US 12,305,250 B2
Steel plate for pressure vessel with excellent cryogenic lateral expansion and manufacturing method therefor
Soon-Taik Hong, Pohang-si (KR)
Assigned to POSCO, Pohang-si (KR)
Appl. No. 17/639,705
Filed by POSCO, Pohang-si (KR)
PCT Filed Aug. 25, 2020, PCT No. PCT/KR2020/011278
§ 371(c)(1), (2) Date Mar. 2, 2022,
PCT Pub. No. WO2021/045425, PCT Pub. Date Mar. 11, 2021.
Claims priority of application No. 10-2019-0109135 (KR), filed on Sep. 3, 2019.
Prior Publication US 2022/0290266 A1, Sep. 15, 2022
Int. Cl. C21D 8/02 (2006.01); C21D 6/00 (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); C22C 38/12 (2006.01)
CPC C21D 8/0263 (2013.01) [C21D 6/001 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (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); C22C 38/12 (2013.01); C21D 2211/001 (2013.01); C21D 2211/002 (2013.01); C21D 2211/008 (2013.01)] 4 Claims
 
1. A steel plate for a low-temperature pressure vessel, the steel plate comprising:
by wt %,
0.05 to 0.15% of C,
0.20 to 0.40% of Si,
0.3 to 0.6% of Mn,
0.015% or less of P,
0.015% or less of S,
0.02 to 0.10% of Al,
2.5 to 5.5% of Ni,
0.2 to 0.4% of Mo,
0.05 to 0.15% of Pd,
with a remainder of Fe and inevitable impurities,
wherein a steel microstructure comprises, by area fraction, 0.5 to 5.0% of retained austenite, 25 to 85% of tempered bainite, and a remainder of tempered martensite.