Speaker
Description
The development of nanobainitic steels requires the simultaneous optimization of alloy composition and thermomechanical processing routes to achieve targeted microstructures and mechanical properties. This inherently demands a coupled understanding of material behavior across both macroscopic and microscopic scales. In this work, an Integrated Computational Materials Engineering (ICME) framework is developed to link computational alloy design, thermomechanical processing, and microstructure evolution within a unified simulation environment.
Alloy design is performed using CALPHAD-based tools such as Thermo-Calc, where compositions are selected based on phase stability and transformation temperatures relevant to bainitic microstructure formation. The resulting compositions are then used to define temperature-dependent material properties for macroscopic process simulations. Thermomechanical processing, including forging following casting, is simulated using Abaqus, incorporating user-defined subroutines to account for phase transformation and grain evolution.
The local thermo-mechanical history (temperature, strain, and strain rate) obtained at each material point during processing is transferred to microstructure models. Precipitation kinetics, including carbide and intermetallic phase formation, are modeled using MatCalc, while microstructure morphology evolution is captured using MICRESS. In addition, segregation profiles derived from solidification simulations are incorporated to account for chemical inhomogeneities and their influence on subsequent microstructure evolution.
All simulation steps are coupled through an automated Python-based workflow, enabling consistent data transfer across length scales and process stages. The framework enables the prediction of key microstructural descriptors, including phase fractions, prior austenite grain size, dislocation density, and precipitation state, along with corresponding mechanical properties after forging. The approach further allows optimization of alloy composition and process parameters to balance mechanical performance with downstream manufacturability requirements.
This work demonstrates a scalable ICME methodology for the integrated design of alloys and thermomechanical processing routes for advanced bainitic steels.