Title:
HIGH-STRENGTH HOT-ROLLED STEEL SHEET AND MANUFACTURING METHOD THEREFOR, AND HIGH-STRENGTH ELECTRIC RESISTANCE WELDED STEEL PIPE AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2022/239591
Kind Code:
A1
Abstract:
Provided are a high-strength hot-rolled steel sheet and manufacturing method therefor, and a high-strength electric resistance welded steel pipe and manufacturing method therefor. In the high-strength hot-rolled steel sheet according to the present invention, the steel structure at the thickness center contains bainite and ferrite at specific volume ratios, the average crystal grain size is 9.0 μm or less, the dislocation density is 1.0 x 1014m-2 to 1.0 x 1015m-2, inclusive, the steel structure at a depth of 0.1 mm from the plate surface contains bainite and ferrite in specific volume ratios, the average crystal grain size is 9.0 μm or less, the dislocation density is 5.0 x 1014m-2 to 1.0 x 1015m-2, inclusive, the maximum low-angle grain boundary density is 1.4 x 106m-1 or less, and the thickness is 15 mm or more.
Inventors:
MATSUMOTO AKIHIDE (JP)
IDE SHINSUKE (JP)
IDE SHINSUKE (JP)
Application Number:
PCT/JP2022/017541
Publication Date:
November 17, 2022
Filing Date:
April 11, 2022
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C21D8/02; C21D8/10; C22C38/00; C22C38/58
Domestic Patent References:
| WO2020067210A1 | 2020-04-02 | |||
| WO2020178943A1 | 2020-09-10 | |||
| WO2015030210A1 | 2015-03-05 | |||
| WO2020085888A1 | 2020-04-30 |
Foreign References:
| JP2018168441A | 2018-11-01 | |||
| JP2010196160A | 2010-09-09 | |||
| JP2020063500A | 2020-04-23 | |||
| JP2020012168A | 2020-01-23 | |||
| JP2017179482A | 2017-10-05 |
Other References:
T. UNGARA. BORBELY, APPL. PHYS. LETT., vol. 69, 1996, pages 3173
M. KUMAGAIM. IMAFUKUS. OHYA, ISIJ INTERNATIONAL, vol. 54, 2014, pages 206
M. KUMAGAIM. IMAFUKUS. OHYA, ISIJ INTERNATIONAL, vol. 54, 2014, pages 206
Attorney, Agent or Firm:
KUMASAKA Akira et al. (JP)
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