US3776781A - Thermocouple with nickel-silicon-magnesium alloy negative element - Google Patents
Thermocouple with nickel-silicon-magnesium alloy negative element Download PDFInfo
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- US3776781A US3776781A US00350641A US3776781DA US3776781A US 3776781 A US3776781 A US 3776781A US 00350641 A US00350641 A US 00350641A US 3776781D A US3776781D A US 3776781DA US 3776781 A US3776781 A US 3776781A
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- Prior art keywords
- percent
- nickel
- silicon
- alloy
- thermocouple
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- 229910000861 Mg alloy Inorganic materials 0.000 title description 4
- TVCIIEGEAQCZHX-UHFFFAOYSA-N [Si].[Mg].[Ni] Chemical compound [Si].[Mg].[Ni] TVCIIEGEAQCZHX-UHFFFAOYSA-N 0.000 title description 3
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 32
- 239000000956 alloy Substances 0.000 claims abstract description 32
- 239000011777 magnesium Substances 0.000 claims abstract description 20
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 16
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 14
- 239000010703 silicon Substances 0.000 claims abstract description 14
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 abstract description 28
- 229910052759 nickel Inorganic materials 0.000 abstract description 12
- 230000003647 oxidation Effects 0.000 abstract description 7
- 238000007254 oxidation reaction Methods 0.000 abstract description 7
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 11
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910021484 silicon-nickel alloy Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/80—Constructional details
- H10N10/85—Thermoelectric active materials
- H10N10/851—Thermoelectric active materials comprising inorganic compositions
- H10N10/855—Thermoelectric active materials comprising inorganic compositions comprising compounds containing boron, carbon, oxygen or nitrogen
Definitions
- Nickel-base alloys have been in use as thermoelements since the early part of this century.
- One of the commonly used thermocouples is the type K thermocouple (designated by the Instrument Society of America).
- the positive type K thermoelement is a nickel base alloy containing 9.25 Cr, 0.4 Si, balance essentially nickel.
- the negative type K thermoelement is a nickel base alloy containing'ZAl, 2.5 Mn, 1 Si, with small amounts of Fe and Co.
- type K thermocouples There are numerous commercial suppliers of type K thermocouples.
- the type K thermocouple is recommended to be used in air atmosphere. At high temperatures in air the negative type K thermoelement is the weaker link of the couple. It fails much sooner than the positive type K thermoelement because of its poorer oxidation resistance. In addition, a much larger portion of the EMF drift of the couple as a whole is attributed to the EMF change of the negative thermoelement. As a result,
- an alloy consisting essentially of from about 3 .25 percent to about 5.0 percent by weight of silicon, from about 0.03 percent to about 0.25 percent by weight of magnesium and the balance nickel.
- thermocouple has become more important than the actual EMF at a particular temperature. It has been found that the alloys of this invention change very little even after being exposed in air from over 21,000 hours at l,800 F. When compared to the negative thermoelement now in use, the error in a thermocouple is greatly reduced.
- the alloys of this invention consist essentially of from about 3.5 to about 5 percent by weight of silicon and from about 0.03 percent to about 0.25 percent by weight of magnesium and the balance nickel. Preferred are alloys containing from about 3.75 to about 4.25 percent by weight of silicon and from about 0.10 to about 0.20 magnesium with balance of nickel. Especially preferred is an alloy containing 4% silicon, 0.15 percent magnesium and balance nickel.
- EXAMPLE 1 A. Individual Thermoelement EMF at 1800 F, vs. Pt MV EMF Initial After 21,196 Hr. in MV positive type K thermoelement negative type K thermoelement B. Thermocouple After 21,196 Hrs.
- thermoelectric power at 1800" F is 0.022 MV per F and the other two thermocouples (2 and 3) the thermoelectric power is 0.023 MV per F.
- the range of magnesium content is from 0.03 to about 0.25 percent Mg, with the preferred amount of from 0.10 to 0.20 percent Mg.
- the presence of Mg in nickel in trace amounts of 0.01 percent or below does not have any beneficial effect on EMF stability and the presence of Mg above 0.25 percent impairs the workability of the alloy.
- the range of silicon content is from 3.25 to 5.00 percent. A minimum of about 3.25 percent is needed for oxidation resistance. Above about 5 percent Si, the workability of the alloy is impaired. Preferred is from about 3.75 to about 4.25 percent silicon.
