Effect of hydride orientation on deformation process of pipes made of zirconium alloy e635

A method for numerical modeling of the influence of the orientation of zirconium hydrides on the deformation process and the distribution of local stresses in pipes made of zirconium alloy E635 (Zr-Nb-Sn-Fe) is presented. The modeling was performed, using the finite element method in the ANSYS software package, taking into account the crystallographic texture of the material at room temperature. It is shown that radially oriented hydrides, unlike tangential ones, create sharper stress drops. The S-shaped dependence of the maximum von Mises stresses in the product on the hydride orientation coefficient Fn is confirmed, indicating the existence of a ductile-brittle transition in the range of Fn = 0.20-0.35. The modeling results are consistent with the experimental data, which confirms the applicability of the developed technique for predicting the mechanical properties of hydrogenated zirconium alloy pipes.