Abstract: A method of and system for controlling the temperature of a continuous furnace through which steel bodies are transported at a constant speed, in which the temperature is controlled so as to keep the distance from the entry port of the furnace to a position in the furnace where the furnace temperature is substantially equal to the desired delivery temperature of a steel body to be heated at a predetermined value which is determined in accordance with the dwell time, shape and size of the steel body.

Abstract: A tension control system for use with a universal mill such as an H beam mill, in which a tension force in a billet, to be rolled, between roll stands is controlled so as to be maintained at zero. Providing that effective loads (Pu) are obtained by linearly summing horizontal and vertical rolling loads, the tension control system controls roll driving motors so as to maintain the respective ratios T/Pu of rolling torques T to effective loads (Pu) constant, thereby performing a non-tension control.

Abstract: In a tandem rolling mill consisting of at least a first rolling stand and a second rolling stand, the interstand tension is controlled by the steps of detecting the rolling force P.sub.10 and rolling torque G.sub.10 at the first rolling stand after a workpiece is fed into the nip between the rolls of the first rolling stand but before the workpiece is fed into the nip between the rolls of the second rolling stand, storing in a memory the ratio G.sub.10 /P.sub.10 representative of the reference torque arm value for the first rolling stand in a tension-free state, detecting the rolling forces P.sub.1B, P.sub.2B and rolling torques G.sub.1B, G.sub.2B at the respective rolling stands immediately after the workpiece is fed into the nip between the rolls of the second rolling stand, computing the reference torque arm value G.sub.20 /P.sub.20 for the second rolling stand in a tension-free state on the basis of these detected values, and controlling the rolling speed of the first or second rolling stand so that (G.