Investigation of J-integral for Hydrogen Saturated Zr-2.5Nb Zirconium Alloy.

This paper represents an investigation of hydrogen concentration and temperature influence on nuclear power reactor fuel channel tube material - Zr-2.5Nb zirconium alloy (TMT-2) fracture characteristics from the positions of nonlinear fracture mechanics. Zirconium free and made-up hydrogen saturated seminatural compact specimens were tested at various hydrogen concentration levels from 52 up to 140 ppm in order to examine temperature and hydrogen concentration influence onto fracture criteria J-integral of the alloy. Testing temperatures were selected with corresponding various operating regimes of the reactor and comprises 20, 170 and 200°C. Experimental data that has been given during experiment enabled to construct experimental J-R curves from which critical J-integral values J_1c were calculated. Dependence of J_1c to various mechanical characteristics of the alloy has been analysed and satisfactory correlation of J-integral critical value J_1c to modified plasticity criterion Z_mod of the alloy was obtained. [ABSTRACT FROM AUTHOR]