The chemical diffusion coefficients for Cr in the ferritic steel were determined by using diffusion couples and electron probe microanalysis techniques. The average chemical volume diffusion coefficient, for compositions ranging from 14 to 28at%Cr, at 800 to 1000C was described by:

D (cm2/s) = 1.5 x 10-1 exp[-210(kJ/mol)/RT]

P.I.Williams, R.G.Faulkner: Journal of Materials Science, 1987, 22[10], 3537-42