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Process Description
The ESR process
uses AC power to heat an electrically resistive slag contained in a water-cooled mold. The heated slag melts the electrode and the droplets of molten metal descend through the slag to form
a pool of molten metal under the slag-metal interface. The electrode is continuously advanced into the slag as it melts to build up an ingot of improved structure and composition.
Electromagnetic Fields in the Slag and the Ingot during an ESR Process for In-718 Alloy
Comprehensive Treatment of Process Physics
COMAPCT-ESR performs a rigorous analysis of the process by considering all the
physical phenomena as listed below:
Electromagnetic phenomena with AC power to determine Joule heating in the
slag, current flow in the slag and the ingot including the Skin effect in the ingot, and the distribution of Lorentz forces in the slag and the ingot Use of the two-equation k-e model for an accurate treatment of the turbulent
flow in the molten pool and the slag Convective heat transfer in the slag and the molten pool, and phase change in
the mushy region of the ingot, and conduction heat transfer in the solidified ingot Formation of the slag skin on the mold and the growth of the ingot within the
solidified slag skin Heat loss from the ingot surface to the mold due to the combined effect of
radiation and contact heat transfer in presence of the slag skin Effect of ingot shrinkage on the loss of contact heat transfer between the ingot
and the mold Macrosegregation of the alloying elements caused by the selective rejection or
absorption of the alloying elements by the solid and the redistribution of the elements within the molten metal pool Motion and dissolution of inclusions Treatment of temperature-dependent material properties of the alloy
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Velocity and Temperature Fields, and Pool Region During an ESR Process for In-718 Alloy
Efficient Computational Solution
The control-volume method is used for performing the solution of the governing
equations in an axisymmetric domain. The computational method incorporates many algorithms that address specific aspects of the ESR process as described below:
A single computational domain for an implicit treatment of the electromagnetic,
flow, and thermal interactions across the slag-metal interface Use of complex-variables in the solution of the magnetic diffusion equation for
the analysis of the periodic steady state of electromagnetics with AC power Automatic determination of the time step Robust treatment of nonlinear heat loss from the top, bottom, and side surfaces
of the ingot Thus, COMPACT-ESR provides a robust and efficient computational solution of
the equations governing the physical processes in the slag and the ingot.
Axial Variation of the Hest Flux Over the Mold Surface During an ESR Process for In-718 Alloy
Easy Model Setup and Visualization of Results
COMPACT-ESR allows easy creation of a process model by specifying process
geometry, temperature-dependent slag and alloy properties, and melt schedule through a user-friendly graphical interface. Results of analysis are conveniently
examined using powerful visualization software.
Streamlines and Turbulent Viscosity in the Slag and the Ingot During an ESR Process for IN-718 Alloy
Engineering Benefits
COMPACT-ESR has been shown to accurately predict the observed pool profiles and
alloy concentrations in practical processes for Nickel superalloys. It is being actively used in the following manner by leading alloy producers to obtain substantial
cost-savings in process design:
Optimization of Melt Schedule Investigation of Process Anomalies Design of Process Variants Processing of Superalloys and Steel
 
Predicted and Measured Pool Shapes in a IN-718 Alloy Ingot Produced Using an ESR Process
Technical Publication and Brochure
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