N-1 alloy creep at 1170?1370 K

Creep behavior of niobium-modified zirconium alloys

“…Given that the oxygen impurity was kept at a very small level and no quantitative oxygen content was reported, the relevant temperature of transformation then becomes a subject of speculation. However, Alymov et al [28] reported an activation energy value of 110 kJ/mol, which is identical to the activation energy ($110 kJ/mol) for lattice self-diffusivity of Zr in Zr-1Nb alloy in the b-Zr phase regime [31]. Alymov et al [28] reported an apparent stress exponent of 3.5.…”

“…However, Alymov et al [28] reported an activation energy value of 110 kJ/mol, which is identical to the activation energy ($110 kJ/mol) for lattice self-diffusivity of Zr in Zr-1Nb alloy in the b-Zr phase regime [31]. Alymov et al [28] reported an apparent stress exponent of 3.5. They argued that some deformation mechanism between the viscous glide and dislocation climb may be operating in this regime.…”

“…Very high temperature creep and tensile tests (897-1097°C) of Zr-1Nb alloy were also conducted by Alymov and coworkers [28]. In this temperature range, Zr presumably remains in the b-Zr form due to higher temperatures.…”

“…Alymov and coworkers [26,[28][29][30]] generated a vast amount of high temperature deformation data in a wide range of conditions. The work was carried out in the single phase regime of the alloy at a temperature range of 377-597°C and a stress range of 10-150 MPa (2 · 10 À4 -4 · 10 À3 E) [26].…”

Influence of grain size on the high-temperature creep behaviour of M5Framatome1 zirconium alloy under vacuum

“…In the single-phase β domain, only a dislocation creep regime has been reported in literature with a stress exponent in the range 3.2-4.3 [Ardell 1964, Abramyan et al 1967, Rose and Hindle 1973, Hardy 1973, Clendening 1975, Hunt and Foote 1977 Alymov et al 1987]. Namely, as for titanium alloys, β grain growth is fast in zirconium alloys, preventing from testing purely β microstructures with a rather fine grain size.…”