By use of X-ray texture analysis characteristic features of phase transformations in sheets,
tubes and welding seams of the Zr–2.5%Nb alloy were studied. Main attention was given
to inhomogeneity of phase transformation development, connected with inhomogeneous
distribution of strain hardening in grains with different crystallographic orientations. The
typical manifestation of phase transformation inhomogeneity in cold-rolled sheets is a
shift of the initial texture maximum to the region of increased strain hardening. In
channel tubes in consequence of phase transformations α−β−α
the texture component
{112−0}〈101−0〉
gains, testifying that tangential stresses favour corresponding alignment of
basal normals accompanied by absorption of grains with other orientations. Competition
between recrystallization and phase transformation in conditions of heating was considered.
As strain hardening increases, recrystallization prior to phase transformation
becomes more probable, being predominant within α-grains of some orientations. Parallel
development of recrystallization and phase transformation in the zone of thermal
influence by arc welding of rolled sheets was considered. It was shown that, as the distance
from the melting zone decreases, different combinations of these processes realize.
Inhomogeneity of Phase Transformations β→ω and β→α in the Quenched Cold-Rolled Alloy Zr-20 %Nb