Invention Grant
- Patent Title: Hot rolled steel sheet
- Patent Title (中): 热轧钢板
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Application No.: US10571023Application Date: 2004-09-02
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Publication No.: US07662243B2Publication Date: 2010-02-16
- Inventor: Tatsuo Yokoi , Tetsuya Yamada , Osamu Kawano
- Applicant: Tatsuo Yokoi , Tetsuya Yamada , Osamu Kawano
- Applicant Address: JP Tokyo
- Assignee: Nippon Steel Corporation
- Current Assignee: Nippon Steel Corporation
- Current Assignee Address: JP Tokyo
- Agency: Dorsey & Whitney LLP
- Priority: JP2003-314590 20030905
- International Application: PCT/JP2004/013088 WO 20040902
- International Announcement: WO2005/024082 WO 20050317
- Main IPC: C22C38/02
- IPC: C22C38/02 ; C22C38/04 ; C22C38/06

Abstract:
An exemplary hot rolled steel sheet can included, in terms of percent by mass, C of 0.01 to 0.2%; Si of 0.01 to 2%; Mn of 0.1 to 2%; P of ≦0.1%; S of ≦0.03%; Al of 0.001 to 0.1%; N of ≦ 0.01%; and as a remainder, Fe and unavoidable impurities. For example, a microstructure can be substantially a homogeneous continuous-cooled microstructure, and an average grain size of the microstructure may be more than 8 μm and 30 μm or less. An exemplary method for manufacturing a hot rolled steel sheet can include subjecting a slab having the above composition to a rough rolling so as to obtain a rough rolled bar, subjecting the rough rolled bar to a finish rolling so as to obtain a rolled steel under conditions in which a finishing temperature is (Ar3 transformation point +50° C.) or more; and starting cooling the rolled steel after 0.5 seconds or more pass from the end of the finish rolling at a temperature of the Ar3 transformation point or more. At least in the temperature range from the Ar3 transformation point can be cooled to 500° C. at a cooling rate of 80°C./sec or more, a further cooling can be effectuated until the temperature is 500° C. or less to obtain a hot rolled steel sheet and coiling the hot rolled steel sheet.
Public/Granted literature
- US20060266445A1 Hot rolled steel sheet and method for production thereof Public/Granted day:2006-11-30
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