US3833431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for continuously annealed silicon steel using tension-producing glass
Assignee: ABB Inc USA
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Filing: 1971-12-09
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Granted: 1974-09-03
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Expires: 1991-12-09
Abstract
Abstract A process is described for producing silicon steel containing nominally 3.25 percent silicon, by a continuous annealing process. The magnetic characteristics exhibited by the fully processed steel approach those of commercially available silicon steel but without the necessity of extensively desulfurizing the steel from that sulfur content which is usually obtained employing a commercial process. Essentially, the process consists of selecting a cold worked, decarburized semiprocessed silicon steel which is thereafter subjected to a continuous strand annealing at a temperature in the range between about 1,000*C and about 1,100*C in order to substantially completely recrystallize the steel by a secondary recrystallization process and the application of a tensile stress of at least 200 psi to the underlying steel for producing improved watt losses over that material having substantially the same sulfur content but which was manufactured by regular commercial processes.
Inventors
- 👤 K Foster
- 👤 J Shilling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:11
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/14766; H01F1/14775; H01F1/14783; C; C21; C21D; C21D1/00; C21D1/68; C21D1/70; C21D8/00; C21D8/12; C21D8/1277; C21D8/1288; C23; C23D; C23D5/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
31 words
The process of claim 1 in which the steel is continuously annealed at a temperature of about 1,050*C for a time period of between about 5 minutes and about 10 minutes.
Claim 2
Dependent Claim
24 words
The process of claim 1 in which the steel is annealed in an atmosphere of hydrogen having a dew point of less than -40*C.
Claim 3
Dependent Claim
185 words
In the process for producing silicon steel having a cube-on-edge orientation employing a continuous annealing process in which the sulfur content is in excess of 150 ppm and in which the steel is melted, hot worked, cold worked in one or more operations to the desired finish gauge and decarburized, the steps comprising applying to the surface of the steel a coating of a slurry of a silicate glass having a coefficient of thermal expansion of the order of less than about 8.5 X 10 6 in./in. per degree centigrade which will effect a tensile stress within the range between about 200 psi and 800 psi when the glass is fused to said surface of the steel, said glass not adversely affecting the other properties of the steel and continuously annealing the coated steel as a strand at a temperature within the range between about 1,000*C and 1,100*C to fuse the glass to the steel surface and for a period of time sufficient to develop the cube-on-edge orientation and to effect substantially complete secondary crystallization and grain growth in the steel without any appreciable desulfurization.
Claim 4
Dependent Claim
25 words
The process of claim 4 in which the fused glass has a total thickness within the range between 0.25 mil and 1.0 mil in thickness.
Claim 5
Dependent Claim
15 words
The process of claim 4 in which the annealing takes place in a non-reducing atmosphere.
Claim 6
Dependent Claim
195 words
In the process for producing silicon steel having a cube-on-edge orientation in which the final sulfur content is in excess of 75 ppm and in which the steel is melted, hot worked, cold worked in one or more operations to the desired finish gauge and decarburized, the steps comprising, continuously annealing the decarburized steel as a strand at a temperature within the range between 1,000*C and 1,100*C in a dry, reducing atmosphere for a time period sufficient to develop the cube-on-edge orientation and to effect substantially complete crystallization and grain growth without an appreciable change in the sulfur content applying to the surface of the recrystallized steel a slurry of a silicate glass having a coefficient of thermal expansion of the order of less than about 8.5 X 10 6 in./in. per degree centigrade when when fused to the surface of the steel exerts a tensile stress in the steel within the range between about 400 psi and about 800 psi and thereafter fusing the glass to the surface of the steel at a temperature within the range between about 750*C and 800*C, said fused glass not adversely affecting the other properties of the steel.
Claim 7
Dependent Claim
24 words
The process of claim 7 in which the glass has a total thickness within the range between about 0.25 mil and about 1.0 mil.
Claim 8
Dependent Claim
37 words
The process of claim 7 in which the strand annealing for recrystallization takes place in a protective reducing atmosphere and the fusing of the glass to the surface of the steel takes place in a non-reducing atmosphere.
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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) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |