Glossary of Terms
that, in addition to carbon, contains one or more elements
in sufficient amounts to appreciably alter properties compared
with those of carbon steel. Materials are alloyed to enhance
physical and mechanical properties such as strength, ductility,
||A heat treating operation wherein
metal is heated to a temperature above its critical range,
held at that temperature long enough to allow full recrystallization,
then slowly cooled through the critical range. Annealing removes
working strains, reduces hardness, and increases ductility.
||Steels containing such proportion
of an alloying element or elements that the austenitic structure
is retained at room temperature.
||Also often called a bloom.
A semifinished product of square, rectangular, or even round cross section, hot rolled, or forged.
Producing billets or blooms from ingots by forging is called cogging, while by rolling it is called blooming.
||A disc-type forging produced
by upsetting and rounding starting stock.
||Machining a hole or enlarging
an existing one with the objective of producing a more accurate
hole than by drilling.
ingot produced by pouring molten steel into a vertical trumpet
where the steel flows down the trumpet, through runners, and
then enters the ingot mold from the bottom. This method provides
substantially improved surface quality and internal soundness,
as well as ingot yield advantages, over top-poured ingots.
||A measurement of a metal hardness
(or ability to resist penetration). A steel ball is forced
into the surface of the material tested under a specific load.
The diameter of the depression is measured, and the hardness
is the ratio of load to spherical area of the impression.
||Steel that owes its properties
chiefly to various percentages of carbon with only residual
amounts of alloying elements (except those added for composition
control such as silicon and manganese).
||Process of pouring molten metal
into a prepared mold cavity of a desired shape and allowing
the metal to solidify.
||Casting process that consists
of pouring molten metal into the cavity of a rotating mold,
which can be made of various materials.
||An impact test in which a specially
V-notched specimen is broken by the impact of a falling pendulum. The energy absorbed in fracture is a measure of the
impact strength or notch toughness of the sample.
||Also called Impression Die Forging.
A forging that is formed to the required shape and size by machined impressions in specially prepared dies that exert three-dimensional control on the workpiece.
||Having a common center.
||Torch cutting or flame cutting
a part to achieve a specific shape or contour.
||A forging die is a steel block
with a flat or contoured working face, which is used in a
hammer or press for shaping metal.
||The property of a metal that
enables it to stretch before rupturing.
||Not having the same center.
||Rate at which electrons move
through atoms causing current to flow.
||The amount of permanent stretch
in a tensile test specimen before rupture.
||Employee Stock Ownership Plan,
describing the employee ownership of a company.
||A part produced by any of a
number of fabricating processes such as forming, rolling,
punching or welding, but especially associated with weldments,
the joining of two or more individual pieces by welding.
||The ability of a metal to withstand
repeated and varying loads.
||Metals that contain iron as
the major alloying element.
||Process of working metal to
the desired shape by impact or pressure from hammers, presses
or forging machines. The metal object so produced is termed
hollow forging with one or more protruding ?ribs? or flanges
on the outside diameter.
gear fabrication including the
outer ring, inner hub, and torch cut stiffening plates.
||The average size of the crystals
or grains in a metal as measured against an accepted standard.
||The mechanical forming of metal
by means of a hammer.
The action of the hammer is that of an instantaneous
application of pressure in the form of a sudden blow.
||The ability of a metal to resist
penetration, defined in terms of the measurement (Brinell,
||A test used to determine the
relative resistance to indentation or displacement of metals
by pressure, or by resistance to abrasion. Common methods
of testing include Brinell, Rockwell, and Vickers tests.
||An operation or combination
of operations involving the heating and cooling of a metal
or alloy in the solid state to attain certain desired microstructure
||The process of producing circular
hollow, tube-like parts by expanding or lengthening the hot
workpiece over a mandrel.
||Part that has been upset forged
using loose tools. This process produces a shape with a smaller
diameter projection from either one or both sides of the major
diameter of the part.
||A casting suitable for working
or remelting; the basic starting stock for the forging process.
||Corrosion of a metal along
its grain boundaries.
||An international family of
specifications and standards for quality assurance management
systems involving a third party for inspection and registration.
||A hardenability test for steel
to determine the depth of hardening obtainable by a specified
||Process to remove excess or
unwanted stock by the use of machine tools for rough or finish
turning, boring, drilling, or milling.
||A nondestructive method of
inspection for determining the existence and extent of possible
defects in ferro-magnetic materials.
