Hydrogen in the martensitic steel MANET : Diffusivity, solubility and surface recombination rate measurements
MANET is a martensitic steel proposed as a first wall and structural material for NET. During the sample-loading phase, the gas concentration in the sample was increased until equilibrium was reached with the external pressure. A quick pumping down of the chamber unbalanced this equilibrium, initiating the release of gas from the material. Allowances for the contribution of the chamber inner wall outgassing were made, based on blank runs performed under identical experimental conditions. Hydrogen isotope solubilities were then calculated from the total pressure increase while diffusivities were obtained from the time development of the pressure increase curve. Preliminary results for hydrogen obtained by data-fitting with a diffusion -limited model showed that: - the diffusivity was in the range from 1.0 E-9 to 1.0 E-8 m2/s, i.e. about one order of magnitude higher than for AISI 316L (austenitic steel); - the solubility was in the range 3 x 1.0 E-8 to 1.0 E-7 at.frac./Pa(-½), i.e. about an order of magnitude lower than in the temperature and loading pressure range studied. For temperatures below 623 K, the diffusivity appears to be a decreasing function of time. Equations describing the temperature dependence of these hydrogen-material interaction parameters in MANET are presented in the temperature range 623-873 K and loading pressure between 1.0 E3 and 1.0 E5 Pa.
Bibliographic Reference: Paper presented : 4th Topical Meeting on Tritium Technology in Fission and Isotopic Applications, Albuquerque (US), Sept. 29 - Oct. 4, 1991
Availability: Available from (1) as Paper EN 36257 ORA
Record Number: 199110807 / Last updated on: 1994-12-02
Original language: en
Available languages: en