US2585613A - Method of heat-treating electrical resistance alloy - Google Patents
Method of heat-treating electrical resistance alloy Download PDFInfo
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- US2585613A US2585613A US110671A US11067149A US2585613A US 2585613 A US2585613 A US 2585613A US 110671 A US110671 A US 110671A US 11067149 A US11067149 A US 11067149A US 2585613 A US2585613 A US 2585613A
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- electrical resistance
- heat
- temperature
- alloy
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- 238000000034 method Methods 0.000 title claims description 17
- 229910045601 alloy Inorganic materials 0.000 title description 33
- 239000000956 alloy Substances 0.000 title description 33
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 18
- 238000010438 heat treatment Methods 0.000 description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 229910052804 chromium Inorganic materials 0.000 description 9
- 239000011651 chromium Substances 0.000 description 9
- 229910052759 nickel Inorganic materials 0.000 description 7
- 229910018487 Ni—Cr Inorganic materials 0.000 description 6
- 229910052742 iron Inorganic materials 0.000 description 6
- VNNRSPGTAMTISX-UHFFFAOYSA-N chromium nickel Chemical compound [Cr].[Ni] VNNRSPGTAMTISX-UHFFFAOYSA-N 0.000 description 5
- 229910000623 nickel–chromium alloy Inorganic materials 0.000 description 5
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 4
- 239000000470 constituent Substances 0.000 description 4
- 238000000137 annealing Methods 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 2
- 239000000788 chromium alloy Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 229910018084 Al-Fe Inorganic materials 0.000 description 1
- 229910018192 Al—Fe Inorganic materials 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- KDYFGRWQOYBRFD-UHFFFAOYSA-N succinic acid Chemical compound OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
- C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
- C22C19/058—Alloys based on nickel or cobalt based on nickel with chromium without Mo and W
Definitions
- This invention relates to nickel chromium alloys o-f the type employed as electrical resistance elements and more particularly to a method of processing such alloys and electrical resistance wire comprised thereof to materially improve the electrical resistance and temperature coefiicient of resistance properties of such alloys, and this application isacontinuation-impart of application-serial No. 562,901, filed November 10., 19.44, now abandoned, which is assigned to the same assignee as the present application.
- the object of the invention is to provide an electrical resistance element having a low temperature coefficient within the range 20 to 30.0 C'. and high electrical resistance which is suitablefor use in electrical devices requiring resistor'elements of high accuracy, such as radio; radar, television and the like devices.
- Another object is to provide a methodof treatin' electrical resistance elements comprised ofia nickel chrom'ium electrical resistance alloy consisting of -30% Cr, balance mainly Ni, to imiprove the'normal temperature coefficient and electrical resistance properties of such alloys.
- Still another object is to provide a method of treating electrical resistance wire comprised of an alloy consisting of 10% to 30% chromium, b'al-' ance mainly nickel, to condition the wire for use as an electrical resistor element in high accuracy electrical devices.
- a further object is to provide a method of processing wire comprised of a nickel-chromium alloy of the 80/20 type; containing approximately chromium, balance mainly nickel, except for associated constituents not detrimental to the electrical resistance and temperature coefiicient properties of the alloy, to impart thereto a relatively low temperature coefiicient within the range 0 to 300 C. and a relatively high elec- Other objects will be apparent as the invention is more fully hereinafter disclosed.
- the nickel-chromium alloy is first reduced by hot and cold working methods common and well known in the art to a desired final size in accordance with prior art practice and is preferably; subjected-to the usual final annealing operation at a temperature within the range 1700-1950 F. for the required time interval effective to soften the wire structure by'recrystallization to the desired extent best adapting the wire product for forming into the desired type of electrical resistor element, such as a coil.
- the time and temperature employed in this final anneal operation is selected to yieldwhat is commonly known as a fully annealed' product for forming into an electrical resistance element, such as a.coil.c
- the mechanically deformed product such as a wire
- the desired typeof electrical resistor element such as a coil
- This heat-treatment operation may be practiced under boxanneal conditions, common in the art,'or on succ'essive spools in a continuous feed and discharge furnace provided with heated and cooled sections.
