Deuterium profilemetry and diffusion coefficient in electrocharged stainless steel

The method of nuclear microanalysis using the reaction D(d,p)T is used to measure concentration-depth profiles of deuterium in austenitic Type 310 stainless steel electrocharged in 1 N D2SO4 with arsenic poison at room temperature. The influence of aging after charging is examined. A near-surface density of 0.6 deuterium atoms per metal atom (i.e., 38 at. %) is found for the initially charged condition. Associated with this high gas concentration is considerable microstructural damage. An analysis of the deuterium depth profiles yields a room-temperature diffusion coefficient for deuterium of 1.4 x 10-16 m2s-1 at high concentrations which is consistent with extrapolation of higher-temperature data available from other techniques for annealed material. At lower deuterium concentrations, < 10-2, in the aged material the extracted diffusion coefficient is a factor of three higher, implying a dependence on concentration. At concentrations < 10-3, diffusion may be hindered by dislocation trapping