Patent ID: 7454941
Filing Date: 2008-11-25
Classification: B21J

Abstract:
1. An upsetting method for working a metal slug, having a slenderness, the method comprising: heating said slug; at least partly positioning the slug in the direction of its length in an upsetting pot defining a cylindrical housing, and exerting pressure on the slug in the direction of its length with a punch until the slug fills a whole section of the housing, so as to reduce its slenderness and to obtain a cylindrical slug with a section equal to that of the housing, wherein said exerting pressure begins on said slug having a slenderness larger than 12 to 1, and ends after said slug has a slenderness substantially equal to 3 to 1, wherein said slenderness of said slug is defined by a length-over-section-diameter ratio of said slug, wherein said exerting pressure is performed with a plurality of upsetting operations, during which pressure is applied to said slug so as to reduce its slenderness, each operation having a working rate larger than 30%, wherein said working rate is defined as a ratio of a first length of said slug before an upsetting operation over a second length of said slug after said upsetting operation.