Simulation of hydrogen embrittlement in zirconium alloys under stress and temperature gradients

A finite element model is presented for hydrogen embrittlement of zirconium alloys. The model takes into account the coupled processes of hydrogen dif fusion, non-mechanical energy flow, hydride precipitation, hydride/solid so lution deformation and fracture. The model has been tested successfully aga inst the Sawatzky experiment and exact analytical solutions on hydrogen dif fusion and hydride precipitation under a temperature gradient. Based on thi s model, the hydrogen embrittlement of a Zircaloy-2 cracked plate, is studi ed under tensile stress and temperature gradient. The initial and boundary conditions are according to those encountered in the fuel cladding of light water reactors during operation. The strong effect of crack tip stress int ensification on hydrogen diffusion and initial hydride precipitation is sho wn. The problem is also studied by considering near-tip material damage whi ch affects hydride precipitation significantly. (C) 2000 Elsevier Science B .V. All rights reserved.