D
D&I (Drawn & Ironed)
Stock material primarily used for two
piece beer and beverage cans. (Draw a cup approximately finished can
diameter and iron the sidewall to the can height.) Primarily BA T1
materials matte tin plate 60-100 micro inch finish.
Deburris
Horizontal knife used to remove burrs after slitting.
Deep Drawing
The fabrication process of flat rolled steel to
make drawn parts. The part is mechanically formed through or in a die.
The blank diameter is reduced; the blank contracts circumferentially as
it is drawn radially inward. (See Deep Drawing Applications).
Deep
Drawing Applications
Parts/applications that require deep drawing in their fabrication.
Examples are motor shells, fenders, quarter panels, door panels.
Defect
1. Anything that renders the steel unfit for the
specific use for which it was ordered. What is defective for one
customer may be prime steel for another. 2. A variety
of quality problems in a coil. Examples are punchmarks, roll marks, oil
spots, and scratches.
Deflector Roll
A roll used to
change the direction of the strip.
Degas Heat
A heat of degas steel is a heat
that is produced to extremely low carbon levels through vacuum
degassing.
Delay Code
A four-character code used to
identify the type and reason for a delay.
Delivery End
The exit end of the line.
Delivery Tail End
The outside lap of the produced
coil on the delivery reel.
Demineralized Water
City water which is circulated
through a series of three demineralizing filters to soften it and remove
residuals. It is then delivered to a storage tank for use in overflowing
the superheater elements and headers on the boiler during hydrostatic
tests. Filling the superheaters with demineralized water prevents the
raw water used in a hydrostatic test from entering the superheaters
where it could cause corrosion problems
Descaling
The process of removing scale from
the surface of steel. Scale forms most readily when the steel is hot by
union oxygen with iron. Common methods of descaling are: (1) crack the
scale by use of roughened rolls and remove by a forceful water spray,
(2) throw salt or wet sand or wet burlap on the steel just previous to
its passage through the rolls.
Dezincing
A coating defect consisting of the
removal of the zinc oxide in a "C" enamel film by chemical
reaction with food products. Dezincing appears as a lack of opacity in
the film and usually occurs in a random pattern.
Dies
(Galvanize)
Air pressure devices in the Sheet
Mill which, depending on distance from coil, determine coating thickness
by removing excess metal from the strip; the farther the die is from the
steel, the heavier the coating – also called "knives" on this line.
Differential Coatings
Coatings on flat rolled products whereby the thickness of the coating on
the one side is heavier than the other side. At Weirton Steel, the term
is applied to a tin plate product which requires one side of the steel
to have a heavier tin coating than the other side.
Dimentional
Tolerance
A range by which a product's width and gauge can deviate from those
ordered and still meet the order's requirements. (Also See Commercial
Tolerance)
Diversion
1. A situation
that occurs when a coil/s intended for an order doesn’t meet quality
standards or customers specifications and is therefore diverted to meet
another customer's specifications. In addition, coils can be diverted to
complete another customer's order or for other reasons as necessary.
2. Removing a product from it’s original order. Synonymous with
Reapplication.
Diverted Coil (DRV)
A coil that is no longer being
sent to its original order but is being sold elsewhere.
Dolomite
A material that is used to add
magnesium oxide to the sinter.
Double
(Cold) Reduced
(DR)
1. Material that has been cold reduced in thickness twice. The
first reduction is at the tandem Mill (where it is reduced at five
different locations) and the second is at the Weirlite Mill. 2.
Plate given a second major cold reduction following annealing. Double
reduced products are relatively hard, have limited ductility, and highly
directional mechanical properties. Aim Rockwell hardness 30T hardness is
76; Aim yield strength (varying from materials) is 80,000 psi to 90,000
psi; approximate tensile strength is 90,000 psi.
DQ
"Draw
quality" = more flexible grade of steel.
DR Plate
Double reduced
steel produced on the Weirlite Mills.
Drawn & Ironed (D&I)
A process primarily used to manufacture
two-piece beer or carbonated beverage can bodies, although some canned
food product is packaged in steel D&I can bodies. An appropriately sized
circular disk is drawn into a cup to approximately the finished can
diameter. The side wall height is created by forcing the cup through a
series of rings, ironing the metal thinner than the starting material
thickness. Can bodies are coated with organic lacquers after forming.
Drawn
Mechanically formed by tension
through or in a die.
Draw-Redraw
(DRD)
Two-piece. Process for making two-piece cans in which a circular blank
is drawn into a die to form a shallow cup and then is redrawn on a
second or third die to produce a can body of the desired dimensions.
Plate is coated prior to the forming process.
Draw-Thin-Redraw (DTR)
An enhancement of the DRD process
for making two-piece can body utilizing high tensile TFS that has an
organic polymeric coating applied prior to the forming operations. The
patented DTR process is a means of subjecting the coated feedstock to
forming strains such that the metal and coating avoid compacting and
subsequent sidewall burnishing, thus enhancing the integrity of the
organic coating. The resultant sidewall is thinned during the drawing
and redrawing operations, thus facilitating the specified can body
dimensions using a smaller starting blank size than that required for
DRD.
Drawing
Quality (DQ)
Flat-rolled products produced from either deep
drawing rimmed steel or extra deep drawing aluminum killed steels.
Special rolling and processing operations aid in producing a product,
which can stand extreme pressing, drawing or forming, etc., without
creating defects.
Dross
Sediment which settles in bottom
of the ZINC pot on the galvanize line. Also top dross, which
floats on surface of pot and is skimmed off. A different type of dross
also occurs on the top of the zinc pot, which is skimmed off on a
regular time frame.
Dry Film Weight
Dry coating film
weight is normally calculated in grams per square meter(gm/m²) or
milligrams per square inch(mg/in²). Accurate control of dry film weight
is essential to ensure that the coating material will possess its
intended properties of physical and chemical resistance.
Dryer
Dries the strip after a rinsing
process.
DTR
A Weirton Steel developed and
patented technique for producing a drawn two piece can. See
Draw-Thin-Redraw.
Ductility
A qualitative, subjective property
of material that indicates the extent to which it can be deformed
without fracture in metal working operations such as rolling, extrusion,
fabrication, etc. It is generally expressed as total permanent strain
prior to fracture, measured as elongation or reduction of area during
tensile testing.
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