METHOD TO PRODUCE SUB MICRO-CRYSTALLINE STRUCTURE IN UNALLOYED TITANIUM

摘要

FIELD: process engineering.;SUBSTANCE: proposed method comprises metal forming. Proposed method aims at producing uniform sub micro-crystalline globular structure in unalloyed titanium in forming round-section bars, square-section bars, as well as strips and sections of various shapes. To this end, billet is heated to temperature lower than that of re-crystallisation and formed by three-roller screw rolling with positive or negative twisting and with increased drawing factor and decreased billet temperature during every subsequent stroke in the rage of 650-350°C. Then billet is heated to temperature not higher than that at the last stage of screw rolling and reduced by lengthwise section rolling in calibers with deformation logarithmic degree per a stroke making at least 0.5.;EFFECT: higher efficiency, lower costs and reduced labor input.;5 cl, 1 dwg, 2 ex, 1 tbl