| 摘要 |
PURPOSE:To prevent piping defects, and craking phenomena without producing any undue stress in flow line by heating the parts of a blank material where plural projections are to be formed slightly highly and determining the heating temp. thereof in proportion to the amount extruded from the blank material. CONSTITUTION:At the time of forging an object having plural projections along its axial direction by constituting the positions of heating coils 3 reverse to heating temp. characteristic lines because induction heating is inversely proportional to the clearances between the coils 3 and a blank material 1, the parts of the blank material 1 where plural projections are to be formed are heating slightly highly, and the heating temp. thereof it determined in proportion to the amount extruded from the material 1. Then, the smooth metallic flow meeting molding mode is produced and this makes it possible to prevent the occurrence of piping defects and cracking and to make the edges of the projections fairly accurate. |
