Effect of hydrogen isotope content on tensile flow behavior of Zr-2.5Nb pressure tube material between 25 and 300 °C

• Tensile properties of Zr-2.5Nb pressure tube alloy were evaluated.
• Effect of deuterium content and test temperature were studied.
• Pre-necking tensile properties appeared to unaffected by the deuterium content.
• Post-necking tensile properties captured the effect of hydride embrittlement.

Tensile properties of autoclaved Zr-2.5Nb pressure tube material containing hydrogen isotope between 5 and 200 wppm were evaluated between 25 and 300 °C using specimens with its axis oriented along longitudinal direction of the tube. Analysis of tensile test results showed that both YS and UTS of this alloy decreased linearly with increasing test temperature. The uniform and total plastic strain decreased marginally with increase in test temperature. At all test temperatures, before necking tensile properties were unaffected by hydrogen isotope concentration whereas hydrogen isotope had clear effect on post-necking tensile properties especially at 25 and 100 °C. Post-necking ductility showed a transition behavior at 25 and 100 °C and it was able to capture the effect of hydride embrittlement in this material.