- Nickel-chromium alloys of the 80/20 binary type are, per se, old and well known in the art and are recognized generally as being the best of the many known types of nickel-chromium electrical resistance alloys.
- This type of alloy consists essentially of 20% chromium and 80% nickel but in the commercial production of this alloy it is not unusual to find fractional percentages of iron, manganese, silicon and carbon in the alloy displacing part of the nickel, the total amount of these constituents usually being held to under 2.% with Si approximating 1.00%, Fe .50% max, Mn .10% max, and C 05%. Occasionally iron as high as 1% will be present in such alloys. In some lower grades of this type of alloy considerably higher iron percentages are present.
- Electrical resistors having a T. C. value under .0001 and an E. R. value above 650 are well suited for use in electrical devices and circuits of the high accuracy type, such as in radar, radio and television devices.
- Ni-Cr alloys of the 80/20 type it has heretofore been proposed to add to the alloy small percentages of other alloy constitutents such as Al, Al'Cu, Al-Ag, Al-Fe or Mn, to lower the T. C. value of the alloy in its annealed condition.
- other alloy constitutents such as Al, Al'Cu, Al-Ag, Al-Fe or Mn
- the method of treating a wire comprised of an alloy consisting of 10 to 30% Cr, balance Ni, to impart thereto a temperature coefiicient within the range 20 to 300 C. or" less than .0001 ohm and an electrical resistance above 650 ohms which comprises heat treating the wire in a reducing atmosphere for from 1 to 5 hours at a temperature within the range '780-1000 F. and cooling the heat-treated product slowly down to atmospheric temperatures.
- the method of claim 1 wherein the said alloy contains iron, manganese, silicon and carbon in small fractional percentages and in total amount not exceeding 2 3.
- the alloy consists of 20% Cr, balance Ni, the temperature of heating is 850 F., and the time interval of heating approximates one hour.
- the method of treating a wire comprised of an alloy consisting of 20% Cr, not over 2% of associated alloy constituents consisting of fractional percentages of at least one of the elements of the group consisting of Fe, Mn, Si and C, balance nickel, to impart thereto a temperature coeiTicient less than .0001 and an electrical resistance above 650 ohms and physical properties adapting the same to be formed into resistor elements for electronic electrical devices, which comprises annealing the wire at a temperature within the range 1700 to 1950 F.
- An electrical resistor element having a temperature coefiicient within the range 20 to 300 C. of less than .0001 and an electrical resistance above 650 ohms, said element being comprised of assume the annealed and heat-treated wire product of the method of claim 6.
- An electrical resistor element comprised of the heat-treated wire product of the method of claim 1.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Apparatuses And Processes For Manufacturing Resistors (AREA)
- Non-Adjustable Resistors (AREA)
Description
trical resistance.
Patented Feb. 12, 1952 METHOD OF HEAT-TREATING ELECTRICAL RESISTANCE ALLOY Victor 0. Allen'Madison, N. Jgassignorto Wilbur B. Driver Company, Newark; N; J., a.cor-.. poratiou of New Jersey No Drawing. Application- August 16; 1949, Serial'No. 110,671
9 Claims (01. 148-13) This invention relates to nickel chromium alloys o-f the type employed as electrical resistance elements and more particularly to a method of processing such alloys and electrical resistance wire comprised thereof to materially improve the electrical resistance and temperature coefiicient of resistance properties of such alloys, and this application isacontinuation-impart of application-serial No. 562,901, filed November 10., 19.44, now abandoned, which is assigned to the same assignee as the present application.
The object of the invention is to provide an electrical resistance element having a low temperature coefficient within the range 20 to 30.0 C'. and high electrical resistance which is suitablefor use in electrical devices requiring resistor'elements of high accuracy, such as radio; radar, television and the like devices.
