Abstract:

Diffusion of hydrogen for disordered and ordered Ni₃Fe alloys at room temperature has been studied by cathodic charging with hydrogen. At the same temperature of precharging, the elongation decreases and intergranular (IG) depth increases with increasing precharging time respectively for Ni₃Fe precharged hydrogen. At the same time of precharging, the depth of IG increases with increase of precharging temperature. Relationship between IG depth and temperature and time is in accordance with the solution of Fick law. Based on the time-lag method, the apparent diffusion coefficient of hydrogen in disordered Ni₃Fe alloy is larger than that in ordered Ni₃Fe alloy. The activation energy of hydrogen diffusion in disordered and ordered Ni₃Fe alloys is 44.9 kJ/mol and 29.5 kJ/mol respectively.

Key words: disordered, Ni₃Fe alloy
, ordered, hydrogen diffusion