FORMED SECTION AND FORMED SECTION MANUFACTURE METHOD Russian patent published in 1999 - IPC

FIELD: plastic working of metals, in particular, production of cold-reduced special-purpose sections. SUBSTANCE: formed section has horizontal wall with trapezium-shaped corrugation, inclined side walls and horizontal strips of predetermined size. Strips have flanges of width equal to 4.0-4.5 of section thickness. Flanges are inclined downward at an angle of 68-72 deg relative to strips. Inclination angle between side and horizontal walls is 100-104 deg. Corrugation height is 0.18-0.22 of section height, and corrugation width is 0.39-0.43 of horizontal wall width. Method involves sequentially forming side walls of section in roughing, intermediate and finishing passes; forming corrugation on horizontal wall of section and simultaneously limiting shifting of strip in roughing passes. Corrugation is formed only in roughing passes and tray-shaped profile is formed in intermediate passes, with strip motion being limited in first intermediate pass and bending radius of corrugation member being simultaneously reduced to predetermined value. Flanges on strips are bent downward in finishing passes with minimum bending angle of 2 deg in penultimate finishing pass and maximum bending angle of 32 deg in terminating finishing pass. Flange bending radius is made equal to radius provided in first finishing pass with following reducing it by 2.0-2.5 times in two subsequent passes and increasing it to predetermined value in terminating pass. Section produced by such method may be used for manufacture of main highway guardrails. EFFECT: reduced metal usage and decreased number of rolls employed for production of such sections, improved quality of sections and enhanced reliability in operation. 3 cl, 2 dwg, 1 ex