Title:
THICK STEEL SHEET AND METHOD FOR PRODUCING THICK STEEL SHEET
Document Type and Number:
WIPO Patent Application WO/2023/286536
Kind Code:
A1
Abstract:
The present invention provides a thick steel sheet which has both excellent fatigue crack propagation resistance and total elongation, while exhibiting excellent elongation in the sheet thickness direction. A thick steel sheet which has a component composition that contains, in mass%, 0.01 to 0.16% of C, 1.00% or less of Si, 0.50 to 2.00% of Mn, 0.030% or less of P, 0.020% or less of S and 0.06% or less of Al, with the balance being made up of Fe and unavoidable impurities, and which has a microstructure where bainite accounts for 75 to 97% and pearlite accounts for 3 to 25% in terms of area fractions, with the average circle-equivalent diameter of the crystal grains of bainite being 18 µm or less and the average circle-equivalent diameter of the crystal grains of pearlite being 10 µm or less. This thick steel sheet has a drawing value in the sheet thickness direction of 30% or more.
Inventors:
MURAKAMI SHUNICHI (JP)
HYODO YOSHIHIRO (JP)
YOKOTA TOMOYUKI (JP)
KITSUYA SHIGEKI (JP)
MIURA SHINICHI (JP)
HYODO YOSHIHIRO (JP)
YOKOTA TOMOYUKI (JP)
KITSUYA SHIGEKI (JP)
MIURA SHINICHI (JP)
Application Number:
PCT/JP2022/024603
Publication Date:
January 19, 2023
Filing Date:
June 20, 2022
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C22C38/00; C21D8/02; C22C38/06; C22C38/60
Domestic Patent References:
| WO2020153085A1 | 2020-07-30 |
Foreign References:
| JPH06256842A | 1994-09-13 | |||
| JP2016160474A | 2016-09-05 | |||
| CN110656291A | 2020-01-07 | |||
| JP2006002211A | 2006-01-05 | |||
| JP2015083712A | 2015-04-30 |
Attorney, Agent or Firm:
SUGIMURA Kenji (JP)
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