METHOD OF LONGITUDINAL ROLLING OF PIPES AT AUTOMATIC PIPE ROLLING MILL Russian patent published in 2024 - IPC B21B17/02 B21B37/78 

FIELD: various technological processes.

SUBSTANCE: invention relates to a method for longitudinal rolling of pipes at an automatic pipe-rolling mill. Cylindrical mandrel is installed in the sleeve and the sleeve is reversible into the pipe on the said mandrel in the roll gauge with reduction at forward and reverse strokes of reverse rolling. Prior to forward stroke of reverse rolling, mandrel front end is extended from sleeve front end into deformation zone outlet section at forward stroke of reverse rolling. Mandrel is moved in the process of pipe rolling in the rolling direction at a speed lower than the speed of the pipe movement, which provides the location of the rear end of the mandrel after the rear end of the pipe comes out of the deformation zone in the inlet section of the deformation zone at the forward stroke of reverse rolling. Between forward and reverse strokes of reverse rolling the pipe is turned by turning it through angle of 90° relative to rolling axis. After pipe turning, the pipe is rolled by means of reverse stroke of reverse rolling with movement of the mandrel in the course of rolling, returning it to its initial position.

EFFECT: preventing wear of the mandrel and improving the quality of the inner surface of the rolled pipes.

1 cl, 1 ex