Advances in Modeling of Steel Solidification with IDS

Abstract

IDS (Inter-Dendritic Solidification) is a thermodynamic-kinetic software package that simulates phase changes, compound formation/dissolution, and solute distribution during solidification of steels as well as during their cooling/heating process after solidification. The software package also simulates solid-state phase transformations related to the austenite decomposition process at temperatures below 900/600 °C, and calculates thermophysical material properties from the liquid state down to room temperature. These data are needed in other models, such as heat transfer and thermal stress models, whose reliability heavily depends on the input data. The software package also features a database for thermodynamic, kinetic and microstructure data, as well as for several material properties. Owing to the short calculation times, the IDS tool is suitable for online applications. This paper presents IDS and its modules with the latest developments and validations, along with examples of modeling results.

Thermodynamic, Kinetic, and Microstructure Data for Modeling Solidification of Fe-Al-Mn-Si-C Alloys

“…The thermodynamic data for the modeling of the solidification of Fe-Al-Mn-Si-C alloys are taken from a recent thermodynamic assessment of the Fe-Al-Mn-Si-C system [18] adopted in the Iron Alloy Database (IAD) developed since 2000. The main phases of that system and their modeling are shown in Table I.…”

“…A more detailed discussion of the advantages of this approach in online applications is available elsewhere. [18] The second simplification ignores the B2-ordering of ferrite (bcc structure) in alloys where the Al and Si contents are high. This treatment clearly simplifies the calculations of the IDS tool and is not a problem for typical steels, whose Al and Si contents are relatively low.…”

“…The solution phase thermodynamic data of Table II and the thermodynamic compound data of description [18] have been validated with an extensive amount of experimental data on phase equilibria, solute activity, and mixing enthalpy. [18] Some are presented in Figures 2 through 7, displaying good agreement between the calculations and measurements. [31][32][33][34][35][36][37][38][39][40] Figures 2 and 7 show that increasing the Al and Si alloying contents clearly increases the ferrite stability in Fe-C alloys.…”

“…The effect Table I. Phases and Their Thermodynamic Modeling in the Fe-Al-Mn-Si-C Description of Miettinen et al [18] Phase Modeling RK denotes the Redlich-Kister treatment [19] for the Gibbs excess energy of the phase, and MOT denotes an additional magnetic ordering treatment for the a phase. [11] Table II.…”

Optimization of CCT Equations Using Calculated Grain Boundary Soluble Compositions for the Simulation of Austenite Decomposition of Steels

“…[4] Since 1984, a thermodynamic-kinetic software package, IDS (InterDendritic Solidification), has been developed to simulate the phase change, compound formation/dissolution and solute distribution during the solidification of steels, and the subsequent cooling/ heating process after solidification. [6][7][8] IDS can also be used as a sub-tool in online calculations of continuous casting by coupling it to a proper heat-transfer model of the process. [9] In such a case, the impacts of the casting conditions are considered, by using the calculated nodal cooling rates of the strand as input data for IDS.…”