I

ICI: See Investment Casting Institute.

ID Grinding:  Term for internal (dimension) grinding. IHA . . . Industrial Heating Association.

Illinois Inclusion Count Method: A determination of the index number of cleanliness of steel.

lllite: A mineral, typically KAI:,Si:,O,O(OH)2 found in many clays, large workings of which are found in Illinois and Michigan.

IM & AWI:  See International Molders & Allied Workers Union.

Impact Strength:  The resistance a material is capable of developing against impact blows; usually expressed as the foot pounds of energy necessary
to break a standard specimen. See lzod Test; Charpy Test.

Impact Value: Total energy needed to break a standard specimen by a single blow under standard conditions; e.g., izod and charpy

Impoverishment:  Loss of any constituent from an alloy or from localized areas of an alloy by oxidization, liquidation, volatilization or changes in the
solid state. The term depletion is also used, particularly in referring to the lowering of the concentration of solute in a solid solution, around particles
precipitated from solid solution.

Impregnation:  The treatment of castings with a sealing medium to stop pressure leaks; such as soaking under pressure with or without prior evacuation
and either with hot or cold application. Mediums used include silicate of soda, drying oils with or without styrenes, plastics, and proprietary compounds.

Impurity: Any element unintentionally allowed in a metal or alloy. Some impurities have little effect on properties; others will grossly damage the alloy.

lnconel: An oxidation-resistant alloy, 80% Ni, 14% Cr and 6% Fe.

Indentation Hardness: The resistance of a material to indentation. This is the usual type of hardness test, in which a pointed or rounded indenter is
pressed into a surface under a substantially static load. See Hardness, Brinell and Hardness, Rockwell.

Indirect-Arc Furnace: An electric-arc furnace in which the metal is not one of the poles of the arc.

Induction Furnace: A melting furnace which utilizes the heat of electrical induction.

Induction Heating: Process of heating by electrical induction.

Inert Gas:  A gas that will not support combustion or sustain any chemical reaction; e.g., argon or helium.

Information System: In EDP and automated foundry operation, a feedback system in which quality information concerning the entire operation is automatically gathered, analyzed and disseminated. It should report all facts as soon as they occur relating to castings in order to improve the casting
processes, assist sales, inventory and production.

Infrared Radiation Pyrometer:  This instrument uses the fact that the ratio of the radiated energy in two wavelength bands received from a hot body is
a measure of the body’s surface temperature. Temperatures down to 200 C (392 F) may be measured.

Infrared Rays:  Pertaining to or designating those rays which lie just beyond the red end of the visible spectrum, such as are emitted by a hot non-incadescent body. They are invisible and nonactinic and are detected by their thermal effect. Their wave lengths are longer than those of visible light
and shorter than those of radio waves. Can be applied in the foundry for drying or core baking operations and for heating dies. Infrared radiation and radiant
heat are synonymous.

Infrared Dryer: A core or mold dryer employing infrared lamps.

lnfusorial Earth (Diatomite, Fossil Flour, Mountain Meal, Mountain Flour, Tripolite, Kieselguhr):  A very fine whitish powder composed of the siliceous skeletons of infusorians (Protozoa).

Ingot:  A mass of metal cast to a convenient size and shape for remelting or hot working.

Ingot Iron:  Iron of comparatively high purity produced in open-hearth furnace under conditions that keep down the carbon, manganese and silicon content; e.g., Armco Iron.

Injection Molding: The injection of molten metal or other material under pressure into molds.

lnoculant: Material which when added to molten metal modifies the structure, and thereby changes the physical and mechanical properties to a degree
not explained on the basis of the change in composition resulting from its use.

Inoculation:  Addition to molten metal of substances designed to form nuclei for crystallization. See also Inoculant.

Input: In EDP, information transferred into internal computer storage.

Institute of Scrap Iron & Steel, Inc:  1729 H St., N.W., Washington, D.C. 20006, William S. Story, Executive Vice President.

Instruction:  In EDP, a set of characters defining an operation, with or without addresses, which cause the computer to operate according to
pre-arranged programs.

Insulating Pads and Sleeves: As opposed to chills, insulating material, such as gypsum, diatomaceous earth, etc., used to lower the rate of solidification.
As sleeves on open risers, they are used to keep the metal liquid, thus increasing the feeding efficiency.

Integral Dose (Volume Dose):  A measure of the total energy absorbed by man or any object during exposure to radiation.

Intensity (Radiology): Amount of energy per unit time passing through a unit area perpendicular to the line of propagation at the point in question. Often this term is used incorrectly in the sense of dose rate.

lntercast Process:  A patented procedure for die casting “cast-assembled” units with moving parts.

lntercrystalline Failure:  Cracks or fractures that follow along the grain boundaries in the microstructure of metals and alloys.

lnterdendritic Attack:  A type of electrochemical corrosion that sometimes occurs in as-cast alloys or alloys that have had very little working.

lntergranular Corrosion:  Corrosion in a metal taking place preferentially along the grain boundaries.

