MICRESS Forum

hi.everyone
About austenite to lamellar pearlite transformation, I have the following questions to consult you. I want to simulate lamellar pearlite, as shown in the picture. The following is the driver file I established, but why does not evolution occur? I can't find the reason for the error. Maybe there is something wrong with the establishment of my driver file. I hope to get your help.

The following is part of my supplement. The following situation occurred when T=14s and 18s, and this phenomenon will disappear with the evolution of time. However, I have not found the reason for the error.

Hi shaojielv,

I can see some major issues in your setup:

- The initial composition is not a typical eutectic composition. As a consequence, you get γ-α transformation before, and only part of the domain can transform to eutectic (i.e. you are not the monovariant line).

- You define a very small temperature gradient which accounts for a temperature difference between bottom and top of only 6 mK. This is not sufficient for having stationary growth conditions.

- You use nucleation of "big" grains of α and cementite. This is not allowed in case of concentration coupling (although not explicitly forbidden), because the nucleated phases don't have the correct composition (and the others go to strongly negative in case of stoichiometric cementite). Normally, "small" with radius r=0 are used (or at least r <<interface thickness).

- Don't use "stoich_enhanced_on" (you probably copied that from older input files).

Bernd

Dear,Bernd
First of all, thank you very much for your suggestions. According to your suggestions, I modified some parameters and checked other problems. Therefore, I basically started a new driver file, but the organization did not evolve under the driver file. This is very difficult for me, so I have to turn to you again. I hope you can take part of your time to help me solve this problem, I will be very grateful.

Dear shaojielv,

Can you please describe what is not evolving as you expected?

Bernd

Dear,Bernd
I'm sorry for not clarifying my question. Relevant documents have been sent to you. Thank you very much .

Dear Bernd,

I have a problem with the phase simulation in MICRESS, it would be nice if you could give me a hint.

I am trying to simulate pearlite formation from austenite phase and compare with experimental results. But based on experimental results, I should get the best pearlite formation at 580 C (or 853 K), and as the temperature increases or decreases, the pearlite formation or volume fraction should decrease. But based on my simulation results, I can get the best results at 700 C (or 970). I have changed several parameters for the phases interaction, but there were no particular changes in the microstructure. Could you please tell me what could be the reason for this discrepancy and which parameters I should change to achieve the experimental results?

I sent you per email the experimental results and dri file.

Thank you very much in advance.

Best regards,
Ali

Dear Ali

I am very excited to see your simulation results. Could I ask you for some advice on the pearlite randomly generated at austenite grain boundaries? If it is convenient, can you share how you do the modeling?

Thank you very much.
Lv

Dear Friend,

sorry for my late reply, i missed your message.
If your are interested i can send to you.
Please find below my email address:

ch.darabi@gmail.com

Best regards,
Ali

Dear Ali,

I am very happy to receive your reply, I have sent you a private email, please check it.

lv