Speaker
Description
This project focuses on the development of an advanced numerical modeling platform based on OpenFOAM for the simulation of remelting and solidification processes of metallic alloys through ESR and VAR. The modeling activity was validated through experimental trials carried out at both pilot scale and industrial scale for ingots with diameter above 1000 mm.
The experimental campaign included instrumented molds equipped with thermocouples to record temperature evolution along the mold wall. The produced ingots were then sectioned and analyzed metallurgically. Macrographic examinations provided information on molten pool shape and depth, as well as dendrite morphology, while microstructural analyses supplied data on hardness, SDAS and local chemical composition. These results were used to calibrate and validate the developed numerical models.
The main objective of the modeling framework is to describe the coupled thermal and fluid-dynamic fields within the ingot, in order to predict the evolution of the solidification front and the local conditions governing final ingot quality. Particular attention is given to key thermal parameters at the solidification front, such as thermal gradient, solidification rate, and cooling rate, which directly affect macrostructure, microstructure, segregation, and defect susceptibility.
OpenFOAM was selected because of its capability to represent the strong coupling between temperature and convection in the molten metal in a physically consistent way. Material properties such as density, viscosity, specific heat, and thermal conductivity are temperature-dependent, while fluid flow significantly affects heat transfer and therefore the shape and extent of both the molten pool and the solidification front.
The platform was further extended with a Cellular Automata-based module for macrosegregation prediction and with post-processing tools for microsegregation assessment, including phase fractions and local phase chemistry. The final goal is to support optimized remelting procedures within a digitalized and vertically integrated production chain.
| Speaker Company/University | Italfond (Andrea Febbrari) & RINA (Matteo Gregori) |
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