Question

Also need help with this second homework problem related to metal forming: 2. Given the following for hot rolling a low-carbon steel plate, calculate the number of rolling passes if the maximum load on the roll in each pass is not to exceed 28,400 lb/in^2: - Diameter of the roll: 20 inches (500 mm) - Stock width: 48 inches (1020 mm) - Initial thickness: 1.5 inch (37.5 mm) - Final thickness: 0.4 inch (10 mm) - Flow stress of rolled material: 28,400 lb/in.^2 (200 MN/m^2)

coefficient of low carbon steel: 0.7 (static)

0.6 (kinetic)

Answer 1

Flow (oo) ... Solution - In Manimum Load = 28400 lb/in2 = 200 MN/M2 - 20x lo' N/m2. o strem = 200 MN / m² = 200 x 100 N/m2; 4=0.6 We know, h = 37-5mm = 0.0375 m ho - lomm = 0.01 m. R-500/= 250mm = 0.25 m, Width (W)= 1020 mm -102 m We know, Load=5oxhx W where, L= VRAG rihoada 200x106x v 01 25x10.0375-0.01) x 1.02 in N) ; hood in N = 1.69x 10 = 16,9x106N a which is permissible load limit. For finding no of roll passes; n = die R = 10.6) x0.25 -0.09 -3.27 Picha 00375–0:01) 000275 va - The number of rolling passes required is Ý