Title:
HIGH-STRENGTH HOT-ROLLED STEEL PLATE AND METHOD FOR MANUFACTURING HIGH-STRENGTH HOT-ROLLED STEEL PLATE
Document Type and Number:
WIPO Patent Application WO/2022/244707
Kind Code:
A1
Abstract:
This high-strength hot-rolled steel plate has a specific component composition. The steel structure has, as main phases, martensite and bainite having a total area ratio of 80-100%. The total area ratio of martensite in the bainite is 2-20%. From among the martensite in the bainite, the area ratio of martensite in which the orientation difference between the crystal orientation of the martensite and the crystal orientation in at least one bainite from among the bainite adjacent to the martensite is at least 15° exceeds 50% of the entire amount of martensite. When a region surrounded by a boundary at which the orientation difference between adjacent crystals is at least 15° is deemed to be a crystal grain, the average aspect ratio of crystal grains present in a region up to a depth of 5 μm from the surface of the steel plate is 2 or below.
Inventors:
HASEGAWA HIROSHI (JP)
KIMURA HIDEYUKI (JP)
KIMURA HIDEYUKI (JP)
Application Number:
PCT/JP2022/020292
Publication Date:
November 24, 2022
Filing Date:
May 13, 2022
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C22C38/00; C21D8/02; C21D9/46; C22C38/38; C22C38/60
Domestic Patent References:
| WO2017017933A1 | 2017-02-02 | |||
| WO2020080553A1 | 2020-04-23 | |||
| WO2021090642A1 | 2021-05-14 | |||
| WO2018150955A1 | 2018-08-23 |
Foreign References:
| JP2008156729A | 2008-07-10 | |||
| JP2001032041A | 2001-02-06 | |||
| JP2016204690A | 2016-12-08 |
Attorney, Agent or Firm:
KUMASAKA Akira et al. (JP)
Download PDF: