T.O. 1-1A-9
BILLET. An ingot or bloom that has been reduced through rolling or hammering to an approximate square ranging from
1 1/2 inches square to 6 inches square, or to an approximate rectangular cross-section of equivalent area. Billets are
classified as semi -finished products for re-rolling or forging.
BINARY ALLOY. An alloy containing two elements, apart from minor impurities.
BLACK ANNEALING. A process of box annealing of sheets prior to tinning whereby a black color is imparted to the
surface of the product.
BLUE ANNEALING. A process of annealing sheets after rolling. The sheets, if fairly heavy, are allowed to cool slowly
after the hot rolling; if of lighter gage, as is usually the case, they are passed singly through an open furnace for heating
to the proper annealing temperature. The sheets have a bluish-black appearance.
BLUE BRITTLENESS. Brittleness occurring in steel when in the temperature range of 1490to 3710C (3000 to 700°F), or
when cold after being worked within this temperature range.
BOX ANNEALING. Softening steel by heating it, usually at a sub-critical temperature, in a suitable closed metal box or
pot to protect it from oxidation, employing a slow heating and cooling cycle; also called closed annealing or pot
annealing.
BRIGHT ANNEALING. A process of annealing, usually with reducing gases, such that surface oxidation is reduced to a
minimum, thereby yielding a relatively bright surface.
BRITTLENESS. Brittleness is the property of a material which permits little bending or deformation without fracture.
Brittleness and hardness are closely associated.
BURNING. The heating of a metal to temperatures sufficiently close to the melting point to cause permanent injury.
Such injury may be caused by the melting of the more fusible constituents, by the penetration of gases such as oxygen
into the metal with consequent reactions, or perhaps by the segregation of elements already present in the metal.
BUTT-WELD. The welding of two abutting edges.
CARBON FREE. Metals and alloys which are practically free from carbon.
CARBURIZING (CEMENTATION). Adding carbon to the surface of iron-base alloys by heating the metal below its
melting point in contact with carbonaceous solids, liquids, or gases.
CASE. The surface layer of an iron-base alloy which has been made substantially harder than the interior by the process
of case hardening.
CASE HARDENING. A heat treatment of a combination of heat treatments in which the surface layer of an iron-base
alloy is made substantially harder than the interior by altering its composition by carburizing, cyaniding, or nitriding.
CHAPMANIZING. A process for hardening steel by bubbling ammonia through a cyaniding salt bath and holding the
finished part in the gas stream. This method produces a case almost as hard as nitriding at a time factor of slightly
longer than required for cyaniding.
CHARPY IMPACT. An impact test made by measuring in a Charpy machine the energy required to fracture a standard
notched specimen in bending. The values so obtained are merely comparative between different materials tested by the
same method.
COLD DRAWING. The permanent deformation of metal below its recrystallization temperature; by drawing the bay
through one or more dies.
COLD ROLLING. The permanent deformation of metal below its recrystallization temperature by rolling. This process is
frequently applied in finishing rounds, sheets, strip, and tin plate.
COLD TREATING. Cooling to sub-zero temperature for various purposes, but primarily to promote transformation of
austenite.
COLD WORKING. Plastic deformation of a metal at a temperature low enough to insure strain hardening.
CORE. The interior portion of an iron-base alloy which is substantially softer than the surface layer as the result of case
hardening. Also, that portion of a forging removed by trepanning; the inner part of a rolled section of rimmed steel as
distinct from the rimmed portion or rim; a body of sand or other material placed in a mold to produce a cavity in a
casting.
CONVERSION COATING (CHEMICAL). A film intentionally produced on a metal by subjection to a selected chemical
solution for the purpose of providing improved corrosion resistance or to improve the adhesion of subsequently applied
organic coating.
CYANIDING. Surface hardening by carbon and nitrogen absorption of an iron-base alloy article or portion of it by heating
at a suitable temperature in contact with a cyanide salt, followed by quenching.
COOLING. Any decrease in temperature; however, specific term -usually applies to reducing metal temperature in a
gaseous environment rather than quenching in a liquid.
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