A gaseous permeation technique was used to measure the H diffusivities of specimens, after heat treatment at 210 to 430C. After solutionizing (980C, 1h, water-cool), the results obeyed Arrhenius relationships over the studied temperature range:

cold-rolled (75% deformation):     D (cm2/s) = 4.17 x 10-3 exp[-50.23(kJ/mol)/RT]

unaged:     D (cm2/s) = 1.81 x 101 exp[-45.74(kJ/mol)/RT]

aged (740C, 4h, air cool):     D (cm2/s) = 2.40 x 10-3 exp[-47.21(kJ/mol)/RT]

aged (740C, 8h, air cool):     D (cm2/s) = 3.24 x 10-3 exp[-49.18(kJ/mol)/RT]

aged (740C, 16h, air cool):     D (cm2/s) = 5.99 x 10-3 exp[-51.99(kJ/mol)/RT]

The transport of H in the face-centered cubic alloy was generally controlled only by the lattice diffusion of H.

J.Xu, X.K.Sun, W.X.Chen, Y.Y.Li: Acta Metallurgica et Materialia, 1993, 41[5], 1455-9