Hydrogen transport and solubility in 316L and 1.4914 steels for fusion reactor applications

10.2172/918137

“…The activation energy for diffusion is also assumed to be independent of the mass of the isotope. Diffusion data at subambient temperatures do not support equation 20 for a number of metals [11], however, permeability data at elevated temperatures generally support the inverse square root dependence on mass for nickel [12] and stainless steels [13][14][15][16]. For the purposes of this report we assume that equation 20 is a good approximation for both permeability and diffusivity; implicitly then the solubility is assumed to be independent of the mass of the isotope.…”

“…The relative solubility then provides a indirect indication of the accuracy of the diffusion determination. If we neglect the studies that result in low solubility [15,34,35] and only consider the studies where the solubility determinations cluster at the highest values [29,32,36], the hydrogen diffusivity relationships are in good accord with one another. The relationship of Louthan and Derrick [27], Table 1 and marked by circles in Figure 5, appears to represent a good average of diffusivity for austenitic stainless steels.…”

“…The average relationship of Sun et al was also generated from six alloys in several conditions (solutionized, annealed and cold-worked) [29] and is marked with triangles in Figure 4. The other lines represent permeability determined for type 316 stainless steels from a number of studies [15,16,[32][33][34][35][36].…”

“…The relationships from these studies [15,34,35] are plotted as dotted lines in Figures 5 and 6. High diffusivity implies low solubility ( K = Φ D), and since diffusivity and permeability are similar in magnitude over a wide range of temperature, small differences in diffusivity appear as large relative differences in solubility, Figure 6.…”

Deuterium permeation behavior of erbium oxide coating on austenitic, ferritic, and ferritic/martensitic steels

“…Two parts of the apparatus divided by the sample are separately evacuated up to about 10 −6 Pa, and then deuterium (purity of 99.995%) is introduced into one side Permeation phenomena of hydrogen are represented by following equation [18]:…”