Investigation of the surface element composition influence on hydrogen permeability through vanadium alloy VCr4Ti4.

Vanadium alloys are planned for use as structural materials in fusion react or blankets. To confirm the applicability of these alloys in fusion reactor s hydrogen isotope mass transfer and inventory of vanadium alloys must be u nderstood. In the present work, results obtained by performing experiments on hydrogen permeability through vanadium alloy VCr4Ti4 with different surf ace element compositions of the sample are presented and discussed. Changes of surface element composition were registered by means of Anger Electron Spectroscopy (AES). Experiments were carried out in the temperature range f rom 573 to 873 K, at input pressures of hydrogen from 10(2) to 10(3) Pa. Th e differential variant of steady state technique with the registration of g as quantity permeated through sample by means of mass-spectrometer was used in these experiments. Parameters of hydrogen permeation through the vanadi um alloy at different surface element compositions of the sample were deter mined. Experiments have shown that the concentration of nonmetallic impurit ies sulfur/carbon on the surface has a strong influence on the hydrogen per meability through the vanadium alloy (VCr4Ti4).