Example 4.14: Decarburization of Fe-C Matrix
Purpose: Learn to perform decarburization simulation at constant temperature with a fixed activity at boundary.
Module: PanDiffusion
Thermodynamic and Mobility Database: Fe-Demo.rtdb
Batch file: Example_#4.14.pbfx
Calculation Procedures:
- Create a workspace and select the PanDiffusion module following Pandat User’s Guide: Workspace;
- Load Fe-Demo.rtdb following the procedure in Pandat User’s Guide: Load Database, and select Fe, C two components;
- Click on the menu "PanDiffusion → Diffusion Simulation" or click the icon
and set up the calculation condition as shown in Figure 4.14.1. - First click the red “X” above Regions to delete Region_2 and leave one Region only.
- Click on Region_1 and set the composition as 0.5C-99.5Fe (at%), The length (Diff. Length) as 100 mm, and the # of Grids as 100.
- The Thermal History is a period of 10 seconds with a constant temperature at 1000 °C;
- Click on Lower Boundary Condition (left edge of Region_1) and select fixed “activity”, and set the Value as “a(C:graphite[*])=0.01”;
- In the settings shown in Figure 4.14.1, composition profiles at the initial and final stages will be outputted. Click OK to perform calculations.
- By default, dissolution simulation gives time-evolution of particle size as output. In order to display composition profile at desired moments, click the blue “+” button next to the “Moments for Profile Outputs” and input a time value. As shown in Figure 4.14.1, profiles at 1 second and 5 second will be outputted. Click OK to start calculation;
- Details on these options can be found in Pandat User's Guide: Settings in Particle Dissolution Simulation.
Post Calculation Operation:
- Set the scale of the Y axis to be 0.1-0.6 (at%). Remove composition profile of Fe. The calculated composition profiles are displayed in Figure 4.14.2. Change graph appearance and add text following the procedure in Pandat User’s Guide: Property.
Information obtained from this calculation:
- Decarburization process in Fcc phase in the Fe-C system. Lower boundary condition is a fixed carbon activity (0.01, Graphite as the reference state).
Figure 4.14.1: Setting of the simulation condition
Figure 4.14.2: Simulation result of carbon composition profile