The diffusion of 14C in the ferrite phase of the 9.9Co-5.2Mo-0.82wt%C alloy steel was studied by using a radio-isotope method. The results for 590 to 710C could be described by:

D (cm2/s) = 1.7 x 103 exp[-49.0(kcal/mol)/RT]

The diffusion parameters depended upon whether or not allowance was made for the carbide phase.

I.K.Kupalova, S.V.Zemskii: Izvestia Akademii Nauk, 1974, 4, 123-5