Abstract: The purpose of the present invention is to provide a steel plate for a pressure vessel having excellent resistance to high-temperature post-welding heat treatment, in which deterioration of strength and toughness is minimized even when a long-term post welding heat treatment (PWHT) is applied at high temperature, and a method for manufacturing same.

Abstract: The present invention relates to a pressure vessel steel plate having excellent high temperature PWHT resistance, comprising: 0.10-0.16 weight % C; 0.20-0.35 weight % Si; 0.4-0.6 weight % Mn; 7.5-8.5 weight % Cr; 0.7-1.0 weight % Mo; 0.005-0.05 weight % Al; 0.015 weight % or less P, 0.002 weight % or less S; 0.001-0.025 weight % Nb; and 0.25-0.35 weight % V, with the remainder being Fe and unavoidable impurities.

Abstract: The present invention relates to a method of manufacturing a cryogenic steel plate for a pressure vessel and a cryogenic steel plate for a pressure vessel manufactured thereby, the method comprising the steps of: reheating a slab containing, in weight %, C: 0.05-0.15%, Si: 0.20-0.35%, Mn: 0.5-1.5%, P: 0.012% or less, S: 0.015% or less, Al: 0.02-0.10%, Ni: 6.01-6.49%, Mo: 0.2-0.4%, Cr: and the balance being Fe and inevitable impurities; hot-rolling the reheated steel plate, followed by air cooling; subjecting the air-cooled steel plate to primary heat treatment at 800-880° C. for (2.4×t+(10?40)) minutes (t: slab thickness (mm)), followed by primary water cooling: subjecting the primarily water-cooled steel plate to secondary heat treatment at 700-780° C. for (2.4×t+(10?40)) minutes (t: slab thickness (mm)), followed by secondary water cooling: and tempering the secondarily water-cooled steel plate.

Abstract: Disclosed are a pressure vessel steel sheet and a method for manufacturing the same, the steel sheet comprising: by wt %, 0.10-0.20% of C, 0.15-0.40% of Si, 1.15-1.50% of Mn, 0.45-0.60% of Mo, 0.03-0.30% of Cu, 0.025% or less of P, 0.025% or less of S and 0.005-0.06% of sol. Al; two or more selected from the group consisting of 0.03-0.30% of Cr, 0.002-0.025% of Nb and 0.002-0.025% of Zr, and the balance of Fe and inevitable impurities, wherein the structure comprises a mixture structure of ferrite, perlite and tempered bainite after post weld heat treatment (PWHT) for 60 hours at 600-660° C., and the area fraction of the tempered bainite is at least 10% (excluding 100%).

Abstract: Provided is a steel plate for a pressure vessel with excellent cryogenic lateral expansion and a manufacturing method therefor. The steel plate for a pressure vessel according to the present invention comprises, 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, 4.5 to 5.5% of Ni, 0.2 to 0.4% of Mo, 0.001 to 0.15% of Pd, with a remainder of Fe and inevitable impurities, and the steel plate has a steel microstructure comprising, by area fraction, 0.5 to 5.0% of retained austenite, 25 to 85% of tempered bainite, and a remainder of tempered martensite.

Abstract: Provided are a steel plate for high temperature applications having excellent strength at a high temperature and a method for manufacturing same. The steel plate for high temperature applications having excellent post-weld heat treatment resistance, according to the present invention, comprises by weight percent: C:0.05-0.25%; Mn:0.1-1.0%; Si:0.1-0.8%; Cr:1-3%; Cu:0.05-0.3%; Mo:0.5-1.5%; Ni:0.05-0.5%; Al:0.005-0.1%; and at least one of Ir:0.005-0.10% and Rh:0.005-0.10%, the balance being Fe and inevitable impurities.

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.

Abstract: The present disclosure relates to a middle high temperature pressure vessel steel plate having excellent resistance against a post weld heat treatment (PWHT) and a manufacturing method therefor. The pressure vessel steel plate includes 0.05 to 0.17 wt % of C, 0.50 to 1.00 wt % of Si, 0.3 to 0.8 wt % of Mn, 1.0 to 1.5 wt % of Cr, 0.3 to 1.0 wt % of Mo, 0.003 to 0.30 wt % of Ni, 0.003 to 0.30 wt % of Cu, 0.005 to 0.06 wt % of Sol.Al, 0.015 wt % or less of P, and 0.020 wt % or less of S; additionally two or more elements selected from 0.002 to 0.025 wt % of Nb, 0.002 to 0.03 wt % of V, and 0.002 to 0.15 wt % of Co; and Fe and unavoidable impurities as the reminder, wherein a microstructure of a central portion of the steel plate is formed in a mixed structure of 20 area % or more of tempered martensite and the residue bainite.

