The migration of Fe in alloys which contained a few ppm of S was studied at 1075 to 1200C. The data could be described by:

0.00105wt%S:     D (cm2/s) = 1.0 x 10-1 exp[-255(kJ/mol)/RT]

0.00355wt%S:     D (cm2/s) = 3.0 x 10-2 exp[-247(kJ/mol)/RT]

D.Treheux: Scripta Metallurgica, 1983, 17[7], 933-6