Many people are not aware of the numerous options
available to create some form of rolled steel product. Majority of the processes involve rolling the
steel or other metal material through a series of rollers to create a desired
shape or thickness. Some more intricate,
while others deceivingly simple.
Both
steel sheets as well as bars of steel or other metals can be processed via roll
bending. Roll bending occurs by passing
the metal through a mechanical jig that consists of three different
rollers. As the bar or sheet of steel is
moved through the jig, it begins to take the form of a circular arc. All three rollers are set on their own axle
of which the outer two rollers, generally immobile, are set an equal distance
from the center roller on a horizontal plane. The middle roller sits atop of
the material and when pressure is added, creates the circular arc.
Roll
form is an uninterrupted bending process where, typically, coils of steel are
run through a series of successive rollers.
Each roller, or stand, plays a particular role in a certain type of bend
until the desired shape is reached. This
variance of manipulating steel is ideal for large quantity production and also
producing parts with extensive length.
The
most basic form of rolling steel and other metals is through the process of
flat rolling. With flat rolling, the
material maintains its rectangular shape from beginning to end. Material is fed through two rollers which
rotate in opposite directions. The
desired thickness of the finished product is determined by the gap between the
two rollers. A decrease in material
thickness, caused by the roller gap being thinner than the starting material,
forces the material to stretch and elongate.
Foil Rolling
As
a specialized form of flat rolling, foil rolling is used to produce foil. The foil end product is actually sheet metal
rolled to a thickness less than 0.0079 in.
To reduce the need for small rollers, pack rolling is used. Pack rolling involves rolling multiple sheets
together to raise the active beginning thickness. When sheets move through the rollers, they
are manicured and given slits to cut the material into several sheets.
A
unique version of hot rolling that enhances the diameter of a ring of metal
material is referred to as ring rolling.
The cylindrical material is placed between two rollers, one larger than
the other, of which the larger of the two adds pressure to the material. As the material is pressed, the diameter of
the ring increases while the wall thickness decreases. Some common end uses for this process are
rockets, turbines, pipes, among others.
Structural Shape Rolling
Viewed
as the most cost-effective way of bending certain types of material, structural
shape rolling requires less set-up time and uses pre-made dies that work the
material into the desired shape. Some
shapes capable of being rolled include: I-beams, H-beams, T-beams, U-beams,
angle iron, channels, bar stock, and railroad rails. This process can even manipulate the steel in
full circles.
Controlled Rolling
As
a type of thermomechanical processing, controlled rolling combines monitored
deformation with heat treatment. The
same heat that is applied to the material bring it over its recrystallization
point is the same heat that performs the heat treatments. This efficient process eliminates the need
for any further heat treatment down the road.
For the best results, the entire process must be closely monitored to
ensure the material does not become damaged.
Conclusion
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