US3665080A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Remelting system and process utilizing varying voltage,current and melting rate
Assignee: Individual
•
Filing: 1970-05-28
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Granted: 1972-05-23
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Expires: 1990-05-28
Abstract
Abstract A bifilar electroslag remelting system is provided with a means to vary the voltage applied to the electrodes. As a result the voltage, current, and melting rate can be varied as a function of time to optimize refining efficiency, to minimize formation of cracks and strata in the finished product refined ingot, and to provide the additional advantage of eliminating the necessity of varying the water rate in the cooling element of the remelting system.
Inventors
- 👤 Boris Izrailevich Medovar
- 👤 Jury Vadimorich Latash
- 👤 Oleg Petrovich Bondarenko
- 👤 Alexsey Georgievich Bogachenko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:52
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/0019; H05B3/0023
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
129 words
An electroslag remelting system comprising a mold for forming an ingot under a bath of molten slag, said mold including sidewalls and a bottom plate; at least two consumable electrodes; means for positioning said electrodes in said mold immersed in the molten slag bath within said mold; means for feeding said electrodes downwardly into said molten slag bath; means for applying AC power between said electrodes to cause electric current to flow between said electrodes through said molten slag bath; reference means including a predetermined gradually changing current curve; means for varying the voltage applied to said electrodes according to a predetermined voltage curve; and said means for feeding said electrodes being controlled for instantaneous response by reference of the current flowing between said electrodes to said reference means.
Claim 2
Dependent Claim
129 words
An electroslag remelting system comprising a mold for forming an ingot under a bath of molten slag, said mold including sidewalls and a bottom plate; at least two consumable electrodes; means for positioning said electrodes in said mold immersed in the molten slag bath within said mold; means for feeding said electrodes downwardly into said molten slag bath; means for applying AC power between said electrodes to cause electric current to flow between said electrodes through said molten slag bath; reference means including a predetermined gradually changing current curve; means for varying the voltage applied to said electrodes according to a predetermined voltage curve; and said means for feeding said electrodes being controlled for instantaneous response by reference of the current flowing between said electrodes to said reference means.
Claim 3
Dependent Claim
26 words
An electroslag remelting system as recited in claim 1 wherein said means for varying the voltage is a variable transformer which is connected to said electrodes.
Claim 4
Dependent Claim
35 words
An electroslag remelting system as recited in claim 2 wherein the variable transformer comprises a primary winding and a secondary winding, said secondary winding being connected to said electrodes and having taps spaced along it.
Claim 5
Dependent Claim
21 words
An electroslag remelting system as recited in claim 3 wherein the voltage differential between successive taps does not exceed 4 volts.
Claim 6
Dependent Claim
19 words
An electroslag remelting system as recited in claim 3 wherein the voltage Differential between successive taps is 2.5 volts.
Claim 7
Dependent Claim
34 words
An electroslag remelting system as recited in claim 1 wherein said system additionally comprises a system for automatically controlling voltage, current, and electrode feed rate as a function of time from initiation of remelting.
Claim 8
Dependent Claim
37 words
An electroslag remelting system as recited in claim 2 wherein said system additionally comprises a system for automatically controlling voltage, current and electrode feed rate as a function of time for instantaneous response from initiation of remelting.
Claim 9
Independent Claim
131 words
A method of electroslag remelting comprising preparing a bath of molten slag in an electroslag remelting mold, said slag having immersed therein at least two consumable electrodes; supplying AC power between said electrodes by the application of voltage to the electrodes to cause electric current to flow between said electrodes through said molten slag bath whereby melting of the electrodes is caused to occur and an ingot is formed in said mold; feeding said electrodes downwardly into said slag bath as they melt; varying said voltage as said electrodes melt according to a predetermined voltage curve; comparing the current flowing between said electrode with a predetermined gradually changing current curve; and controlling the feeding of said electrodes for instantaneous response with respect to the current difference resulting from said comparing step.
