Glossary


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Tailored Blanks
A section of sheet or strip that is cut-to-length and trimmed to match
specifications for the manufacturer's stamping design for a particular
part. Because excess steel is cut away (to save shipping costs), all that
remains for the stamper is to impart the three-dimensional shape with a die
press (see Blanking).
Tail Scale (Trickle Scale)
Loose scale which flakes off from the ends during hot-rolling or packs of
pairs of sheets, and finds its way in between the sheets, and is rolled in
during further pack-rolling.
Talbot Process
A modified basic open hearth steel making process adopted for phosphoric
iron, and is claimed to give greater output and speed. It consists in
tapping only a part of the refined steel, from a large tilting furnace, and
then adding a fresh charge to fill up the furnace. The resulting charge
gets refined quickly, when a portion is tapped out followed by refilling
the furnace.
Tandem Mill
A cluster of rolling mills where mill stands are in tandem. The tandem mill
imparts greater strength, a uniform and smoother surface, and reduced
thickness to the steel sheet. Unlike the original single-stand mills, a
tandem mill rolls steel through a series of rolls (generally three to five
in a row) to achieve a desired thickness and surface quality.
Tapping
Taking out refined steel from the furnace into a ladle.
Teeming (Casting, Pouring)
Filling of moulds with finished molten steel from the ladles.
Telescoping Coil
A coil that has not wound properly whose sidewall protrudes out. Tension
problems or a bad start on the exit reel causes this condition.
Temper
A condition produced in a metal or alloy by mechanical or thermal treatment
and having characteristics structure and mechanical properties. A given
alloy may be in the fully softened or annealed temper, or it may be cold
worked to the hard temper, or further to spring temper. Intermediate
tempers produced by cold working (rolling or drawing) are called
'quarter-hard', 'half-hard' and 'three quarters hard', and are determined
by the amount of cold reduction and the resulting tensile properties. In
addition to the annealed temper, conditions produced by thermal treatment
are the solution heat-treated temper and the heat-treated and artificially
aged temper. Other tempers involve a combination of mechanical and thermal
treatments and include that temper produced by cold working after heat
treating, and that produced by artificial aging of alloys that are as-cast,
as-extruded, as-forged and heat treated, and worked.
Temper Code
Industry-standard code that indicates the hardness of the steel.
Tempering
Reheating the quenched steel for a short time to a relatively low
temperature to make it less brittle without too drastically lessening the
hardness obtained by quenching.
Tempered Layer
A surface or subsurface layer in a steel specimen that has been tempered by
heating during some stage of the preparation sequence. When observed in a
section after etching, the layer appears darker than the base material.
Temper Mill
A relatively light cold rolling operation in a cold-rolling mill, usually
with only one or two stands, that may be used on hot rolled, cold rolled
and some coated steel such as galvanized. Temper rolling hot rolled sheet
helps to improve flatness, minimize coil breaks and fluting and alter
mechanical properties. Temper rolling cold reduced and coated sheet steel
improves surface finish (shiny, dull or grooved surface) alters mechanical
properties and reduces the tendency of the steel to flute during
fabrication.
Temper Rolling
A light cold-rolling process that develops the proper stiffness temper in
steel, improves flatness, and imparts a desired surface finish by
preventing stretcher strains.
Tensile (Tension) Test
A destructive mechanical test whereby strength and ductility properties are
measured.
Tensile Strength
The greatest longitudinal stress steel can sustain without breaking.
Tension Bridle
Or Drag Bridle, is a dynamic tension device used in rolling mills whose
function is to produce sufficient drag on the strip to maintain a positive
strip tension throughout the line. It consists of a series of rolls, some
of which may be pinch rolls, through which the strip passes out of the
looper.
Terne Coated Sheet
Sheet steel coated by immersion in a bath of molten terne, an alloy of lead
and tin. Terne (meaning dull) principally is used in the manufacture of
gasoline tanks, although it also can be found in chemical containers, oil
filters and television chassis. Sheet steel coated with terne metal is
duller in appearance than sheet steel coated with tin alone.
Thermo-mechanical Treating (TMT)
Permanent deformation of metal with the objective usually of improvement of
certain physical properties of the metal.
Thomas Process
A basic steel making process in which pig iron is refined in a basic
refractory lined converter by blowing air or a mixture of air, carbon
dioxide and oxygen or steam through the molten metal.
Three-Piece Can
Three-piece cans consist of a body and two ends. The body side seam can be
accomplished by soldering, cementing or welding. The two ends are attached
using a double-rolled seam. The curl on the end, containing the seal
compound and its flange on the can body are indexed and rolled flat. The
sealing compound between fold gives a hermetic seal.
Tin/Chrome Plating
A plating process whereby the molecules from the positively charged tin or
chromium anode attach to the negatively charged sheet steel. The thickness
of the coating is readily controlled through regulation of the voltage and
speed of the sheet through the plating area.
Tin Coated Steel
See Tin Plate.
Tin-Free Steel
Single or double reduced black plate having a thin coating of chromium and
chromium oxide applied electrolytically. Because it is used in food cans
just like tin plate, it ironically is classified as a tin mill product.
Tin-free steel is easier to recycle because tin will contaminate scrap
steel in even small concentrations.
