	US 12,234,526 B2
	Steel plate for pressure vessel with excellent cryogenic toughness and excellent ductility and manufacturing method thereof
Soon-Taik Hong, Pohang-si (KR)
Assigned to POSCO HOLDINGS INC., Seoul (KR)
Appl. No. 17/286,409
Filed by POSCO, Pohang-si (KR)
PCT Filed Oct. 8, 2019, PCT No. PCT/KR2019/013214 § 371(c)(1), (2) Date Apr. 16, 2021, PCT Pub. No. WO2020/085684, PCT Pub. Date Apr. 30, 2020.
Claims priority of application No. 10-2018-0128760 (KR), filed on Oct. 26, 2018.
Prior Publication US 2021/0388457 A1, Dec. 16, 2021
Int. Cl. C21D 9/46 (2006.01); C21D 1/18 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/08 (2006.01); F17C 1/00 (2006.01)

CPC C21D 9/46 (2013.01) [C21D 1/18 (2013.01); C21D 6/001 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0263 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C21D 2211/002 (2013.01); C21D 2211/008 (2013.01); F17C 2203/0639 (2013.01); F17C 2209/2181 (2013.01)]

2 Claims

1. A steel plate for a pressure vessel, consisting of:

in weight %, 0.05 to 0.15% of C, 0.20 to 0.40% of Si, 0.3 to 0.6% of Mn, 0.001 to 0.05% of Al, 0.012% or less of P, 0.015% or less of S, 4.0 to 5.0% of Ni, 0.05 to 0.08% of In, a balance of Fe, and unavoidable impurities,

wherein a steel microstructure is comprised of 15 to 80 area % of tempered bainite and a balance tempered martensite.