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US4615750A
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Process for producing a grain-oriented electrical steel sheet
Assignee: Nippon Steel Corp
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Filing: 1984-05-11
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Granted: 1986-10-07
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Expires: 2004-05-11
Abstract
Abstract The present invention relates to a process for producing a grain-oriented electrical steel sheet by means of the so-called double-rolling process, using Mn, S, and Cu as the precipitation dispersion phases for suppressing the growth of primary-recrystallized crystal grains. A new concept according to the present invention is to suppress the growth of primary crystals by means of an element segregated in the grain boundaries of primary-recrystallized crystals. The present invention is characterized in that the silicon steel starting material contains T.[N] in an amount which satisfies the following formulas (1) and (2): T.[N]>/={[sol Al%]x(14/27)+0.0020}(%) (1) T.[N]</={[sol Al%]x(14/27)+0.0060}(%) (2).
Inventors
- 👤 Kishio Mochinaga
- 👤 Kohichi Fujiwara
- 👤 Kazutaka Higashine
- 👤 Hisashi Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:16
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/16; C; C21; C21D; C21D8/00; C21D8/12; C21D8/1216; C21D8/1222; C22; C22C; C22C38/00; C22C38/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
125 words
A process for producing a grain-oriented electrical steel sheet, wherein the silicon steel starting material consists essentially of, as basic components, 0.085% or less of C, from 2.0% to 4.0% of Si, from 0.030% to 0.090% of Mn, from 0.010% to 0.060% of S, from 0.02% to 0.2% of Cu, and 0.0050% or less of sol.Al, and said silicon steel starting material is hot-rolled, cold-rolled twice so as to form a sheet having a thickness of from 0.35 mm to 0.15 mm, decarburization-annealed and final annealed said silicon steel starting material contain T. [N] in an amount which satisfies the following the formulas (1) and (2): T.[N]≧{[sol Al %]×14/27+0.0020}(%) (1) T.[N]≦{[sol Al %]×14/27+0.0060}(%) (2) thereby segregating excess nitrogen at the grain-boundaries in the decarburization step.
Claim 2
Dependent Claim
125 words
A process for producing a grain-oriented electrical steel sheet, wherein the silicon steel starting material consists essentially of, as basic components, 0.085% or less of C, from 2.0% to 4.0% of Si, from 0.030% to 0.090% of Mn, from 0.010% to 0.060% of S, from 0.02% to 0.2% of Cu, and 0.0050% or less of sol.Al, and said silicon steel starting material is hot-rolled, cold-rolled twice so as to form a sheet having a thickness of from 0.35 mm to 0.15 mm, decarburization-annealed and final annealed said silicon steel starting material contain T. [N] in an amount which satisfies the following the formulas (1) and (2): T.[N]≧{[sol Al %]×14/27+0.0020}(%) (1) T.[N]≦{[sol Al %]×14/27+0.0060}(%) (2) thereby segregating excess nitrogen at the grain-boundaries in the decarburization step.
Claim 3
Dependent Claim
39 words
A process according to claim 1, wherein said silicon steel starting material satisfies at least one of (a) and (b): (a) a specified P content of 0.010% or less and (b) an Sn alloying content of 0.1% or less.
Claim 4
Dependent Claim
208 words
A process for producing a grain-oriented electrical steel sheet, wherein the silicon steel starting material contains, as basic components, 0.085% or less of C, from 2.0% to 4.0% of Si, from 0.030% to 0.090% of Mn, from 0.010% to 0.060% of S, from 0.02% to 0.2% of Cu, and 0.0050% or less of sol.Al, and said silicon steel starting material is hot-rolled, cold-rolled twice so as to form a sheet having a thickness of from 0.35 mm to 0.15 mm, decarburization-annealed and final annealed said silicon steel starting material contains T. [n] in an amount which satisfies the following formulas (1) and (2): T.[N]≧{[sol Al %]×14/27+0.0020}(%) (1) T.[N]≦{[sol Al %]×14/27+0.0060}(%) (2) thereby segregating excess nitrogen at the grain-boundaries in the decarburization step, and wherein the silicon steel starting material is hot-rolled into a strip by a continuous hot-rolling mill including a plurality of stands, the temperature of the strip at the finishing inlet side of the finishing hot-rolling stands being from 1100° C. to 1250° C. and the temperature of the top of the strip at the outlet side of the finishing hot-rolling stands being from 900° C. to 1050° C. that at the middle and bottom of the strip being and from 950° C. to 1150° C.
Claim 5
Dependent Claim
208 words
A process for producing a grain-oriented electrical steel sheet, wherein the silicon steel starting material contains, as basic components, 0.085% or less of C, from 2.0% to 4.0% of Si, from 0.030% to 0.090% of Mn, from 0.010% to 0.060% of S, from 0.02% to 0.2% of Cu, and 0.0050% or less of sol.Al, and said silicon steel starting material is hot-rolled, cold-rolled twice so as to form a sheet having a thickness of from 0.35 mm to 0.15 mm, decarburization-annealed and final annealed said silicon steel starting material contains T. [n] in an amount which satisfies the following formulas (1) and (2): T.[N]≧{[sol Al %]×14/27+0.0020}(%) (1) T.[N]≦{[sol Al %]×14/27+0.0060}(%) (2) thereby segregating excess nitrogen at the grain-boundaries in the decarburization step, and wherein the silicon steel starting material is hot-rolled into a strip by a continuous hot-rolling mill including a plurality of stands, the temperature of the strip at the finishing inlet side of the finishing hot-rolling stands being from 1100° C. to 1250° C. and the temperature of the top of the strip at the outlet side of the finishing hot-rolling stands being from 900° C. to 1050° C. that at the middle and bottom of the strip being and from 950° C. to 1150° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-10-06 | 1990-04-07 | 1990-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-06 | 1994-04-07 | 1994-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-06 | 1998-04-07 | 1998-10-07 | $7700.00 | Window Closed / Lapsed |