MANUFACTURING PIPES METHOD Russian patent published in 2019 - IPC B21B17/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, to the manufacture of hot-rolled steel pipes and can be used in the manufacture of pipes by hot rolling in pipe rolling units. Method includes heating and stitching the workpiece to obtain a thick-walled sleeve, deformation of the sleeve on the mandrel with increasing length and decreasing wall thickness, formation of end sections with a smaller wall thickness S_y, than in the middle, corresponding to an increase in wall thickness in these areas during subsequent reduction, heating and reduction of the pipe.

EFFECT: reduction of the longitudinal differential wall and metal savings due to the exclusion of trimming the pipe ends with a thickened wall is ensured by the fact that the dimensions of the end sections subjected to compression for wall thinning are established, and wall thickness after thinning, that allows to obtain a flat wall in those areas where there could be excessive thickening of the wall during the reduction with tension.

1 cl, 1 dwg