METHOD OF COLD REDUCTION OF WELDED TUBES AND CABLE CASING Russian patent published in 1994 - IPC

FIELD: machine engineering. SUBSTANCE: method, providing enhanced accuracy of geometry dimensions and quality of tubes, comprises steps of cold reduction of tube blanks at changing axis orientation in even-number cross sections in oval roll passes, formed by rotating grooved rolls, determining oval axis ratio in adjacent cross sections according to conditions of biting; keeping a predetermined single-radius geometry in the first and the last cross sections; determining a perimeter of cross sections of all roll passes in dependance upon perimeters before the reduction line and at its output and upon a current value of the perimeter. EFFECT: the method allows to produce a cold reduced welded tube with high-accuracy dimensions along its whole length, having enhanced roundness without visible defects of tube surface, deteriorating its quality. 1 cl, 4 dwg