Computational Modeling of Remelting Processes for Ingot Casting of High- Performance Alloys

摘要

Report developed under SBIR contract for topic AF00-168 describes the research performed towards the development of a comprehensive, efficient, and well-validated model for the ESR, VAR, EB and related remelting processes used for the production of ingots of superalloys and titanium alloys. The computational model incorporates many novel features in the treatment of the underlying electromagnetic, flow, and heat transfer phenomena and their computational solution. Thus, a unified framework for computational analysis of all remelting processes has been developed with an implicit treatment of the interactions across material and phase interfaces. The computational method allows analysis for DC and AC power and incorporates an accurate treatment of the ingot-mold heat transfer. Predictions of the pool shape obtained from the model compare very well with the experimental measurements for industrial-scale VAR and ESR processes. Phase II effort will involve enhancements of the basic model for analysis of electromagnetic stirring, unsteadiness, and ingot microstructure. The computational model will provide a detailed understanding of the physical processes and accurate quantitative information about the effects of process parameters. It will be useful for process optimization and virtual prototyping of process variants. Such use will result in substantial savings in operational costs and capital investments.