The volume and grain-boundary diffusivities of 51Cr and 59Fe in a high-purity Fe-50Cr-8wt%W alloy were determined at 1023 to 1373K (figures 3 and 4) by using the sputter micro-sectioning technique. The bulk diffusion coefficients of Cr and Fe in the Fe-50Cr-

8W alloy were smaller than those in high-purity Fe-50wt%Cr alloy. Linear Arrhenius plots were observed for the bulk self-diffusion coefficients of both tracers over the present temperature range. The activation energies for the bulk diffusion of both components in the Fe-50Cr-8W alloy were somewhat smaller than those in the Fe-50Cr alloy. On the other hand, the grain-boundary diffusivities of Cr and Fe in the Fe-50Cr-8W alloy at 1123K were about 2 orders of magnitude lower than those in the Fe-50Cr alloy. The grain-boundary diffusivity of Cr at 1123K was equal to 7.9 x 10-22m3/s, and that at 1173K was equal to 2.0 x 10-21m3/s. The grain-boundary diffusivity of Fe at 1123K was equal to 2.7 x 10-21m3/s, and that at 1323K was equal to 1.4 x 10-19m3/s.

Diffusion of Cr and Fe in a High-Purity Fe-50Cr-8wt%W Alloy. K.Takasawa, Y.Yamazaki, S.Takaki, K.Abiko, Y.Iijima: Materials Transactions, 2002, 43[2], 178-81