METHOD FOR PRODUCING LONGITUDINALLY WELDED SHAPED PIPES OF SQUARE OR RECTANGULAR CROSS-SECTION Russian patent published in 2016 - IPC B21C37/08 

FIELD: pipes.

SUBSTANCE: invention relates to production of square or rectangular longitudinally welded pipes. Higher accuracy of pipe sizes, especially outer radius of flanges coupling, is provided by non-uniform distribution of reductions over the forming mill gauges: 40-50 % in the first gauge, 20-30 % in the second gauge, 10-20 % in the third gauge, 5-15 % in the fourth gauge, herewith at least one of the rough stage gauges is configured two-radius. Roller body to shape the forming mill gauge has a concave profile and is configured two-radius, so that the central part of the roller body surface is designed to form the shaped tube flange and is formed by the greater radius, and peripheral sections of the roller body surface are intended to form the coupling radii of the shaped tube flanges and are formed by two symmetrically arranged smaller radii.

EFFECT: cylindrical pipe workpieces are shaped in four roller idle gauges.

3 cl, 1 dwg, 1 tbl