Mechanical anisotropy and construction of flow stress diagrams during the annealing of Zr–1% Sn alloy

In the present study the annealing behavior of 60% reduced and stress relieved Zircaloy-4 nuclear fuel cladding tube is studied over a temperature range of 300–1000 °C and an annealing time range of 103 to 105 s. The annealing effects were monitored using Knoop microhardness measurements and flow stress diagrams were developed to study the mechanical anisotropy evolution in the tubing. The determined values of the mechanical anisotropy ratios show that the tubing undergoes a significant mechanical anisotropy evolution during annealing.