Title:
HIGH STRENGTH/HIGH TOUGHNESS STEEL SHEET AND METHOD FOR PRODUCING SAME
Document Type and Number:
WIPO Patent Application WO/2016/157862
Kind Code:
A1
Abstract:
Provided is a high strength/high toughness steel sheet in which the tensile strength, Charpy impact absorption energy, and ductile fracture rate are equal to or greater than specified values. The high strength/high toughness steel sheet comprises, in mass%, 0.03-0.08% of C, 0.01-0.50% of Si, 1.5-2.5% of Mn, 0.001-0.010% of P, 0.0030% or less of S, 0.01-0.08% of Al, 0.010-0.080% of Nb, 0.005-0.025% of Ti, 0.001-0.006% of N, at least one substance selected from among 0.01-1.00% of Cu, 0.01-1.00% of Ni, 0.01-1.00% of Cr, 0.01-1.00% of Mo, 0.01-0.10% of V, and 0.0005-0.0030% of B, and a remainder of Fe and unavoidable impurities. At a position at 1/2 the sheet thickness, the area ratio of island-like martensite is less than 3%, the area ratio of bainite is 90% or more, and the average particle size of cementite within the bainite is 0.5 µm or less.
Inventors:
KIMURA HIDEYUKI (JP)
OTA SHUSAKU (JP)
ISHIKAWA NOBUYUKI (JP)
KAKIHARA SHINICHI (JP)
NAGAO RYO (JP)
OTA SHUSAKU (JP)
ISHIKAWA NOBUYUKI (JP)
KAKIHARA SHINICHI (JP)
NAGAO RYO (JP)
Application Number:
PCT/JP2016/001743
Publication Date:
October 06, 2016
Filing Date:
March 25, 2016
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C22C38/00; C21D8/02; C22C38/58
Domestic Patent References:
| WO2013190750A1 | 2013-12-27 | |||
| WO2013089156A1 | 2013-06-20 |
Foreign References:
| JP2011132600A | 2011-07-07 | |||
| JP2013204103A | 2013-10-07 | |||
| JP2013227671A | 2013-11-07 | |||
| JP2013133476A | 2013-07-08 | |||
| JP2009242849A | 2009-10-22 | |||
| JP2013095926A | 2013-05-20 | |||
| JP2012241266A | 2012-12-10 | |||
| JP2011195883A | 2011-10-06 | |||
| JP2011132601A | 2011-07-07 |
Other References:
See also references of EP 3279351A4
Attorney, Agent or Firm:
KUMASAKA, Akira et al. (JP)
Akira Kumasaka (JP)
Akira Kumasaka (JP)
Download PDF: