POSCO Holdings Inc.
STEEL PLATE FOR PRESSURE VESSEL WITH EXCELLENT CRYOGENIC TOUGHNESS AND EXCELLENT DUCTILITY AND MANUFACTURING METHOD THEREOF

Abstract:

Provided are a steel plate for a pressure vessel with excellent cryogenic toughness and excellent ductility, and a manufacturing method thereof. The steel plate for a pressure vessel of the present invention comprises, 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; 0.001 to 0.10% of In; and the balance being Fe and unavoidable impurities, wherein a steel microstructure consists of 15 to 80 area % of tempered bainite and the balance being tempered martensite.