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US3933537A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for producing electrical steel sheets having a very high magnetic induction

Assignee: JFE Steel Corp
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Filing: 1973-11-23
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Granted: 1976-01-20
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Expires: 1993-11-23
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Abstract

Abstract Electrical steel sheets having a very high magnetic induction are produced by a method in which an electrical steel raw material is hot rolled and annealed and subjected to at least one cold rolling and to a decarburizing annealing and a final annealing to develop the secondary recrystallized grains of (110) [001] orientation characterized in that the raw material contains less than 4.5% of Si, less than 0.06% of C, 0.005-0.100% of Sb and 0.01-0.05% of Al in the electrical steel raw material prior to the hot rolling, annealing at a temperature of 750° - 1,200°C depending upon the Si content before the final cold rolling, final cold rolling at a reduction rate of 40 - 89% and fully developing the secondary recrystallized grains at a temperature range of 800° - 950°C in the final annealing, are carried out in the above described order.

Inventors

  • 👤 Takuichi Imanaka
  • 👤 Takahiro Kan

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 13:33
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/02; C21; C21D; C21D8/00; C21D8/12; C21D8/1244; C21D8/1272; C21D8/1216; C21D8/1233; C21D8/1266

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 190 words
In a method for producing electrical steel sheets having a very high magnetic induction in which an electrical steel raw material is hot rolled, annealed at a temperature of 750°-1200°C the sheet is subjected to at least one cold rolling including, at least a final cold rolling, at a reduction rate of 40-89% to produce a steel sheet having a final gage of 2-4mm, with said 750°-1200°C annealing occurring before said final cold rolling, said cold rolled sheet being subjected to a decarburizing annealing and a final annealing to develop the secondary cyrstallized grain of (110) [001]; the improvement comprising utilizing an electrical steel raw material consisting of less than 4.5% Si, less than 0.06% C, 0.025-0.035% of Sb, 0.01-0.035% of soluble Al, 0.02-0.20% of Mn with the remainder of the composition comprising iron and incidental impurities and the improvement further comprising subjecting the sheet to a final annealing at a temperature of 800°-950°C for from 5 to 120 hours to develop the secondary recrystallized grains of (110) [001] orientation and then subjecting said sheet to a subsequent purifying annealing at a temperature higher than 1000°C to remove the impurities.
Claim 2
Dependent Claim 190 words
In a method for producing electrical steel sheets having a very high magnetic induction in which an electrical steel raw material is hot rolled, annealed at a temperature of 750°-1200°C the sheet is subjected to at least one cold rolling including, at least a final cold rolling, at a reduction rate of 40-89% to produce a steel sheet having a final gage of 2-4mm, with said 750°-1200°C annealing occurring before said final cold rolling, said cold rolled sheet being subjected to a decarburizing annealing and a final annealing to develop the secondary cyrstallized grain of (110) [001]; the improvement comprising utilizing an electrical steel raw material consisting of less than 4.5% Si, less than 0.06% C, 0.025-0.035% of Sb, 0.01-0.035% of soluble Al, 0.02-0.20% of Mn with the remainder of the composition comprising iron and incidental impurities and the improvement further comprising subjecting the sheet to a final annealing at a temperature of 800°-950°C for from 5 to 120 hours to develop the secondary recrystallized grains of (110) [001] orientation and then subjecting said sheet to a subsequent purifying annealing at a temperature higher than 1000°C to remove the impurities.

References Cited (Backward Citations)

US2209686A Cited
US3096222A Cited
US3853641A Cited
US3671337A Cited
US3764406A Cited
US3841924A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-01-19 1979-07-21 1980-01-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-01-19 1983-07-21 1984-01-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-01-19 1987-07-21 1988-01-20 $7700.00 Window Closed / Lapsed

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