UA86284U - Method of hot pilger rolling pipes - Google Patents

Abstract

A method of hot pilger rolling pipes includes deformation of a cupped blank into a pipe to obtain a pilger head at the rear end of cupped blank by rolls on a mandrel with rest of the cupped blank end against the mandrel ring and backing the mandrel and cupped blank from the side of feeder system, fixing position of the resulting pipe by a gate device, partial extraction of the mandrel and simultaneous forced cooling the rolled part of the pipe on the exit side of the mill, rolling the pilger head of cupped blank on the free portion of mandrel without backing against the cupped blank end, locking the rear end of pipe by the dies with its simultaneous cooling and final extraction of the die. Rolling the pilger head is performed with increase in wall thickness for 1.2-2.0 times with respect to the wall of the pipe main part over an area making 0.5-2.0 diameters of the pipe adjacent to its rear end, by lifting the upper roll. Fixing the cooled thickened end of pipe is carried out by the dies, on the working surfaces of which wear-resistant rollers are applied which are arranged transversely to the pipe axis. The like rolls are mutually displaced on both dies.