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Coke Oven Battery
A set of ovens that process coal into coke. Coke ovens are constructed
in batteries of 10--100 ovens that are 20 feet tall, 40 feet long, and
less than two feet wide. Coke batteries, because of the exhaust fumes
emitted when coke is pushed from the ovens, often are the dirtiest
area of a steel mill complex.
Cold Reduction
WHAT Finishing mills roll cold coils of pickled hot-rolled
sheet to make the steel thinner, smoother, and stronger, by applying
pressure, rather heat.
HOW
Stands of rolls in a cold-reduction mill are set very close together
and press a sheet of steel from one-quarter inch thick into less than
an eighth of an inch, while more than doubling its length.
Cold-Rolled Strip (Sheet)
Sheet steel that has been pickled and run through a cold-reduction
mill. Strip has a final product width of approximately 12 inches,
while sheet may be more than 80 inches wide. Cold-rolled sheet is
considerably thinner and stronger than hot-rolled sheet, so it will
sell for a premium (see Sheet Steel).
Cold Working (Rolling)
WHAT Changes in the structure and shape of steel achieved
through rolling, hammering, or stretching the steel at a low
temperature (often room temperature).
WHY
To create a permanent increase in the hardness and strength of the
steel.
HOW
The application of forces to the steel causes changes in the
composition that enhance certain properties. In order for these
improvements to be sustained, the temperature must be below a certain
range, because the structural changes are eliminated by higher
temperatures.
Consumption
Measures the physical use of steel by end users. Steel consumption
estimates, unlike steel demand figures, account for changes in
inventories.
APPARENT SUPPLY.
Derived demand for steel using AISI reported steel mill shipments plus
Census Bureau reported imports,
less Census Bureau reported exports.
Domestic market share percentages are based on this figure, which does
not take into account any changes in inventory. |
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Continuous Casting
WHAT A method of pouring steel directly from the furnace into a
billet, bloom, or slab directly from its molten form.
WHY
Continuous casting avoids the need for large, expensive mills for
rolling ingots into slabs. Continuous cast slabs also solidify in a
few minutes versus several hours for an ingot. Because of this, the
chemical composition and mechanical properties are more uniform.
HOW
Steel from the BOF or electric furnace is poured into a tundish (a
shallow vessel that looks like a bathtub) atop the continuous caster.
As steel carefully flows from the tundish down into the water-cooled
copper mold of the caster, it solidifies into a ribbon of red-hot
steel. At the bottom of the caster, torches cut the continuously
flowing steel to form slabs or blooms.
Continuous Sheet Galvanizing*
A
continuous process used to produce a zinc coating on steel sheet by
immersion in a bath of molten zinc. Controlled wiping of the coating
after galvanizing produces thin uniform coatings of zinc (with no
alloy layers), usually 15 to 20 um (0.6 - 0.8 mils) thick. The coating
is sufficiently ductile to withstand deep drawing or bending.
Contract Sales
Steel products committed to customers through price agreements
extending 3-12 months. About one-half of all flat-rolled steel is sold
on this basis, primarily because the auto companies sign agreements to
cover at least one year's model. Price increases that the steel mills
might announce during the year do not generally affect the revenues
from the contract side of the business.
Corrosion
The gradual degradation or alteration of steel caused by atmosphere,
moisture, or other agents.
Cut-to-Length
Process to uncoil sections of flat-rolled steel and cut them into a
desired length. Product that is cut to length is normally
shipped flat-stacked.
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