WHAT Process that increases the
hardness of steel, i.e., the degree to which steel will resist
cutting, abrasion, penetration, bending, and stretching.
WHY The increased endurance provided
by hardening makes steel suitable for additional applications.
HOW Hardening can be achieved
through various methods, including (1) heat treatment, where
the properties of steel are altered by subjecting the steel
to a series of temperature changes; and (2) cold working,
in which changes in the structure and shape of steel are achieved
through rolling, hammering, or stretching the steel at a relatively
Heat (of steel)
A batch of refined steel. A basic oxygen or electric furnace
full of steel. One heat of steel will be used to cast several
slabs, blooms or billets.
WHAT Altering the properties of
steel by subjecting it to a series of temperature changes.
WHY To increase the hardness,
strength, or ductility of steel so that it is suitable for
HOW The steel is heated and then
cooled as necessary to provide changes in the structural form
that will impart the desired characteristics. The time spent
at each temperature and the rates of cooling have significant
impact on the effect of the treatment.
Heavy Structural Shapes
A general term given to rolled flanged sections that have
at least one dimension of their cross sections three inches
or greater. The category includes beams, channels, tees and
zees if the depth dimension is three inches or greater, and
angles if the length of the leg is three inches or greater.
Steel with more than 0.3% carbon. The more carbon that is
dissolved in the iron, the less formable and the tougher the
steel becomes. High-carbon steel's hardness makes it suitable
for plow blades, shovels, bedsprings, cutting edges, or other
Hot-Dip Galvanizing After Fabrication*
A batch process used to produce a zinc coating on manufactured
steel products by total immersion of structural or fabricated
steel in a bath of molten zinc. The process provides a metallurgically
bonded coating, generally 100 um (4 mils) thick, consisting
of iron-zinc alloy layers covered with zinc.
Hot Band (Hot-Rolled Steel)
A coil of steel rolled on a hot-strip mill (hot-rolled steel).
It can be sold in this form to customers or further processed
into other finished products.
Hot Briquetted Iron (HBI)
Direct reduced iron that has been processed into briquettes.
Instead of using a blast furnace, the oxygen is removed from
the ore using natural gas and results in a substance that
is 90%-92% iron. Because DRI may spontaneously combust during
transportation, HBI is preferred when the metallic material
must be stored or moved.
The section of a steelmaking complex from the furnace up to,
but not including, the hot-strip mill.
The name for the molten iron produced in a blast furnace.
It proceeds to the basic oxygen furnace in molten form or
is cast as pig iron.
A rolling mill of several stands of rolls that converts slabs
into hot-rolled coils. The hot-strip mill squeezes slabs,
which can range in thickness from 2-10 inches, depending on
the type of continuous caster, between horizontal rolls with
a progressively smaller space between them (while vertical
rolls govern the width) to produce a coil of flat-rolled steel
about a quarter-inch in thickness and a quarter mile in length.
HYL I, HYL III
Processes for producing DRI and HBI developed by Hylsa. The
processes reduce iron ore lump or pellets with reformed natural
gas in a vertical shaft furnace. The HYL I process uses four
fixed-bed reactors; HYL III uses a single-shaft furnace.
A forming process in which a tube is placed into a forming
die. The tube is then formed to the shape of the die through
the application of internal water pressure.
The hydroforming process allows for severe shape deformation,
making it ideal for automotive structural parts such as engine
cradles, radiator supports and body rails. Various shaped
and sized holes can be punched in the tube almost anywhere
during the process.