Hydrogen Kinetics and Hydride Formation Effect on Zr-1Nb and Zr-1Nb-1Sn-0.1Fe Alloys for Nuclear Application

Abstract

The purpose of this study was to investigate the kinetics of hydrogen absorption and hydride formation and their effect on the mechanical properties in Zr-1Nb and Zr-1Nb-1Sn-0.1Fe alloys, which were thermomechanically processed and gaseously hydrided at 320ºC under 10 bar hydrogen pressure. X-ray diffraction (XRD) confirmed the formation of α-Zr matrix after final heat treatment. The alloys absorbed almost the same amount of hydrogen, although with different kinetics. Absorption began almost immediately in Zr-1Nb alloy whilst in Zr-1Nb-1Sn-0.1Fe hydrogen absorption started after 11 h besides a faster hydrogen kinetics. Results showed that tensile strengths for both alloys were nearly independent of absorbed hydrogen. Fractographic examinations indicated ductile fractures for unhydrided condition whereas quasi-cleavage features were observed for all hydrided specimens.

Keywords

• hydrogen absorption kinetics
• hydride
• zirconium alloys
• nuclear material