- thermocouple consisting essentially of apositive thermoelement alloy consisting essentially of about 9.25 percent chromium, 0.4 percent silicon and balance nickel and a negative thermoelement alloy consisting essentially of from about 3.25 to about 5.0 percent by weight of silicon and from about 0.03 to about 0.25 percent by weight of magnesium and balance nickel.
- thermocouple according to claim 1 wherein in said negative thermoelement alloy said silicon is from about 3.75 to about 4.25 percent by weight.
- thermocouple according to claim 1 wherein in said negative thermoelement alloy said magnesium is from about 0.10 to about 0.20 percent by weight.
- thermocouple according to claim 2 wherein in said negative thermoelement alloy said magnesium is from about 0.10 to about 0.20 percent by weight.
- thermocouple according to claim 4 wherein in said negative thermoelement alloy said silicon is about 4 percent by weight and said magnesium is about 0.15
Abstract
A nickel-base alloy, useful as a negative thermoelement, is disclosed. The alloy consists essentially of from about 3.25 to about 5.0 percent by weight of silicon and from about 0.03 to about 0.25 percent by weight of magnesium and the balance nickel. The new alloy is more oxidation resistant and has a greater EMF stability than existing type K negative thermoelements.
Description
United States Patent 1 Starr et a].
[451 Dec. 4, 1973 THERMOCOUPLE WITH NICKEL-SILICON-MAGNESIUM ALLOY NEGATIVE ELEMENT [75] Inventors: Carrol Dean Starr, Whippany; Teh P0 Wang, North Caldwell, both of NJ.
[73] Assignee: Wilbur B. Driver Co., Newark, NJ.
[22] Filed: Apr. 12, 1973 [21] Appl. No.: 350,641
Related US. Application Data [62], Division of Ser. No. 173,671, Aug. 20, 1971.
[52] US. Cl 136/239, 136/236, 75/170 [51] Int. Cl H01v 1/22 [58] Field of Search 136/236, 239;
[561 References Cited UNITED STATES PATENTS 1,076,438 10/1913 Marsh 136/239 X 2,224,573 12/1940 Hunter 136/239 2,859,264 11/1958 Hunter 136/239 2,990,440 6/1961 Obrowski et a1... 136/239 3,411,956 11/1968 Sibley 136/236 3,673,003 6/1972 Starr et a1. 136/239 X FOREIGN PATENTS OR APPLICATIQNS 172,087 12/1965 U.S.S.R 136/239 Primary ExaminerLeland A. Sebastian Assistant ExaminerE. A. Miller AztorneyNorman J. OMalley et al.
[5 7 ABSTRACT 5 Claims, N0 Drawings THERMOCOUILE WITH NICKEL-SILICON-MAGNESIUM ALLOY NEGATIVE ELEMENT CROSS-REFERENCE TO RELATED APPLICA- TION This application is a division of Ser. No. 173,671, filed Aug. 20, 1971 and assigned to the assignee of the present invention. Original assignment recorded on Aug. 20, 1971, Reel 2775, Frame 135. BACK- GROUND OF THE INVENTION This invention relates to nickel-base alloys. More particularly, it is related to'nickel-base alloy having a superioroxidation resistance and EMF stability under long time periods of usage than existing type K negative thermoelements.
Nickel-base alloys have been in use as thermoelements since the early part of this century. One of the commonly used thermocouples is the type K thermocouple (designated by the Instrument Society of America). The positive type K thermoelement is a nickel base alloy containing 9.25 Cr, 0.4 Si, balance essentially nickel. The negative type K thermoelement is a nickel base alloy containing'ZAl, 2.5 Mn, 1 Si, with small amounts of Fe and Co. There are numerous commercial suppliers of type K thermocouples.
The type K thermocouple is recommended to be used in air atmosphere. At high temperatures in air the negative type K thermoelement is the weaker link of the couple. It fails much sooner than the positive type K thermoelement because of its poorer oxidation resistance. In addition, a much larger portion of the EMF drift of the couple as a whole is attributed to the EMF change of the negative thermoelement. As a result,
there is a need for a new negative thermoelement with improved oxidation resistance and EMF stability.
