METHOD FOR WORKING METAL SLUG, SLEEVE FOR PERFORMING THIS METHOD AND SLEEVE AND LID ASSEMBLY FOR PERFORMING THIS METHOD

PROBLEM TO BE SOLVED: To apply upsetting to a columnar powder metallurgical slug having high slenderness ratio without causing buckling and oxidation. SOLUTION: The upsetting method in this invention is as the followings. The slug 1 is placed at lengthwise in a sleeve whose internal wall leaves a space to the lateral surface of the slug 1 and the slug 1 and sleeve assembly is placed in an upsetting container 10 and the upsetting force is exerted on the slug 1 on at least one of this traverse surfaces until a determined slenderness ratio is obtained, and the slug 1 is separated from the sleeve. By this invention, the slug is continuously upset but only the slug is upset and this is permitted because of the space formed by the internal wall of the sleeve. For example, the sleeve material made of the steel is not welded or seized to the slag which means that it is unnecessary to be machined in order to separate the two after operation. COPYRIGHT: (C)2006,JPO&NCIPI