Abstract
Austenite reversion and intermetallic precipitation are two key phase transformations in maraging steels which determine the strength and ductility. Usually, an optimum aging temperature/time is determined using trial and error approach with inputs from thermodynamic databases and a-posteriori microscopy/hardness evaluations. In this study, a thermo-kinetic model is developed to predict the precipitation and austenite reversion kinetics during various post-fabrication heat treatments in a Ti-free variant of grade 300 maraging steel manufactured using laser powder bed fusion. The thermo-kinetic model was based on the principles of Scheil solidification and the classical nucleation theory. The predictions from the thermo-kinetic model were verified using suitable microscopy techniques, and the results from the thermo-kinetic model agree well with the experimental measurements. Results highlight the fact that an Integrated Computational Materials Engineering approach can be used to predict the precipitation and austenite reversion kinetics, and be used as an input for an efficient design of heat treatments for achieving optimum mechanical properties.
| Original language | English |
|---|---|
| Pages (from-to) | 18722-18739 |
| Number of pages | 18 |
| Journal | Journal of Materials Science |
| Volume | 56 |
| Issue number | 33 |
| DOIs | |
| State | Published - Nov 2021 |
Funding
The authors would like to acknowledge Dr. Donovan Leonard of Manufacturing Science Division at ORNL, for assistance with the S/TEM measurements. Research was performed at the US Department of Energy’s Manufacturing Demonstration Facility, located at Oak Ridge National Laboratory. Research was performed, in part, using instrumentation (FEI Talos) provided by the Department of Energy, Office of Nuclear Energy, Fuel Cycle R&D Program, and the Nuclear Science User Facilities. Research was co-sponsored by the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the US Department of Energy.