It is believed, therefore, that a new alloy useful as a negative thermoelement which has excellent oxidation resistance and EMF stability is an advancement in the art.
OBJECTS AND SUMMARY OF THE INVENTION It is an object of this invention to provide a new alloy which is oxidation resistant.
It is a further object of this invention to provide an alloy having excellent EMF stability.
It is a further object of this invention to provide a negative thermoelement alloy.
These and other objects are achieved in one aspect of this invention by an alloy consisting essentially of from about 3 .25 percent to about 5.0 percent by weight of silicon, from about 0.03 percent to about 0.25 percent by weight of magnesium and the balance nickel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS the thermocouple has become more important than the actual EMF at a particular temperature. It has been found that the alloys of this invention change very little even after being exposed in air from over 21,000 hours at l,800 F. When compared to the negative thermoelement now in use, the error in a thermocouple is greatly reduced.
Addition of silicon to nickel is known to improve oxidation resistance over the thermoelements now in use, hence longer life; however, the alloys of this invention containing magnesium exhibit better EMF stability than alloys without the magnesium.
The alloys of this invention consist essentially of from about 3.5 to about 5 percent by weight of silicon and from about 0.03 percent to about 0.25 percent by weight of magnesium and the balance nickel. Preferred are alloys containing from about 3.75 to about 4.25 percent by weight of silicon and from about 0.10 to about 0.20 magnesium with balance of nickel. Especially preferred is an alloy containing 4% silicon, 0.15 percent magnesium and balance nickel.
EXAMPLE 1 A. Individual Thermoelement EMF at 1800 F, vs. Pt MV EMF Initial After 21,196 Hr. in MV positive type K thermoelement negative type K thermoelement B. Thermocouple After 21,196 Hrs.
EMF in MV Temp. in F 1 K vs. K +0549 +25 2 K vs. Ni/4Si +0403 +18 3 K vs. Ni/4Sl/0.15Mg +0.167 +7 (1) For a type K couple the thermoelectric power at 1800" F is 0.022 MV per F and the other two thermocouples (2 and 3) the thermoelectric power is 0.023 MV per F.
The above long term atest at a high temperature of l,800 F decisively demonstrates that the Ni/4Si/0.15 Mg alloy is far superior to the others to both the conventional type K thermoelement and to a 4 percent silicon-nickel alloy.
The beneficial effect in EMF stability is attributed to the addition of the proper amount of magnesium to the Ni/4Si alloy base.
The range of magnesium content is from 0.03 to about 0.25 percent Mg, with the preferred amount of from 0.10 to 0.20 percent Mg. The presence of Mg in nickel in trace amounts of 0.01 percent or below does not have any beneficial effect on EMF stability and the presence of Mg above 0.25 percent impairs the workability of the alloy.
The range of silicon content is from 3.25 to 5.00 percent. A minimum of about 3.25 percent is needed for oxidation resistance. Above about 5 percent Si, the workability of the alloy is impaired. Preferred is from about 3.75 to about 4.25 percent silicon.
While there has been shown and described what is at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined by the appended claims.
What is claimed is:
1. A thermocouple consisting essentially of apositive thermoelement alloy consisting essentially of about 9.25 percent chromium, 0.4 percent silicon and balance nickel and a negative thermoelement alloy consisting essentially of from about 3.25 to about 5.0 percent by weight of silicon and from about 0.03 to about 0.25 percent by weight of magnesium and balance nickel.
2. A thermocouple according to claim 1 wherein in said negative thermoelement alloy said silicon is from about 3.75 to about 4.25 percent by weight.
3. A thermocouple according to claim 1 wherein in said negative thermoelement alloy said magnesium is from about 0.10 to about 0.20 percent by weight.
4. A thermocouple according to claim 2 wherein in said negative thermoelement alloy said magnesium is from about 0.10 to about 0.20 percent by weight.
5. A thermocouple according to claim 4 wherein in said negative thermoelement alloy said silicon is about 4 percent by weight and said magnesium is about 0.15
percent by weight.
Claims (4)
- 2. A thermocouple according to claim 1 wherein in said negative thermoelement alloy said silicon is from about 3.75 to about 4.25 percent by weight.
- 3. A thermocouple according to claim 1 wherein in said negative thermoelement alloy said magnesium is from about 0.10 to about 0.20 percent by weight.
