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US3767831A
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Process and apparatus for electro-slag remelting metals and in particular steel
Assignee: Gebrueder Boehler and Co AG
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Filing: 1972-08-23
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Granted: 1973-10-23
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Expires: 1992-08-23
Abstract
Abstract An apparatus and method for electro-slag-remelting of metals and in particular steel. The electric current flowing through the to be molten electrode changes periodically. The current which is being fed to the apparatus may be either an ordinary alternating current or a three-phase alternating current and is converted into a substantially different current having a base frequency (f) which periodically changes its direction. It is the latter current which supplies the power for remelting the electrode.
Inventors
- 👤 E Plockinger
- 👤 W Holzgruber
- 👤 P Machner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:27
CPC Classifications
C; C22; C22B; C22B9/00; C22B9/16; C22B9/18
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
81 words
A process for producing refined metallic ingots of improved metallurgical properties by electroslag remelting a consumable metallic electrode, said process being also characterized by an improved fusing rate, comprising the steps of converting an alternating poly-phase power supply current into a uni-phase current, the direction of which periodically changes and the basic frequency (f) of which is substantially different from the frequency of said power supply current, and conducting said converted current to said metallic electrode and thereby remelting said electrode.
Claim 2
Dependent Claim
81 words
A process for producing refined metallic ingots of improved metallurgical properties by electroslag remelting a consumable metallic electrode, said process being also characterized by an improved fusing rate, comprising the steps of converting an alternating poly-phase power supply current into a uni-phase current, the direction of which periodically changes and the basic frequency (f) of which is substantially different from the frequency of said power supply current, and conducting said converted current to said metallic electrode and thereby remelting said electrode.
Claim 3
Dependent Claim
55 words
The process for electro-slag-remelting as set forth in claim 1, wherein said converted current flows in one direction during a period T1, and in an other direction during a period T2, said electrode forming respectively during said periods the positive and the negative pole in an electric circuit; and selectively adjusting said basic frequency (f).
Claim 4
Dependent Claim
34 words
The process for electro-slag-remelting as set forth in claim 1, in which the basic frequency (f) is in the range of 5-10 cycles and is substantially below the frequency of said power supply current.
Claim 5
Dependent Claim
23 words
The process for electro-slag-remelting as set forth in claim 2, wherein the relationship of the periods T1 and T2 is different than 1.
Claim 6
Independent Claim
105 words
An apparatus for electro-slag-remelting of metallic electrodes by means of a three - phase power supply current, comprising in combination, a consumable electrode; a base plate; a mold mounted on said base plate; a three-phase transformer operatively connected to said three-phase power supply current; converter means operatively connected to said transformer and having one line connected to said electrode and an other line connected to said base plate; said convertor means converting said three-phase power supply into uni-phase current having a basic frequency (f) which is substantially lower than the frequency of said power supply current and periodically changing the direction of said uni-phase current.
Claim 7
Independent Claim
105 words
An apparatus for electro-slag-remelting of metallic electrodes by means of a three - phase power supply current, comprising in combination, a consumable electrode; a base plate; a mold mounted on said base plate; a three-phase transformer operatively connected to said three-phase power supply current; converter means operatively connected to said transformer and having one line connected to said electrode and an other line connected to said base plate; said convertor means converting said three-phase power supply into uni-phase current having a basic frequency (f) which is substantially lower than the frequency of said power supply current and periodically changing the direction of said uni-phase current.
Claim 8
Dependent Claim
67 words
The apparatus for electro-slag-remelting of metallic electrodes as set forth in claim 5, wherein said convertor means comprising three selenium rectifiers each of which is respectively connected to a different phase of said three-phase power supply current, on the one hand, and to the neutral point of said three-phase power supply current, on the other hand, thereby converting said three-phase current into a weakly pulsating direct current.
Claim 9
Dependent Claim
38 words
The apparatus for electro-slag-remelting of metallic electrodes as set forth in claim 5, wherein said convertor means comprise thyristor means which are operatively connected to said selenium rectifiers and which periodically change the direction of said direct current.
Claim 10
Dependent Claim
93 words
The apparatus for electro-slag-remelting of metallic electrodes as set forth in claim 7, including auxiliary electrode means mounted in said apparatus, said electrode and said auxiliary electrode means extending into said mold, and switch means having a pair of terminals which are respectively connected to the star point of said three-phase transformer and to the output lead of said transformer, and movable contact means connected to said auxiliary electrode means, said switch means being adapted to thus selectively connect the positive or the negative pole of said transformer to said auxiliary electrode means.
Claim 11
Dependent Claim
22 words
The apparatus for electro-slag-remelting of metallic electrodes as set forth in claiM 5, including electronic control means for adjusting the operation thereof.
Claim 12
Dependent Claim
23 words
The apparatus for electro-slag-remelting of metallic electrodes as set forth in claim 9, wherein said electronic control means comprise a set of thyristors.
Claim 13
Dependent Claim
74 words
A process for producing refined metallic ingots of improved metallurgical properties by electroslag remelting, said process being also characterized by an improved fusing rate, comprising the steps of converting an alternating poly-phase power supply current of 50 to 60 cycles per second into a uni-phase current of 5 to 10 cycles per second, and conducting said converted current to a metallic electrode immersed in a liquid layer of slag and thereby remelting said electrode.
Claim 14
Dependent Claim
74 words
A process for producing refined metallic ingots of improved metallurgical properties by electroslag remelting, said process being also characterized by an improved fusing rate, comprising the steps of converting an alternating poly-phase power supply current of 50 to 60 cycles per second into a uni-phase current of 5 to 10 cycles per second, and conducting said converted current to a metallic electrode immersed in a liquid layer of slag and thereby remelting said electrode.
Claim 15
Dependent Claim
53 words
The apparatus for electro-slag-remelting of metallic electrodes as set forth in claim 5, that a three or six phase thyristor group is connected to said three phase transformer, which convert the three phase current into a uni-phase current, the direction of which changes periodically, said consumable electrode being connected to said thyristor group.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |