Papers by Keyword: Nuclear Material

Abstract: Small Angle Neutron Scattering (SANS) technique allows characterizing the nanomicrostructure of the ferritic Oxide Dispersion Strengthened (ODS) steels which are candidates for the structure material of fusion reactor and fast reactor. A SANS study of domestic ferritic ODS alloys are presented. The main objective is to study the evolution of the oxide dispersion nanoparticle during the different stages of the fabrication and different content.

Abstract: Annealing behaviour of ferritic HT-9 stainless steel plates was investigated through evolution of microstructural, textural and mechanical properties. Microstructural observations showed two important findings: (a) abnormal grain growth occurs at higher annealing temperatures, (b) drop in in-grain misorientation with increasing annealing temperature. However, textural results showed an increase in texturing till 500oC annealing and a clear drop in texturing beyond 500oC annealing. The strength (both yield and tensile) decreased with increase in testing temperature and the micro-hardness values decreased with increase in annealing temperature. Dynamic strain ageing was observed at certain strain rates and testing temperatures. The onset of the serrated yielding at low temperature limit estimated from the strain rate-temperature plot was found out to be ~ 94kJ/mol identifiable with that for migration of C and N.

Abstract: The oxide film, which is formed on the Zr-2.5% Nb pressure tube surface serves as a protective barrier against hydrogen ingress. Hydrogen ingress is a diffusion process and therefore is affected by the distributions of oxide orientation, grain size, shape, and boundary. Our previous research has focused on understanding the oxidation mechanism and predicting the hydrogen ingress and oxidation kinetics. In this paper, a simple model has been established to simulate the effects of cracks/voids on diffusion process. This model can be potentially used to study the influences of oxide cracks on hydrogen permeation. The effects of the volume fractions, orientation and distributions of cracks on the steady state diffusion flux are simulated.