Alloying Effects on Hydrogen Solubility and Hydrogen Permeability for V-Based Alloy Membranes

Abstract

The alloying effects of chromium, molybdenum, tungsten, iron and cobalt on the hydrogen solubility of vanadium have been investigated systematically. The addition of iron or cobalt into vanadium decreases the hydrogen solubility more significantly than chromium, molybdenum and tungsten. Thus, the addition of iron or cobalt into vanadium improves the resistance to hydrogen embrittlement of the vanadium alloy itself effectively. It is also found that, in view of the new description of hydrogen permeation based on hydrogen chemical potential, these alloying elements enhance the hydrogen flux through the vanadium alloy. This is because the PCT factor, f_PCT, increases by the addition of iron or cobalt. Thus, alloying these elements into vanadium improves not only the resistance to hydrogen embrittlement, but also the hydrogen permeation ability.