form a molten salt on a metal iurfuce that f1uxes, destroys, or disrupts the n ...

One of the relatively scarce and valuable metals: gold, silver, and the platinum-group metals. Also called noble metal(s).

Corrosion testing in a boiling solution of nitric acid. This test is mainly used to detect the susceptibilty to intergranular corrosion of stainless steel.

The region of an anodic polarization curve, noble to and; above the passive potential range, in which there is a significant increase in current density (increased metal dissolution) as the potential becomes more positive (noble).

Hardening caused by the precipitation of a constituent from a supersaturated solid solution. See also age hardening and aging.

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 maximum or minimum value at the normal stress at a point in a plane considered with respect to all possible orientations of the considered plane. On such principal planes the shear stress is zero. There are three principal stresses on three mutually p ...