METHOD OF PRODUCTION OF THIN WALL PIPES AT PIPE-ROLLING PLANTS WITH THREE-ROLL REELER Russian patent published in 2015 - IPC B21B19/16 

FIELD: metallurgy.

SUBSTANCE: method includes piercing of the solid blank to hollow shell at helical rolling mills on the moved mandrel, and further shell rolling in three-roll helical reeler. The rear end of the blank is pierced in the direction opposite to the rolling direction, with shell wall cobbing due to increased internal diameter equal to 0.8Δ-1.7Δ at length 21Δ-28Δ from the shell end, where Δ is wall cobbing degree before the roll tip of the tree-roll reeler.

EFFECT: exclusion of defect of triangular bell during rolling of the rear end of thin wall pipes in three-roll helical reeler.

5 dwg, 1 tbl