METHOD FOR MAKING ROLLED BARS OF TITANIUM ALLOYS Russian patent published in 2001 - IPC

FIELD: plastic metal working, namely processes for making rolled bars such as round rods of hard-to-form titanium alloys by multipass helical rolling. SUBSTANCE: method comprises steps of heating blank up to temperature value being less by 10-20 C than temperature of complete polymorphous conversion; realizing multipass rolling at constant revolution number of rolls in stable deforming mode; setting reduction value at each pass in dependence upon temperature drop of rolled metal and determining it according to given expression ε₁ = Δtd•C•ρ/P_c, where ε₁ - logarithmic deformation degree; Δtd - increment of metal temperature due to deformation energy, C; C - metal heat capacity at deformation temperature, J/(kg x C); ρ - metal density, kg/cub. m; P_c - mean specific pressure. Invention provides conditions approximating isothermic deformation of blank and allows to make rolled pieces having equiaxial, fine-grain, dull structure with minimum anisotropy of its mechanical properties along article due to stabilized temperature in deformation zone. EFFECT: possibility for making high-quality rolled bars. 3 dwg, 3 ex _