Finely divided magnetic
particles, applied to the magnetized
part, are attracted to and outline the pattern of any magnetic
leakage fields created by discontinuities.
||A bar used to retain the cavity
or enlarge the bore during hollow forging.
||A mechanical device for handling
an ingot or a billet during forging.
||Those properties of a material
that reveal the elastic and inelastic reaction when force
is applied, or that involve the relationship between stress
and strain. Mechanical properties are dependent on chemical
composition, forging, and heat treatment.
||Study of the microscopic features
of material surfaces that have been specially prepared by
cutting, grinding, polishing, and etching.
||Science of metals and alloys
devoted to the study of engineering materials.
||Testing technique used for
measuring the hardness of the constituents in the microstructure
of a metal.
||A type of machining operation
used on flat surfaces.
of testing performed on an object that
leaves it unchanged.
||Metals that do not contain
iron as the major alloying element.
||Commonly used heat treatment
that decreases pearlite interlamellar spacing and refines
grain size. The process consists of heating steels above the
transformation temperature range, holding at temperature,
and then cooling in air.
||The mechanical forming of metals
between flat or shaped dies where flow of the metal is not
Die Press, Hydraulic
||A forging press with a hydraulically
round bar that has been centerless machined to remove its
outer surface. The peeling process takes less than one-fourth
the time of conventional lathe-turning operations.
||A finishing operation used
to obtain closer tolerances and a smoother surface on a round
||A custom-designed, computer
controlled GFM single-stand bar mill.
After an initial forging process, bars from 6? to 16?
diameter are sent through a series of reversing passes on
the planishing mill where they are rolled to a smooth surface
in less than 5 minutes.
||Mechanical forming of metals
by means of a press.
The action is that of kneading the metal by relatively
slow application of force as compared with the action of hammering.
||A forged rolled ring with a
contoured or profiled cross section achieved during the rolling
||Rapid cooling of a heated metal,
generally by immersion in liquids, to increase strength and
hardness. Quenching is always followed by a temper to increase
||Equipment used to produce forged
rolled rings. A metal ring preform is rolled between two rolls
that move toward each other to form a continuously reducing
||Material that has been upset
and pierced to form a hollow ?donut?. This is the starting
stock needed to produce a rolled ring.
||A forged seamless ring produced
on a ring mill.
||A machining operation that
allows stock for subsequent finish machining.
||Metalworking process used to
cut starting ingot or billet stock to length in preparation
for the forging process and also to trim forged parts to size.
||As used in this reference,
all metalworking processes that follow the forging process.
Typical secondary processes are heat treating, rough machining,
trimming, torch cutting, and testing.
that warehouses and markets semifinished
metal products such as bars, plate, sheet or structurals.
metal cleaning or finishing process in which a fluid blast
blows abrasive steel balls against the surface.
performed to verify a material chemistry.
||Also referred to as a stepdown
shaft. A longitudinal bar-type product with more than one
diameter or cross section size.
Hammer, Open Die
uses steam both to drive the hammer down for a working blow
to the workpiece and reposition it for the next blow.
||Also referred to as a spindle.
A longitudinal bar-type product with more than one diameter
or cross section size.
||Round bars 6? to 16? diameter
with a forged center and rolled bar surface produced only
by Scot Forge.
||Heat treat process performed
after quenching or normalizing. The forging is heated to a
temperature below the critical temperatures and cooled at
a suitable rate. Tempering steel after hardening to relieve
quenching stresses ensures dimensional stability and obtains
specified mechanical properties.
||The maximum load per unit of
initial cross-sectional area obtained before rupture in a
||A tension-testing machine mechanically
or hydraulically applies a tensile load to a specimen. The
test establishes ultimate strength, yield strength, and ductility
(elongation and reduction of area).
||The cutting or parting of steel
objects with a torch using a flame with excess oxygen to completely
oxidize or ?burn? the steel directly in the path of the flame;
||Test used to assess the resistance
of metals to brittle fracture propagation (spreading) in the
presence of stress raisers.
||Removing metal from the outside
of a part by means of a tool in a lathe or similar machine
||A method of nondestructive
testing of solid metal for internal flaws utilizing high frequency
||Working metal so that the cross-sectional
area of a portion or all the stock is increased.
||A die having two working surfaces
at equal opposing angles to the vertical.