- 4. A thermocouple according to claim 2 wherein in said negative thermoelement alloy said magnesium is from about 0.10 to about 0.20 percent by weight.
- 5. A thermocouple according to claim 4 wherein in said negative thermoelement alloy said silicon is about 4 percent by weight and said magnesium is about 0.15 percent by weight.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US35064173A | 1973-04-12 | 1973-04-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3776781A true US3776781A (en) | 1973-12-04 |
Family
ID=23377582
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US00350641A Expired - Lifetime US3776781A (en) | 1973-04-12 | 1973-04-12 | Thermocouple with nickel-silicon-magnesium alloy negative element |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3776781A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3972740A (en) * | 1975-07-31 | 1976-08-03 | Wilbur B. Driver Company | Thermocouple with improved EMF stability |
| US5043023A (en) * | 1986-09-08 | 1991-08-27 | Commonwealth Scientific And Industrial Research Organization | Stable metal-sheathed thermocouple cable |
| US5437745A (en) * | 1994-03-25 | 1995-08-01 | Thermo Electric Corporation | High copper alloy composition for a thermocouple extension cable |
| US20200194652A1 (en) * | 2018-12-13 | 2020-06-18 | Battelle Energy Alliance, Llc | Techniques for making high-temperature thermocouples and related thermocouples and methods |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1076438A (en) * | 1912-09-30 | 1913-10-21 | Hoskins Mfg Company | Thermo-electric element. |
| US2224573A (en) * | 1939-10-25 | 1940-12-10 | Driver Harris Co | Alloy |
| US2859264A (en) * | 1954-08-06 | 1958-11-04 | Driver Harris Co | Thermocouple element composition |
| US2990440A (en) * | 1958-05-17 | 1961-06-27 | Degussa | Thermocouple |
| SU172087A1 (en) * | 1964-03-25 | 1965-06-22 | Государственный научно исследовательский , проектный икстит | thermocouples |
| US3411956A (en) * | 1963-10-15 | 1968-11-19 | Hoskins Mfg Company | Thermocouple with nickel-containing elements |
| US3673003A (en) * | 1969-09-18 | 1972-06-27 | Driver Co Wilbur B | Thermocouple for nuclear environment |
-
1973
- 1973-04-12 US US00350641A patent/US3776781A/en not_active Expired - Lifetime
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1076438A (en) * | 1912-09-30 | 1913-10-21 | Hoskins Mfg Company | Thermo-electric element. |
| US2224573A (en) * | 1939-10-25 | 1940-12-10 | Driver Harris Co | Alloy |
| US2859264A (en) * | 1954-08-06 | 1958-11-04 | Driver Harris Co | Thermocouple element composition |
| US2990440A (en) * | 1958-05-17 | 1961-06-27 | Degussa | Thermocouple |
| US3411956A (en) * | 1963-10-15 | 1968-11-19 | Hoskins Mfg Company | Thermocouple with nickel-containing elements |
| SU172087A1 (en) * | 1964-03-25 | 1965-06-22 | Государственный научно исследовательский , проектный икстит | thermocouples |
| US3673003A (en) * | 1969-09-18 | 1972-06-27 | Driver Co Wilbur B | Thermocouple for nuclear environment |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3972740A (en) * | 1975-07-31 | 1976-08-03 | Wilbur B. Driver Company | Thermocouple with improved EMF stability |
| US5043023A (en) * | 1986-09-08 | 1991-08-27 | Commonwealth Scientific And Industrial Research Organization | Stable metal-sheathed thermocouple cable |
| US5437745A (en) * | 1994-03-25 | 1995-08-01 | Thermo Electric Corporation | High copper alloy composition for a thermocouple extension cable |
| US20200194652A1 (en) * | 2018-12-13 | 2020-06-18 | Battelle Energy Alliance, Llc | Techniques for making high-temperature thermocouples and related thermocouples and methods |
| US11963446B2 (en) * | 2018-12-13 | 2024-04-16 | Battelle Energy Alliance, Llc | Methods for making high-temperature thermocouples |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: CARPENTER TECHNOLOGY CORPORATION READING PENNSYLVA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:AMAX INC., A CORP OF NEW YORK;REEL/FRAME:004284/0609 Effective date: 19840427 |