(1) A cathode, usuully corrugated to give variable current densities, that is plated at low current densities to preferentially remove impurities from a plating solution. (2) A substitute cathode that is used during adjustment of operating conditions.

A generic term covering several processes applicable to steel that change the chemical composition of the surface layer by absorption of carbon, nitrogen, or a mixture of the two and, by diffusion, create a concentration gradient. The outer portion, or ca ...

Breaks in a coating that extend through to the underlying surface.

(1) A solid solution of one or more elements in body-centered cubic iron. Unless otherwise designated (for instance, as chromium ferrite), the solute is generally assumed to be carbon. On some equilibrium diagrams, there are two ferrite regions separated ...

Improving paint adhesion on aluminum or aluminum alloys, mainly aircraft skins, by treatment with a solution of' chromic acid. Also called chromodizing or chromatizing. Not to be confused with chromating or chromizing.

A coating consisting of' a compound of the surface metal, produced by chemical or electrochemical treatments of the metal. Examples include chromate coatings on zinc, cadmium, magnesium, and aluminum and oxide and phosphate coatings on steel. See also chr ...

Corrosion that is accompanied by a flow of electrons between cathodic and anodic areas on metallic surfaces.

A thin, inhibiting paint, usually chromate pigmented with a polyvinyl butyrate binder.

See conductivity.

A list of elements arranged according to their standard electrode potentials, with "noble" metals such as gold being positive and "active" metals such as zinc being negative.

A fractographic term describing ductile fracture that occurs through the formation and coalescence of microvoids along the fracture path. The fracture surface of such a ductile fracture appears dimpled when observed at high magnification and usually is mo ...

The absorption of carbon into a metal surface; may or may not be desirable.

Cooking liquor from the kraft pulping process produced by recausticizing green liquor with lime.

The stress at which a material exhibits a specified deviation from proportionality of stress and strain. An onset of 0.2% is used for many metals.

(1) Permanently damaging a metal or alloy by heating to cause either incipient melting or intergranular oxidation. See also over-heating. (2) In grinding, getting the work hot enough to cause discoloration or to change the microstructure by tempering or h ...

A metastable aggregate of ferrite and cementite resulting from the transformation of austenite at temperatures below the pearlite range but above M

The condition of an electrode when the rate of anodic dissolution just balances the rate of cathodic plating.885

Forming austenite by heating a ferrous alloy into the transformation range (partial austenitizing) or above the transformation range (complete austenitizing). When used without qualification, the term implies complete austenitizing.

A condition in which the interfacial tension between a liquid and a solid is such that the contact angle is 0

Corrosion that occurs under organic films in the form of randomly distributed threadlike filaments or spots. In many cases this is identical to filiform corrosion.