METHOD FOR OBTAINING MATERIAL FOR HIGH-STRENGTH FASTENERS Russian patent published in 2023 - IPC C22F1/18 C22C14/00 B21C1/00 

FIELD: metallurgy.

SUBSTANCE: production of materials based on a titanium alloy with desired mechanical properties for the manufacture of fasteners used in various industries, mainly in the aircraft industry. The method for obtaining material for high-strength fasteners includes obtaining an intermediate workpiece for drawing from a titanium alloy, obtaining a cold-drawn workpiece and its final heat treatment. An intermediate workpiece for drawing is obtained from a titanium alloy containing, wt.%: aluminum 3.0-6.5, nitrogen NMT 0.05, oxygen 0.05-0.3, carbon NMT 0.1, zirconium NMT 2.0, vanadium 4.0-6.5, molybdenum 4.0-6.5, chromium 2.0-3.5, iron 0.2-1.0, and structural aluminum[ Al]_eq and molybdenum equivalents [Mo]_eq - structural molybdenum equivalents, range from 5.1 to 9.3 and from 12.4 to 17.4, respectively, where[Al]_equiv.=[Al]+[O]×10+[C]×10+[N]×20+[Zr]/6, wt.% and [Mo]_equiv.=[Mo]+[V]/1.4+[Cr]×1.67+[Fe]×2.5 wt.%. The intermediate workpiece before drawing is annealed at a temperature (T_pt-20)°C-(Tpt-50)°C and cooled to room temperature at an arithmetic mean rate of at least 15 °C/min, obtaining a cold-drawn workpiece is carried out by drawing with a drawing ratio from 1.8 to 5. The final heat treatment of a cold-drawn workpiece is carried out according to the following mode: treatment for a solid solution after heating the metal to a temperature (T_pt-50)°C - (T_pt-80)°C with exposure for 1-8 hours and subsequent cooling at an arithmetic mean rate of more than 10 °C/min to a temperature below or equal to the temperature of subsequent aging, aging at a metal heating temperature of 400-530 °C for at least 8 hours, followed by cooling to room temperature, where T_pt is the temperature of the polymorphic transformation.

EFFECT: increasing the strength characteristics of the material while maintaining a high level of plasticity.

9 cl, 1 dwg, 2 tbl