Claim 10
Independent Claim
131 words
A method of electroslag remelting comprising preparing a bath of molten slag in an electroslag remelting mold, said slag having immersed therein at least two consumable electrodes; supplying AC power between said electrodes by the application of voltage to the electrodes to cause electric current to flow between said electrodes through said molten slag bath whereby melting of the electrodes is caused to occur and an ingot is formed in said mold; feeding said electrodes downwardly into said slag bath as they melt; varying said voltage as said electrodes melt according to a predetermined voltage curve; comparing the current flowing between said electrode with a predetermined gradually changing current curve; and controlling the feeding of said electrodes for instantaneous response with respect to the current difference resulting from said comparing step.
Claim 11
Dependent Claim
43 words
A method of electroslag remelting as recited in claim 8 wherein electrode feed rate variation as a function of time and voltage variation as a function of time are utilized to vary the current flowing between the electrodes and the electrode melting rate.
Claim 12
Dependent Claim
30 words
A method of electroslag remelting as recited in claim 8 wherein the voltage at any point in time is not changed by a step of more than about 4 volts.
Claim 13
Dependent Claim
27 words
A method of electroslag remelting as recited in claim 10 wherein voltage changes at any point in time are carried out in steps of about 2.5 volts.
Claim 14
Dependent Claim
84 words
A method of electroslag remelting as recited in claim 8 wherein the voltage applied to the electrodes is varied as a function of time so that the voltage is increased at a decreasing rate during at least a portion of the first quarter of the remelting cycle; the voltage is gradually decreased during an intermediate portion of the remelting cycle; the voltage is then decreased at an increasing rate; and finally the voltage is maintained substantially constant at the end of the remelting cycle.
Claim 15
Dependent Claim
24 words
A method of electroslag remelting as recited in claim 12 wherein the gradual decrease in said intermediate portion of the remelting cycle is linear.
Claim 16
Dependent Claim
28 words
A method of electroslag remelting as recited in claim 13 wherein said linear decrease is caused to occur at a rate of 2 to 6 volts per hour.
Claim 17
Dependent Claim
104 words
A method of electroslag remelting as recited in claim 8 wherein the initial voltage is at least about 125 percent of the average voltage utilized during the remelting cycle; the voltage is then increased before the end of the first quarter of the remelting cycle to at least about 130 percent of said average voltage; the voltage is then gradually decreased during at least one-third of said remelting cycle to at least about 125 percent of said average voltage; the voltage is then decreased rapidly over no more than one-eighth of said remelting cycle to at least about 95 percent of said average voltage.
Claim 18
Dependent Claim
64 words
A method of electroslag remelting as recited in claim 8 wherein the current applied to said electrodes is increased during at least a portion of the first quarter of the remelting cycle; the current is gradually decreased during an intermediate portion of the remelting cycle; and the current is decreased at an increasing rate during at least the final portion of the remelting cycle.
Claim 19
Dependent Claim
24 words
A method of electroslag remelting as recited in claim 16 wherein the gradual decrease in said intermediate portion of the remelting cycle is linear.
Claim 20
Dependent Claim
27 words
A method of electrosLag remelting as recited in claim 17 wherein the rate of said linear decrease ranges from about 900 to about 1,300 amps. per hour.
Claim 21
Dependent Claim
110 words
A method of electroslag remelting as recited in claim 8 wherein the initial current applied to said electrodes is at least about 100 percent of the average current utilized during the remelting cycle; the current is then increased before the end of the first quarter of the remelting cycle to at least about 103 percent of said average current; the current is then gradually decreased during at least one-third of said remelting cycle to at least 95 percent of said average current; and finally the current is decreased rapidly starting at a point in the final quarter of the remelting cycle to at least 65 percent of said average current.
Claim 22
Dependent Claim
60 words
A method of electroslag remelting as recited in claim 12 wherein the current is increased during at least a portion of the first quarter of the remelting cycle; the current is gradually decreased during an intermediate portion of the remelting cycle; and the current is decreased at an increasing rate during at least the final portion of the remelting cycle.
Claim 23
Dependent Claim
26 words
A method of electroslag remelting as recited in claim 20 wherein the gradual decrease in current in said intermediate portion of the remelting cycle is linear.
Claim 24
Dependent Claim
29 words
A method of electroslag remelting as recited in claim 21 wherein the rate of said linear decrease in current ranges from about 900 to about 1,300 amps. per hour.
