Effect of stress annealing on texture and recrystallization behavior of Zr–4 alloy

The texture of Zr–4 alloy not only affects its irradiation growth performance, but also affects mechanical properties, stress corrosion cracking, and water-side corrosion. Therefore, it is important to control the texture of Zr–4 alloy during processing. The effect of the applied external stress, annealing temperature, and annealing time on texture evolution and recrystallization of Zr–4 alloy is still unclear. Based on controllable process conditions, the stress annealing process of zirconium alloy in practical production was simulated by designing a simple experimental device. The texture and recrystallization behavior of Zr–4 alloy after annealing at different temperatures and stresses were studied by X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) techniques. The results show that applying external stress and increasing annealing temperature significantly change the evolution of recrystallized texture. With an increase in stress and annealing temperature, the texture of the zirconium alloy (\overline 1 2\overline 1 5)10 \overline 1 0, and the polar density decreases, thereby resulting in a decrease in material anisotropy. The annealing temperature has a significant effect on the amount of small-angle grain boundary and recrystallization ratio during material recrystallization. With an increase in applied stress and annealing temperature, dynamic recovery and recrystallization occur inside the material. The sub-structures in dynamic recovery and the dislocation sub-structures in the grains that undergo dynamic recrystallization gradually disappear. The small-angle grain boundary in the material recrystallization process is reduced significantly. The process is accelerated and the recrystallization ratio of the material is significantly increased. The application of applied external stress and the increase of annealing temperature are beneficial to the acceleration of the internal recrystallization process of the material. The main results from this paper can guide the optimization of annealing treatment of Zr–4 alloy, and provide a scientific basis for solving the problems encountered in the engineering application of Zr–4 alloy.