Creep properties of annealed Zr–Nb–O and stress-relieved Zr–Nb–Sn–Fe cladding tubes and their performance comparison

Creep performance of Zr-1Nb-0.75Sn-0.1Fe cladding tubes with optimized Sn content

“…The creep strain rate is usually expressed by the following power law type relationship [15][16][17][18][19]: where, ε is the steady state creep rate, σ is the applied stress, A and B are material property related con stants, n is the stress exponent, Q c is the activation energy for creep deformation, R is the gas constant, and T is the absolute temperature. The stress exponent n remains constant (5)(6) in the stress range of the present study for Zr-1Nb-0.75Sn-0.1Fe, unlike Zr⎯1Nb-1Sn-0.1Fe, in which the transition of the stress exponent from 5-7 to 3-4 was observed [20]. The transition of stress exponent has been associated with the transition of the creep deformation mecha nism, from climb controlled creep, to glide controlled creep [16].…”

“…The transition of stress exponent has been associated with the transition of the creep deformation mecha nism, from climb controlled creep, to glide controlled creep [16]. Hong [17][18][19][20] explained the transition of the stress exponent in terms of the dynamic solute dis location interaction. In the dynamic solute disloca tion interaction model, the transition of the stress exponent from 5-7 to 3-4 can be attributed to the increasing solute drag stress, due to dynamic solute dislocation interaction with increase of creep rate (i.e.…”

Deformation behavior of cold-rolled and annealed Zr–1.5Nb and Zr–1.5Nb–S alloys

“…The effect of sulphur on the reduction of ductility is more evident in the annealed Zr-1.5Nb because dynamic strain aging effect is more pronounced. In the cold worked Zr-1.5Nb, the dynamic strain aging effect is less pronounced because of the strengthening effect of the high dislocation density [16,17]. As observed in many Zr and Ti alloys, at the strain rate of 1 Â 10 À4 s, the ductility decreased more rapidly at intermediate temperatures (200$400°C), which is typically associated with the effect of dynamic strain aging due to oxygen atoms.…”

Out-of-Pile Mechanical Performance and Microstructure of Recrystallized ZR-1.5 Nb-O-S Alloys

“…Fig. 4 were suggested to be β-Nb and Fe-containing intermetallics [13]. In the recrystallized alloys, wavy and curved dislocations and loosely knit tangles were observed at room temperature, suggesting an easier cross slip.…”

“…EDS analysis revealed that the small, round particles in Fig. 1 are Fe-containing intermetallics, and the rod-shaped particles are β -Nb [13]. Figure 2 shows the stress-strain responses of recrystallized Zr-1.5Nb-O (both without and with sulfur contents, 25 ppm and 160 ppm) at both room temperature and 300ºC.…”