Drawing of rods, wires and tubes

Example: Determine the draw stress to produce a 20%
reduction in a 10-mm stainless steel wire. The flow stress is
given by σσσσ o = 1300εεεε 0.30 (MPa). The die angle is 12o and µ µ µ µ = 0.09.
B
From Eq.5
From Eq.9
= µ cotα
=
( 0.
09)
cot
1 1
ε1
= ln = ln =
1−
r 1−
0.
2
_ n
0
Kε1
1300(
0.
223)
σ = =
n + 1 1.
30
σ
σ
xa
xa
_
= σ
o
6
o
0.
223
. 30
=
_ ⎛ + B ⎞
⎡ ⎛
= σ ⎜ ⎟⎢1
−
B ⎜
⎝ ⎠⎢
D
⎣ ⎝
0.
8571
= 637MPa
Suranaree University of Technology Tapany Udomphol
Jan-Mar 2007
D
D
2
Ab
1.
0
ln ( 1+
B)
= 637ln
2
A
0.
8
a
b
a
= 10mm
=
D
b
( 1
( 1.
8571)
− r)
=
2B
1 Da
⎞ ⎛ 1.
8571⎞
8571
b
⎟
⎠
⎤
⎥ = 637⎜
⎟
⎥ ⎝ 0.
8571
⎦
⎠
10(
0.
8)
= 527MPa
= 8mm
2×
0.
[ 1−
0.
8 ] = 438MPa
~ 20% difference