Study of Texture Evolution in Two-Phase Zr-2.5wt%Nb Pressure Tube Material Fabricated Through Double-Pass Pilgering Route

The present paper deals with the study of texture evolution during the fabrication of Pressure Tube through a double-pass pilgering route and correlated to its microstructure using Orientation Distribution Function in the double-pass pilgering route. Two-phase Zr-2.5 wt% Nb alloy is the material used for pressure tube manufacturing at Nuclear Fuel Complex (NFC). This alloy develops strong textures on thermo-mechanical processing of HCP Zirconium metal, which in turn determines its in-service behavior. The study has shown that a strong orientation fibre parallel to working direction develops with hot working (extrusion). The texture thus formed after extrusion alone gets strengthened with increasing amount of deformation during subsequent cold-working. Presence of a soft secondary phase (β) at the α phase grain boundary is the reason for this phenomenon. However, new components of textures are generated with cold deformation after hot extrusion in single-phase Zircaloy-4 material due to interaction between grains.