METHOD OF PIPES RECEIVING WITH PROFILED EDGE LINES Russian patent published in 2010 - IPC B21D51/16 B21D41/00 B21D39/06 F28F9/16 

FIELD: metallurgy.

SUBSTANCE: there are implemented set-up labors on pipes - dressing, cutting sufficiently, finishing of external surface of ends, expansion - calibration of pipe end by rigid punch, cascading radial breaking-down of calibrated section by segments of split die. Herewith it is used matrix, containing finishing, preliminary etchings and working between them. Then it is reshaped calibrated section for maximal and minimal cogged sections and conic transition point between them, with following shaping compensation volume by means of burnishing of cavity of maximal cogged section. Additionally shaped edge line is formed by two compensation volumes in the form of doughnut and thickened section of cloth. Additionally collar is formed successively: at stage of cascade radial breaking-down - its external tapered surface, and at burnishing - intermediate compensatory volume in the form of thickened section of cloth of calibrated section with following giving to it of final shape of collar in finishing etching of matrix by means of shear lateral deformation in cloth of calibrated section at its radial annular overclamping. Thickened section of cloth in final form is formed by repeated burnishing of edge line cavity after receiving of collar with extrusion of pipe material into prliminary etching.

EFFECT: upgraded quality.

8 dwg