A model for hydride-induced embrittlement in zirconium-based alloys

The critical stress intensity factor for hydrided zirconium-alloys is calculated using a Dugdale type model for a finite crack. The hydride platelets are assumed to surround the ends of the crack. They are located in the process region of the crack tip. The model is used to calculate the temperature dependence of the critical stress intensity factor and the results are compared with measurements performed on Zr-2.5Nb and Zircaloy. The model in general describes the experimental data satisfactorily, nevertheless, it gives implausible results for a certain range of temperatures. The deficiency is attributed to the lack of appropriate constitutive relations for the hydrided zirconium-based alloys. (C) 1997 Elsevier Science B.V.