The simultaneous bulk diffusion of 51Cr tracer, at 960 to 1400C in 20Ni-15at%Cr alloys, was measured by using the serial sectioning technique. At all temperatures, the diffusivities (table 157) were such that:

DCr > DFe > DNi

with DCr/DNi = 2.55 and DFe/DNi = 1.67. The activation enthalpies for diffusion of the major components in the alloy were quite close to each other. No correlation was found between swelling under irradiation, and the diffusion behavior of the major constituents. Grain boundary diffusion was found at surprisingly high temperatures.

S.J.Rothman, L.J.Nowicki, G.E.Murch: Journal of Physics F, 1980, 10[3], 383-98

Table 157

Diffusion Coefficients for 51Cr in Fe-20Ni-15at%Cr