Chapter 3 - Rolling of metals

h o
The maximum reduction
v o
The critical variables are
L p and h
A
α
R
R-a
B C
L p
A large diameter roll will permit a
thicker slab to enter the rolls than will
a small-diameter roll.
= tanα =
R
L p
D
a
h
R∆h
≈ ≈
− ∆h
/ 2 R − ∆h
/ 2
∆h
R
From triangle ABC, we have
Suranaree University of Technology Tapany Udomphol
Jan-Mar 2007
R
L
L
2
2
p
2
p
=
=
L
R
2
p
2
+ ( R − a)
− ( R
= 2Ra
− a
2
2
2
− 2Ra
+
As a is much smaller than R, we
can then ignore a 2 .
L p
≈ 2Ra
≈
R∆h
Where ∆∆∆∆h = h o – h f = 2a
2
( ∆h)
= µ R
a
2
)
…Eq.6
µ …Eq.7
max