Z94.12.2 Foundry/Casting

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CARBON DIOXIDE PROCESS (CO2 PROCESS). A process for hardening cores or molds in which carbon dioxide gas is blown for a few seconds through a sand bonded by sodium silicate.  The sand mass instantly becomes rigid because of the formation of a silica gel.

CARBON STEEL. Steel that owes its properties chiefly to the presence of carbon, without substantial amounts of alloying elements; also termed "ordinary steel,'' "straight carbon steel,'' "plain carbon steel,'' etc.

CASTING. (noun) Metal object cast to the required shape by pouring or otherwise injecting liquid metal into a mold, as distinct from one shaped by a mechanical process.

CASTING. (verb) Act of pouring metal into a mold.

CASTING, CENTRIFUGAL. A process of filling molds by (1) pouring the metal into a sand or permanent mold that is revolving about either its horizontal or its vertical axis; or (2) pouring the metal into a mold that is subsequently revolved before solidification of the metal is complete.

CASTING, DIE. (verb) The injection of molten (primarily nonferrous) metal into a metal mold under pressure.

CASTING, MACHINE. (verb) Process of casting by machine.

CASTING, OPEN SAND. (noun) Casting poured into an uncovered mold.

CASTING, PERMANENT MOLD. A casting produced in a re-useable metal or refractory mold.

CASTING, PLASTER. A casting made in a plaster mold.

CASTING, PRECISION. A casting of high dimensional accuracy produced by such processes as investment casting, plaster mold.

CASTING, SAND. A casting produced in a mold made of green sand, dried sand, or a core sand.

CASTING YIELD. The weight of casting or castings divided by the total weight of metal poured into the mold, expressed as a percent.

CAST IRON. Essentially an alloy of iron, carbon, and silicon in which the carbon is present in excess of the amount which can be retained in solid solution. It is austenite at the eutectic temperature. When cast iron contains a specially added element or elements in amounts sufficient to produce a measurable modification of the physical properties of the section under consideration, it is called alloy cast iron. Silicon, manganese, sulphur, and phosphorus, as normally obtained from raw materials, are not considered as alloy addition.

CAST IRON, WHITE. Cast iron in which substantially all the carbon is present in the form of iron carbide. Such a material has a white fracture.

CAVITY. (1) The impression in a mold produced by withdrawal of the pattern and to be filled by the casting metal. (2) A hollow or sunken space, or a void in the interior of a casting.

CEMENT SAND. A synthetic sand that is bonded with Portland cement.

CERAMIC MOLDING. A molding process that uses a ceramic shell or mold made by alternately dipping a pattern in dipcoat slurry and stuccoing with coarse ceramic particles until the shell of desired thickness is obtained.

CEREAL BINDER. A binder used in core mixtures and molding sands, derived principally from corn flour.

CHAPLETS. Metal supports or spacers used in molds to maintain cores, or parts of the mold which are not self-supporting in their proper positions during the casting process.

CHARGE. A given weight of metal or fuel introduced into the cupola or furnace.

CHECK. A minute crack in the surface of a casting caused by unequal expansion or contraction during cooling.

CHEEK. Intermediate section of a flask that is inserted between cope and drag to decrease the difficulty of molding unusual shapes or to fill a need for more than one parting line.

CHILL. (1) Addition of solid metal to molten metal in ladle to reduce temperature before pouring. (2) Depth to which chilled structure penetrates a casting.

CHILL BLOCK. A cast iron test block in which the depth of chill, as determined by fracture, is used as an estimate of the cast iron's quality.

CHILLS. Metal inserts in molds or cores at the surface of a casting or within the mold to hasten solidification of heavy sections and cause the casting to cool at a uniform rate.

CHOKE. A restriction in the gating system for the purpose of keeping dirt, or slag from entering the casting proper.

CHROMITE. A naturally occurring mineral which is a solid solution of chromium and iron oxides, used as a molding sand for cores and molds.

CLAMP-OFF. An indention in the casting surface due to displacement of sand in the mold.

