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
Lace
Area where the strip is joined together (with wire, bands, etc.) after
being broken.
Lacquer
A coating composition which is based on synthetic thermoplastic film
forming material dissolved in organic solvent and which dries primarily by
solvent evaporation during stoving operations.
Ladle Injection
A process by which deoxidizers, special materials and rare earth metals are
added to ladles of steel. The process is the best of all secondary
steel-making processes for achieving excellent inclusion morphology in
steel.
Ladle Refining Furnace (LRF)
A ladle refining furnace has the ability to reheat the liquid steel. This
allows the steel-makers to add greater amounts of alloys to the liquid
steel. The furnaces’ capacity to provide heat during refining by
arc-reheating gives the steel-makers the capability to desulphurize,
deoxidize and perform metallurgical operations with synthetic slag. The
ladle refining step comes after the steel is melted and refined in the
electric arc or basic oxygen furnace, but before the steel is sent to the
continuous caster.
Ladle Rigging
A mechanism for raising and lowering the stopper rod vertically to open and
close the bottom hole of a steel ladle.
Lagging
Slack in the strip.
Lamellar Tear
A system of cracks or discontinuities aligned generally to the worked
surface of a plate. This is usually associated with a fusion weld in thick
plate.
Laminations
Imperfections resulting from the presence of foreign inclusions, laps,
blisters or other discontinuity in the steel typically aligned parallel to
the worked surface or rolling direction of the metal. This imparts a
tendency to split into layers along the direction of rolling.
Lap (Overlap, Shut)
A surface imperfection on worked metal caused by folding over a fin
overfill or similar surface condition, then impressing this into the
surface by subsequent working without welding it.
Lap Weld
Done at platers; coil ends are "lapped" over one another and welded; it
doubles the thickness of the steel at the weld and is marked by a hole
punch.
Lattens
A measure of thickness, and refers to those hot rolled sheets having
thickness from 0.56 to 0.4 mm.
LD-AC (Arbed Cockerill Process)
This process is an extension of the LD process developed in Belgium whereby
lime powder is introduced vertically into an LD converter along with the
oxygen in order to make the LD process suitable for refining high
phosphorus (up to 2 percent) bearing molten pig iron.
LD Process (Linz Donawitz Process)
A process of steel making where the impurities are oxidized by blowing high
purity oxygen through a lance at supersonic speeds vertically on the
surface of the molten pig iron held in a stationary basic lined converter
which itself is kept vertical.
Lead Annealing
A process to anneal wire, it consists of drawing the wire through a bath of
molten lead heated to the proper temperature.
Lead-Time
Delivery time for an item of inventory to be moved from a source location
to a destination via a specific route. Detail is specific to the level of
the location. Also the time to produce a customer's order from order
placement to shipment.
Leveling
The process by which a leveling machine flattens metal strip, coil, or
sheets beyond its yield point by bending it up and down over the
interrupting arcs of upper and lowers sets of long, slender work rolls.
Machines generally employ 17, 19, or 21 relatively small diameter rolls
whose deflection under load is controlled by additional back-up rollers and
a rigid frame.
Leveling Line
A process to flatten any shape deficiencies (wavy edges and buckles) in the
sheet, prior to final shipment. Most cold-rolled sheet initially has a
crowned cross-section that, if such a shape is undesirable to the customer,
must be flattened in the leveling line.
Leveling Rolls
A set of five adjustable rolls that flatten or level the front end strip of
steel when running through the feeders.
Life Cycle Costing
An accounting method of costing where expenses are allocated over the life
of the product. Life cycle costs are often lower for stainless steel than
for alternatives despite a higher initial outlay, because stainless
products generally last longer and require little maintenance.
Lift
A stack of sheared-to-length plates or sheets.
Light Gauge (Defect)
Product with a thickness below the customer’s minimum gauge
tolerance.
Light-Gauge Steel
Very thin steel sheet that has been temper-rolled or passed through a
cold-reduction mill. Light gauge steel normally is plated with tin or
chrome for use in food containers.
Light Special Treatment
A surface treatment of dried-in-place chromate for electro-galvanized
product which provides corrosion resistance. A lighter film weight is
applied as compared to special treatment. (See Special Treatment)
Lime
A product (calcium oxide, CaO) obtained by burning limestone (calcium
carbonate, CaCo3) and is used in basic steel making practice as a flux, and
to a limited extent as mould wash.
Limestone
Naturally occurring mineral comprising mainly calcium cabonate (CaCo3)
containing various impurities, chiefly silica and alumina and used as flux
in steel industry.
Lineal Footage Counter
Electronic device used to count lineal footage of a coil.
Line Marking
Lines are used as the identifying marks on the heavy Tin coated side of the
strip to identify it to the customer.
Line Pipe
Pipe used in the surface transmission of oil, natural gas and other fluids.
Line Speed
Speed at which the coil is processed through the line; Platers may run
1800+ feet per minute.
Location
A coding system that defines the physical placement of materials, usually
to a high degree of specificity.
Lock Out / Tag Out
Terminology used to describe the process of securing an energy source so
that work may be done. This is accomplished by locking out all the energy
sources pertaining to the device, tagging out the resources, and trying out
the device to make sure that it is de-energized and safe for work to be
done.
Lockseam Test
A test performed on a galvanized product to evaluate the adherence of the
zinc to the steel substrate. This test involves bending the steel to form
an 'S' shape and assessing the adherence of the coating along the apexes.
Logistics
The science of identifying, maintaining, and transporting materials.
Longitudinal Direction
The principal direction of flow in a worked metal.
Long Products
Classification of steel products that includes bar, rod and structural
products, that are "long", rather than "flat".
Looper / Loop Tower
1. Area where the strip accumulates enabling the line to continue running
while making a weld.
2. Collecting unit used for storing steel. This enables the Entry or
Delivery End of the line to stop without stopping production.
Loose Wrap
A coil that is not wound tight. Using too little tension when winding
causes this condition.
Lot No.
Identifies groups of coils for a particular customer order to be processed
at a certain time; identifies a particular group of coils to load.
Low Coating
A condition that occurs when the coating thickness is less than customer
specifications.
Lowboy (or Stabilizer Roll)
Submerged roll in the pot used to stabilize the strip as it exits the pot
before entering the dies.
Low Temperature Steel
Steels which are especially suited for extremely cold climates and for the
handling of relatively 'warm' (to –100o) liquefied gases such as propane,
anhydrous ammonia, carbon dioxide and ethane.
Luting
The original method of sealing the doors of coke ovens by trowelling and
smoothening ground 'mud' into the V-shaped opening between the door and the
door jamb. In recent years, there have been developed self-sealing doors
that do not require luting.
Liquid Carburizing
A light, hard case, which is also a mixture of carbides and nitrides, is
obtained by immersing the steel in a molten salt bath containing about 30%
sodium cyanide at 870o C for periods of about ½ to 1 hour. This results in
a case depth of about 0.25mm.
Low-Carbon Steel
Steel with less than 0.005% carbon is more ductile (malleable): It is
capable of being drawn out or rolled thin for use in automotive body
applications. Carbon is removed from the steel bath through vacuum
degassing.
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