Characterization of the crystallographic textures and mechanical anisotropy factors in two modifications of Zr-2.5Nb pressure tube materials

Zr-2.5Nb alloy is used for the pressure tubes in CANDU reactors. Current as-manufactured tubes are produced in a cold-worked and stress-relieved metallurgical condition. The tubes installed in reactors normally operate at ∼300°C. In a hypothetical loss-of-coolant-accident (LOCA), the pressure tube may be overheated to 1000°C. During the temperature transient, a phase transformation occurs that changes the microstructure and affects the material's high-temperature deformation behaviour. In this study, improvements to enhance the performance of pressure-tube materials are being explored by modifying the texture and microstructure of as-manufactured pressur