METHOD OF PRODUCTION OF ROLLED SHEET FROM TITANIUM ALLOY OF GRADE BT8 Russian patent published in 2019 - IPC C22F1/18 B21B3/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy of titanium alloys and can be used for production of rolled sheet from (α+β)-titanium high alloy of BT8 grade. Proposed method comprises deformation of ingot into slab, machining of slab, multi-pass hot rolling and hardening thermal treatment. Deformation of ingot is performed by forging in two stages, at first of which forging is performed with degree of deformation of not less than 80 % after ingot heating, at second – forging is performed with degree of deformation of 50–70 % with cooling after forging at rate of 30–50 °C/min. Multi-pass hot rolling is performed in three stages, at the first stage, rolling is performed for rolling with degree of deformation of not less than 70% with cooling of rolled stock in air to room temperature, at second step, rolling is performed on strip with total degree of deformation of 40–60 % with subsequent cooling of strip in air to room temperature and further strip opening to billets, at third stage, sheet metal is produced by means of multi-pass rolling of workpieces in transverse direction with deformation degree of 50–60 %. Hardening heat treatment is carried out by quenching with heating to temperature (Tpp-80)–(Tpp-120) °C, holding for at least 1 hour and cooling in air with subsequent aging by heating to temperature (Tpp-370)–(Tpp-420) °C, holding for 4–12 hours and subsequent cooling in air.

EFFECT: high-quality sheet metal is obtained, having a high complex of mechanical properties at room and elevated temperature, as well as low anisotropy of mechanical properties owing to control of formation of texture in thermomechanical processing.

1 cl, 3 dwg, 2 tbl