Tin Mill
Continuous tin-plating facility to produce tin mill steel sheet to be used
in food and beverage cans and other containers.
Tin Mill Product
Tin Plate, Tin-Free Steel, or Black Plate.
Tin Plate
Thin sheet steel with a very thin coating of metallic tin. Tin plate is
used primarily in canmaking.
Tolerances
A customer's specifications can refer to dimensions or to the chemical
properties of steel ordered. The tolerance measures the allowable
difference in product specifications between what a customer orders and
what the steel company delivers. There is no standard tolerance because
each customer maintains its own variance objective. Tolerances are given as
the specification, plus or minus an error factor; the smaller the range,
the higher the cost.
Toll Processing
The act of processing steel for a fee ('toll'). Owners of the steel sheet
may not possess the facilities to perform needed operations on the material
(or may not have the open capacity). Therefore, another steel mill or
service center will slit, roll, coat, anneal, or plate the metal for a fee.
Ton
Unit of measure for steel scrap and iron ore. 
Gross Ton 2,240 pounds (1,016.05 kg). 
Long (Net) Ton 2,240 pounds (1,016.05 kg). 
Short (Net) Ton 2,000 pounds (907.185 kg). Normal unit of statistical raw
material input and steel output in the United States. 
Metric Ton 1,000 kilograms (2,204.6 pounds or 1.102 short tons).
Tongs
Long-handled pliers used to remove scrap pieces from the welder or other
sections of the line.
Tool Steels
Steels that are hardened for the use in the manufacture of tools and dies.
Top Blowing
Injection of oxygen from the top through a water-cooled lance into the
liquid bath during oxygen steelmaking. The blowing end of this lance
features three to five special nozzles that deliver the gas jets at
supersonic velocities. The stirring created by these focused, supersonic
jets cause the necessary slag emulsion to form and keeps the vigorous bath
flows to sustain the rapid reactions.
Torpedo Car (or Ladle)
The refractory-lined hot metal railcar used to carry molten iron from the
blast furnace to steel making units.
Toughness
The ability of a metal to absorb energy and deform plastically before
fracture.
Tramlines
An overall or lap usually occurring in parallel pairs of lines. Long
straight marks due to drawn out inclusions on rolled sheet are also called
tramlines.
Transverse
Literally, 'across', usually signifying a direction or plane perpendicular
to the direction of working. In rolled plate or sheet, the direction across
the width is often called long transverse, and the direction through the
thickness, short transverse.
Trepanning (Hollow Punching)
Removing a core from a piece of steel either by machining with tubular
cutter or by hollow punching that is by pressing a hollow punch through the
hot steel.
Tribology
A science that deals with the design, friction, wear and lubrication of
interacting surfaces in relative motion.
Triple Spot Test
See Minimum Triple Spot Average Coating.
Trough Castings (Tundish Castings)
Casting or pouring effected through a refractory basin or trough, placed
between the ladle and the mould, with the object of minimizing the force of
impact of the liquid steel on the bottom plate and thus counteract violent
splashings resulting from direct teeming from the ladle into the mould.
Tubing
When referring to OCTG, tubing is a separate pipe used within the casing to
conduct the oil or gas to the surface. Depending on conditions and well
life, tubing may have to be replaced during the operational life of a well.
Tundish
The shallow refractory-lined basin on top of the copper mould continuous
caster. It is an intermediate vessel between the ladle and the mould. It
receives the liquid steel from the ladle prior to the cast, allowing the
operator to precisely regulate the flow of metal into the mould.
Tundish Nozzle
It is a critical link in the continuous-casting system because it must
deliver a constant and controlled flow of steel to the mould with minimum
stream flare to minimize splatter, spray, and atmospheric oxidation.
Because the ferro-static head remains substantially constant in the tundish
throughout casting of much of each heat, the bore of the nozzle must remain
at a constant diameter throughout the cast. High purity, stabilized
zirconia, having low thermal conductivity and good erosion resistance, has
demonstrated the most desirable overall properties of any type of nozzle
used to date.
Tunnel Furnace
Type of furnace whereby stock to be heated is placed upon cars which are
then pushed or pulled slowly through the furnace.
Turbo-Blower
A steam-turbine-driven centrifugal blower used to provide air blast for
blowing the blast furnace.
Tuyeres
The inlets for air to the blast furnace are water-cooled openings called
tuyeres and are located at the top of the hearth.
Twist
A bar defect wherein the ends of a bar have been forced to rotate in
relatively opposite directions about its longitudinal axis.
Twisting
Torsional displacement of parts of a forging as in the manufacture of a
crankshaft.
Type D
Base-metal steel, aluminum killed; sometimes required to minimize severe
fluting and stretcher strain hazards for severe drawing applications.
Taconite
What Natural mineral containing less than 30% iron. It is the primary ore
used in blast furnaces in USA. Why In USA, domestic supplies of iron-rich
ores (greater than 50% iron) were largely depleted in the 1940s, so
integrated steel companies now process the lower-grade taconite to make it
useful.
Top Dross
Skimmings for the continuous galvanize pot. Composition consists of
approximately 87% zinc, 5% aluminum, and 6% to 8% iron.
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