Question

In a single pass rolling operation, a 20 mm thick plate with plate width of 100 mm, is reduced to 18 mm. The roller radius is 250 mm and rotational speed is 10 rpm. The average flow stress for the plate material is 300 MPa. The power required for the rolling operation in kW is closest to

• A. 15.2
• B. 18.2
• C. 30.4
• D. 45.6

Answer 1

The correct option is A 15.2

Given data:
$h_1=20mm;h_2=18mm;R=250mm$

Width = 100mm, N = 10 rpm

${\sigma }_0=300MPa$

$\therefore Load={\sigma }_0\times L\times W$

when L = $\sqrt{R\Delta h}$

Load:
$=300\times {10}^6\times \sqrt{0.25\times (0.02-0.018)\times 0.1}$
$=670$ kN

Power:
$=2T\times \omega$ $=2\times 670\times 0.5\times \sqrt{0.25\times (0.02-0.018)}\times 2\pi \times \frac{10}{60}$
$=15.68kW=15.2kW$