Invention Grant
- Patent Title: High strength hot rolled steel sheet having tensile strength of 780 MPa or more
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Application No.: US14778339Application Date: 2014-03-11
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Publication No.: US10400316B2Publication Date: 2019-09-03
- Inventor: Katsumi Nakajima , Yoshimasa Funakawa , Nobuyuki Nakamura
- Applicant: JFE STEEL CORPORATION
- Applicant Address: JP Tokyo
- Assignee: JFE STEEL CORPORATION
- Current Assignee: JFE STEEL CORPORATION
- Current Assignee Address: JP Tokyo
- Agency: Oliff PLC
- Priority: JP2013-056487 20130319
- International Application: PCT/JP2014/001379 WO 20140311
- International Announcement: WO2014/148001 WO 20140925
- Main IPC: C21D1/20
- IPC: C21D1/20 ; C21D6/00 ; C22C38/50 ; C22C38/00 ; C22C38/14 ; H01F1/16 ; C21D8/12 ; C22C38/02 ; C22C38/04 ; C22C38/06 ; C22C38/08 ; C22C38/12 ; C22C38/16 ; C22C38/28 ; C22C38/42 ; B32B15/01 ; C22C38/58 ; C23C2/06 ; C23C2/40 ; C21D9/46

Abstract:
A high strength hot rolled steel sheet with good formability, which has good magnetic properties, excellent punchability, and a tensile strength of 780 MPa or more. The high strength hot rolled steel sheet having a chemical composition containing C: 0.070% to 0.140%, Si: 0.10% to 1.00%, Mn: 1.00% to 1.80%, P: 0.050% or less, S: 0.0050% or less, N: 0.0080% or less, Al: 0.010% to 0.100%, Ti: 0.050% to 0.150%, and the remainder composed of Fe and incidental impurities, on a percent by mass basis, and 95% or more of bainite microstructure on a volume fraction basis, wherein carbides constituting 80% or more of total precipitation carbides are dispersed at grain boundaries of bainitic ferrite constituting the bainite microstructure and 80% or more of total precipitation carbides have particle grain sizes of 20 to 300 nm.
Public/Granted literature
- US20160138141A1 HIGH STRENGTH HOT ROLLED STEEL SHEET HAVING TENSILE STRENGTH OF 780 MPA OR MORE Public/Granted day:2016-05-19
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