Table of Contents
Example P10: AlN precipitation in steel, part 3: Concurrent precipitation of VN and AlN
Compatibility
MatCalc version: 5.44.1002
Database: mc_fe.tdb, mc_x_FeAlCCrMnNSiV.tdb, mc_sample_fe.ddb
Author: Georg Stechauner
Created: 2012-01-20
Revisions:
Objectives
Related documents
- P10-1 - AlN precipitation in austenite
- P10-2 - AlN precipitation in ferrite
- P. König, W. Scholz und H. Ulmer, Archiv für das Eisenhüttenwesen, 32(8) (1961) 541-556.
Complementary files
Click here to view the script for this tutorial.
Main document
Setup thermodynamics
Set up the thermodynamics by either loading the mc_fe database, or the corresponding example database mc_x_FeAlCCrMnNSiV.
Select the following phases, elements and enter the chemical composition in wt-%:
| Elements | Chemical composition | Phases |
|---|---|---|
| Al | 0.052 | AlN |
| C | 0.2 | FCC_A1 |
| Mn | 1.34 | |
| N | 0.023 | |
| Si | 0.52 | |
| V | 0.14 |
Set Fe to reference element.
Conclude the thermodynamic setup by loading the diffusion database for Fe.
Experimental data
The script contains several tables with the experimental data from König et. al. Enter the CIE table, and one temperature if you are only interested in one curve. Enter all tables for the full spectrum of results.
Create the following tables:
| CIE_VN | |
|---|---|
| Temperature / C | Value |
| 1073 | 1 |
| 1123 | 1 |
| 1173 | 0.94 |
| 1223 | 0.85 |
| 1273 | 0.69 |
| 1373 | 0.69 |
| VN, 900C | AlN, 900C | ||
|---|---|---|---|
| x-Value: time / s | y-value: phase fraction | x-Value: time / s | y-value: phase fraction |
| 3600 | 0.00024 | 3600 | 0.00016 |
| 10800 | 0.00104 | 10800 | 0.00016 |
| 21600 | 0.00112 | 21600 | 0.00024 |
| VN, 950C | AlN, 950C | ||
|---|---|---|---|
| x-Value: time / s | y-value: phase fraction | x-Value: time / s | y-value: phase fraction |
| 3600 | 0.00008 | 3600 | 0.00008 |
| 10800 | 0.00048 | 10800 | 0.00016 |
| 21600 | 0.00056 | 21600 | 0.00016 |
| 72000 | 0.00064 | 72000 | 0.0004 |
| 86400 | 0.00056 | 86400 | 0.00048 |
| 108000 | 0.00048 | 108000 | 0.00064 |
| 144000 | 0.00032 | 144000 | 0.00112 |
| 360000 | 0.00016 | 360000 | 0.00152 |
Precipitation domain and precipitates
Next we enter the data for the precipitation domain. To do so, open the precipitation domain dialog and create a new domain. Select fcc_a1 as its matrix phase. Enter the following data in the corresponding tabs:
| Tab | Option | Value |
|---|---|---|
| Structure | Grain diameter | 50e-6 |
| Dislocation density | 1e11 | |
| Special | Young's modulus | (193000-73.333*T$C)*1e6 |
| Diffusion ratio grain boundary and bulk (substitutional) | (10^(11-0,005*T$C)) | |
| Diffusion ratio grain boundary and bulk (interstitional) | (10^(11-0,005*T$C)) | |
| Diffusion ratio dislocation and bulk (substitutional) | (10^(7-0,0025*T$C)) | |
| Diffusion ratio dislocation and bulk (interstitional) | (10^(7-0,0025*T$C)) |
Follow by setting up the precipitates. Bring up the phase status dialog window and select the AlN phase. Click 'Create new phase' and select 'precipitate'. Repeat this step for VN.
| Precipitate | Tab | Option | Value |
|---|---|---|---|
| AlN_p0 | Precipitate | #size classes | 50 (Initialize!) |
| AlN_p0 | Attached to pd | austenite | |
| AlN_p0 | Use interface energy size correction | ✔ | |
| AlN_p0 | Nucleation | Restrict nucleation to prec domain | ✔, select ferrite |
| AlN_p0 | Nucleation sites | grain boundary | |
| AlN_p0 | Structure | ignore for prec. strengthening | ✔ |
| Precipitate | Tab | Option | Value |
|---|---|---|---|
| VN_p0 | Precipitate | #size classes | 50 (Initialize!) |
| VN_p0 | Attached to pd | austenite | |
| VN_p0 | Interface energy | No flag, enter: cie$vn*cie_vn(T) |
|
| VN_p0 | Use interface energy size correction | ✔ | |
| VN_p0 | Nucleation | Restrict nucleation to prec domain | ✔, select ferrite |
| VN_p0 | Nucleation sites | dislocations |
Understanding the script
Start precipitation simulation
To ensure correct thermodynamic values and no driving force errors (DFM-errors), set automatic start values and calculate an equilibrium at 1250C.
Set end time to 1e6 and temperature to the either 900 or 950C. Check the figure below for correct settings. Press Go! to start the simulation.
Plotting the results
Create a new X-Y-Plot (p1) and add two new plots. Set a default x-axis to logarithmic with a scaling from 1e-6.. and label the axis time / s.
- Plot the phase fractions of the precipitates in the first figure (
f_prec$…) and the corresponding experimental data from the table. - Plot the mean radius of the precipitates in the second figure (
r_mean$…). Add a scaling factor of 1e9 to display the size in nm. - Plot the number density of the precipitates in the third figure (
num_part$…).
Label the y-axes accordingly.
Results not added yet
Consecutive articles
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