JPS5617140A - Preforming method of cut portion of continuously cast ingot and forging tool for preforming - Google Patents

Abstract

PURPOSE:To make the yield and productivity of rolling better than those of conventional methods by using the special tools for the cut portions of a continuously cast ingot, forming parallel parts of equal thickness and build-up parts of a triangular pyramid shape on both sides of plane trapezoids and preforming the broadside sections to a dog-bone shape. CONSTITUTION:In preforming the cut portions of a continuously cast ingot 2, a pair of tools 5 each having tapered faces 6 which assume a crest shape in plane shape and are formed with a groove 7 of fixed depth on the broadside compression side at the intended cutting line (m) of the ingot 2 are used. Said groove 7 has the parallel groove parts 7b adjacent to the bottom part 7a parallel to the tapered faces 6 and of groove width equal to the thickness of the ingot 2 and the groove parts 7c expanding symmetrically toward the tapered faces 6. The shapes of the portions corresponding to the ends of the ingot after the cutting by the tools 5 are formed to plane trapezoidal shapes (c), (c) and parallel parts 2b of equal thickness and build-up parts 2c of a triangular pyramid shape are formed on both sides of the trapezoids (c), whereby the ingot is preformed to a dog-bone shape E of which the broadside sections have the build-up parts 2c of an obtuse triangle shape.