Invention Grant
- Patent Title: Hot-pressed steel sheet member, method of manufacturing the same, and steel sheet for hot pressing
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Application No.: US15102042Application Date: 2013-12-27
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Publication No.: US10253387B2Publication Date: 2019-04-09
- Inventor: Koutarou Hayashi , Toshinobu Nishibata
- 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
- International Application: PCT/JP2013/085205 WO 20131227
- International Announcement: WO2015/097891 WO 20150702
- Main IPC: C21D9/46
- IPC: C21D9/46 ; C22C38/00 ; C21D7/13 ; C21D8/02 ; C21D1/673 ; C22C38/02 ; C22C38/04 ; C22C38/06 ; C22C38/08 ; C22C38/12 ; C22C38/14 ; C22C38/16 ; C22C38/18 ; C22C38/38 ; C21D1/18

Abstract:
A hot-pressed steel sheet member includes a specific chemical composition and further includes a steel structure in which an area ratio of ferrite in a surface layer portion ranging from a surface to 15 μm in depth is equal to or less than 1.20 times an area ratio of ferrite in an inner layer portion being a portion excluding the surface layer portion, and the inner layer portion contains a steel structure represented, in area %, ferrite: 10% to 70%; martensite: 30% to 90%; and a total area ratio of ferrite and martensite: 90% to 100%. A concentration of Mn in the martensite is equal to or more than 1.20 times a concentration of Mn in the ferrite in the inner layer portion, and a tensile strength of the hot-pressed steel sheet member is 980 MPa or more.
Public/Granted literature
- US20160312325A1 HOT-PRESSED STEEL SHEET MEMBER, METHOD OF MANUFACTURING THE SAME, AND STEEL SHEET FOR HOT PRESSING Public/Granted day:2016-10-27
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