JPS5741802A - Hot rolling method - Google Patents

Abstract

PURPOSE: To forcibly feed the tip of a material into an edging roll, to prevent generation of an edge drop, and to improve the yield of the edging pass, by slowing down the circumferential speed of the edging roll on the run-out side of a horizontal mill when the material is bitten by the edging roll, and by making the circumferential speed of the edging roll after biting the material synchronize with the speed of the material.

CONSTITUTION: The circumferential speed VE of an edging roll 1 is set by equation I. In which, VH is the circumferential speed of a horizontal mill roll 2, (f) is the forward slip of the horizontal mill roll 2, and α is a control factor. The smaller the value of α is, the smaller the value of VE is; and this makes the edge drop effect large, and worsens the threadability of the material. At a stage of biting a material by the edging roll 1, α=0.5 is set; according to the detected variation of the electric current caused by feeding the material into the edging roll 1, the value of α is increased to a final value α=1.0 by which the circumferential speed VE of the edging roll 1 synchronizes with the material speed (1+f)VH on the run-out side of the horizontal mill roll 2; then, only the tip of the material is forcibly fed to the edging roll 1 by the horizontal roll, so that the edge drop in the tip of the material is prevented.

COPYRIGHT: (C)1982,JPO&Japio