METHOD OF COMBINED INTENSIVE PLASTIC DEFORMATION OF BLANK Russian patent published in 2015 - IPC B21J5/06 B21C23/04 C21D7/10 

FIELD: machine building.

SUBSTANCE: blank of extruded and twisted through constricted and expanded middle helical part of the channel. The channel has input and output parts, along their axes permanent cross-section of the blank is ensured. At that prior to extrusion and twisting through the middle helical part the blank is extruded through the part of channel constricted to cross-section equal to 0.8 of cross-section of lead-in part, and through the stabilising area. After extrusion and twisting the blank is pressed through the calibrating area of the channel.

EFFECT: structure grinding is provided due to joint action of the extrusion and helical pressing, excluding possibility of the blank twisting at output of the channel.

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