Steel Terms Glossary
Additions: Materials, typically alloy elements,
added to molten steel to produce the chemical
specifications for the desired steel grade.
Alloy: A substance that has metallic properties
and is composed of two or more chemical
elements of which at least one is a metal.
Alloy steel: Steel containing one or more alloying
element. Steel is classified as alloy when the
maximum content of alloying elements exceeds
one or more of the following: manganese 1.65%,
silicon 0.60%, copper 0.60%.
Alloying elements: Chemical elements added for
improving the properties of the finished products.
Some alloying elements are nickel, chromium,
manganese, molybdenum, and silicon.
Annealing: A process involving heating and
cooling, usually applied to induce softening of
steel. The term also refers to treatments intended
to alter mechanical or physical properties, produce
a definite microstructure or remove gasses.
Argon shroud: A procedure using argon gas to
shield molten steel from oxygen as it is teemed
from the ladle.
Argon stirring: An inert gas introduced through
the a nozzle to stir molten steel to promote
chemical and temperature homogenization and
float out inclusions.
Austenite: High-temperature solid form of steel
with face-centered cubic crystal structure.
Billet: A semifinished piece of steel that results
from rolling an ingot or a bloom. It may be square
but is never more than twice as wide as thick. Its
cross-sectional area is usually not more than 36
square inches.
diameter of an indentation made by a steel ball
under a given load.
Butt: An unfinished or incomplete ingot.
Carbide: A compound of iron (or other element)
and carbon in steel forming a very hard
nonmetallic substance (Fe3C). Fe3C is also called
cementite.
Casting: Pouring molten metal into a mold, or the
metal object (i.e. Ingot) produced by such pouring.
Casting powder: A powder applied to the inside
of a mold before teeming to prevent the metal
from sticking to the mold.
Charge: To load a furnace with scrap and flux
prior to melting, or to load a soaking pit with
ingots for reheating.
Chemistry: The chemical constituents of a heat of
steel.
Cold working: Rolling or drawing semi-finished
steel products to provide higher physical
properties or better surfaces than can be produced
by hot-working
Continuous caster: A machine used to
continuously produce blooms from molten steel
with no interruptions or intermediate operations.
Creep: Failure of a metal caused by gradual
elongation due to constant stress.
Crystal: Physically uniform solids composed of
atoms bonded together in a definite geometrical
pattern or structure.
Critical temperature: The temperature at which a
steel transforms one crystal structure into another
because of atom rearrangement.
Bloom: A semifinished piece of steel resulting
from the rolling or forging of an ingot. A bloom
is square or not more than twice as wide as thick
and usually not less than 36 square inches in
cross-sectional area.
Continuous Thermal Treatment Facility
(CTTF): Facility at Gambrinus that includes
austenitizing and tempering furnaces, straightener,
carbide saw, cooling beds, and transfer tables that
are used for heat treatment of steel.
Bloom shear: A shear used to cut a rolled ingot
into shorter bloom lengths or to cut off the ends of
a blooms.
Decarburization: Loss of carbon at the steel
surface caused by poor atmosphere control.
Blowhole: An internal cavity in steel produced by
gases during the solidification of the metal.
Degassing: Lowering the hydrogen and oxygen
content of the steel by placing the molten steel in a
vacuum.
Bottom pouring: The process of pouring ingots
using a refractory runner system to fill them from
the bottom of the ingot molds.
Dendrites: Crystals that form in a tree-like pattern
during solidification.
Breakout: Liquid steel flowing through the shell
of a ladle or EAF.
Diffusion: Movement of atoms in solids. Heat
provides the energy for atom movement.
Brinnel hardness: A hardness test commonly
used for soft steel and metals which measures
Draw: To empty a soaking pit one ingot at a time
to feed rolling operations (FSP), or to pull steel
Deoxidize: Removal of oxygen from steel.
Steel Terms Glossary
(usually cold) through a die to change its
dimensions and mechanical properties.
Ductility: Ability to undergo permanent changes
of shape without rupturing.
Elastic deformation: Temporary distortion of a
material under the action of applied stresses.
