Monochromatic imaging studies of a low pressure arc burning on molten Inconel 718 alloy electrodes during vacuum arc remelting
Vacuum arc remelting (VAR) is a melting and solidification process used to produce high quality ingots of chemically reactive or segregation sensitive alloys. Melting is accomplished through the use of a sustained high current (several kiloamperes) dc arc. Energy from the arc is used to melt a consumable electrode (cathode) which is cast from the alloy to be remelted. The molten material drips down into a water-cooled copper crucible (anode) where it solidifies as a larger diameter, homogeneous, porosity-free, cylindrical ingot. Solidification is driven mainly by radial heat extraction from the molten pool atop the ingot and is influenced by magnetically and buoyancy driven fluid flows that are coupled to the arc behavior. The paper reports the initial results of efforts to characterize the VAR furnace arc during remelting of Inconel 718 alloy using monochromatic imaging. This technique allows one to examine how individual atomic species are distributed throughout the arc plasma in the electrode gap. Because only species existing in excited electronic states are able to emit light, the images also give insight into the energy distribution in the gap. Chromium and manganese distributions were investigated. Chromium was chosen to represent one of the major alloy constituents, while manganese represents a highly volatile trace component. 13 refs., 7 figs.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 7092735
- Report Number(s):
- SAND-87-2582C; CONF-8804182-1; ON: DE88012855
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360101* -- Metals & Alloys-- Preparation & Fabrication
ALLOYS
ARC FURNACES
CHROMIUM
CHROMIUM ALLOYS
DISTRIBUTION
ELECTRIC FURNACES
ELECTRODES
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY DENSITY
ENERGY LEVELS
EXCITED STATES
FURNACES
IMAGES
INCONEL 718
INCONEL ALLOYS
MANGANESE
MECHANICS
MELTING
METALS
MOLYBDENUM ALLOYS
MONOCHROMATIC RADIATION
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM ALLOYS
PHASE TRANSFORMATIONS
PLASMA
RADIATIONS
SOLIDIFICATION
TRANSITION ELEMENTS
VACUUM MELTING