solid-solid phase transformation

solid-solid phase transformations, influence of stresses and strains
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kaiyang
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solid-solid phase transformation

Post by kaiyang » Mon Jul 17, 2023 2:50 am

The desired effect is to form a ferrite at the triple junction, and then to generate lamellar beads at the grain boundary.

According to the iron carbon phase diagram analysis, the difference between the formation temperature of ferrite and pearite is about 70℃, and the cooling speed is 0.3℃ / s.

But in our model, ferrorites always grow too fast, resulting in the entire simulation domain before the pearlet is nucleated.

We tried to reduce the interface energy between the phases, but the organization effect was very bad.

Want to ask that we can change those parameters to solve the above problems.
Last edited by kaiyang on Tue Oct 31, 2023 2:41 am, edited 1 time in total.

Bernd
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Joined: Mon Jun 23, 2008 9:29 pm

Re: solid-solid phase transformation

Post by Bernd » Mon Jul 17, 2023 6:53 pm

Dear Kaiyang,

What do you mean with "organization effect"?

I did not find any obvious problems in your driving file. There may be different numerical reasons why you do not get cementite as expected. Depending on whether you do observe nucleation events for cementite or not, I could imagine the following reasons:


a) no nucleation of cementite happens at all (see .log-ouput)
- you have specified a too high critical nucleation undercooling for cementite which is not reached
- growth of ferrite is unstable, so that nucleation is not possible at 1/2-interface
- missing updating of thermodynamic data. Please apply updating of linearisation data either for all interfaces (in "database" section), or for each phase interaction separately (in phase interaction data).
- something went wrong when creating the .GES5-file

b) nucleation happens, but cementite cannot grow
- limited number of nucleation events of cementite (500) is spent before growth conditions are suitable
- growth of cementite is unstable, e.g. because of too high interface energy or interface mobility
- cementite seed is overgrown by ferrite before it can get bigger

Bernd

kaiyang
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Re: solid-solid phase transformation

Post by kaiyang » Tue Oct 31, 2023 2:45 am

Dear Bernd,
When I was doing a case related to Fe-C solid state phase transition, when I coupled the Mn element in the model, the following error appeared in the run log. I hope to get your help.
trying hard phases 2 3 level: 7 zp= 65758 error= 3
trying hard phases 2 3 level: 8 zp= 163858 error= 3
trying hard phases 2 3 level: 5 zp= 74298 error= 3
trying hard phases 2 3 level: 3 zp= 74298 error= 3
trying hard phases 2 3 level: 8 zp= 53752 error= 3
trying hard phases 2 3 level: 7 zp= 63800 error= 3
trying hard phases 2 3 level: 7 zp= 205031 error= 3
trying hard phases 2 3 level: 7 zp= 163762 error= 3
trying hard phases 2 3 level: 4 zp= 163762 error= 3
trying hard phases 2 3 level: 9 zp= 58974 error= 3
trying hard phases 2 3 level: 9 zp= 30391 error= 3
trying hard phases 2 3 level: 6 zp= 30391 error= 3
trying hard phases 2 3 level: 9 zp= 152717 error= 3
trying hard phases 2 3 level: 8 zp= 738 error= 3
trying hard phases 2 3 level: 8 zp= 738 error= 3

Bernd
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Joined: Mon Jun 23, 2008 9:29 pm

Re: solid-solid phase transformation

Post by Bernd » Tue Oct 31, 2023 9:09 am

Dear kaiyang,

More information is required. Please attach input files or send them as PM if confidential.

kaiyang
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anti_bot: 333

Re: solid-solid phase transformation

Post by kaiyang » Wed Nov 01, 2023 9:06 am

Dear Bernd,
Thank you very much for your reply. The previous problem has been solved.

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