Title:
METHOD FOR MANUFACTURING DIRECTIONAL ELECTROMAGNETIC STEEL SHEET, AND HOT-ROLLED STEEL SHEET FOR DIRECTIONAL ELECTROMAGNETIC STEEL SHEET
Document Type and Number:
WIPO Patent Application WO/2022/186299
Kind Code:
A1
Abstract:
The purpose of the present invention is to provide a method for manufacturing a directional electromagnetic steel sheet that expresses electromagnetic properties that are superior compared to prior art, by highly controlling a primary recrystallized sheet texture while actively utilizing an inhibitor. The present invention provides a method for manufacturing a directional electromagnetic steel sheet, the method including: slab-heating a steel slab to a temperature over a γ-phase precipitation temperature and up to 1380°C; performing rough rolling that includes at least two passes of rolling carried out such that the introduced sheet thickness true strain εt is 0.50 or above at a temperature equal to or higher than (the temperature at which the γ-phase fraction is at its maximum – 20°C); performing finishing rolling such that the rolling end temperature is 900°C or above to obtain a hot-rolled sheet; performing, within two seconds of the end of the finishing rolling, cooling for at least one second at a cooling speed of 70°C/s or above; performing winding at a winding temperature of 600°C or below; performing hot-rolled sheet annealing in which soaking is performed at a soaking temperature between 750°C and (1080 - 5Y)°C inclusive, where Y represents the recrystallization rate of a plate thickness center layer of the hot-rolled sheet after winding; and then performing cold rolling, primary recrystallization annealing, and secondary recrystallization annealing.
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Inventors:
TAKAJO SHIGEHIRO (JP)
YAMAGUCHI HIROI (JP)
YAMAGUCHI HIROI (JP)
Application Number:
PCT/JP2022/008969
Publication Date:
September 09, 2022
Filing Date:
March 02, 2022
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C21D8/12; C22C38/00; C22C38/60; H01F1/147
Domestic Patent References:
| WO2013145784A1 | 2013-10-03 | |||
| WO2020130328A1 | 2020-06-25 |
Foreign References:
| JPH02274814A | 1990-11-09 | |||
| JP2011219793A | 2011-11-04 | |||
| JP2013512332A | 2013-04-11 | |||
| KR20060074649A | 2006-07-03 | |||
| US20130174940A1 | 2013-07-11 | |||
| JPS4015644B1 | ||||
| JPS5113469B2 | 1976-04-28 | |||
| JPS4623820B1 | ||||
| JP2001060505A | 2001-03-06 |
Other References:
See also references of EP 4276204A1
Attorney, Agent or Firm:
SUGIMURA Kenji (JP)
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