The aim of his study is to investigate the effect of hydrogen embrittlement of Zr-2.5Nb CANDU pressure tube. The tests were performed at various of hydrogen contents for CCT specimens. The specimens were directly machined from the tube retaining origi...
The aim of his study is to investigate the effect of hydrogen embrittlement of Zr-2.5Nb CANDU pressure tube. The tests were performed at various of hydrogen contents for CCT specimens. The specimens were directly machined from the tube retaining original curvature using electric discharge machine. From the fracture toughness test, it was found that fracture toughness dJ/da was decreased with speedily increasing hydrogen content. And it observed constant value about 70-80ppm of hydrogen content. In fractography by SEM, we observed dimple fracture in AR materials, dimple and short fissure in 30ppm, and quesi-cleavage and large fissure in 80ppm. The decrease of fracture toughness with the addition of hydrogen is due the distribution of hydride and habit plane(10.7) of zirconium grain.