Tracer Diffusion of 54Mn and 60Co in SS 316 LN in Presence of Sodium

Abstract

The diffusivity of cobalt and manganese in cold-worked and vacuum-annealed AISI type. SS 316 LN in presence of sodium in the temperature range 773–873 K was measured by the standard tracer technique.  In vacuum-annealed SS 316 LN specimens, the penetration depth of cobalt was only up to 2–5 μm from the surface even after diffusion annealing for a long duration of ~ 5000 h in the temperature range from 823 to 873 K. The activation energy for diffusion of cobalt in presence of sodium is almost four times higher than that of manganese in SS 316 LN matrix.

Keywords: Diffusivity, sodium, tracer technique