Title:
NONORIENTED ELECTROMAGNETIC STEEL SHEET EXCELLENT IN BLANKABILITY AND MAGNETIC CHARACTERISTICS AFTER STRAIN REMOVAL ANNEALING, AND METHOD FOR PRODUCTION THEREOF
Document Type and Number:
WIPO Patent Application WO/2005/100627
Kind Code:
A1
Abstract:
A nonoriented electromagnetic steel exhibiting excellent blankability and also exhibiting good and stable iron loss after the annealing for strain removal, which has a chemical composition, in mass %, that Si: 1.5 % or less, Mn: 0.4 to 1.5 %, Sol.Al: 0.01 to 0.04 %, Ti: 0.0015% or less, N: 0.0030 % or less, S: 0.0010 to 0.0040%, Sn: 0.01 to 0.50%, B: an amount satisfying 0.5 ≤ B/N ≤1.5, and the balance: Fe and inevitable impurities, wherein 10 % or more, in terms of the number of pieces, of the sulfide containing Mn precipitates in a composite form with a B precipitate, and wherein it has a crystal grain diameter of 30 µm or less and exhibits a crystal grain diameter of 50 µm or more after the annealing for strain removal at 750°C for 2 hours; and a method for producing the above nonoriented magnetic steel which comprises holding a slab for hot rolling at a temperature of 1150 to 1250°C for five minutes or more, subsequently holding it at a temperature of 1050°C or higher and lower than 1150°C for 15 minutes or more, and immediately thereafter, subjecting the resultant slab to a hot rolling with a finishing output temperature T (°C) of T ≥ 900 - 1000 x Sn [mass %].
Inventors:
ARITA YOSHIHIRO (JP)
MURAKAMI HIDEKUNI (JP)
KIRISHIKI KOUICHI (JP)
MATSUMOTO YUTAKA (JP)
MURAKAMI HIDEKUNI (JP)
KIRISHIKI KOUICHI (JP)
MATSUMOTO YUTAKA (JP)
Application Number:
PCT/JP2005/007653
Publication Date:
October 27, 2005
Filing Date:
April 15, 2005
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
ARITA YOSHIHIRO (JP)
MURAKAMI HIDEKUNI (JP)
KIRISHIKI KOUICHI (JP)
MATSUMOTO YUTAKA (JP)
ARITA YOSHIHIRO (JP)
MURAKAMI HIDEKUNI (JP)
KIRISHIKI KOUICHI (JP)
MATSUMOTO YUTAKA (JP)
International Classes:
C21D8/12; C21D9/46; C22C38/00; C22C38/14; C22C38/16; H01F1/147; H01F1/16; (IPC1-7): C22C38/00; C21D8/12; C21D9/46; C22C38/14; C22C38/16; H01F1/16
Foreign References:
| JP2003064456A | 2003-03-05 | |||
| JPH1088298A | 1998-04-07 | |||
| JPH05140649A | 1993-06-08 | |||
| JPH0387313A | 1991-04-12 |
Attorney, Agent or Firm:
Aoki, Atsushi (ISHIDA & ASSOCIATES Toranomon 37 Mori
Bldg., 5-1, Toranomon 3-chome, Minato-k, Tokyo 23, JP)
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