Circumferential creep properties of stress-relieved Zircaloy-4 and Zr–Nb–Sn–Fe cladding tubes

Effect of Cr on the creep properties of zirconium alloys

“…1 Previously, Pahutová et al [10] reported excellent creep resistance of Mo containing zirconium alloys. They suggested the solute atom atmosphere caused by Sn is known to increase creep strength of zirconium alloys, and thus considered the most typical alloying element [8,9,13]. On the other hand, Sn is also known to degrade the corrosion resistance.…”

“…Since their solubility in zirconium is very low and these elements are easy to form second phase precipitates, creep strength improvement by solidsolution hardening is hardly expected. In fact, it was reported that Fe and Cu were less effective than Nb or Sn [12,13]. Kim et al [12] suggested that high diffusivity of Fe and Cu might mitigate the interaction between their precipitates and moving dislocations.…”

“…Kim et al [12] suggested that high diffusivity of Fe and Cu might mitigate the interaction between their precipitates and moving dislocations. Lee et al [13] considered Sn to be the major effective element other than Fe and Cr in commercial zirconium alloys. However, we found some experimental evidence that Cr increases the creep resistance of zirconium alloys.…”

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

“…In this study, a special grip with two half-cylinders with 1 mm wide space between them was used to strain the ring specimen with maintaining a circular configuration of the ring in contact with the grips all the way during the tests [10,11]. The radius of the half-cylinders was 4.35 mm, which is a half of the inner diameter of the cladding tubes.…”

“…The radius of the half-cylinders was 4.35 mm, which is a half of the inner diameter of the cladding tubes. It was experimentally confirmed that the deformation occurred in the left and right-hand sides of the ring within 5 mm width centered on the split line of two half-cylinders and the optimum gage length was assumed to be 5 mm [10][11][12]. The load was applied to the ring specimen against the surface of the half cylinder and the force normal to the surface of half cylinder due to the applied load is close to zero in left and right-hand sides of the ring.…”