Internal Friction:  Ability of a metal to transform vibratory energy into heat; generally refers to low stress levels of vibration; damping has a broader connotation since it may refer to stresses approaching or exceeding the yield strength.

Internal Shrinkage: A void or network of voids within a casting caused by improper feeding of that section during solidification.

Internal Stresses: A system of balanced forces existing within a part when not subjected to a working load. These stresses are frequently caused by
contraction of a casting as it cools.

International Molders & Allied Workers Union of America:  900 15th St., N.W., Washington, D.C. 20005, W. A. Boyle, President.

Interrupted Quench: Removing the casting from a quenching bath before it has reached the temperature of the bath.

Invar:  An alloy having practically no expansion when heated, 36% Ni, 0.5% Mn, 0.2% C and the balance Fe.

Inverse Segregation:  A concentration of certain alloy constituents that have lower melting points in the region corresponding to that first solidifying; caused by interdendritic flow of enriched liquid through channels where the pressure drops with contraction of dendrites. The internal evolution of
hydrogen may also give a positive pressure, aiding this flow and causing a liquated surface as tin sweat. See also Segregation.

Inversion: A change in crystal form without change -in chemical composition, as from quartz to cristobalite.

Inversion Casting: 1. The metal is fed through a bottom feeder, the mold being inverted for pouring, 2. the mold is directly attached to the electric furnace
in which the metal is melted in a reducing atmosphere so no slag is formed. On inverting the furnace the metal runs into the mold. There are no heavy
feeders and oxidation is prevented.

Investing:  The process of pouring the investment slurry into the flask surrounding the pattern to form the mold.

Investment:  A flowable mixture of a graded refractory filler, a binder and a liquid vehicle which when poured around the patterns conforms to their shape
and subsequently sets hard to form the investment mold.

Investment Casting Institute:  3525 W. Peterson Road, Chicago, Ill. 60645, Ray E. Pritchard, Executive Director.

Investment Precoat:  An extremely fine investment coating applied as a thin slurry directly to the surface of the pattern to reproduce maximum surface
smoothness. The coating is surrounded by a coarser, cheaper, and more permeable investment to form the mold. See Dip Coat.

Inwall Brick: Refractory lining of the inwall section of blast furnace or cupola.

Ionization: The process or the result of any process by which a neutral atom or molecule acquires either a positive or a negative charge.

Ionization Chamber: An instrument designed to measure quantity of ionizing radiation in terms of the charge of electricity associated with ions produced
within a defined volume.

Iridium: A noble metal of the platinum group.

Iron: 1. A metallic element, mp 1535 C (2795 F) 2. irons not failing into the steel categories, as Gray Iron, Malleable Iron, White Iron, Ingot and Wrought Iron.

Iron Carbide: See Cementite.

Iron, Hard or White:  Irons (Fe,,C) possessing white fractures because all or substantially all of the carbon is in the combined form. Irons to be malleabled,
ire cast white, as are many abrasion-resistant irons.

Iron-Iron Carbide Diagram:  A diagram plotting temperatures vertically and carbon contents horizontally representing metastable equilibrium conditions
between Fe and Fe:,C over the entire range of carbon steels and cast irons.

Iron-Carbon (Graphite) Diagram:  A diagram plotting temperatures vertically and carbon content horizontally, representing stable equilibrium conditions
between iron and graphite (pure carbon) phase over the entire range of iron and steel.

Iron, Malleable:  A mixture r of iron and carbon, including smaller amounts of silicon, manganese, phosphorus and sulfur, which after being cast (white iron,
carbon in combined form ‘as carbides) is converted structurally by heat treatment into a matrix of ferrite containing nodules of temper carbon (graphite).

Iron Oxide:  This material as prepared -for foundry use generally contains about 85% ferric oxide and is produced by pulverizing a high grade of pure iron ore. It can be added to core sand mixes to assist in keeping the core from cracking before the metal solidifies during the casting operation and also helps
to resist metal penetration during this period. It is also added to molding sand mixtures for control of finning and veining.

Iron, Pearlitic Malleable: A malleable iron having a more or less pearlitic matrix.

Iron Sand:  See lserine.

IS&R: In EDP, information storage and retrieval.

Iserine: A black sand which consists mainly of magnetic iron ore but also contains a considerable amount of titanium.

Isocure: Proprietary name for a binder system developed for use in Ashland (cold box) Process, itself a proprietary process.

lsocyanate Acid: Isomeric cyanic acid (HNCO).

lsomorphous: Phases with crystal structures of the same type.

Isothermal:  Pertaining to changes or other phenomena occurring at a constant temperature.

Isothermal Annealing:  A process in which a ferrous alloy is heated to produce a structure partly or wholly austenitic, and is then cooled to and held at a
temperature that causes transformation of the Austenite to a relatively soft ferrite-carbide aggregate.

Isothermal Transformation:  1. The process of transforming Austenite in a ferrous alloy to Ferrite or a ferrite-carbide aggregate at any constant temperature within the transformation range, 2. transformation of one phase in an alloy system to another phase at,any constant temperature.