公开(公告)号：DE1933483A1

公开(公告)日：1970-02-05

申请号：DE1933483

申请日：1969-07-02

Applicant: PRESS UND STANZWERK AG

Inventor： ROLF WE HMUELLER ,  GREINER PAUL ,  XANDER FRANZ

IPC: B21J5/06 ,  B21K21/04 ,  C21D9/16 ,  F42B5/28 ,  B21D51/54

Abstract: 1,263,938. Making cartridge cases; upsetting. WERKZEUGMASCHINEN-FABRIK OERLIKON-BUHRLE A.G. 11 July, 1969 [12 July, 1968; 16 July, 1968 (2)], No. 35107/69. Headings B3A and B3H. [Also in Division F3] A cartridge case is made by cold upsetting a blank sheared from a bar stock, backward extruding the blank and axially pressing the cupped article formed to shape the base of the case in one pressing. The degree of upsetting is selected so that any defects in the blank become visible as surface cracks. The defective blanks are sorted out either visually, mechanically, electrically or pneumatically. The bar stock is steel with a carbon content of below 0À3%, preferably 0À16 to 0À25%. The cupped article is heat treated to restore the strain-hardening property to the steel. The heat treatment comprises heating the article to above the A3 transformation point, holding this temperature for 1 to 5 minutes and rapidly cooling at 50‹ to 100‹ C. per minute. The heating may be induction or by a gas or oil furnace. This treatment prevents the formation of coarse grains particularly between the base and side walls of the case.