METHOD FOR CONTROLLING TENSION IN BAR AND WIRE ROLLING MILL

PROBLEM TO BE SOLVED: To highly accurately control the tension of a rolled stock traveling at high speed regardless of a distance between rolling mills in finish rolling or the like for a bar and wire. SOLUTION: The diameter of roll-free surface of the rolled stock is measured on the outlet side of a front rolling mill and tension is controlled based on the variation Δd1F in the measured value just after the tip of the rolled stock is bitten by the rear rolling mill. The diameter of the roll-free surface is measured on the outlet side of a rear rolling mill and the tension is controlled based on the variation Δd2F generated by Δd1F. The tension control is performed based on Δd1F and Δd2F. The diameter of the roll-free surface is measured on the outlet side of the rear rolling mill and the tension of the next rolled stock is controlled based on the variation Δd2T in the measured value just after the tail end of the rolled stock is passed through the front rolling mill. Then, the tension is easily controlled with simple equipment, the manifacturing yield of the first-class goods is improved, in addition, the generation of trouble in the post process is reduced and stable operation is realized.