金属板片の面内圧縮機作による鍛造用スラグの作製

Abstract

In a forging process, especially in a cold forging, metal slugs having a diameter-height ratio of from about 2.5 to 4.5 are generally accepted as blank material. The conventional preparation process of them is that, first a bar stock is cut into pieces to have a diameter-height ratio of from about 1/1.5 to 1/1.0 and then they are upset axially so as the said ratio of slugs to be attained. In this paper, it is suggested that a sheet stock can be employed as the starting material, and a way to carry out the balanced biaxial compression of sheet metal pieces is referred to. Tandem tooling of a blanking die and a extrusion die with a punch is available for this purpose. The procedure is that once individually blanked metal pieces are successively forced into the extrusion die so to make them into a stock pile which, by passing through the die, separates again into pieces of a reduced diameter. Based on the experiment on aluminium, points essential to this scheme are enumerated. It is concluded that though the conditions for a technologically admissible, stable process can be specified, application of the process to real production appears somewhat limited mainly due to economical reasons.