Claim 25
Dependent Claim
106 words
A method of electroslag remelting as recited in claim 12 wherein the initial current is at least about 100 percent of the average current utilized during the remelting cycle; the current is then increased before the end of the first quarter of the remelting cycle to at least about 103 percent of said average current; the current is then gradually decreased during at least one-third of said remelting cycle to at least 95 percent of said average current; and finally, the current is decreased rapidly starting at a point in the final quarter of the remelting cycle to at least 65 percent of said average current.
Claim 26
Dependent Claim
38 words
A method of electroslag remelting as recited in claim 8 wherein said power is applied to provide an ingot having on its surface a slag skin of uniform thickness as defined in the cross-hatched area of FIG. 7.
Claim 27
Dependent Claim
81 words
A method of electroslag remelting as recited in claim 9 wherein the weight melting rate of said electrodes is varied as a function of time so that the weight melting rate is increased during at least a portion of the first quarter of the remelting cycle; the weight melting rate is then gradually decreased during an intermediate portion of the remelting cycle; and the weight melting rate is decreased at an increasing rate during the final one-eighth of the remelting cycle.
Claim 28
Dependent Claim
28 words
A method of electroslag remelting as recited in claim 25 wherein said gradual decrease in weight melting rate in said intermediate portion of the remelting cycle is linear.
Claim 29
Dependent Claim
30 words
A method of electroslag remelting as recited in claim 26 wherein said linear decrease in weight melting rate is caused to occur at the rate of 20-150 kilograms per hour.
Claim 30
Dependent Claim
110 words
A method of electroslag remelting as recited in claim 9 wherein the weight-melting rate is varied so that the initial weight melting rate is at least about 110 percent of the average melting rate utilized during the remelting cycle; the weight melting rate is then increased to at least 115 percent of said average melting rate at a point during the first quarter of said remelting cycle; the weight melting rate is then decreased linearly during at least one-third of said remelting cycle to at least 100 percent of said average melting rate; the weight melting rate is then decreased to zero during the final one-eighth of said remelting cycle.
Claim 31
Dependent Claim
82 words
A method of electroslag remelting as recited in claim 20 wherein the weight melting rate of the consumable electrodes is varied as a funCtion of time so that the weight melting rate is increased during at least a portion of the first quarter of the remelting cycle; the weight melting rate is then gradually decreased during an intermediate portion of the remelting cycle; and the weight melting rate is decreased at an increasing rate during the final one-eighth of the remelting cycle.
Claim 32
Dependent Claim
28 words
A method of electroslag remelting as recited in claim 29 wherein the gradual decrease in weight melting rate in said intermediate portion of the remelting cycle is linear.
Claim 33
Dependent Claim
38 words
A method of electroslag remelting as recited in claim 30 wherein said gradual decrease in weight melting rate in said intermediate portion of the remelting cycle is caused to occur at the rate of 20-150 kilograms per hour.
Claim 34
Independent Claim
127 words
A method of electroslag remelting comprising preparing a bath of molten slag in an electroslag remelting mold, said slag having immersed therein at least two consumable electrodes; supplying AC power between said electrodes by the application of voltage to the electrodes to cause electric current to flow between said electrodes through said molten slag bath whereby melting of the electrodes is caused to occur and an ingot is formed in said mold; feeding said electrodes downwardly into said slag bath as they melt; increasing said power during at least a portion of the first quarter of the remelting cycle; gradually decreasing said power during an intermediate portion of the remelting cycle; and decreasing said power at an increasing rate during the final portion of the remelting cycle.
Claim 35
Independent Claim
127 words
A method of electroslag remelting comprising preparing a bath of molten slag in an electroslag remelting mold, said slag having immersed therein at least two consumable electrodes; supplying AC power between said electrodes by the application of voltage to the electrodes to cause electric current to flow between said electrodes through said molten slag bath whereby melting of the electrodes is caused to occur and an ingot is formed in said mold; feeding said electrodes downwardly into said slag bath as they melt; increasing said power during at least a portion of the first quarter of the remelting cycle; gradually decreasing said power during an intermediate portion of the remelting cycle; and decreasing said power at an increasing rate during the final portion of the remelting cycle.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |