Chapter 3 - Rolling of metals

The torque M T is equal to the total rolling
load P multiplied by the effective moment
arm a. Since there are two work rolls, the
torque is given by
M T
= 2Pa
…Eq.23 hf During one revolution of the top roll the
resultant rolling load P moves along the
circumference of a circle equal to 2ππππa.
Since there are two work rolls, the work
done W is equal to
Work 2( 2πa)
P
= …Eq.24
Since power is defined as the rate of doing work, i.e., 1 W = 1 J s -1 , the
power (in watts) needed to operated a pair of rolls revolving at N Hz (s -1 ) in
deforming metal as it flows through the roll gap is given by
W 4πaPN
Where P is in newtons and a is in metres.
Suranaree University of Technology Tapany Udomphol
Jan-Mar 2007
h o
= …Eq.25
P
P
a
a
R
R
M T = Pa