kinetics in full-equilibrium, NPLE and para mode

[chika]

Dear all,

I would like to ask a question about the influence of equilibrium mode on kinetics.
I am trying some fundamental 1D calculations which simulate the growth of thin austenite film in ferrite-matrix during iso-thermal holding.
I have calculated that with full-equilibrium, nple and para-equilibrium mode with coupling Thermo-Calc database of Fe-C-Mn alloy.

Austenite growth in para-equilibrium mode is the most fastest, and that in nple is the most slowest as shown in the result graph.
I am not sure why austenite growth in nple is much slower than that in full-equilibrium mode.
If anyone has any idea what the cause of this might be, I'd appreciate it if you could let me know.
The input files and result-graph are attached.

Best regards,
Chika

[Bernd]

Dear Chika,

Welcome to the MICRESS forum!

When you do not apply any "redistribution_control" model in MICRESS, "normal" redistribution is used for all elements. However, this is only legitimate and can be interpreted as full_equilibrium if the diffusion lengths of all elements are large in comparison to the interface thickness. This is obviously not the case for Mn in your case. Then, using "normal" redistribution for Mn leads to undefined behavior with kinetics lying somewhere between "nple" and "para". Only if you would make grid resolution so fine that the solute pile-up is fully resolved, you would get full_equilibrium behavior (which I would expect to coincide with or at least come close to "nple" then).

Best wishes
Bernd

[chika]

Dear Bernd,

I am grateful for your comment!
I would like to confirm the influence of grid solution on the kinetics in normal redistribution condition.

Best regards,
Chika