Electric arc furnace (EAF): A refractory-lined
steel vessel used to melt steel. An electric arc
generates the heat.
Electrode: A carbon (graphite) rod that carries
electricity to melt the scrap in an eaf.
Endothermic: A chemical change in which there
is absorption of heat.
Etch: A steel sample treated with acid to reveal its
microstructure; used to visually check conditions
such as porosity, large inclusions, or other
nonconformities.
Exothermic: A chemical change in which there is
liberation of heat.
Fatigue: Failure of metal due to repeated cyclic
stressing.
Fettle: To prepare a furnace for charging and
melting by repairing eroded areas of the
refractory.
Heat treatment: A combination of heating and
cooling operations applied to a metal or alloy to
obtain desired microstructure conditions or
properties.
Heel: Molten steel left in the furnace after
tapping.
Hot top: An insulated reservoir on top of an ingot
mold that retains heat and holds excess molten
metal to feed the ingot and it shrinks.
Hot top compound: Insulating material placed on
top of the molten metal after the mold is filled.
Hot working: Plastic deformation of metal at
specific temperature and rate to prevent strain
hardening from occurring.
Immersion sample: Sample taken directly from
the molten steel for chemical analysis.
Impact test: A test to determine energy
absorption obtained by fracturing a test bar at high
velocity.
Inclusion: Particles of nonmetallic impurities that
are mechanically held in steel during
solidification, usually oxides, sulphides, and
silicates.
Ingot: Steel, formerly in a molten state,
transferred to an ingot mold to solidify.
Flash sticker: An ingot that will not separate from
the mold because of leakage that occurred
between the mold and the mold stool.
Ingot mold: A form into which molten steel is
poured to solidify.
Flux: A slag-making ingredient or the increased
fluidity of slag.
Iron: A pure metal that serves as the basis for
steel, cast iron, stainless steel. Iron is relatively
weak and soft when in its pure form.
Forging: Forming hot metal in the desired shape
by means of hammering or pressing.
Freeze: Solidify molten steel as it cools from the
liquid to solid state.
Grade: Classification of steel based on carbon
content or mechanical properties.
Grain: Orderly arrangement of atoms or crystal
structure. Individual crystal of a microstructure.
Grinding: Method of conditioning steel by
removing surface flaws using a power-driven
grinding wheel.
Hardenability: The depth and distribution of
hardness below the surface of steel.
Hardening: The process of increases the hardness
of steel through controlled heating and cooling.
Hardness: Resistance to indentation.
Heat: An individual batch of metal as it is treated
in a furnace.
Jominy test: Hardenability test usually performed
on alloy steels.
Killed steel: Steel that is deoxidized with a strong
deoxidizing agent such as silicon or aluminum.
Reducing the oxygen content minimizes chemical
reaction between carbon and oxygen during
solidification.
Ladle: A vessel for receiving and handling liquid
steel. It is constructed of a refractory-lined steel
shell.
Ladle refining system (LRS): System where
alloys are added to meet exact chemistries, gases
are removed by vacuum, argon bubbles stir the
molten mixture to remove impurities and mix the
alloying elements. Arc heating maintains steel
temperature.
Low-alloy steel: Steel containing up to 5%
alloying elements other than carbon.
Makeup: Relining ladles or furnace with
refractories.
Steel Terms Glossary
Martensite: Room temperature structure of steel
formed as a result of a rapid quench from the
austenitic condition. Hard, strong, and brittle
structure.
Mechanical properties: Those properties of a
material that reveal the elastic and inelastic
reaction when force is applied or that improve the
relationship between stress and strain.
Melt down: The process in which steel is
transferred from the solid state into the liquid state
by introducing electrical power to the scrap in the
electric furnace.
Microstructure: Microscopic structure of steel.
Under a microscope, certain elements of the
solidified metal are visible (crystal structure).
Modulus of elasticity: A measurement of the
stress per unit strain--an indication of the
resistance of the steel to deformation within its
elastic limit.
Mold: An iron casting container used to hold and
cool molten metal as it solidifies.
