The Study of the Heterogeneity of the Structure of a VT41 Titanium Alloy Billet after Thermomechanical Treatment

The heterogeneity of the structural state of a VT41 pseudo-α-titanium alloy after hot upset is studied. The analysis of the distribution of deformation upon upset and characteristic features of the formation of each of the structural components of the specimen is performed. Globular grains are deformed by the mechanism of intergranular slipping. β grains and α plates make the greatest contribution to plastic deformation. Lamellar grains of the α phase undergo recrystallization in the zone of localization of deformation. The dimensions of the zone where the recrystallization occurs coincide with the zone of localization of deformation estimated by the macrostructure. When quenching the billet, the β phase breaks down into α plates in the center of the specimen and into smaller grains that probably are needle-like β-titanium martensite in the near-surface regions. A decrease in the microhardness in the central regions may be due to both recrystallization and the fact that the surface layers are subjected to martensite quenching.