F
Fading
A coating defect consisting of the
condition in a colored coating where the color, either transparent or
opaque, appears to get lighter or bleached out. Heat, light, or chemical
exposure usually causes fading.
Feather Edge
A sharp reduction in gauge on the
edge of a band which is caused be grooves worn in rolls due to extensive
rolling of the same width material. This is done for coating control on
edge. The gauge variations on a feathered edge generally does not
extend in from the edge more than one inch.
Finishes
The texture of the steel surface
which is determined by the grit on the rolls (See Shot Blast Roll
Finish) or by the grind on the rolls in the case of bright finish (See
Ground Roll Finish).
Finishing Stand
The last stand in a rolling mill,
which determines the surface finish and final gauge.
Finishing Temperature
The temperature at which hot
mechanical working of metal is completed.
Fire Cracks
An irregular pattern of lines on
the surface of a sheet caused by rolling with a fire cracked roll. Fire
cracks will develop when a roll is not properly cooled.
Fish Eyes
A coating defect consisting of the
undissolved particles in the coating usually surrounded by a circular
crater. The particles are usually resinous and are raised up from the
cured surface with the appearance of the eye of a fish.
Flash Stain
A stain that occurs in the rinse
tanks when the line has stopped. It appears blue, green, or black.
Flashburn
A defect made by contact rolls
when an arc is passed through the strip. Generally on lighter baseweight.
(D.R. coils)
Flashing
A coating defect consisting of the
uneven, random distribution of a coating on coated substrate. A
variation in the color of a coating which is due to variations of the
Film weight. A coating defect consisting of the flame weight fluctuation
is caused by disproportionate amount of coating transferring from the
application roll.
Flat Coil
Coil that has collapsed center.
Flat Rolled Steel
Steel produced on rolling mills
utilizing relatively smooth, cylindrical rolls. The width to thickness
ratio of flat rolled products is usually fairly large. Examples of flat
rolled steel are hot-rolled, cold-rolled, and coated sheets and coils,
tin mill products, etc.
Flatness
The absence of any gap or
clearance when a strip is placed, without applying any pressure, between
two parallel-faced plates. Wherever a gap exists under this condition,
the strip is "unflat". There are two kinds of "unflatness"--thickness
non-uniformity (such as frown, profile, etc.) and geometric
non-uniformity called shape defects such as (wavy strip, bent strip,
coil set, center buckle, etc.).
Flocculation
A coating defect consisting of the
formation of clusters of particles separable by relatively weak
mechanical forces, or by a change in the physical forces at the
interface between the liquid and the dispersed particles.
Flow Marks
A coating defect consisting of the
poor flow out of the coating on the substrate causing a ribbed (ribbing)
or ridged appearance.
Fluting
1. Visible line markings
that sometimes appear on the surface of flat rolled products during
forming; associated with non-uniform yielding of the metal; occurs when
the steel is formed into cylindrical or arc shaped parts. 2. The
kinking, or breaking of a sheet generally caused by curing the sheet on
two small a diameter. Fluting, or paneling as it is often called, can be
avoided by working the steel before bending. Steel with a definite yield
point (a visible break in the stress-strain curve) will generally tend
to flute.
Footage of Coil
The length of the steel strip that makes up a
coil.
Front End
The inside lap of the produced
coil, or the outside lap of the consumed coil.
Full Hard Cold Rolled
Hot rolled pickled steel that is
cold reduced to a specified thickness and subject to no further
processing (not annealed or temper rolled). The product is very stiff;
it is intended for flat work where deformation is very minimal.
Full Hard Temper
Full Hard Cold Rolled steel produced to a Rockwell
hardness of 84 and higher on the B scale.
Full Hard
Cold rolled coils
coming from the Strip Steel that have not been annealed.
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