Method for the Cold Deformation of a Continuous Metal Strip

Abstract

The invention relates to the pressure treatment of metals, specifically to producing a metal strip using cold deformation. A strip is consecutively drawn with back and front tension through bending devices. Moreover, the degree of deformation of a strip is regulated in each bending device by means of changing the ratio of the speed of the strip exiting a bending device to the speed of said strip entering said device, in such a way as to avoid a break in the metal, the required number of bending devices being selected on the basis of the total stretch factor of a strip and on the maximum allowable stretch factor of same. The result is increased deformation of a strip and reduced energy consumption.

What is claimed is: 
     
         1 . A method for cold deformation of a continuous metal strip, comprising:
 drawing the strip under backward and forward tension between three non-driven rollers of a bending device, wherein a middle roller with a diameter less than a diameter of outer rollers is encircled by the strip to more than 180° of its circumference and is forced together with the strip, by a tension of the strip, against the outer rollers having a gap between them greater than two thicknesses of the strip;   regulating a magnitude of deformation of the strip by adjusting its tension while maintaining the forward tension below the level of tensile stress in the strip corresponding to 0.85 of a tensile yield strength of its metal;   wherein drawing the strip comprises sequentially drawing the strip under the backward and forward tension in each bending device first through:
 a plurality of bending devices comprising at least two bending devices, and then through at least one separate bending device by means of a tensioning device mounted before an inlet side of a first bending device of the plurality of the bending devices in the process stream; 
 auxiliary pulling devices, the first one of which is mounted at an exit side of the last bending device of the plurality of the bending devices, and each of the remaining auxiliary pulling devices is mounted at an exit side of each separate bending device except the last one; and 
 a pulling device mounted at the exit side of the last separate bending device; and 
   wherein a magnitude of deformation of the strip is controlled, in the plurality of bending devices and in each separate bending device within ranges characterized by an upper boundary not exceeding a maximum permissible elongation ratio of the strip for the plurality of bending devices and for each separate bending device, respectively, by changing a ratio of an exit speed of the strip from the last bending device of the plurality to its entry speed into the first bending device of the group, and a ratio of the exit speed of the strip from each separate bending device to its entry speed into that bending device, respectively.