Question

A U-channel of 85-15 brass will be shape formed, but first must be flat rolled to a thickness of 0.9 mm. The strip has a width of 25 mm and an initial thickness of ho=1.5 mm. A preliminary process design suggests a 40% reduction in a single pass on a rolling mill with 150 mm-diameter rolls. If the roll surface speed is 1 m/s, and the coefficient of friction is μ=0.1, calculate the rolling force and power requirements. Repeat the problem if two passes were taken to achieve the desired reduction.

Answer 1

ANSWER:-

hi » initial height = 1.smm. hfa final height -0.9mm. R a radius of rollers = 75nn. u=co-efficient of friction=o. S sh 1.5-0.9 of = 0.6mm. wawidth of sheet = 25mm. Na velocity of roll surface = inis. -.2 -Troh 135706 = 6.7 mm -- 6. 7x com. Rolling force, fo6o LW 6o = Roll seperating to ree byield 28028 altimate For 85-15 bran chat drawing Gyield 386 rupa Gultimate : 3.3impa

no 386 + 3.31 2 . .. 712 60 = 358.5 mpa z r = 358.5 X 6 io x 6.7 x -3 -3 10x 25 x 10 F-.60122.2814 v=WR a wa Angular ve cocity = VIR 13-33S az arm length=0.52 l Hot rolling/ 0.5 x 6. 77.10 3.3:35xion. Ta Torauta foa - 60122.28 3.35x10 . 201.656 un. po power = 25W - 2x 201.656 x 13.33 = 5377 sw

af rolling is done is "q" pages. 2 20. 3nm. . : Roh a $7580.3 4.74 x 10^ :- 358.50 16x 4.74 x 16 x 25 x 10 - 42512.87N w13.135 I a. arn length o.o.5223.35 16m. (Hot rolling) To 42512.87 8.35810 1 142.592 nm. Pa 2x 142.592*13.33 -3802.47 w