The diffusivity of Mn in vacuum-annealed and cold-worked alloy D9 in the presence of Na was measured by using standard tracer techniques. The lattice diffusion coefficient of Mn in vacuum-annealed alloy D9 specimens at 773 to 873K was given by,

D (m2/s) = 2.24 x 10-14 exp[-60.764(kJ/mol)/RT]

and that in cold-worked alloy D9 specimens by:

D (m2/s) = 4.62 x 10-16 exp[-38.880(kJ/mol)/RT]

The activation energy for diffusion in cold-worked specimens was less than that in vacuum-annealed specimens. The activation energy for diffusion of Mn in the presence of Na was almost 4 times less than that reported for various austenitic stainless steels.

R.Sudha, P.Muralidaran, G.Periaswami, V.Ganesan: Journal of Nuclear Materials, 2006, 348[3], 302-10