Computational Modeling of the Electroslag Remelting (ESR) Process Used for the Production of Ingots of High-Performance Alloys
Abstract
The Electroslag Remelting (ESR) process is used for the production of defect-free ingots of high-performance alloys for the manufacture of components in aerospace and land-based turbines. In the present study, a comprehensive computational model for the prediction of the performance of the ESR process is presented for axisymmetric, steady state conditions. Analysis of electromagnetics in presence of Alternating Current determines the distribution of Joule heating and Lorentz forces in the slag and the ingot. Turbulent flow, created by the buoyancy and Lorentz forces, is analyzed by solving the time-averaged mass and momentum conservation equations. Nonuniform turbulent mixing is modeled using the two-equation k-ε model. The temperature fields in the slag and the molten metal region are determined by solving the energy conservation equation. The mathematical formulation accounts for all interactions between the slag and the metal phases and loss of heat to the mold wall in a rigorous manner. A control-volume computational method is used for the solution of the governing equations. The computational model is applied for the analysis of a practical low-melt-rate ESR process of IN718. Detailed plots of the flow, temperature, electromagnetic, and turbulent quantities provide valuable information about the process performance. The predicted pool shape also agrees well with the measured pool profile.