METHOD OF ROLLING PIPE WORKPIECES Russian patent published in 2020 - IPC B21B19/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metal forming and can be used for production of seamless tubes by rolling hollow tubular billets in helical rolling mill. Hollow tubular billet - sleeve is subjected to rolling in four-roll mill of helical rolling, all rolls of which are drive, with squeezing along the wall up to 60 % on cylindrical mandrel. Two rolls have the same dimensions and are arranged in the mill by a cup-like pattern; the other two rolls have the same dimensions and are placed in the mill by a mushroom-like pattern. Rolls are made so that ratio of diameter in contact of cup-like roll to diameter in height of mushroom roll is 1.1–1.4, rolls are arranged so that roll-out angle for bowl rolls ranges from -3° to -10°, rolling angle for mushroom rolls ranges from 3° to 10°, feed angle for all rolls is from 6° to 12°.

EFFECT: invention enables reducing variation in wall thickness and out-of-roundness of pipes.

1 cl, 2 tbl, 3 dwg