Thermodynamic, Kinetic, and Microstructure Data for Modeling Solidification of Fe-Al-Mn-Si-C Alloys
- PDF / 1,919,119 Bytes
- 17 Pages / 593.972 x 792 pts Page_size
- 49 Downloads / 212 Views
ADVANCED High-Strength Steels (AHSS) belonging to the family of Fe-Al-Mn-Si-C alloys have been extensively studied due to their high strength and good formability.[1] To control the continuous casting process, it is necessary to have a thermodynamic–kinetic software that can reproduce and interpolate measurement data with high accuracy. Modern solidification models apply computational thermodynamics and kinetic equations along with corresponding databases.[2] The reliability and self-consistency of the thermodynamic descriptions are especially important for the optimization routines. Furthermore, in online applications, the computational expense of the thermodynamic–kinetic description should be reasonably low, especially in 3D modeling applications.
JYRKI MIETTINEN, VILLE-VALTTERI VISURI, and TIMO FABRITIUS are with the Process Metallurgy Research Unit, University of Oulu, PO Box 4300, 90014 Oulu, Finland. Contact e-mail: ville-valtteri.visuri@oulu.fi SAMI KOSKENNISKA, MAHESH SOMANI, and JUKKA KO¨MI are with the Materials and Mechanical Engineering Research Unit, University of Oulu, PO Box 4200, 90014 Oulu, Finland. Manuscript submitted April 14, 2020; accepted September 6, 2020.
METALLURGICAL AND MATERIALS TRANSACTIONS B
The first aim of this investigation was to outline the necessary thermodynamic, kinetic, and microstructure data to conduct the thermodynamic–kinetic simulations for Fe-Al-Mn-Si-C alloys. To validate the modeling results, electron probe microanalysis (EPMA) measurements were taken. Finally, simulations were performed to investigate the solidification behavior of high-AlMnSi steels as a function of their compositions and cooling rate/s. Also simulated, below the solidus, were the ferrite/austenite transformations and the solute microsegregation, including the determination of the soluble grain boundary compositions. As these compositions, instead of the nominal ones, are expected to control the start of austenite decomposition,[3] they will play an important role in a later study, in which we plan to extend the current simulation work on high-AlMnSi (Al ‡ 0.5 wt pct, Mn ‡ 2 wt pct, Si ‡ 1 wt pct) steels to their austenite decomposition process. These simulations will apply new continuous cooling transformation (CCT) equations, which take into account the Al alloying that was not considered in the previously optimized CCT equations of Miettinen et al.[3] A. IDS Tool The developed descriptions are implemented in the IDS software,[47] which is a thermodynamic–kinetic software for the simulation of phase change, compound formation/dissolution, and solute distribution during the
solidification of steels and their cooling/heating process after solidification. The package also simulates the solid-state phase transformations related to the austenite decomposition process below 900 C (1173 K) and calculates important thermophysical material properties (such as enthalpy, thermal conductivity, and density) from the liquid state to room temperature. The calculations of the IDS tool have been compared with num
Data Loading...