Another object is to provide a methodof treatin' electrical resistance elements comprised ofia nickel chrom'ium electrical resistance alloy consisting of -30% Cr, balance mainly Ni, to imiprove the'normal temperature coefficient and electrical resistance properties of such alloys.
Still another object is to provide a method of treating electrical resistance wire comprised of an alloy consisting of 10% to 30% chromium, b'al-' ance mainly nickel, to condition the wire for use as an electrical resistor element in high accuracy electrical devices.
A further object is to provide a method of processing wire comprised of a nickel-chromium alloy of the 80/20 type; containing approximately chromium, balance mainly nickel, except for associated constituents not detrimental to the electrical resistance and temperature coefiicient properties of the alloy, to impart thereto a relatively low temperature coefiicient within the range 0 to 300 C. and a relatively high elec- Other objects will be apparent as the invention is more fully hereinafter disclosed.
In accordance with these objects I have discovered that when an electrical resistance alloy consisting of 10% to chromium, balance mainly nickel, is heat-treated for an extended time ranging from 1 to 5 hours at a temperature within the range 780 to 1000 F. followed by slow cooling to atmospheric temperatures,- the temperature coefiicient and electrical resistance 2 properties of the alloy are stabilized at values which are markedly lower and higher, respectively, than the heretofore accepted rated values normally present therein.
The reason for obtainin such an improvement in these properties in such alloys by such a heattreatment operation is not clearly apparent but it is believed that some internal rearrangement of atoms or grains resulting in-a stabilized crystal structure is primarily responsible for this im-e provement.
In the adaptation of this? discovery in the art of forming or producing. electrical resistor elements the nickel-chromium alloy is first reduced by hot and cold working methods common and well known in the art to a desired final size in accordance with prior art practice and is preferably; subjected-to the usual final annealing operation at a temperature within the range 1700-1950 F. for the required time interval effective to soften the wire structure by'recrystallization to the desired extent best adapting the wire product for forming into the desired type of electrical resistor element, such as a coil. In
most instances, the time and temperature employed in this final anneal operation is selected to yieldwhat is commonly known as a fully annealed' product for forming into an electrical resistance element, such as a.coil.c
In accordance with the present invention the mechanically deformed product, such as a wire, preferably-after such final annealing operation and prior to forming into the desired typeof electrical resistor element, such as a coil, is heattreated in an inert or reducing atmosphere, for from 1 to 5' hours at a temperature within the range 780 -1000 F., preferably at 850 F., and is permitted to cool slowly in the same inert atmosphere down to normal (room) temperatures from the heat-treating temperature. This heat-treatment operationmay be practiced under boxanneal conditions, common in the art,'or on succ'essive spools in a continuous feed and discharge furnace provided with heated and cooled sections.
As one specific example of the practice of the present invention, but not as a limitation of the same, the procedure't'o be followed in the heattreatment of a nickel-chromium alloy of theessentially binary /2O'type (20% Cr and '80 Ni) will be described.
Nickel-chromium alloys of the 80/20 binary type are, per se, old and well known in the art and are recognized generally as being the best of the many known types of nickel-chromium electrical resistance alloys. This type of alloy consists essentially of 20% chromium and 80% nickel but in the commercial production of this alloy it is not unusual to find fractional percentages of iron, manganese, silicon and carbon in the alloy displacing part of the nickel, the total amount of these constituents usually being held to under 2.% with Si approximating 1.00%, Fe .50% max, Mn .10% max, and C 05%. Occasionally iron as high as 1% will be present in such alloys. In some lower grades of this type of alloy considerably higher iron percentages are present.
In this standard type of high quality binary type of 80/20 nickel-chromium electrical resistance alloy, wherein the associated constituents are g held under about 2.0% the accepted and rated values for the temperature coeiiicient- (T. C.) and electrical resistance (E. R.) properties of drawn wire at final size usually approximates the following:
Annealed (at Hard Drawn R) T. C. (100 C.) -i 00018 00013 E. R .i 600 650 On heat-treatment of such wire products, in accordance with the present invention, at 850 F. in a hydrogenous reducing atmosphere for varying time intervals of from 1 to 3 hours the following T. C. and E. R. values were obtained:
HARD DRAWN In addition to the improvement in the T. C. and E. R. values an increase in tensile strength of about 10% was obtained in each instance.
