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tutorials:t20 [2019/08/13 17:56] – [Grain growth of supersaturated Fe-matrix - solute drag effect] pwarczok | tutorials:t20 [2023/08/18 13:36] – [Grain growth of pure Fe-matrix] pwarczok |
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//This tutorial was tested on\\ | //This tutorial was tested on\\ |
MatCalc version 6.01 rel 1.003\\ | MatCalc version 6.03 rel 1.000\\ |
license: free\\ | license: free\\ |
database: mc_fe.tdb; mc_fe.ddb// | database: mc_fe.tdb; mc_fe.ddb// |
Next, in the **'MS Evolution'** tab select the **'Grainstructure'** sub-tab. By default, the evolution model for grain size is set to **'None - no evolution'**. This is the option that has been used in all kinetic simulations so far; the grain size, as well as other microstructural parameters such as dislocation density, has been taken as constant. Instead, set this to **'Single class model'**. A set of options will appear as shown in the diagram below. Leave the values with default settings and click on 'OK' button. | Next, in the **'MS Evolution'** tab select the **'Grainstructure'** sub-tab. By default, the evolution model for grain size is set to **'None - no evolution'**. This is the option that has been used in all kinetic simulations so far; the grain size, as well as other microstructural parameters such as dislocation density, has been taken as constant. Instead, set this to **'Single class model'**. A set of options will appear as shown in the diagram below. Leave the values with default settings and click on 'OK' button. |
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{{:tutorials:t20:img:t20_precipitation_domains_msevol_grainstructure_6011003.png?650|}} | {{:tutorials:t20:img:t20_precipitation_domains_msevol_grainstructure_6050006.png?650|}} |
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Using **Calc > precipitation kinetics**, set up an isothermal simulation with an end-time of 3600 s (1 hour) and a temperature of 900°C. Click on **'Go'**. The simulation will be over very rapidly compared to precipitation simulations. | Using **Calc -> precipitation kinetics**, set up an isothermal simulation with an end-time of 3600 s (1 hour) and a temperature of 900°C. Click on **'Go'**. The simulation will be over very rapidly compared to precipitation simulations. |
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Create a plot of type 'p1'. In the **'variables'** window, find the section entitled **'prec domain struct sc'** ('sc' standing for 'single class') and expand to show **GD$***-variables. Expand this one step further to show **GD$austenite**, and drag this to the plot window. Change the (default x-axis label to read **time [h]** and modify the scaling factor to **1/3600**. Change the y-axis title to **Grain diameter [μm]** and modify the scaling factor to **1e6**. | Create a plot of type 'p1'. In the **'variables'** window, find the section entitled **'prec domain struct sc'** ('sc' standing for 'single class') and expand to show **GD$***-variables. Expand this one step further to show **GD$austenite**, and drag this to the plot window. Change the (default x-axis label to read **time [h]** and modify the scaling factor to **1/3600**. Change the y-axis title to **Grain diameter [μm]** and modify the scaling factor to **1e6**. |
The final simulation demonstrates the effect of the precipitates on the grain growth. In order to account for this effect. a precipitate phase needs to be defined which will appear in the simulation. In the **'Phase status'** window, create the precipitate phase for **'FCC_A1#01'** phase, and select the dislocations as nucleation sites (in **'nucleation'** tab). | The final simulation demonstrates the effect of the precipitates on the grain growth. In order to account for this effect. a precipitate phase needs to be defined which will appear in the simulation. In the **'Phase status'** window, create the precipitate phase for **'FCC_A1#01'** phase, and select the dislocations as nucleation sites (in **'nucleation'** tab). |
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{{:tutorials:t20:img:t20_nbc_nucleation_sites_6011003.png?650|}} | {{:tutorials:t20:img:t20_nbc_nucleation_sites_6050006.png?650|}} |
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Once again, setup the isothermal simulation for 3600 s at 900°C and plot the grain diameter of austenite when the calculation is completed. | Once again, setup the isothermal simulation for 3600 s at 900°C and plot the grain diameter of austenite when the calculation is completed. |
{{:tutorials:t20:img:t20_grain_growth_prec_pinning_6021003.png?650|}} | {{:tutorials:t20:img:t20_grain_growth_prec_pinning_6021003.png?650|}} |
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A further decrease of the grain rate can be observed, once the precipitate phase is present. On the first sight, one might get an impression that the effect of the precipitates is not that big. However, it must be remarked that the precipitates were created in this simulation and phase fraction of these has a minor value of 4e-6 after one hour, compared to around 4e-4 in equilibrium at this temperature. The difference in the grain sizes gets more and more significant, as the amount of precipitates increases, which can be observed for the increased tempering times. | A further decrease of the grain rate can be observed, once the precipitate phase is present. On the first sight, one might get an impression that the effect of the precipitates is not that big. However, it must be remarked that the precipitates were created in this simulation and phase fraction of these has a minor value of almost 4e-6 after one hour, compared to around 4e-4 in equilibrium at this temperature. The difference in the grain sizes gets more and more significant, as the amount of precipitates increases, which can be observed for the increased tempering times. |
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