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Manufacturing:
Surface Finishing
Heat Treatment - Stress Relieving
Stress Relieving consists
of heating the steel to a temperature below
the critical range to relieve the stresses
resulting from cold working, shearing, or
gas cutting. It is not intended to alter
the microstructure or mechanical properties
significantly.also a process for making
material softer. However stress relieving
does not change the material properties
as does annealing and normalizing. A material
can be stress relieved by heating it to
a specific temperature that is lower than
that of annealing or normalizing and letting
it cool to room temperature inside or outside
of the oven. This heat treatment is typically
used on parts that have been severely stressed
during fabrication.
It is worth noting that many
heat treatments and welding processes cause
stresses in the material that can lead to
warpage either after the heat treating process
or during subsequent machining operations.
Of specific concern is the stress induced
by welding. If a weldment is to be machined
it should almost always be stress relieved
or normalized before the machining process.
This is because machining chunks of material
from a stressed weldment redistributes the
internal stresses and can cause the part
to warp. If the stresses are first relaxed
then abrupt changes in geometry after machining
are reduced.
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