Mold cluster: A series of 6 or 8 molds positioned
in a circular arrangement interconnected by
runners.
Mold stool: Metal plate used to support each mold
on the stool plate.
Ore: A mineral from which the metal can be
extracted.
Oxidation: Process in carbon combines with
oxygen to form oxides.
Plain carbon steel: Iron-carbon alloys with
minimal alloy content.
Plastic deformation: Permanent distortion of a
material under the action of applied stresses.
Powder injection: The injection of certain
materials into the molten bath at the ladle refining
station. The material is usually injected through a
consumable lance using argon as a carrier gas.
Pulpit: An enclosed operator's platform.
Quenching: The process of rapidly cooling the
steel from a temperature above the critical
temperature.
Quench cracks: Cracks formed in a steel part
during or after quenching that result from highstress in cooling.
Reduction: Process in which oxygen in removed
from a compound.
Refractory: A substance which is infusible at the
highest temperature it may be required to
withstand in service; heat resistant material.
Rockwell hardness: An indentation hardness test
that measures hardness by determining, under
load, the depth of penetration of a indenter such as
a steel ball. The hardness number is related to the
depth of indentation; the greater the number, the
harder the material.
Runner: A channel through which molten metal
or slag is passed from one receptacle to another.
Rotary/teeming nozzle: Mounted on the bottom
of the ladle and used to regulate the flow of
molten metal from the ladle into the trumpet.
Scale: An oxide of iron which forms on the
surface of hot steel exposed to air or oxygen.
Scarf: To remove surface defects from ingots,
blooms, or billets, usually with a gas torch.
Scrap: Iron or steel discard, cuttings, or raw
material which will be reprocessed.
Seam: Surface crack on a rolled product which
has been closed but not by welding.
Shear: A machine for cutting steel products.
Side boards: Sometimes referred to as hot top.
Used to insulate top of mold to avoid large cavity
in the top of the ingot as it cools.
Skull: A solid piece of steel left in a refractorylined vessel after use that must be removed in
order for the vessel to be reused; mainly used in
reference to the ladle.
Slag: A crust formed on top of molten steel which
primarily acts as an insulator. A medium through
which chemical reactions occur across the
boundary between the slag and the molten metal.
Soaking pit: A furnace or pit for the heating of
ingots to make their temperature uniform
throughout in preparation for the rolling operation.
Spalling: Breaking away of refractory.
Spider: A refractory brick that distributes the flow
of molten metal from the trumpet toward the
separate molds.
Stand of rolls: The simplest unit of a rolling mill
consisting of a set of rolls, the housings, bearings,
and guides which are required for the rolling of
steel.
Stainless steel: High-alloy steel, designed for
resistance to corrosion and/or oxidation,
containing high percentages of chromium (>4%).
Some grades may also contain quantities of nickel.
Steel Terms Glossary
Steel: Iron-based alloy containing carbon and
other elements.
any rate desired. Relieves internal stresses and
imparts toughness and ductility.
Sticker: An ingot that has not separated from the
mold.
Tensile strength: A measurement of the
maximum load per unit of original area that a steel
has prior to fracture.
Stool plate: Large metal plate that has grooves for
refractory runners that feeds to each mold and
supports clusters of molds.
Strength: Ability to resist applied forces.
Stress: The load per unit of area.
Surface inspection: The inspection of the surface
of products for defects such as ingot cracks, scabs,
seams, burned steel, laps, twist, guide marks, etc.
Tapping: The act of draining the molten metal
from furnace to ladle.
Teeming: Pouring metal into ingot molds.
Tempering: A process of reheating quenchhardened or normalized steel to a temperature
below the transformation range, then cooling at
Tool steel: Steel with high tempering
temperatures with 1/2% to 1-1/2% carbon,
significant (75%) alloy content and usually
containing carbide stabilizers such as; chromium,
manganese, molybdenum, vanadium and tungsten.
Toughness: Ability to absorb impact energy.
Trumpet: A funnel which serves to deliver
molten metal to a junction of 6 or 8 runners.
