Title:
HIGH-STRENGTH HOT-ROLLED STEEL SHEET, HOT-ROLLED PLATED STEEL SHEET, AND MANUFACTURING METHODS THEREFOR
Document Type and Number:
WIPO Patent Application WO/2022/108220
Kind Code:
A1
Abstract:
A hot-rolled steel sheet according to one aspect of the present invention comprises, by wt%, 0.1-0.25% of carbon (C), 0.2-2.0% of manganese (Mn), 0.3% or less of silicon (Si), 0.05% or less of aluminum (Al), 0.05% or less of phosphorus (P), 0.03% or less of sulfur (S), 0.01% or less of nitrogen (N), 0.005-0.05% of titanium (Ti), 0.0005-0.005% of boron (B), 0.01% or less of niobium (Nb), 0.1% or less of molybdenum (Mo), 0.1% or less of vanadium (V), and the balance of iron (Fe) and inevitable impurities, comprises, in a microstructure, 55-90% of bainite and 10-45% of ferrite by volume fraction, the number per unit area of carbides having a major axis length of 25-500 nm from among carbides present in the bainite is 3*106/mm2 or more, and the average aspect ratio (major axis/minor axis) of the carbides present in the bainite can be 2.0 or less.
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Inventors:
PARK KYONG-SU (KR)
SON CHANG-YOUNG (KR)
SON CHANG-YOUNG (KR)
Application Number:
PCT/KR2021/016320
Publication Date:
May 27, 2022
Filing Date:
November 10, 2021
Export Citation:
Assignee:
POSCO (KR)
International Classes:
C22C38/00; C21D8/02; C21D9/46; C22C38/02; C22C38/04; C22C38/06; C22C38/12; C22C38/14; C23C2/06
Foreign References:
| KR20180088707A | 2018-08-06 | |||
| KR20150000897A | 2015-01-05 | |||
| KR20180068099A | 2018-06-21 | |||
| KR20160041850A | 2016-04-18 | |||
| JP2005307339A | 2005-11-04 | |||
| KR20050113247A | 2005-12-01 | |||
| JP2002322542A | 2002-11-08 | |||
| JP2006161112A | 2006-06-22 | |||
| KR20060033489A | 2006-04-19 | |||
| JP2005298967A | 2005-10-27 | |||
| US20050155673A1 | 2005-07-21 | |||
| EP1396549A1 | 2004-03-10 |
Attorney, Agent or Firm:
C&S PATENT AND LAW OFFICE (KR)
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