Evaluation of anisotropic deformation behaviors in H-charged Zircaloy-4 tube

In this paper, we focus mainly on evaluating the anisotropy evolution in Zircaloy-4 tubes with respect to hydrogen pickup which tends to affect the deformation behavior and fracture elongation due to embrittlement phenomenon induced by Zr hydrides. To capture the complex material behaviors of the H-charged (166 ppm) Zircaloy-4 tubes, we have applied the Hill anisotropic yield criterion by carrying out several material tests, such as the axial tensile, ring tensile, and axial crushing tests, for calibrating the anisotropic coefficients based on the directional strength and strain ratios. It makes possible to simulate the directional flow curves of the as-received and the H-charged Zircaloy-4 tubes based on the directional strength ratios along the axial and hoop directions, respectively, as well as a variation in deformation modes in the axial crushing test with substantial accuracy.