Invention Grant
- Patent Title: High-strength steel sheet and method for manufacturing the same
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Application No.: US16092323Application Date: 2017-03-22
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Publication No.: US11193180B2Publication Date: 2021-12-07
- Inventor: Katsutoshi Takashima , Yoshimasa Funakawa , Takashi Kobayashi
- Applicant: JFE Steel Corporation
- Applicant Address: JP Tokyo
- Assignee: JFE Steel Corporation
- Current Assignee: JFE Steel Corporation
- Current Assignee Address: JP Tokyo
- Agency: RatnerPrestia
- Priority: JPJP2016-080947 20160414
- International Application: PCT/JP2017/011288 WO 20170322
- International Announcement: WO2017/179372 WO 20171019
- Main IPC: C21D9/46
- IPC: C21D9/46 ; C21D6/00 ; C21D8/02 ; C22C38/00 ; C22C38/02 ; C22C38/04 ; C22C38/06 ; C22C38/42 ; C22C38/44 ; C22C38/46 ; C22C38/48 ; C22C38/50 ; C22C38/52 ; C22C38/54

Abstract:
A high-strength steel sheet having a chemical composition containing, by mass %, C: 0.15% to 0.25%, Si: 1.00% to 2.20%, Mn: 2.00% to 3.50%, P: 0.05% or less, S: 0.005% or less, Al: 0.01% to 0.50%, N: 0.010% or less, B: 0.0003% to 0.0050%, one, two, or more selected from Ti: 0.005% to 0.05%, Cu: 0.003% to 0.50%, Ni: 0.003% to 0.50%, Sn: 0.003% to 0.50%, Co: 0.003% to 0.05%, and Mo: 0.003% to 0.50%, and the balance being Fe and inevitable impurities and a microstructure including, in terms of volume fraction, 15% or less (including 0%) of ferrite, 2% to 15% of retained austenite, 10% or less (including 0%) of martensite, and the balance being bainite and tempered martensite, in which the average number of cementite grains having a grain diameter of 0.04 μm or more existing in the bainite and tempered martensite grains is 10 or more.
Public/Granted literature
- US20210207234A1 HIGH-STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME Public/Granted day:2021-07-08
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