A plurality of tests on other melts of similar composition 80/20 Ni-Cr alloys have indicated that as a result of such heat-treatment a T. C. value of approximately .0000? ohm and an electrical resistance of approximately 6'75 ohms (C. M. F.) can be consistently obtained. On longer heating at- 850 F. higher electrical resistance values are obtainable Without substantial change in the T. C. value, such that with 5 hours heating E. R. values approximating 700 ohms -(C. M. F.) may be consistently obtained.
Electrical resistors having a T. C. value under .0001 and an E. R. value above 650 are well suited for use in electrical devices and circuits of the high accuracy type, such as in radar, radio and television devices.
In Ni-Cr alloys of the 80/20 type it has heretofore been proposed to add to the alloy small percentages of other alloy constitutents such as Al, Al'Cu, Al-Ag, Al-Fe or Mn, to lower the T. C. value of the alloy in its annealed condition. The
Lil
present heat-treatment operation on the annealed wire comprised of such low T. C. improvement alloys is effective to still further lower the T. C. value of these alloys closer to zero and by the term /20 nickel-chromium electrical resistance alloys as it hereinafter appears in the claims I mean to include such improvement alloys as being within the scope of the present invention.
In general I have found that as the temperature of heat-treatment is increased within the range 780-1000 F. the time at temperature may be decreased and vice versa to obtain equivalent results.
Having hereinabcve disclosed the invention generically and specifically and given one specific embodiment of the practice or" the same it is believed apparent that the invention may be widely varied and adapted for use on a plurality of nickel-chromium electrical resistance alloys without essential departure therefrom and all such modifications and adaptations of the same are contemplated as may fall Within the scope of the following claims.
What I claim is:
1. The method of treating a wire comprised of an alloy consisting of 10 to 30% Cr, balance Ni, to impart thereto a temperature coefiicient within the range 20 to 300 C. or" less than .0001 ohm and an electrical resistance above 650 ohms which comprises heat treating the wire in a reducing atmosphere for from 1 to 5 hours at a temperature within the range '780-1000 F. and cooling the heat-treated product slowly down to atmospheric temperatures.
2. The method of claim 1, wherein the said alloy contains iron, manganese, silicon and carbon in small fractional percentages and in total amount not exceeding 2 3. The method of claim 1, wherein the alloy consists of 20% Cr, balance Ni, the temperature of heating is 850 F., and the time interval of heating approximates one hour.
4. The method of claim 1, wherein'the heattreating is conducted in a hydrogenous reducing atmosphere at a temperature approximating 850 F.
5. The method of claim 1, wherein prior to said heat-treatment the wire is annealed at a temperature within the range 1700-1950 F.
6. The method of treating a wire comprised of an alloy consisting of 20% Cr, not over 2% of associated alloy constituents consisting of fractional percentages of at least one of the elements of the group consisting of Fe, Mn, Si and C, balance nickel, to impart thereto a temperature coeiTicient less than .0001 and an electrical resistance above 650 ohms and physical properties adapting the same to be formed into resistor elements for electronic electrical devices, which comprises annealing the wire at a temperature within the range 1700 to 1950 F. to condition the wire for forming, heat-treating the annealed wire in a hydrogenous reducing atmosphere for from 1 to 5 hours at a temperature within the range I80 to 1000 F., and slowly cooling the'annealed and heat-treated wire product to atmospheric temperatures in the same atmosphere.
7. The method of claim 6, wherein the said heat-treating temperature approximates 850 F. and the time interval of heating is 1 to 3 hours.
