We study the influence of the rate of cooling from the temperature of solid- β -solution treatment on the mechanism of decomposition of the metastable β -phase of VT22 titanium alloy under the conditions of subsequent aging, its final microstructure, and mechanical properties. The procedure of hardening in water increases the number of point defects, which leads to the decomposition of the metastable β -phase with the formation of intermediate ω - and α″(α′) -phases. As a result, the mechanical characteristics of alloys increase due to the formation of more homogeneous and more dispersed microstructures.