METHOD FOR PRODUCING TITANIUM ALLOY BILLETS FOR PRODUCTS EXPERIENCING VARIABLE MECHANICAL LOADS Russian patent published in 2019 - IPC C22F1/18 B21J5/00 

FIELD: technological processes.

SUBSTANCE: invention relates to thermomechanical treatment of titanium-based alloys with (α + β) structure and can be used to create blanks, having a high energy intensity, a finely dispersed microstructure with a grain size (0.5–5.0) mcm, for products experiencing varying mechanical loads. Method for obtaining a billet from (α + β) titanium alloys for products experiencing varying mechanical loads, includes multi-stage forging workpiece. In the first and third stages of forging, the titanium alloy blank is heated to a temperature T₁, which is higher than the temperature of the complete polymorphic transformation T_β + 40 ≤ T₁ ≤ T_β + 130, where T_β – temperature of the alpha-beta phase transition, in the second stage, the billet from the titanium alloy is heated to a temperature T₂, which is lower than the polymorphic transformation of T_β – 60 ≤ T₂ ≤ T_β. At all stages, forging is carried out with a deformation of 1.1–1.5 for 10–20 minutes when the billet rotates about its axis according to a scheme including one complete rotation of the billet with a rotation of 90°, the second full turn with a turn of a preparation on 45°, the third complete revolution with the rotation of the workpiece by 22°, after each step, hardening or cooling the preform into water is carried out, In this case, after the third stage, all subsequent steps of forging are carried out when the preform is heated to a temperature T_β – 60 ≤ T₂ ≤ T_β and with a deformation of 1.1–1.6 for 10–20 minutes when the workpiece rotates about its axis by 90°. Stages of forging, conducted after the third stage, is repeated until a uniform, fine-grained microstructure with grain size (0.5–5.0) mcm, containing equiaxed αphase in an amount of 40–80 % in the transformed β-matrix without the formation of a continuous grid α-phase at the boundaries β grains, then the resulting workpiece is annealed at a temperature of (830–870) °C for 40–80 minutes and cool.

EFFECT: blanks are characterized by high values of mechanical properties and energy intensity.

1 cl, 5 ex, 3 tbl