About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Additive Manufacturing Modeling, Simulation, and Machine Learning: Microstructure, Mechanics, and Process
|
| Presentation Title |
Sigma Phase Precipitation Prediction During Duplex Stainless Steels Welding, Cladding and Additive Manufacturing |
| Author(s) |
Andres Acuna, Kaue C. Riffel, Henry León-Henao, Antonio J. Ramirez |
| On-Site Speaker (Planned) |
Kaue C. Riffel |
| Abstract Scope |
Duplex stainless steels (DSS) offer excellent mechanical and corrosion resistance, yet sigma phase precipitation in super (SDSS) and hyper duplex (HDSS) stainless steels remains a challenge. This work develops an Integrated Computational Materials Engineering (ICME) framework to predict sigma phase kinetics in welded deposits. The approach combines CALPHAD-based simulations, JMAK kinetics, finite element thermal modeling, and experiments. Thermo-Calc® and the Kampmann-Wagner-Numerical model enabled nucleation, growth, and coarsening predictions, yielding a validated time–temperature–transformation (TTT) diagram. JMAK analysis produced transformation equations linked with welding thermal histories, allowing prediction of sigma volume fraction under varying heat input and interpass conditions. Results show HDSS retains superior mechanical and corrosion properties but both alloys are vulnerable to sigma formation, with SDSS showing higher kinetics due to lower activation energy. Impact toughness tests confirmed that even small sigma fractions increase DBTT and reduce USE. A cooling rate above 4 °C/s effectively suppresses sigma formation. |