Zircaloy canning tubes. Production and mechanical properties

The production and resulting mechanical properties of Zircaloy tubing are reviewed. Of basic importance is the anisotropy of the hexagonal crystal of the low-temperature modification of zirconium. The crystal anisotropy causes a pronounced texture and a mechanical anisotropy of polycrystalline Zircaloy material. By careful control of how the wall thickness and diameter are reduced during cold rolling in tube production, desired texture and mechanical properties can be achieved. Tensile properties from room temperature up to 400 deg C are presented as a function of annealing temperature. The effects of the degree of cold work and of texture are shown. Burst properties obtained in open-end and closed-end burst testing are given and the effects of annealing temperature and texture are demonstrated. The difference in creep behaviour at 300 and 400 deg C is emphasized and the effects of creep stress, annealing temperature, cold work, and texture on the 400 deg C transverse creep properties are reported. Of special importance for the transverse ductility is the hydride orientation. The effects of annealing temperature and texture on hydride orientation are demonstrated. (author)