Invention Grant
- Patent Title: Hot stamped steel and method for producing the same
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Application No.: US14371481Application Date: 2013-01-11
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Publication No.: US09725782B2Publication Date: 2017-08-08
- Inventor: Toshiki Nonaka , Satoshi Kato , Kaoru Kawasaki , Toshimasa Tomokiyo
- Applicant: Nippon Steel & Sumitomo Metal Corporation
- 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: JP2012-004552 20120113
- International Application: PCT/JP2013/050377 WO 20130111
- International Announcement: WO2013/105631 WO 20130718
- Main IPC: C22C38/02
- IPC: C22C38/02 ; C22C38/04 ; C22C38/06 ; C22C38/12 ; C22C38/14 ; C22C38/18 ; C21D8/02 ; C23C2/06 ; C23C2/12 ; C23C2/26 ; C23C2/28 ; C23C2/02 ; C21D9/46 ; C22C38/00 ; C22C38/08 ; C22C38/16 ; C22C38/22 ; C22C38/28 ; C22C38/32 ; C22C38/38 ; C21D1/673

Abstract:
In a hot stamped steel, when [C] represents an amount of C (mass %), [Si] represents an amount of Si (mass %), and [Mn] represents an amount of Mn (mass %), an expression of 5×[Si]+[Mn])/[C]>10 is satisfied, a metallographic structure includes 80% or more of a martensite in an area fraction, and optionally, further includes one or more of 10% or less of a pearlite in an area fraction, 5% or less of a retained austenite in a volume ratio, 20% or less of a ferrite in an area fraction, and less than 20% of a bainite in an area fraction, TS×λ, which is a product of TS that is a tensile strength and λ that is a hole expansion ratio is 50000 MPa·% or more, and a hardness of the martensite measured with a nanoindenter satisfies H2/H1
Public/Granted literature
- US20150050519A1 HOT STAMPED STEEL AND METHOD FOR PRODUCING THE SAME Public/Granted day:2015-02-19
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