Invention Grant
- Patent Title: High-strength steel plate, method of producing the same, and high-strength steel pipe
- Patent Title (中): 高强度钢板及其制造方法,高强度钢管
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Application No.: US11887018Application Date: 2006-03-30
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Publication No.: US08758528B2Publication Date: 2014-06-24
- Inventor: Junji Shimamura , Shigeru Endo , Mitsuhiro Okatsu
- Applicant: Junji Shimamura , Shigeru Endo , Mitsuhiro Okatsu
- Applicant Address: JP Tokyo
- Assignee: JFE Steel Corporation
- Current Assignee: JFE Steel Corporation
- Current Assignee Address: JP Tokyo
- Agency: RatnerPrestia
- Priority: JP2005-103090 20050331; JP2006-089276 20060328
- International Application: PCT/JP2006/307285 WO 20060330
- International Announcement: WO2006/104261 WO 20061005
- Main IPC: C22C38/00
- IPC: C22C38/00 ; C22C38/08 ; C21D9/08 ; C21D8/00

Abstract:
The present invention provides a high-strength steel plate having excellent resistance to cutting crack, excellent Charpy absorbed energy, excellent DWTT properties, a low yield ratio, and a tensile strength of 900 MPa or more, a method of producing the steel plate, and a high-strength steel pipe using the steel plate. As solving means, a steel plate contains, by % by mass, 0.03 to 0.12% of C, 0.01 to 0.5% of Si, 1.5 to 3% of Mn, 0.01 to 0.08% of Al, 0.01 to 0.08% of Nb, 0.005 to 0.025% of Ti, 0.001 to 0.01% of N, and at least one component of 0.01 to 2% of Cu, 0.01 to 3% of Ni, 0.01 to 1% of Cr, 0.01 to 1% of Mo, and 0.01 to 0.1% of V; wherein the contents of Ca, O, and S satisfy the equation below; the microstructure includes ferrite and a second hard phase, the area fraction of ferrite being 10 to 50%; cementite in the second phase has an average grin size of 0.5 μm or less; and the total amount of Nb and the like contained in carbides thereof present in steel is 10% or less of the total content in steel. 1≦(1−130×[O])×[Ca]/(1.25×[S])≦3 (1)
Public/Granted literature
- US20090120541A1 High-Strength Steel Plate, Method of Producing the Same, and High-Strength Steel Pipe Public/Granted day:2009-05-14
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