8. An electrical resistor element having a temperature coefiicient within the range 20 to 300 C. of less than .0001 and an electrical resistance above 650 ohms, said element being comprised of assume the annealed and heat-treated wire product of the method of claim 6.
9. An electrical resistor element comprised of the heat-treated wire product of the method of claim 1.
VICTOR 0. ALLEN.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS OTHER REFERENCES Bulletin T-7, published by International Nickel 00., New York, 1939, pages 5 and 8.
Claims (1)
1. THE METHOD OF TREATING A WIRE COMPRISED OF AN ALLOY CONSISTING OF 10 TO 30% CR, BALANCE NI, TO IMPART THERETO A TEMPERATURE COEFFICIENT WITHIN THE RANGE 20 TO 300* C. OF LESS THAN .0001 OHM AND AN ELECTRICAL RESISTANCE ABOVE 650 OHMS WHICH COMPRISES HEAT TREATING THE WIRE IN A REDUCING ATMOSPHERE FOR FROM 1 TO 5 HOURS AT A TEMPERATURE WITHIN THE RANGE 780-1000* F. AND COOLING THE HEAT-TREATED PRODUCT SLOWLY DOWN TO ATMOSPHERIC TEMPERATURES.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US110671A US2585613A (en) | 1949-08-16 | 1949-08-16 | Method of heat-treating electrical resistance alloy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US110671A US2585613A (en) | 1949-08-16 | 1949-08-16 | Method of heat-treating electrical resistance alloy |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2585613A true US2585613A (en) | 1952-02-12 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US110671A Expired - Lifetime US2585613A (en) | 1949-08-16 | 1949-08-16 | Method of heat-treating electrical resistance alloy |
Country Status (1)
| Country | Link |
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| US (1) | US2585613A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2944889A (en) * | 1957-11-20 | 1960-07-12 | John F Klement | Aluminum bronze alloy containing chromium and having improved wear resistance |
| WO2000058530A1 (en) * | 1999-03-31 | 2000-10-05 | American Superconductor Corporation | Alloy materials |
| US6458223B1 (en) | 1997-10-01 | 2002-10-01 | American Superconductor Corporation | Alloy materials |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US811859A (en) * | 1905-03-15 | 1906-02-06 | Hoskins Company | Electric resistance element. |
| US1715541A (en) * | 1929-06-04 | Oratories | ||
| US1910309A (en) * | 1931-07-22 | 1933-05-23 | Telegraph Constr & Main Co | Magnetic alloy |
| DE612178C (en) * | 1933-04-13 | 1935-04-15 | Heraeus Vacuumschmelze Akt Ges | Process for the production of objects with high rigidity and spring force |
| US2460590A (en) * | 1946-05-11 | 1949-02-01 | Driver Harris Co | Electric resistance element and method of heat-treatment |
-
1949
- 1949-08-16 US US110671A patent/US2585613A/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1715541A (en) * | 1929-06-04 | Oratories | ||
| US811859A (en) * | 1905-03-15 | 1906-02-06 | Hoskins Company | Electric resistance element. |
| US1910309A (en) * | 1931-07-22 | 1933-05-23 | Telegraph Constr & Main Co | Magnetic alloy |
| DE612178C (en) * | 1933-04-13 | 1935-04-15 | Heraeus Vacuumschmelze Akt Ges | Process for the production of objects with high rigidity and spring force |
| US2460590A (en) * | 1946-05-11 | 1949-02-01 | Driver Harris Co | Electric resistance element and method of heat-treatment |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2944889A (en) * | 1957-11-20 | 1960-07-12 | John F Klement | Aluminum bronze alloy containing chromium and having improved wear resistance |
| US6458223B1 (en) | 1997-10-01 | 2002-10-01 | American Superconductor Corporation | Alloy materials |
| WO2000058530A1 (en) * | 1999-03-31 | 2000-10-05 | American Superconductor Corporation | Alloy materials |
| US6475311B1 (en) * | 1999-03-31 | 2002-11-05 | American Superconductor Corporation | Alloy materials |
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