The diffusivity was measured by using an electrochemical permeation method. The diffusivity in annealed specimens, at 311 to 332K, at a charging current of 50A/m2, could be described by:

D (cm2/s) = 4.41 x 10-3 exp[-53.51(kJ/mol)/RT]

Cold-rolled specimens exhibited a higher diffusivity, and this was attributed to the presence of cold-worked α-prime martensite.

Y.Sakamoto, H.Katayama: Journal of the Japan Institute of Metals, 1982, 46[8], 805-14