The diffusion of Cu into solid Fe was studied at 1100 to 1130C. On the basis of the results, it was deduced that the diffusivity was described by:

D (cm2/s) = 7.8 x 10-4 exp[-19.0(kcal/mol)/RT]

R.R.Hough, R.Rolls: Metallurgical Transactions, 1971, 2[9], 2471-5