The diffusion of 14C in the ferrite phase of the 9.8Co-5.7W-0.9wt%C alloy steel was studied by using a radio-isotope method. The results for 590 to 710C could be described by:

D (cm2/s) = 8.9 x 102 exp[-46.5(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