Title:
STEEL SHEET AND METHOD FOR PRODUCING SAME
Document Type and Number:
WIPO Patent Application WO/2022/045352
Kind Code:
A1
Abstract:
Provided is a steel sheet having a chemical composition of, in mass percentage, 0.040-0.160% of C, 0.01-0.50% of Si, 0.70-2.50% of Mn, 0.030% or less of P, 0.020% or less of S, 0.001-0.100% of Al, 0.0010-0.0080% of N, 0.003-0.050% of Nb, 0.003-0.050% of Ti, and a balance of Fe and impurities, wherein the metal structure at a 1/4t point in the C-section contains bainite occupying 80% or more of the area thereof, the average length of bainitic ferrite forming said bainite, in the direction of the long axis thereof, is 10μm or less, the average length of prior austenite grains at a 1/4t point in the L-section, in a thickness direction, is 20μm or less with the average aspect ratio thereof being 2.5 or more, and the crystal grain boundary density at a 1/10t point, a 1/4t point, and a 1/2t point in the C-section is 500-1100mm/mm2, 400-1000mm/mm2, and 300-900mm/mm2, respectively.
Inventors:
NAKAI KEISUKE (JP)
IMAJO DAIKI (JP)
NAKAMURA SHINGO (JP)
SHINTAKU YOSHIAKI (JP)
NAKASHIMA KIYOTAKA (JP)
IMAJO DAIKI (JP)
NAKAMURA SHINGO (JP)
SHINTAKU YOSHIAKI (JP)
NAKASHIMA KIYOTAKA (JP)
Application Number:
PCT/JP2021/031921
Publication Date:
March 03, 2022
Filing Date:
August 31, 2021
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
C21C7/06; B21B1/00; B21B37/74; B22D11/22; C21D8/02; C22C38/00; C22C38/14; C22C38/60
Domestic Patent References:
| WO2009072559A1 | 2009-06-11 | |||
| WO2020262638A1 | 2020-12-30 |
Foreign References:
| JP2018090872A | 2018-06-14 | |||
| JP2020117779A | 2020-08-06 | |||
| JPH10306316A | 1998-11-17 | |||
| JP2018003062A | 2018-01-11 |
Attorney, Agent or Firm:
BRIGHTAS IP ATTORNEYS (JP)
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