CLAY. An earthy or stony mineral aggregate consisting essentially of hydrous silicates of alumina, plastic when sufficiently pulverized and wetted, rigid when dry, and vitreous when fired at a sufficiently high temperature. Clay minerals most commonly used in the foundry are montmorillonites and kaolinites.

CLAY SUBSTANCE (A.F.S. CLAY). That portion of foundry sand which, when suspended in water, fails to settle 1 inch per minute and which consists of particles less than 20 microns (0.02 mm or 0.0008 inches) in diameter.

CLAY-WASH. Thin emulsion of clay and water for coating gaggers and the inside of flasks. Also used as grout.

COKE. A porous, gray infusible product resulting from the dry distillation of bituminous coal, petroleum, or coal tar pitch, which drives off most of the volatile matter. Used as a fuel in cupola melting.

COLD BOX PROCESS. A two part organic resin binder system, mixed in conventional mixers and blown into shell or solid core shapes at room temperature. A vapor mixed with air is blown through the sand, resulting in instant curing, stripping, setting and immediate pouring of metal around it.

COLD SETTING BINDER. Term used to describe any binder that will harden the core sufficiently at room temperature so that the core can be removed from its box without distortion. Commonly used in reference to oil-oxygen types of binders.

COLD SETTING PROCESS. Any of several systems for bonding mold or core aggregates by means of organic binders, relying on the use of catalysts rather than heat for polymerization (curing).

COLD SHUT. A casting defect caused by imperfect fusing of molten metal coming together from opposite directions in a mold, or due to folding of the surface.

COLLAPSIBLE SPRUE. A sprue pattern of flexible material or of spring tube design for use in the squeeze molding of match plate patterns. Frequently a pouring cup is incorporated in the design.

COLLIODAL CLAY. Finely divided clay of the montmorillonite (bentonite), kaolinite (fire clay) or illite class; prepared for use as sand binders.

COLLOIDAL MATERIAL. Finely divided materials which are less than 0.5 micron (0.000015 in.) such as albumin, glue, starch, gelatin, and bentronite.

COLUMNAR STRUCTURE. A course structure of parallel columns of elongated grains which is caused by a highly directional solidification pattern which results from steep thermal gradients across the mold metal interface.

COMBINED CARBON. Carbon in iron and steel which is combined chemically with other elements; not in the free state as graphitic or temper carbon.

COMBINED WATER. That water in mineral matter which is chemically combined and drives off only at temperatures above 110°C (230°F).

COMPRESSIVE STRENGTH, SAND. Maximum stress in compression which an AFS Standard compacted sand specimen is able to withstand without significant dimensional deformation.

CONTINUOUS CASTING. A process for forming a bar of constant cross section directly from molten metal by gradually withdrawing the bar from the die as the metal flowing into the die solidifies.

CONVEYOR, BELT. A continuously moving belt used in an automated or semi-automated foundry to move material from one station to another.

CONVEYOR, PALLET. A material handling conveyor that holds one or more molds per section and transports them from the molding station, through pouring to shake out.

COPE. Upper or topmost section of a flask, mold, or pattern.

COPE, FALSE. Temporary cope used only in forming the parting and therefore not a part of the finished mold.

COPING OUT. The extension of sand of the cope downward into the drag, where it takes an impression of a pattern.

CORE. A preformed sand aggregate inserted in a mold to shape the interior or that part of a casting which cannot be shaped by the pattern.

CORE ASSEMBLY. Putting together a complex core made of a number of sections.

CORE BINDER. Any material used to hold the grains of core sand together.

CORE BLOW. A gas pocket in a casting adjacent to a cored cavity and caused by entrapped gases from the core.

CORE BOX. Wood, metal, or plastic structure, the cavity of which has the shape of the desired core which is to be made therein.

CORE BREAK-OFF. A core designed to produce a sharp break line in the gate for removal of the feeder.

CORE COLLAPSIBILITY. The rate of disintegration of a core at elevated temperatures.

CORE DRIERS. Supports used to hold cores in shape while being baked; constructed from metal or sand for conventional baking, or from plastic material for use with dielectric core baking equipment.

