Effect of Hydrogen Content on Low-Cycle Fatigue Behavior of Zr-Sn-Nb Alloy

The effects of absorbed hydrogen on behavior of NZ2 zirconium alloy (Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr, in wt% designated as NZ2) were investigated. The sheet specimens were hydrided with different hydrogen contents: unhydrided (original hydrogen content), 200, 450 and 730 μg/g H and tested at room temperature and 375 °C, respectively. The results show that dynamic strain ageing (DSA) can be observed during cyclic deformation of NZ2 alloy at 375 °C. Even if the hydriding content is up to 730 μg/g it has no influence on DSA. Hydrogen can improve the fatigue life of NZ2 alloy at 375 °C and cause the cyclic softening.