Phase-Field Simulation of Intermetallic Phase Precipitation in a High-Al Alloyed Lightweight High-Strength Steel

Abstract

Intermetallic phase precipitation is of great interest for designing novel nanostructured high-strength alloys. In this study, phase-field simulations were employed to simulate the microstructure evolution and elemental distribution during the nano-sized Fe3AlC intermetallic phase precipitation within the austenite matrix in a lightweight high-strength steel. The phase-field simulations were carried out in a two-dimensional rectangular domain of 200 × 200 cells with an ultra-fine grid spacing of 2 nm to simulate the nano-sized intermetallic phase precipitation at 800 °C. The elemental redistribution and the partitioning characteristics in the material were further studied experimentally by atom probe tomography. The simulated results were compared with the experimental data. The results show that during the κ-phase precipitation, the C and Al atoms are highly enriched in the κ-phase precipitates, while the Ni and Mn are depleted in the κ-phase precipitates. The elemental redistribution and partitioning features, i.e. Al, C, Mn, Ni, during the intermetallic phase precipitation in the steel was further discussed.