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1. A dilatometric investigation [7] and data on the hardness have shown the formation of ω-phase in the VT3-1, VT6, VT8, VT14, VT15, and VT16 alloys after certain conditions of recovery treatment. This phase is formed in the metastable supersaturated β-solid solution. 2. The recovery treatment makes it possible to determine the region of the existence of the ω- and α-phases, which are the transformation products of the solid solution. 3. It should be kept in mind that it is possible for the ω-phase to form in commercial (α+β) titanium alloys in the following cases (as the result of aging at temperatures up to 400–450°C): a) after quenching from temperatures below the normal temperatures; b) after hot deformation: c) after welding, and possibly after brazing, if the temperature reaches 700–850°C. 4. The amount of ω-phase formed depends on the composition of the alloy and the method of heat treatment. The effect of ω-phase on the mechanical properties, especially the plasticity, should be determined in a special investigation.

1. The transformations of the β-phase are the basic transformations occurring during aging of the industrial VT3-1 alloy. After aging at temperatures up to 350–370°C the alloy has the αρ+β+ω structure; aging at 350–450°C products an αρ+β+ω+ας structure; aging at temperatures above 425–450°C products an αρ+β+ας structure. 2. The transformations occurring in the VT6, VT8, VT14, and VT16 alloys quenched from the two-phase region are similar to those occurring in the VT3-1 alloy. 3. One should avoid subjecting the VT3-1 alloy to temperatures of 400–450°C after quenching alone without subsequent aging. 4. We have shown that recovery in the case of aging can be utilized as a method of determining the phase composition of alloys in cases where the ω-phase participates in the hardening of the alloy.