Question

Q.6 Rolling

A 28+Y mm thick, 275+X mm wide metal strip is fed through a two – high rolling mill; each roll has a radius of 240+Z mm having a rotational speed of 48+Z rpm. The strip thickness is to be reduced to 24+Y mm in one pass. The strength coefficient of the work material is 270 MPa and strain-hardening exponent is 0.12.

Determine:

1. a- The minimum coefficient of friction between the strip and roll surface μ (Use dmax = μ2.R ).

2. b- If μ =0.6 : Is rolling is feasible (successful)? (i.e. dmax > d)

3. c- Determine the rolling force.

4. d- torque and

5. e- power required for rolling

X=2

Y=5

Z=2

Answer 1

je o -tar51(4) → max. angle of acteptance ,U= 016 then max. a nol le of acceptar) nu i n be tan-ı (0,6) = 3046 ni hich is nwill mot be puved in ollerS. Hence ,at this condiHon solling is not Jeasible c) Rolling Force 8

Pa Ah-= (28+5) _ (24-t i mm ) 8- j L(240+2)x4 33.11 m 2. Rolting Force 2 x31 Jb 2- 33 7 39 33.318×33.11 = 6 6 o 60 = 292429 91ld 2q2. 43 kw