The migration of 51Cr into samples of 3N-purity 18Cr-10wt%Ni alloy, or into samples which were doped with 0.007wt%S, was investigated at 700 to 1050 by using the Suzuoka method. The results were described by:

850-1050, S-doped:     D (cm3/s) = 2.00 x 10-4 exp[-245(kJ/mol)/RT]

700-850, S-doped:     D (cm3/s) = 6.94 x 10-10 exp[-114(kJ/mol)/RT]

700-1050, undoped:     D (cm3/s) = 4.40 x 10-6 exp[-189(kJ/mol)/RT]

It was found that the presence of S decreased the true diffusion kinetics of Cr. It was concluded that segregation led to the precipitation of compounds of Cr and S at the grain boundaries. The true diffusion kinetics of Cr were faster at precipitate/matrix interface boundaries than along boundaries which were drained of S.

D.Juve-Duc, D.Treheux: Acta Metallurgica, 1984, 32[11], 2063-8