Effect of Sliding and Rolling Friction on the Energy-Force Parameters during Hot Rolling in Four-High Stands

A procedure for the calculation of the main-drive power for a hot-rolling wide-strip mill is developed. It takes into account that 85-99% of the lengths of the deformation zones in the working stands of such mills are occupied by stick zones, in which a strip undergoes static friction stresses (which do useful work only in the backward slip zone). This procedure also takes into account the rolling friction energy losses, which account for 83-93% of the power consumed for the rotation of idle backup rolls or 29-68% of the total energy consumed by the main mill drive. The average power calculation error for this procedure is 5%, and the maximum error is 10%, which is three to five times smaller than the errors of well-known calculation procedures. Our procedure has a high potential for revealing the reserves of decreasing the contact stresses in rolls and the saving of electric power via the redistribution of the reductions and tensions between stands and an increase in the temperature of the semi-finished rolled products.