Alloy VT22
Designation
Description
Alloy VT22 is used: for the manufacture of semi-finished products (sheets, strips, foils, strips, plates, bars, rods, profiles, tubes, forgings and forged blanks) by the strain, and bars; high-loaded parts and structures, continuously operating at temperatures up to +350−400 °C (up to 2000 hours); power in aircraft fuselage parts, wing, forgings, parts, control systems, fasteners of the type ushkovyh bolts. High strength alloy with a strength of 1250 MPa and high hardenability (to 200 mm) for large power structures of the glider.
Note
Alloy VT22 (a+b) class refers to signalground high strength alloys of the system Ti-Al-Mo-V-Fe-Cr. The content of b-stabilizing elements in alloy VT22 close to the second critical concentration (K*~of 1.0). Structure and properties of VT22 alloy are highly dependent on fluctuations of the chemical composition within the limits set by the specifications. Depending on the content of alloying elements the structure after quenching from the b-region can be represented by one or b-phase or b-phase and martensite. Thus, the structure in the hardened state is an alloy of the transition class.
The alloy has good technological plasticity during hot metal forming.
Alloy welded satisfactorily by fusion welding, argon arc welding, submerged arc welding, roller and spot welded. After welding it is necessary to conduct annealing to improve mechanical properties of welded joints.
Standards
Chemical composition
According to GOST 19807-91 and OST 1 90013-81 the total content of other impurities is ≤ 0.30%. The mass fraction of hydrogen is indicated for ingots. In the alloy, a partial replacement of molybdenum by tungsten in an amount not exceeding 0.3% is allowed. The total mass fraction of molybdenum and tungsten should not exceed the norms specified in the table for molybdenum. The mass fraction of copper and nickel should not be more than 0.10% (in total), including nickel not more than 0.08%.
