US3982972A
Expired / Lapsed
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Semihard magnetic alloy and a process for the production thereof
Assignee: Proterial Ltd
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Filing: 1975-03-21
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Granted: 1976-09-28
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Expires: 1995-03-21
Abstract
Abstract The semihard magnetic alloy of the present invention consists essentially of, by weight, 17 to 45 % chromium, 3 to 14 % cobalt, 0.2 to 5 % silicon and balance substantially iron, preferably 23 to 35 % chromium, 6 to 12 % cobalt, 0.3 to 3 % silicon and balance substantially iron and has a residual magnetic flux density of 7,000 Gauss or more and a coersive force of 100 to 600 Oersted. Said alloy is produced by solution treating an alloy having the above indicated composition at a temperature of 650°C. to 1,300°C., preferably 850°C. to 1,085°C., and then either maintaining the solution-treated alloy at a temperature of not higher than 650°C. for a given period of time and repeatedly aging said alloy in multi-stage at gradually lowered temperatures, or cooling the solution-treated alloy continuously from a temperature of not higher than 700°C. down to at least 550°C. at a rate of not higher than 50°C. per hour.
Inventors
- 👤 Masao Iwata
- 👤 Yoichi Ishijima
- 👤 Osamu Fujita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:41
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/30; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
55 words
A heat-treated magnetic alloy having a residual magnetic flux density of 7,000 Gauss or more and a coersive force of 100 to 600 Oersted and consisting essentially of 17 to 45% by weight of chromium, 3 to 14% by weight of cobalt, 0.2 to 5% by weight of silicon and a balance of substantially iron.
Claim 2
Dependent Claim
55 words
A heat-treated magnetic alloy having a residual magnetic flux density of 7,000 Gauss or more and a coersive force of 100 to 600 Oersted and consisting essentially of 17 to 45% by weight of chromium, 3 to 14% by weight of cobalt, 0.2 to 5% by weight of silicon and a balance of substantially iron.
Claim 3
Dependent Claim
35 words
The magnetic alloy according to claim 1 consisting essentially of 23 to 35% by weight chromium, 6 to 12% by weight cobalt, 0.3 to 3% by weight of silicon and a balance of substantially iron.
Claim 4
Dependent Claim
106 words
A process for producing a magnetic alloy having a residual magnetic flux of 7,000 Gauss or more and a coersive force of 100 to 600 Oersted which comprises solution-treating an alloy consisting essentially of 17 to 45% by weight chromium, 3 to 14% by weight cobalt, 0.2 to 5% by weight silicon and a balance of substantially iron, at a temperature of 650° C. to 1,300° C., maintaining the solution-treated alloy at a temperature of not higher than 600° C. for a given period of time and then repeatedly aging said alloy in a multi-stage sequence at gradually lowered temperatures selected to yield said magnetic alloy.
Claim 5
Dependent Claim
106 words
A process for producing a magnetic alloy having a residual magnetic flux of 7,000 Gauss or more and a coersive force of 100 to 600 Oersted which comprises solution-treating an alloy consisting essentially of 17 to 45% by weight chromium, 3 to 14% by weight cobalt, 0.2 to 5% by weight silicon and a balance of substantially iron, at a temperature of 650° C. to 1,300° C., maintaining the solution-treated alloy at a temperature of not higher than 600° C. for a given period of time and then repeatedly aging said alloy in a multi-stage sequence at gradually lowered temperatures selected to yield said magnetic alloy.
Claim 6
Dependent Claim
20 words
The process according to claim 3, wherein said alloy is solution-treated at a temperature from 850° C. to 1,085° C.
Claim 7
Dependent Claim
66 words
The process according to claim 3, wherein the alloy which is solution-treated consists essentially of 23 to 35% by weight of chromium, 6 to 12% by weight of cobalt, 0.3 to 3% by weight of silicon and a balance of substantially iron, to yield a magnetic alloy hving a residual flux density of 7,000 Gauss or more and a coersive force of 120 to 600 Oersted.
