Title:
HOT-ROLLED STEEL SHEET
Document Type and Number:
WIPO Patent Application WO/2023/038084
Kind Code:
A1
Abstract:
This hot rolled steel sheet has a prescribed chemical composition. If a region corresponding to 1/8 to 3/8 of the sheet thickness in the sheet thickness direction from the surface is defined as the 1/4 depth position, the metal structure at the 1/4 depth position contains less than 3.0% of retained austenite, less than 30.0% of ferrite and less than 5.0% of pearlite in terms of areal ratio. At the 1/4 depth position, the average density by number of Ti-based carbides having lengths of 15 nm or more is 1.0×104 carbides/mm2 or more. The average crystal grain diameter dq is 15.0 μm or less, and a tensile strength is 980 MPa or more.
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Inventors:
YOSHIDA MITSURU (JP)
HIKIDA KAZUO (JP)
HIKIDA KAZUO (JP)
Application Number:
PCT/JP2022/033730
Publication Date:
March 16, 2023
Filing Date:
September 08, 2022
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
C22C38/00; C21D9/46; C22C38/58
Domestic Patent References:
| WO2019009410A1 | 2019-01-10 | |||
| WO2021124864A1 | 2021-06-24 |
Foreign References:
| JP2021146231A | 2021-09-27 | |||
| JPH10168544A | 1998-06-23 | |||
| JP2005298924A | 2005-10-27 |
Attorney, Agent or Firm:
MATSUNUMA Yasushi et al. (JP)
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