Question $5$:

A $200$ mm wide strip with an initial thickness of $10$ mm is

fed through a rolling mill with two powered rolls, each of

radius $300$ mm $.$ The workpiece thickness is reduced to $7$

mm in a single pass. The roll speed is $60$ revolutions per

minute $($RPM$),$ and the coefficient of friction between the

rolls and the workpiece is $0\mathrm{.}15.$ The flow curve of the

material is defined by $K=250$MPa and $n=0\mathrm{.}2.$

Calculate:

The draft in the rolling operation.

The contact length between the rolls and the workpiece.

The rolling force required.

The power needed to perform the rolling operation.