Invention Grant
- Patent Title: Cold-rolled steel sheet
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Application No.: US15047990Application Date: 2016-02-19
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Publication No.: US09771638B2Publication Date: 2017-09-26
- Inventor: Seiji Furuhashi , Jun Haga , Takayuki Nishi
- 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: Clark & Brody
- Priority: JP2007-054511 20070305; JP2007-263481 20071009
- Main IPC: C22C38/14
- IPC: C22C38/14 ; C22C38/04 ; C22C38/12 ; C23C2/06 ; C23C2/28 ; C22C38/00 ; C22C38/02 ; C22C38/06

Abstract:
A high strength cold-rolled steel sheet has excellent surface appearance and a composition consisting essentially of, in mass %, C: 0.0005-0.025%, Si: at most 0.2%, Mn: 0.3-2.5%, P: at most 0.15%, S: at most 0.02%, N: at most 0.006%, sol. Al: less than 0.005%, Ti: 0.005-0.05%, and Nb: 0.020-0.200% with the mass ratio (Nb/Ti) of the contents of Nb and Ti being at least 2, either boron at most 0.0020% or one or more of Cr, Mo, V, W, Cu, and Ni, each at most 1%, and a remainder of Fe and impurities. The sheet has excellent press formability and tensile strength by having an r value in a direction at 45° with respect to the rolling direction (r45) of at least 1.80 and/or a mean r value (rm) of at least 1.60, and a tensile strength of at least 340 MPa.
Public/Granted literature
- US20160168669A1 COLD-ROLLED STEEL SHEET Public/Granted day:2016-06-16
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