Assessment and Evaluation of Mobilities for Diffusion in the bcc Cr-V-Fe System

Abstract

Assessments of diffusion mobility parameters are performed for the bcc Cr-V-Fe alloy system by taking available literature data into account. The main focus is on the diffusion of V in the bcc phase where, in addition to all binaries, ternary interaction parameters are assessed. An experiment is performed in order to study the coarsening of V-rich MC carbide, where the diffusion of V is believed to be of major importance. The measured coarsening rate is compared with the rate calculated using DICTRA, and found to be in satisfactory agreement. The aspects of coarsening experiments as a method to evaluate diffusion mobility data are discussed.

Assessment and Evaluation of Mobilities for Diffusion in the bcc Cr-Mo-Fe System

“…Comparisons of experimentally measured precipitate coarsening rates with simulated rates have also been used to validate mobility parameters. [4,5] In the current work the assessed parameters were validated by comparing calculated ternary diffusion coefficients with experimentally measured coefficients and by comparing a calculated coarsening rate of a Mo rich M 6 C carbide with its measured coarsening rate. For the latter comparison a coarsening experiment was performed.…”

“…However, some reported assessments exist; Jönsson [3] performed assessments for the diffusion of several elements in both the fcc and the bcc phases with focus on iron based systems, Bratberg et al [4] revised the kinetic description of Cr and V diffusion in the fcc phase and Lindwall and Frisk [5] assessed parameters for the diffusion in the bcc V-Cr-Fe system. The latter work focused on the V diffusion.…”