| 摘要 |
PURPOSE:To preliminarily form the section in the breadth direction of the end of the blank slab into a dog bone shape, by forming the tip and the tail ends of the blank slab into a trapezoid shape using the specially shaped forging tool, and next, by forming the triangular pyramid type protuberance at both side planes of this trapezoid. CONSTITUTION:The inclined plane 5 is formed in the tool's main body 4 at the side to compress the end of the blank slab 1 in the breadth direction, and the groove 6 of specified depth is formed in the inclined plane 5. The knocking part 7 is installed at the tip of the groove 6 for knocking the front end face 1a of the blank slab 1. A couple of this tool 4 is used in forging work for reducing the tip of the blank slab 1 in the breadth direction; hereby, the trapezoid shape C is formed at the end plane of the slab 1, and also, the triangular pyramid type protuberance is formed at both side planes of the trapezoid. The tail end of the slab 1 is similarly formed and the section of both ends of the slab 1 in the breadth direction is preliminarily formed into a dog bone shape E possessing the protuberance. Hereby, the crop length caused by the rolling work is shortened, and the yield of the rolling work is improved. |
