DEVELOPMENT OF CALCULATING METHOD OF THE DEFORMATION PARAMETERS DURING ROLLING OUT IN A THREE-ROLL MILL LINERS OF SCREW ROLLING

Abstract

The main features of the process of screw rolling of steel pipes by a three-roll mill of screw rolling are considered. Taking into account the variety in distribution of specifi c forces at the deformation zone, the calculation method for the deformation parameters of rolling process of pipe liner in the deformation at the mandrel length was deve loped. The design procedure of partial reductions and contact of the metal surface area with the roll in zones of compression in diameter (reduction) and compression of the liner wall, which takes into account the tangential outfl ow of the metal in the gaps between the rollers, are characteristic for rolling processes of thin-walled pipes with diameter ratio of the thickness Dт /Sm wall > 8. The results of the study are intended for industrial use in the production of pipes with the ratio Dt/Sm = 8 – 15 with tolerances on wall thickness ±6 %; diameter ±0,5 %. These results would increase the understanding and especially the process of obtaining thin-walled pipes on pipe-rolling units with roll-off of screw rolling mills.