Invention Grant
- Patent Title: High-strength hot-rolled steel sheet and method of manufacturing the same
- Patent Title (中): 高强度热轧钢板及其制造方法
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Application No.: US13583537Application Date: 2011-03-09
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Publication No.: US09121079B2Publication Date: 2015-09-01
- Inventor: Yuzo Takahashi , Junji Haji , Osamu Kawano
- Applicant: Yuzo Takahashi , Junji Haji , Osamu Kawano
- Applicant Address: JP Tokyo
- Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
- Current Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
- Current Assignee Address: JP Tokyo
- Agency: Birch, Stewart, Kolasch & Birch, LLP
- Priority: JP2010-053774 20100310; JP2010-053787 20100310
- International Application: PCT/JP2011/055556 WO 20110309
- International Announcement: WO2011/111758 WO 20110915
- Main IPC: C21D8/02
- IPC: C21D8/02 ; C22C38/02 ; C22C38/04 ; C22C38/06 ; C22C38/12 ; C22C38/14 ; B21B3/00 ; C21D9/46 ; C22C38/00

Abstract:
On a cross section with a sheet width direction of a high-strength hot-rolled steel sheet set as a normal line, with regard to an inclusion having a major diameter of 3.0 μm or more, a maximum of a major diameter/minor diameter ratio expressed by (a major diameter of the inclusion)/(a minor diameter of the inclusion) is 8.0 or less, and a sum total of a rolling direction length per 1 mm2 cross section of a predetermined inclusion group composed of plural inclusions each having a major diameter of 3.0 μm or more and a predetermined extended inclusion having a length in a rolling direction of 30 μm or more is 0.25 mm or less. The plural inclusions composing the predetermined inclusion group congregate in both the rolling direction and a direction perpendicular to the rolling direction 50 μm or less apart from each other. The predetermined extended inclusion is spaced over 50 μm apart from all the inclusions each having a major diameter of 3.0 μm or more in at least either the rolling direction or the direction perpendicular to the rolling direction.
Public/Granted literature
- US20130000791A1 HIGH-STRENGTH HOT-ROLLED STEEL SHEET AND METHOD OF MANUFACTURING THE SAME Public/Granted day:2013-01-03
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