Temperature Dependences of the Delayed Hydride Cracking Rate of Fuel Claddings Made of Zirconium Alloys of Various Compositions

摘要

The temperature dependences of the delayed hydride cracking (DHC) rate of Zr-INb and Zr- 0.8Nb-0.8Sn-0.3Fe alloy claddings are' studied in the range 127-300℃ in comparison with the data obtained for Zr-2.5Nb and Zircaloy-4 alloys earlier. The samples are in the state of cold deformation and stress relief at 400℃ for 24 h and in the state of preliminary hydrogen saturation to a hydrogen concentration of 0.02 wt %. As the strength of a zirconium alloy decreases and its ductility increases, the DHC rate and its high-temperature limit for a linear Arrhenius equation decreases, and the fractographic patterns of the fracture surfaces are different.