Title:
THICK STEEL SHEET AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2024/038612
Kind Code:
A1
Abstract:
Provided is a thick steel sheet that has a high degree of strength, a low yield ratio, and a high degree of toughness, and that has excellent toughness of the joint bond section even with high heat-input welding where the welding heat input exceeds 40 kJ/mm. This thick steel sheet has a prescribed component composition and a microstructure, and has an Mn concentration distribution in which the proportion by area of an average Mn concentration region defined as a region with an Mn concentration of 0.9 to 1.1 times the average Mn content (% by mass) is less than 90%, the proportion by area of a high Mn concentration region defined as a region having an Mn concentration of 1.15 times or greater the average Mn content (% by mass) is 1.0% or greater, and the averaged equivalent circle diameter of the high Mn concentration region is 7.0 μm or less, the Charpy absorbed energy vE0 at 0°C being 70 J or greater.
Inventors:
YUGA MASAO (JP)
SATO YUYA (JP)
MURAKAMI SHUNICHI (JP)
MURAKAMI YOSHIAKI (JP)
SUEYOSHI HITOSHI (JP)
HYODO YOSHIHIRO (JP)
SATO YUYA (JP)
MURAKAMI SHUNICHI (JP)
MURAKAMI YOSHIAKI (JP)
SUEYOSHI HITOSHI (JP)
HYODO YOSHIHIRO (JP)
Application Number:
PCT/JP2022/031459
Publication Date:
February 22, 2024
Filing Date:
August 19, 2022
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C21D8/02; C22C38/00; C22C38/14; C22C38/58
Foreign References:
| JP2018090872A | 2018-06-14 | |||
| JP2020117796A | 2020-08-06 | |||
| JP2020204075A | 2020-12-24 | |||
| JP2006291349A | 2006-10-26 | |||
| JP2013129885A | 2013-07-04 | |||
| US20200392608A1 | 2020-12-17 |
Attorney, Agent or Firm:
SUGIMURA Kenji (JP)
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