METHOD OF MAKING SHAPED CIRCULAR ARTICLES Russian patent published in 2013 - IPC B21D41/02 B21H1/06 

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to production of shaped annular articles from tubular billets with wall thickness-to-wall OD of 0.04-0.12. Billet with mandrel and disc are fitted in grooves of rings and plate 6 of hydraulic press. At force P billet initial plastic compressive deformation occurs with blank ends squeezed by mandrel and rings. At increased of said force P plastic loss of stability occurs at billet lateral boundary length L with formation of symmetric shaped profile, its shape depending on displacement of ring confined by disc thickness. Note here that force P and billet height are defined by relationship indicated in formula.

EFFECT: ductility effect is ensured.

1 dwg, 1 tbl