ROD AND TUBE DRAWING

1
ROD AND TUBE DRAWING
2
(No Transcript)
3
ROD AND TUBE DRAWING
Specific work done for drawing rod by an
increment, Dl, is
4
ROD AND TUBE DRAWING
5
ROD AND TUBE DRAWING
Maximum Reduction Per Pass
6
Effect of Friction
With redundant work included
7
ROD AND TUBE DRAWING
8
ROD AND TUBE DRAWING
Under non-ideal conditions, i.e., with friction
and redundant work, we define an efficiency, h,
where
9
ROD AND TUBE DRAWING
Maximum Drawing Ratio (because the stress after
the die cannot be larger then the yield strength)
Under non-ideal conditions, we have
These are the maximum strains that can be
achieved per die.
Non-ideal
Ideal
sKen
sdKen1/h(n1)
sflow
sdKen1/(n1)
elnR
10
ROD AND TUBE DRAWING
Die pressure
At yielding seff Y So, sx pY, where sx is
equal to sd near exit. So, p Y - sd
p
sx
p
Residual Stresses
Low reduction Compressive on surface and
tensile in interior High Reduction Tensile on
surface and compressive on interior.
11
Tube Drawing
12
SWAGING