Features of the structural phase state of a weld produced by electron-beam welding in the submicrocrystalline grade 2 titanium alloy

This paper presents the results of structural studies for a welded joint of the Grade 2 titanium alloy in submicrocrystalline and microcrystalline states produced by electron beam welding when joining 2-mm-thick plates. Microhardness distribution patterns of the Grade-2 titanium alloy in micro- and submicrocrystalline states are identified in the weld zone and heat-affected zone. These patterns reflect a difference in structural phase states. It is assumed that one of the key factors affecting both the structural state and microhardness distribution in the weld zone and heat-affected zone during electron-beam welding is high concentration of oxygen atoms embedded into the crystal lattice of α–Ti-based solid solution