METHOD OF METAL PLASTIC STRUCTURE FORMATION AND DEVICE TO THIS END Russian patent published in 2011 - IPC B21J5/00 B21J13/02 C21D7/10 C22F1/00 

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming and may be used in metal preparation for die forging. Billet is subjected, first, to open swaging, then, to close swaging, close piercing and back extrusion. Note here that moving female die and top and bottom made dies are used. Close piercing is carried out by applying deforming force to billet top face from top male die and counter pressure to biller sides by moving female die. Back extrusion is performed on acting by moving female die on biller side and by top male die on billet face center. Proposed device comprises hydraulic cylinder with drive and washer-like plunger. Top male die has working fluid chamber and drive and is built in hydraulic cylinder to drive plunger on outer surface of top male die. Bottom male die with flange is provided with detachable semi-rings.

EFFECT: billet with uniform equal-density structure and cured casing defects.

2 cl, 5 dwg