Drop short control of electrode gap
Abstract
During vacuum consumable arc remelting the electrode gap between a consumable electrode and a pool of molten metal is difficult to control. The present invention monitors drop shorts by detecting a decrease in the voltage between the consumable electrode and molten pool. The drop shorts and their associated voltage reductions occur as repetitive pulses which are closely correlated to the electrode gap. Thus, the method and apparatus of the present invention controls electrode gap based upon drop shorts detected from the monitored anode-cathode voltage. The number of drop shorts are accumulated, and each time the number of drop shorts reach a predetermined number, the average period between drop shorts is calculated from this predetermined number and the time in which this number is accumulated. This average drop short period is used in a drop short period electrode gap model which determines the actual electrode gap from the drop short. The actual electrode gap is then compared with a desired electrode gap which is selected to produce optimum operating conditions and the velocity of the consumable error is varied based upon the gap error. The consumable electrode is driven according to any prior art system at this velocity. In the preferredmore »
- Inventors:
-
- Albuquerque, NM
- Sandia Park, NM
- Issue Date:
- Research Org.:
- AT&T
- OSTI Identifier:
- 865797
- Patent Number(s):
- 4578795
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Classifications (CPCs):
-
Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02P - CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
H - ELECTRICITY H05 - ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR H05B - ELECTRIC HEATING
- DOE Contract Number:
- AC04-76DP00789
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- drop; control; electrode; gap; vacuum; consumable; remelting; pool; molten; metal; difficult; monitors; shorts; detecting; decrease; voltage; associated; reductions; occur; repetitive; pulses; closely; correlated; method; apparatus; controls; based; detected; monitored; anode-cathode; accumulated; time; reach; predetermined; average; period; calculated; model; determines; compared; desired; selected; produce; optimum; operating; conditions; velocity; error; varied; driven; according; prior; preferred; embodiment; microprocessor; utilized; perform; calculations; monitor; duration; exceeds; preset; rapidly; retracted; distance; prevent; bonding; remelt; electrode gap; operating conditions; molten metal; preferred embodiment; predetermined distance; consumable electrode; operating condition; molten pool; repetitive pulses; desired electrode; gap based; /373/
Citation Formats
Fisher, Robert W, Maroone, James P, Tipping, Donald W, and Zanner, Frank J. Drop short control of electrode gap. United States: N. p., 1986.
Web.
Fisher, Robert W, Maroone, James P, Tipping, Donald W, & Zanner, Frank J. Drop short control of electrode gap. United States.
Fisher, Robert W, Maroone, James P, Tipping, Donald W, and Zanner, Frank J. Wed .
"Drop short control of electrode gap". United States. https://www.osti.gov/servlets/purl/865797.
@article{osti_865797,
title = {Drop short control of electrode gap},
author = {Fisher, Robert W and Maroone, James P and Tipping, Donald W and Zanner, Frank J},
abstractNote = {During vacuum consumable arc remelting the electrode gap between a consumable electrode and a pool of molten metal is difficult to control. The present invention monitors drop shorts by detecting a decrease in the voltage between the consumable electrode and molten pool. The drop shorts and their associated voltage reductions occur as repetitive pulses which are closely correlated to the electrode gap. Thus, the method and apparatus of the present invention controls electrode gap based upon drop shorts detected from the monitored anode-cathode voltage. The number of drop shorts are accumulated, and each time the number of drop shorts reach a predetermined number, the average period between drop shorts is calculated from this predetermined number and the time in which this number is accumulated. This average drop short period is used in a drop short period electrode gap model which determines the actual electrode gap from the drop short. The actual electrode gap is then compared with a desired electrode gap which is selected to produce optimum operating conditions and the velocity of the consumable error is varied based upon the gap error. The consumable electrode is driven according to any prior art system at this velocity. In the preferred embodiment, a microprocessor system is utilized to perform the necessary calculations and further to monitor the duration of each drop short. If any drop short exceeds a preset duration period, the consumable electrode is rapidly retracted a predetermined distance to prevent bonding of the consumable electrode to the molten remelt.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1986},
month = {1}
}