Claim 8
Dependent Claim
44 words
The process according to claim 5, wherein said alloy is solution-treated at a temperature of from 850° to 1,085° C and the resulting magnetic alloy has a magnetic flux density of 7,000 Gauss or more and a coersive force of 150 to 600 Oersted.
Claim 9
Dependent Claim
109 words
A process for producing a magnetic alloy having a residual magnetic flux density of 7,000 Gauss or more and a coersive force of 150 to 600 Oersted which comprises solution-treating an alloy consisting essentially of 17 to 45% by weight chromium, 3 to 14% by weight of cobalt, 0.2 to 5% by weight of silicon and a balance of substantially iron at a temperature of 650° C. to 1,300° C. and then cooling the solution-treated alloy continuously from a temperature of not higher than 700° C. down to at least 550° C. at a rate of not higher than 50° C. per hour selected to yield said magnetic alloy.
Claim 10
Dependent Claim
109 words
A process for producing a magnetic alloy having a residual magnetic flux density of 7,000 Gauss or more and a coersive force of 150 to 600 Oersted which comprises solution-treating an alloy consisting essentially of 17 to 45% by weight chromium, 3 to 14% by weight of cobalt, 0.2 to 5% by weight of silicon and a balance of substantially iron at a temperature of 650° C. to 1,300° C. and then cooling the solution-treated alloy continuously from a temperature of not higher than 700° C. down to at least 550° C. at a rate of not higher than 50° C. per hour selected to yield said magnetic alloy.
Claim 11
Dependent Claim
21 words
The process according to claim 7, wherein said alloy is solution-treated at a temperature of from 850° C. to 1,085° C.
Claim 12
Dependent Claim
64 words
The process according to claim 7, wherein the alloy which is solution-treated consists essentially of 23 to 35% by weight chromium, 6 to 12% by weight cobalt, 0.3 to 3% by weight silicon and a balance of substantially iron to yield a magnetic alloy having a residual magnetic flux density of 7,000 Gauss or more and a coersive force of 180 to 600 Oersted.
Claim 13
Dependent Claim
21 words
The process according to claim 9, wherein said alloy is solution-treated at a temperature of from 850° C. to 1,085° C.
Claim 14
Dependent Claim
71 words
A heat-treated magnetic alloy having a residual magnetic flux density of 7000 Gauss or more and a coersive force of 100 to 600 Oersted and consisting essentially of 17 to 45% by weight chromium, 3 to 14% by weight cobalt, 0.2 to 5% by weight of silicon, and a balance of iron and up to 0.1% by weight carbon and up to 1% by weight calcium, magnesium and manganese as impurities.
Claim 15
Dependent Claim
71 words
A heat-treated magnetic alloy having a residual magnetic flux density of 7000 Gauss or more and a coersive force of 100 to 600 Oersted and consisting essentially of 17 to 45% by weight chromium, 3 to 14% by weight cobalt, 0.2 to 5% by weight of silicon, and a balance of iron and up to 0.1% by weight carbon and up to 1% by weight calcium, magnesium and manganese as impurities.
Claim 16
Dependent Claim
76 words
The process according to claim 3, wherein aging of said solution-treated alloy is effected in at least two stages, said aging being carried out in a first stage at a temperature from 650° C. down to 600° C. for 0.1 to 5 hours and then at subsequent stages each of which is at a temperature of 5° to 30° C. lower than that of the last preceding stage for 0.2 to 20 hours for each stage.
Claim 17
Dependent Claim
24 words
The process according to claim 7, wherein said solution-treated alloy is cooled from a temperature of 700° C. down to at least 550° C.
References Cited (Backward Citations)
US1866925A
Cited
US3806336A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-28 | 1980-03-29 | 1980-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-28 | 1984-03-29 | 1984-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-28 | 1988-03-29 | 1988-09-28 | $7700.00 | Window Closed / Lapsed |