Casting Terms Flashcards
The removal of material from a surface when hard particles slide or roll across the surface under pressure.
Abrasive Wear
A test performed on material assemblies that are meant to produce failures caused by the same failure mechanism as expected in field operation but in significantly shorter time.
Accelerated Testing
A highly sub structured none-quiaxed ferrite formed upon continuous cooling by a mixed diffusion and shear mode of transformation that begins at a temperature slightly higher than the transformation temperature range for upper bainite.
Acicular Ferrite
A measure of integrity of a material, as determined by sound emission when a material is stressed.
Acoustic Emission
The negative direction of electrode potential; also used to describe corrosion and its associated potential range when an electrode potential is more negative than an adjacent depressed corrosion rate (passive) range.
Active
Wear due to localized bonding between contacting solid surfaces leading to material transfer between the two surfaces or loss from either surface.
Adhesive Wear
A change in the properties of certain metals and alloys that occurs at ambient or moderately elevated temperatures after hot working or a heat treatment or after a cold-working operation.
Aging (Age Hardening)
A steel containing sufficient carbon and other alloying elements to harden fully during cooling in air or other gaseous media from a temperature above its transformation range.
Air-Hardening Steel
Composite wrought product comprised of an aluminum alloy core having one or both surfaces a metallurgically bonded aluminum or aluminum alloy coating that protects the core against corrosion.
Alclad
(1) A near synonym for polymorphism. Allotropy is generally restricted to describing polymorphic behavior in elements, terminal phases, and alloys whose behavior closely parallels that of the predominant constituent element. (2) The existence of a substance, especially an element, in two or more physical states (for example, crystals).
Allotropy
A substance having metallic properties and being composed of two or more chemical elements of which at least one is a metal.
Alloy
The body-centered cubic form of pure iron, stable below 910 °C (1670 °F).
Alpha Iron
Not having a crystal structure; noncrystalline.
Amorphous
The characteristic of exhibiting different values of a property in different directions with respect to a fixed reference system in the material.
Anisotropy
Term denoting a treatment consisting of heating to and holding at a suitable temperature followed by cooling at a suitable rate, used primarily to soften metallic materials, but also to simultaneously produce desired changes in other properties or in microstructure.
Annealing
The electrode of an electrolyte cell at which oxidation occurs. Electrons flow away from the anode in the external circuit. It is usually at the electrode that corrosion occurs and metal ions enter solution.
Anode
Forming a conversion coating on a metal surface by anodic oxidation; most frequently applied to aluminum.
Anodizing
The weight per unit volume of a powder, in contrast to the weight per unit volume of the individual particles. Is always less than the true density of the material itself.
Apparent Density
A secondary refining process for the controlled oxidation of carbon in a steel melt.
Argon Oxygen Decarburization (AOD)
Aging above room temperature.
Artificial Aging
The gradual degradation or alteration of a material by contact, with substances present in the atmosphere, such as oxygen, carbon dioxide, water vapor, and sulfur and chlorine compounds.
Atmospheric Corrosion
A heat treatment for ferrous alloys in which a part is quenched from the austenitizing temperature at a rate fast enough to avoid formation of ferrite or pearlite and then held at a temperature just above M, until transformation to bainite is complete. Steel consists of two phase mixtures containing ferrite and carbide, while ductile iron consists of two phase mixtures containing ferrite and austenite.
Austempering
A solid solution of one or more elements in face-centered cubic iron (gamma iron).
Austenite
The most common grade is the 1818 or 304 grade which contains 18% chromium and 8% nickel.
Austenitic Stainless Steel
Heating a ferrous alloy into the transformation range (partial) or above the transformation range.
Austenitizing
A metastable aggregate of ferrite and cementite resulting from the transformation of austenite at temperatures below the pearlite range but above M the martensite start temperature.
Bainite
Inhomogeneous distribution of alloying elements or phases aligned in filaments or plates parallel to the direction of working.
Banding
Refractories whose major constituent is lime, magnesia, or both, and which may react chemically with acid refractories, acid slags, or acid fluxes at high temperatures.
Basic Refractories
Macroscopic progression marks on a fatigue fracture or stress-corrosion cracking surface that indicate successive positions of the advancing crack front. The classic appearance is of irregular elliptical or semielliptical rings, radiating outward from one or more origins.
Beach Marks
A black finish on a metal produced by immersing it in hot oxidizing salts or salt solutions.
Black Oxide
A shaft furnace in which solid fuel is burned (usually coke) with an air blast to smelt ore in a continuous operation. Where the temperature must be high, as in the production of pig iron, the air is preheated.
Blast Furnace
A process for cleaning or finishing metal objects with an air blast or centrifugal wheel that throws abrasive particles against the surface of the workpiece.
Blast Cleaning
A hole in a casting or a weld caused by gas entrapped during solidification.
Blowhole
Exhibited by some steels after being heated to some temperature within the range of about 205 to 370 °C (400 to 700 °F), particularly if the steel is worked at the elevated temperature.
Blue Brittleness
A relatively short protrusion or projection from the surface of a forging or casting, often cylindrical in shape; usually intended for drilling and tapping for attaching parts.
Boss
A copper-zinc alloy containing up to 40% Zn, to which smaller amounts of other elements may be added.
Brass
A test for determining the hardness of a material by forcing a hard steel or carbide ball of specified diameter (typically, 10 mm) into it under a specified load.
Brinell Hardness Test
Separation of a solid accompanied by little or no macroscopic plastic deformation.
Brittle Fracture
The tendency of a material to fracture without first undergoing significant plastic deformation.
Brittleness
A copper-rich copper-tin alloy with or without small proportions of other elements such as zinc and phosphorus.
Bronze
A mode of failure generally characterized by an unstable lateral material deflection due to compressive action on the structural element involved.
Buckling
Deviation from edge straightness, usually referring to the greatest deviation of side edge from a straight line.
Camber
The phenomenon of intrusion of a liquid into interconnected small voids, pores, and channels in a solid, resulting from surface tension.
Capillary Action
A compound of carbon with one or more metallic elements.
Carbide
For rating of weldability.
Carbon Equivalent (CE = C + Mn/6 + Ni/15 + Cu/15 + Cr/5 + Mo/5 + V/5)
A case-hardening process in which a suitable ferrous material is heated above the lower transformation temperature in a gaseous atmosphere of such composition as to cause simultaneous absorption of carbon and nitrogen by the surface and, by diffusion, create a concentration gradient.
Carbonitriding
A measure of the ability of an environment containing active carbon to alter or maintain, under prescribed conditions, the carbon level of a steel.
Carbon Potential
Steel having no specified minimum quantity for any alloying element.
Carbon Steel (Low-carbon steels contain up to 0.30% C, medium-carbon steels contain from 0.30 to 0.60% C, and high-carbon steels contain from 0.60 to 1.00% C.)
Absorption and diffusion of carbon into solid ferrous alloys by heating, to a temperature usually above Ac3, in contact with a suitable carbonaceous material. A form of case hardening that produces a carbon gradient extending inward from the surface, enabling the surface layer to be hardened.
Carburizing
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.
Case Hardening
A complex combination of liquid-metal properties and solidification characteristics that promotes accurate and sound final castings.
Castability
Pouring molten metal into a mold to produce an object of desired shape.
Casting
Any imperfection in a casting that does not satisfy one or more of the required design or quality specifications.
Casting defect
