METHOD OF BARREL HOT DIE FORGING Russian patent published in 2010 - IPC B21K21/00 B21J13/02 B21C23/08 B21C25/00 

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming and can be used in metallurgy and machine building for hot die forging of barrel-like half stuffs. Cylindrical billet is extruded through axially symmetric pass. Said pass is formed by mandrel surfaces and container through stepwise hole. Billet is placed inside container smaller-diametre stage, while mandrel is located in larger-diametre stage zone. Aforesaid pass comprises variable- and invariable-diametre zones. Billet is subjected to additional plastic deformation in variable-diametre zone that adjoins the invariable diametre zone. For this extrusion direction is varied zigzag like in the biller plane by aligned convex-concave surfaces. Said surfaces constrict the pass from inside and outside. Each of said surfaces comprises a pair of toroid convex and concave surfaces that contact each other. Pass sizes in said zones are defined by given relationships.

EFFECT: higher quality of finished products.

1 dwg, 2 ex