CORE, DROP. A type of core used in forming comparatively small openings occurring above or below the parting; the seat portion is so shaped that the core is easily dropped into place.

CORE FILLER. Material used to replace sand in the interior of large cores - coke, cinder, saw dust, etc. Usually added to aid collapsibility to reduce weight and to save core binders.

CORE, GREEN SAND. (1) A core formed from the molding sand and generally an integral part of the pattern and mold. (2) A core made of unbaked molding sand. (See CORE SAND.)

COREMAKER. A craftsman skilled in the production of cores for foundry use.

CORE OIL. Linseed base or other oil used as a binder for baked cores.

CORE OVENS. Low-temperature ovens used for baking cores. Maximum operation temperature is 600°F.

CORE PASTE. A prepared adhesive for joining sections of baked or cured cores.

CORE PRINT. Projections attached to a pattern in order to form recesses in the mold at points where cores are to be supported.

CORE, SAG. A decrease in the height of a core, usually accompanied with an increase in width, as a result of insufficient green strength of the sand tosupport its own weight.

CORE SAND. Sand for making cores to which a binding material has been added to obtain good cohesion and porosity after curing. (See CORE, GREEN SAND.)

CORE SHIFT. A variation from specified dimensions of a cored section because of a change in position of the core or misalignment of cores in assembling.

CORE SHOOTER. A device using low air pressure to fluidize a core sand mix. The air is released quickly so that it forces the mix into a core box.

CORE, STRAINER. A baked sand or a refractory disc with holes of a uniform size through its thickness. Used to control the discharge of metal from pouring basins or to regulate the flow of metal in gating systems of molds; also to prevent entrance of dross or slag into the mold cavity.

CORE VENTS. (1) A wax product, round or oval in cross section, used to form the vent passage in a core. Also refers to a metal screen or slotted piece used to form the vent passage in the core box employed in a core blowing machine. (2) Holes made in a core to facilitate the escape of gases.

CORE WASH. A suspension of fine clay or graphite applied to cores by brushing, dipping or spraying to improve the cast surface of the cored portion of the casting.

CRACK, HOT TEAR. A rupture occurring in a casting at or just below the solidifying temperature by a pulling apart of the soft metal; caused by thermal contraction stresses.

CRACKING STRIP. A fin of metal molded on the surface of a casting to prevent cracking.

CRITICAL TEMPERATURE. Temperature at which metal changes phase. In usual iron alloys, the temperature at which alpha iron transforms to gamma iron or vice versa. Actually, a temperature range for cast irons.

CRONING PROCESS (C PROCESS). Now called shell molding or shell core practice. The process was named after its German inventor Johannes Croning. (See SHELL MOLDING.)

CRUCIBLE. A ceramic pot or receptical made of material such as graphite or silicon carbide, with relatively high thermal conductivity, bonded with clay or carbon, and used in melting metals; sometimes applied to pots made of cast iron, steel, or wrought steel. The zone in the cupola between the bottom and the tuyere is also known as the crucible zone. The name is derived from the cross (crux) with which ancient alchemists adorned it.

CRUCIBLE FURNACE. A furnace fired with coke, oil, gas, or electricity in which metals are melted in a refractory crucible.

CUPOLA. A cylindrical shaft furnace lined with refractories for melting metal in direct contact with the fuel by forcing air under pressure through openings near its base.

CUPOLA DROP. The sand bottom, bed, and unmelted charges dropped from the cupola at the end of a heat.

CURING TIME (NO BAKE). That period of time needed before a sand mass reaches maximum hardness and rigidity.

CUTOFF MACHINE, ABRASIVE. A device which uses a thin, bonded abrasive wheel rotating at high speed to cut off gates and risers from castings.

CUTS. Defects in a casting resulting from erosion of the sand by metal flowing over the mold or cored surface.

CYCLONE (CENTRIFUGAL COLLECTOR). In air pollution control, a controlled descending vortex created to spiral objectionable gases and dust to the bottom of a collector cone.


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