Microsegregation During Solidification

This example shows only a few of the capabilities of Thermo-Calc together with the Add-on Diffusion Module (DICTRA) to investigate and predict microsegregation (solute redistribution) during solidification.

It is based on a real case where the elemental distribution of a continuously cast steel was measured revealing the concentration of the elements Si, Mn, and P as sketched in Figure 1. The profile results from the well-known segregation across secondary dendrite arms. The interesting point is that the elements Si and Mn show the expected positive segregation (higher concentrations) in the interdendritic regions. The peak of the P content, on the other hand, is shifted compared to Si and Mn, and, in fact, shows negative segregation in the interdendritic region. This is unexpected and counterintuitive.

To run this example, open Thermo-Calc and navigate to the Help Menu → Example Files…→ Diffusion Module – DICTRA. This example includes one calculation file:

• D_08_Diffusion_Microsegregation_During_Solidification: requires a license for Thermo-Calc 2021b or newer, the Diffusion Module (DICTRA), and the Steel and Fe-alloys Databases TCFE11 and MOBFE6 or newer.

This example includes a PDF with in-depth explanations of all the calculations and interpretation of the results.