6. A steel plate is rolled to reduce its thickness from 25 mm to 18 mm using a 2-Hi mill roll with a roll diameter of 500 mm. Assuming the friction coefficient at roll-plate interface as 0.15, check whether it is possible to roll this plate in one pass. If it is not possible to roll in one pass using this mill, you have an option to change the roll size. Calculate what should be the size of the roll if this plate has to be rolled in one pass assuming the coefficient of friction remains same as above. If the rolls rotate at 100 rpm, calculate the roll force and power required in this operation. Assume the width the plate is 150 mm and the average flow stress of the material as 180 MPa