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I-Beams
Structural sections on which the flanges are tapered and are
typically not as long as the flanges on wide-flange beams. The
flanges are thicker at the cross sections and thinner at the
toes of the flanges.
ID
Inside Diameter (of coil or pipe).
Immersed Scanning
In ultrasonic, a planned,
systematic movement of the beam relative to the object being
inspected, the search unit being coupled to this object
through a column of liquid. In most cases the object and the
search unit are submerged in water.
Impact Energy (Impact Value)
The amount of energy required to fracture a material,
usually measured by means of an Izod or Charpy test. The type
of specimen and testing conditions affect the values and
therefore should be specified.
Impact
Test
Test designed to determine
the resistance of metal to breakage by impact, usually by
concentrating the applied stress to a notched specimen.
Impurities
Elements or compounds whose
presence in a material is undesired.
Included angle
The angle between the planes of the fusion faces of parts to
be welded.
Inclusion
A nonmetallic material in a solid metallic martial
Slag or other foreign matter entrapped during welding. The
defect is usually more irregular in shape than a gas pore.
Inclusion Shape Control
The use of rare earth
metals or calcium alloys to control the morphology of
inclusions, in order to provide improved mechanical
properties for select applications.
Incomplete root penetration
Failure of weld metal to extend into the root of a joint.
Incompletely filled
groove
A continuous or intermittent channel in the surface of a
weld, running along its length, due to insufficient weld
metal. The channel may be along the centre or along one or
both edges of the weld.
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.
Induction
Hardening
A process of hardening a ferrous alloy by heating it above
the transformation range by means of electrical induction,
and then cooling as required. Quench hardening in which the
heat is generated by electrical induction.
Induction
Heating
A process of heating by
electrical induction.
Inert-Gas Shielded-Arc Welding
Arc welding in an inert gas such as argon or helium.
Intercoat Adhesion
The adherence which
is observed between the primer and topcoat of a paint system.
Intercrystalline
Between crystals, or between grains. Same as
intergranular.
Intermittent weld
A series of welds at intervals along a joint.
Internal Oxidation
Formation of oxides
beneath the surface of a metal.
Interrupted Aging
The aging of an alloy at two or more temperatures by steps,
and cooling to room temperature after each step.
Ingot
A form of semi-finished steel. Liquid steel is teemed
(poured) into molds, where it slowly solidifies. Once the
steel is solid, the mold is stripped, and the 25- to 30-ton
ingots are then ready for subsequent rolling or forging.
Ingot casting
A technique for solidifying molten steel by pouring it into
cast iron ingot molds.
Ingot
Iron
Commercially pure
open-hearth iron.
Inhibitor
A substance which retards
some specific chemical reaction. Pickling inhibitors retard
the sis solution of metal without hindering the removal of
scale from steel.
Inmetco
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WHAT
Inmetco is a coal-based process similar to FASTMET
that uses iron oxide fines and pulverized coal to produce a
scrap substitute. Mill scale and flue dust, inexpensive
byproducts of steelmaking, can be mixed with the iron oxide
fines. Inmetco, unlike other direct reduction products, is
intended to be hot charged into an EAF, with attendant energy
savings.
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HOW
The process includes three steps. First, iron oxide
fines, pulverized coal and a binder are formed into pellets.
Second, the pellets, two to three layers deep, are heated in a
gas-fired rotary hearth furnace for 15-20 minutes to produce
sponge iron. Subsequently, the iron must be de-sulphurized. The
coal in the pellets provides much of the energy required in
the second phase.
Integrated Mills
These facilities make steel by processing iron ore and other
raw materials in blast furnaces. Technically, only the hot end
differentiates integrated mills from mini-mills. However, the
differing technological approaches to molten steel imply
different scale efficiencies and, therefore, separate
management styles, labor relations and product markets. Nearly
all domestic integrated mills specialize in flat-rolled steel
or plate.
Integrated Producer A producer who also owns the smelting and semi-fabricating facilities.
Interleaving
The placing of a sheet of
paper between two adjacent layers of metal to facilitate
handling and shearing of rectangular sheets, or to prevent
sticking or scratching.
Intermediate Annealing
An annealing treatment given to wrought metals following cold work hardening for the purpose of softness prior to further cold working.
(See Process Annealing)
Interrupted Aging
The aging of an alloy at two or more temperatures by steps, and cooling to room temperatures after each step. Compare with
Progressive Aging.
Interstitial Free Steel
A recently developed sheet steel product with very low carbon
levels that is used primarily in automotive deep-drawing
applications. Interstitial Free Steel's improved ductility
(drawing ability) is made possible by vacuum degassing.
Investment
Casting
(1) Casting metal into a mold produced by surrounding
(investing) an expendable pattern with a refractory slurry
that sets at room temperature after which the wax, plastic, or
frozen mercury pattern is removed through the use of heat.
Also called precision casting, or lost-wax process.
(2) A
casting made by the process.
Iron
(Chemical symbol Fe.)
Element No. 26 of the periodic system; Atomic weight 55.85. A
magnetic silver white metal of high tensile strength, ductile
and malleable. Melting point of pure iron about 2795 (degrees)
F. Chemically iron is chiefly base forming. The principal
forms of commercial iron are steel, cast iron and wrought
iron.
Iron Carbide
One of several substitutes for high-quality, low-residual
scrap for use in electric furnace steelmaking.
Iron carbide producers use natural gas to reduce iron ore to
iron carbide.
Iron Ore
Mineral containing enough iron to be a commercially viable
source of the element for use in steelmaking. Except for
fragments of meteorites found on Earth, iron is not a free
element; instead, it is trapped in the earth's crust in its
oxidized form.
Ironing
Thinning the walls of deep drawn articles by reducing the clearance between punch and die.
Isothermal Annealing
A process on 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
A change in phase at any constant temperature.
Isothermal Transformation (IT) Diagram
A diagram that shows the isothermal time required for
transformation of austenite to commence and to finish as a
function of temperature. Same as
time-temperature-transformation (TTT) diagram or S-curve.
Izod Test
A pendulum type of single-blow impact test in which the
specimen, usually notched, is fixed at one end and broken by a
falling pendulum. The energy absorbed, as measured by the
subsequent rise of the pendulum, is a measure of impact
strength or notch toughness.
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