METHOD FOR FORMING A PIPE BILLET Russian patent published in 2022 - IPC B21D5/10 

FIELD: pipe production.

SUBSTANCE: invention relates to pipe production, namely to the production of large diameter welded pipes with a single longitudinal seam using roll forming of a pipe billet. The workpiece is bent by vertical movement of the upper roll by a value not exceeding H₀ and subsequent rotation of all rolls with simultaneous continuation of vertical movement of the upper roll by a value H greater than H₀. The movement of the upper roll and its speed are determined by mathematical dependencies. The value of the angle of rotation of the upper roll during its vertical movement from H₀ to H does not exceed the ratio of the axial distance of the lower rolls to the diameter of the upper roll.

EFFECT: accuracy of the geometric dimensions of the finished pipes is improved by minimizing the unevenness of deformation when forming in one pass in the transition area from the flat section of the workpiece to the main perimeter.

1 cl, 2 dwg, 1 ex