Superalloy Melting in an ac Electroslag Remelt Furnace with Automatic Melt Control and rms Current Regulation

A stationary mold-ingot bottom withdrawal ac consumable electrode electroslag furnace with electrode change capability has been installed for melting superalloys at Teledyne-Allvac. The furnace, which utilizes melt voltage and rms current regulation for automatic melt control and its operation are described. The stationary mold-ingot bottom withdrawal and auto-melt control concepts have proven successful and solution hardening superalloys are in routine production with high quality and good yield. Additionally, experimental melting of the nickel base and iron base precipitation hardening superalloys (containing titanium and aluminum) is in process, and initial results look encouraging with respect to quality and chemistry control.