About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Thermodynamics and Kinetics of Alloys IV
|
| Presentation Title |
CALPHAD assessment of Fe-B-C ternary alloys: addressing boride formation and metatectic reactions via improved solid solution modeling |
| Author(s) |
Kyaw Hla Saing Chak, Yijia Gu, Ronald O'Malley |
| On-Site Speaker (Planned) |
Kyaw Hla Saing Chak |
| Abstract Scope |
Boron is one of the most economical and effective elements for enhancing the hardenability of steel, but its addition often leads to casting difficulties in commercial production. These issues are primarily linked to the metatectic reaction (δ→γ+Liquid) and the formation of low-temperature borides such as Fe2B and FeB. Existing CALPHAD models predict a very narrow boron composition range (<0.003wt%) for the metatectic reaction, limiting practical accuracy. In this study, we present an improved thermodynamic description of the Fe–B–C system within the CALPHAD framework. The FCC and BCC phases are described as (Fe)1(B, C, VA)1 and (Fe,B)1(B, C, VA)3, respectively, allowing boron to occupy both substitutional and interstitial sites in BCC. This refinement increases the predicted boron solubility in BCC to 0.035 wt%, consistent with experimental data. Model parameters are optimized using available experimental results. A Scheil solidification study using the revised model is underway to evaluate boron-induced casting defects. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Iron and Steel, Phase Transformations |