To withdraw a molten charge from the melting unit.
Opening in a furnace through which molten metal is tapped into the forehearth or ladle. See Ladle.
Ladle with external spout wherein the molten metal is poured from the bottom rather than from the top. See Ladle.
Same meaning as hot crack, but developing before the casting has solidified completely. See Hot Crack.
Defect caused by backdraft, damaged pattern or uneven drawing of pattern. See Defect.
Reheating hardened, normalized or mechanically worked steel to a temperature below the critical range to soften it and improve impact strength. The moisture content of a sand at which any certain physical test value is obtained, i.e., temper with respect to green compressive strength, permeability, retained compressive strength, etc. To mix material with enough liquid to develop desired molding properties.
Brittleness that results when certain steels are held within or cooled slowly through a certain range of temperature below the transformation range. The brittleness is revealed by notched-bar impact tests at room temperature or lower temperatures.
Carbon in nodular form, characteristic of malleable iron.
Quenching in water from the tempering temperature to improve fatigue strength.
Degree of warmth or coldness in relation to an arbitrary zero measured on one or more of accepted scales, as Centigrade, Fahrenheit, etc.
Temperature above the critical phase transformation range at which castings are held as a part of the heat treatment cycle. The temperature maintained when metal is held in a furnace, usually prior to pouring.
The temperature of the metal as it is poured into the mold.
Martensite that has been heated to produce to BCC iron and a fine dispersion of iron carbide. See Martensite.
Addition of water to and mixing molding sand to obtain uniform distribution of moisture. See Molding Sand.
A measure of the amount of mechanical stress a material can withstand before it fractures. Measured in pounds per square inch (PSI), or thousands of pounds per square inch (KSI).
An alloy that contains three principal elements.
Standard specimen bar designed to permit determination of mechanical properties of the metal from which it was poured.
A lug cast as a part of the casting and later removed for testing purposes.
The property of matter by which heat energy is transmitted through particles in contact. For engineering purposes, the amount of heat conducted through refractories is usually given in Btu per hour for one square foot of area, for a temperature difference of one degree Fahrenheit, and for a thickness of one inch, Btu/hr·ft·F/in.
The decrease in a linear dimension and volume of a material accompanying a change of temperature.
The increase in a linear dimension and volume of a material accompanying a change of temperature.
Failure resulting from rapid cycles of alternate heating and cooling.
Stress developed by rapid and uneven heating of a material.
Breaking up of refractory from stresses which arise during repeated heating and cooling.
Resistance of a material to drastic changes in temperature.
Exothermic, self-propagating processes in which finely divided aluminum powder is used to reduce metal oxides to free metals by direct oxidation of aluminum to aluminum oxide, with accompanying reduction of the less stable metal oxide. See Exothermic Reaction, Endothermic Reaction.
A device for measuring temperatures by the use of two dissimilar metals in contact; the junction of these metals gives rise to a measurable electrical potential which varies with the temperature of the junction. Thermocouples are used to operate temperature indicators or heat controls.
The technique of obtaining a photographic record of heat distribution in a solid or fluid.
Rod-bar or rod-shaped part of the casting added to prevent distortion caused by uneven contraction between separated members.
A chemical element having symbol Sn, formula weight 118.70, specific gravity 7.31, and melting point 231.85°C.
Beads or exudations of a tin-rich low-melting phase found on the surface of or on risers of bronze castings, which are usually caused from absorption of hydrogen by the molten metal.
A white metallic element, melting point 1660°C (3020°F), having a high strength-to-weight ratio; useful in aircraft parts.
The permissible deviation of a dimension from the nominal or desired value. Minimum clearance between mating parts.
Metal instrument with two legs joined by a hinger for grasping and holding things, e.g., crucible tongs.
Any high-carbon or alloy steel used to make a cutting tool for machining metals and for metal-casting dies.
The fixed positions on the casting surfaces used for references during layout and machining.
A wood board on the cope half of the mold to permit squeezing the mold. See Squeeze Board.
The ability of the metal to absorb energy and to deform plastically during fracture. Toughness values obtained in testing depend upon the test temperature, the rate of loading, the size of the test specimen, as well as the presence of a notch and its acuity.
Vertical, continuous core oven with suspended shelves attached to sprocket-driven chains.
Tramp Element (Trace)
Contaminant in the components of a furnace charge, or in the molten metal or casting, whose presence is felt to be either unimportant or undesirable to the quality of the casting.
Transformation (Temperature) Range
The critical temperature at which a change in phase occurs. To distinguish between the critical points in heating and cooling those in heating are referred to as the Ac points (c for Chauffage or heating) and those in cooling, Ar (r for Refroidissement).
Die for shearing (or shaving) flash from a die-casting.
Tool for sleeking, patching, and finishing a mold.
A revolving metal, wood box, or barrel in which castings are cleaned.
Steel-gray, metallic element, mp 3380°C (6116°F) used for electric lamp filament, x-ray tube target, and as alloy element in high-speed steels.
The base on which a centrifugal casting mold rests.
Opening in the cupola where the air blast enters. See Cupola.