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US3932236A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for producing a super low watt loss grain oriented electrical steel sheet

Assignee: Nippon Steel Corp
•
Filing: 1974-01-18
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Granted: 1976-01-13
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Expires: 1994-01-18
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Abstract

Abstract A method for producing a grain-oriented electrical steel sheet showing super low watt loss, comprising making a silicon steel ingot containing 2.5 to 4.0% of Si, subjecting the ingot treatments including hot rolling, annealing and at least one cold rolling to obtain a final size, subjecting the steel to decarburization annealing and a finishing annealing which completes secondary recrystallization, subjecting the steel to remove surface product and then subjecting the steel to chemical polishing or electrolytic polishing to polish the steel surface to mirror condition.

Inventors

  • 👤 Toshiya Wada
  • 👤 Tadao Nozawa
  • 👤 Toshihiko Takata

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 04:18
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/12; C21D8/1277

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 104 words
In a method for producing a grain-oriented electrical steel sheet having super low watt loss wherein a silicon steel sheet ingot or slab containing 2.5 to 4.0% Si is subjected to hot rolling, annealing and at least one cold rolling to a final thickness, and the steel is subjected to decarburization annealing and a finishing annealing to complete the secondary recrystallization, and the surface of the steel is then cleaned, the improvement which comprises after said surface cleaning step, polishing the surface of the steel to a mirror finish by electrolytic or chemical polishing and applying a thin metal plating to the polished surface.
Claim 2
Dependent Claim 104 words
In a method for producing a grain-oriented electrical steel sheet having super low watt loss wherein a silicon steel sheet ingot or slab containing 2.5 to 4.0% Si is subjected to hot rolling, annealing and at least one cold rolling to a final thickness, and the steel is subjected to decarburization annealing and a finishing annealing to complete the secondary recrystallization, and the surface of the steel is then cleaned, the improvement which comprises after said surface cleaning step, polishing the surface of the steel to a mirror finish by electrolytic or chemical polishing and applying a thin metal plating to the polished surface.
Claim 3
Dependent Claim 17 words
The method of claim 1 wherein an insulating film is applied and baked onto the plated surface.

References Cited (Backward Citations)

US2385332A Cited
US2394047A Cited
US2528216A Cited
US3223602A Cited
US3347718A Cited
US3575739A Cited
US3834952A Cited
US3764406A Cited
US3833431A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-01-12 1979-07-14 1980-01-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-01-12 1983-07-14 1984-01-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-01-12 1987-07-14 1988-01-13 $7700.00 Window Closed / Lapsed

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