Title:
HIGH TOUGHNESS HIGH CARBON COLD ROLLED STEEL SHEET HAVING EXCELLENT FORMABILITY, AND METHOD FOR MANUFACTURING SAME
Document Type and Number:
WIPO Patent Application WO/2022/139282
Kind Code:
A1
Abstract:
One embodiment of the present invention provides: a high toughness high carbon cold rolled steel sheet having excellent formability comprising, by weight%, C: 0.80% to 1.25%, Mn: 0.2% to 0.6%, Si: 0.01% to 0.4%, P: 0.005% to 0.02%, S: 0.01% or less, Al: 0.01% to 0.1 %, Cr: 0.01% to 1.0%, Sn: 0.05% to 0.5%, the remainder being Fe and other unavoidable impurities, in which a microstructure includes, by area%, retained austenite: 1% to 10%, martensite: 1% to 10%, ferrite: 5% or less (including 0%), the remainder being bainite, and has an average grain size of 3 μm to 20 μm, and an internal oxide layer formed directly under the surface has a thickness of 10 μm or less; and a method for manufacturing same.
Inventors:
JANG JE-WOOK (KR)
KIM HAK-JUN (KR)
KIM SUN-MI (KR)
KIM HAK-JUN (KR)
KIM SUN-MI (KR)
Application Number:
PCT/KR2021/018742
Publication Date:
June 30, 2022
Filing Date:
December 10, 2021
Export Citation:
Assignee:
POSCO (KR)
International Classes:
C22C38/18; C21D8/02
Foreign References:
| JP2018048374A | 2018-03-29 | |||
| KR100847045B1 | 2008-07-17 | |||
| KR20140044925A | 2014-04-15 | |||
| KR20160071462A | 2016-06-21 | |||
| JPH07179936A | 1995-07-18 |
Other References:
See also references of EP 4265775A4
Attorney, Agent or Firm:
C&S PATENT AND LAW OFFICE (KR)
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