METHOD FOR MANUFACTURING PLATES FROM TWO-PHASE TITANIUM ALLOYS Russian patent published in 2022 - IPC C22F1/18 B21B3/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to the processing of metals by pressure, in particular to the thermomechanical processing of two-phase titanium alloys, and is intended for the manufacture of flat rolled products used in the aviation industry, as well as mechanical engineering. The method for manufacturing plates from two-phase titanium alloys includes hot deformation of the ingot to obtain a slab, a preliminary stage of rolling the slab in several stages to obtain a semi-finished rolled product, while the final step of the stage is carried out at temperatures of (α+β)-region, the final stage of rolling to obtain plates, heat treatment of plates and finishing operations. After the preliminary stage of rolling, the intermediate hardening of the semi-finished rolling product is carried out in water after heating to above the polymorphic transformation temperature (PTT) by 10…60°C and holding at the temperature for 15…100 min, the final stage of rolling in the (α+β)-region is carried out in two phases, in the first of which rolling is carried out with a total degree of deformation 30…60% after heating the semi-finished rolling product to a temperature 40…120°C below the PTT, and in the second conducting longitudinal-transverse rolling with a total degree of relative deformation 30…75% after heating to a temperature 20…80°C below the PTT. The heat treatment of the plates is carried out according to a two-stage mode: at the first stage, heating is carried out to a temperature 20…60°C below the PTT with an exposure time of no more than 250 min, followed by air cooling, and the second stage is carried out by creeping at 700…850°C and intermediate cooling with a furnace up to 180…200°C and onwards in the air.

EFFECT: optimal microstructure of plates is obtained, which ensures a low rate of fatigue crack development while maintaining a high and stable level of strength and plastic properties.

1 cl, 3 dwg, 4 tbl