Ultrasound: High-frequency sound waves used to
detect product defects.
Vacuum arc degassing (VAD): See ladle refining
Yield strength: A measurement of the amount of
stress that gives the initial significant plastic, or
permanent, deformation of the steel.
Timken Training
BASIC – Product Application / Services
Course Title: Steelmaking and Clean Steel
Alloy Summary
Aluminum (Al)
 Usually added as deoxidizer and grain refiner
 As an alloy, creates Aluminum Nitrides that provide grain size control
 Most Al is removed from the steel as Aluminum Oxides in the slag
Chromium (Cr)
 Adds corrosion and wear resistance
 Very effective in adding hardenability
 Adds high-temperature strength and heat resistance
 An expensive but essential element not found in the US
Manganese (Mn)
 Combines with Sulfur to form Manganese Sulfides, a relatively benign inclusion that
improves machinability and adds strength and hardenability
 All grades of steel contain some manganese.
Molybdenum (Mo)
 Improves high temperature tensile strength
 Reduces susceptibility to brittleness after tempering
 Promotes hardenability
 Somewhat expensive element, replaced with Chromium and Manganese for
hardenability when possible
Nickel (Ni)
 Improves toughness and increases fatigue resistance
 Improves response to a quench/temper heat treatment
 Moderately increases hardenability
 Replaced with lower cost Chromium and Manganese for hardenability when
possible
 Relatively large amounts used
Silicon (Si)
 Increases hardenability, but not as well as Mn
 Increases “hot hardness”
 Deoxidizer
 Present to some extent in all steel
Sulfur (S)
 Residual elements from scrap, found in all steels
 We sometimes add sulfur to increase machinability
 Decreases toughness and weldability
Undesirable elements
Copper (Cu)
 Hot shortness (tendency of grain boundaries to break down / crumble)
Timken Training
BASIC – Product Application / Services
Course Title: Steelmaking and Clean Steel
Alloy Summary
Hydrogen (H)
 Causes flakes or cracks
Lead (Pb)
 Toxic, adds brittleness
Phosphorus (P)
 Decreases toughness
Tin (Sn)
 Hot shortness
Timken Training
BASIC – Product Application / Services
Course Title: Steelmaking and Clean Steel
Faircrest Map
Timken Technical and Commercial Training
Core – Technical Product/Application/Service
Course Title: Steelmaking and Clean Steel
Knowledge Check
Name: __________________________________
Date: _____________
1. The primary raw material for Timken steel is ________________________ .
2. Timken uses ___________________
_____________ furnaces to melt steel.
3. During the melt cycle, _____________________ may be added to adjust the chemistry
of the steel.
4. Why is having the exact chemistry in steel so important?
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5. After melting, the next step in steelmaking is _____________________________ ,
where adjustments to chemistry are made.
6. To stir the molten steel in the refining ladle, _____________ gas is circulated through
the steel.
7. After the chemistry has been adjusted, the next step in the process
is ___________________ , using a vacuum to remove ___________________,
___________________________ and other unwanted gasses.
8. To remove additional oxygen from the steel, deoxidants like ____________________
are added to the steel.
9. Name the two casting methods used by Timken, and the key advantage of each.
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Timken Technical and Commercial Training
Core – Technical Product/Application/Service
Course Title: Steelmaking and Clean Steel
Knowledge Check
10. Number the following steel products 1 through 4 in order of size
( 1 = largest , 4 - smallest):
____ Bloom
____ Ingot
____ Bar
____ Billet
Timken Technical and Commercial Training
Core – Technical Product/Application/Service
Course Title: Steelmaking and Clean Steel
Knowledge Check
11. Why do we call our caster a “continuous” caster?
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12. Describe one way that bottom pouring provides superior steel quality.
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13. In addition to reducing the physical size of steel, name two other major changes to the
steel caused by the rolling process.
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14. To make seamless steel tubes, billets of steel are charged into the ______________
___________________ ___________________ where they are reheated, and then to
a ____________________ ______________________ where the billets are
converted tubes.
15. The primary reason for the 1985 bearing ratings increase was _________________
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