Abstract: A high strength steel plate according to an aspect of the present disclosure includes, by weight: 0.05 to 0.20% of C, 0.15 to 0.55% of Si, 0.9 to 1.75% of Mn, 0.001 to 0.05% of Al, 0.03% or less of P, 0.03% or less of S, 0.05 to 0.3% of Cr, 0.05 to 0.6% of Ni, 0.005 to 0.35% of Cu, 0.05 to 0.2% of Mo, 0.005 to 0.07% of V, 0.005 to 0.04% of Nb, 0.0005 to 0.005% of Ca, 0.005 to 0.025% of Ti, 0.002 to 0.006% of N, less than 0.0005% of B, and a balance of Fe, with inevitable impurities, satisfies relationships of Cu+Ni+Cr+Mo: 1.5% or less, Cr+Mo: 0.4% or less, V+Nb: 0.1% or less, and Ca/S: 1.0 or higher, and includes a combined structure of tempered martensite and tempered bainite as a microstructure.

Abstract: The present invention relates to steel for pressure vessels used in a boiler, a pressure vessel fittings, etc. of a power station and, more particularly, to steel for pressure vessels with excellent resistance to high-temperature tempering heat treatment and post-weld heat treatment; and a manufacturing method therefor.

Abstract: Disclosed are a pressure vessel steel sheet and a method for manufacturing the same, the steel sheet comprising: by wt %, 0.10-0.20% of C, 0.15-0.40% of Si, 1.15-1.50% of Mn, 0.45-0.60% of Mo, 0.03-0.30% of Cu, 0.025% or less of P, 0.025% or less of S and 0.005-0.06% of sol. Al; two or more selected from the group consisting of 0.03-0.30% of Cr, 0.002-0.025% of Nb and 0.002-0.025% of Zr, and the balance of Fe and inevitable impurities, wherein the structure comprises a mixture structure of ferrite, perlite and tempered bainite after post weld heat treatment (PWHT) for 60 hours at 600-660° C., and the area fraction of the tempered bainite is at least 10% (excluding 100%).

Abstract: The present disclosure relates to a middle high temperature pressure vessel steel plate having excellent resistance against a post weld heat treatment (PWHT) and a manufacturing method therefor. The pressure vessel steel plate includes 0.05 to 0.17 wt % of C, 0.50 to 1.00 wt % of Si, 0.3 to 0.8 wt % of Mn, 1.0 to 1.5 wt % of Cr, 0.3 to 1.0 wt % of Mo, 0.003 to 0.30 wt % of Ni, 0.003 to 0.30 wt % of Cu, 0.005 to 0.06 wt % of Sol.Al, 0.015 wt % or less of P, and 0.020 wt % or less of S; additionally two or more elements selected from 0.002 to 0.025 wt % of Nb, 0.002 to 0.03 wt % of V, and 0.002 to 0.15 wt % of Co; and Fe and unavoidable impurities as the reminder, wherein a microstructure of a central portion of the steel plate is formed in a mixed structure of 20 area % or more of tempered martensite and the residue bainite.

Abstract: The present disclosure relates to a steel plate having excellent PWHT resistance and low-temperature toughness for a low-temperature pressure vessel and a method for manufacturing the same, wherein the steel plate comprises, in terms of wt %, 0.07-0.17% of C, 0.15-0.40% of Si, 0.3-0.7% of Mn, 0.012% or less of P, 0.015% or less of S, 3.0-4.0% of Ni, 0.03-0.25% of W, and a balance of Fe and inevitable impurities, has a micro-structure comprising 25-80 area % of tempered bainite and the balance of tempered martensite, and has a tensile strength of 600 MPa or more.

Abstract: There are provided a steel for deep drawing, and a method for manufacturing the steel and a high pressure container. The steel for deep drawing includes, by weight: C: 0.25 to 0.40%, Si: 0.15 to 0.40%, Mn: 0.4 to 1.0%, Al: 0.001 to 0.05%, Cr: 0.8 to 1.2%, Mo: 0.15 to 0.8%, Ni: 1.0% or less, P: 0.015% or less, S: 0.015% or less, Ca: 0.0005 to 0.002%, Ti: 0.005 to 0.025%, B: 0.0005 to 0.0020% and the balance of Fe and inevitable impurities, wherein a microstructure of the steel has a triphase structure of ferrite, bainite and martensite. The steel for deep drawing may be useful to further improve the strength without the deterioration of the toughness by adding a trace of Ti and B, compared to the conventional steels having a strength of approximately 1100 MPa.

Abstract: There is provided a high strength steel plate including, by weight: 0.03% to 0.20% C, 0.15% to 0.55% Si, 0.9% to 1.5% Mn, 0.001% to 0.05% Al, 0.030% or less P, 0.030% or less S, 0.30% or less Cr, 0.2% or less Mo, 0.6% or less Ni, 0.07% or less V, 0.04% or less Nb, 5 ppm to 50 ppm Ca, 0.005% to 0.025% Ti, 0.0020% to 0.0060% N, 0.0005% to 0.0020% B, the balance of F and unavoidable impurities. The steel plate may be formed of tempered martensite, and conditions for cooling and recrystallization controlled rolling are optimized so as to control an average grain size of a microstructure and an aspect ratio of structure grains. Accordingly, a superior high-strength steel plate that can be used for an atomic plant, for example, an atomic plant rated at IOOOMW or more by having a tensile strength of at least 650 MPa and an impact toughness of at least 200 J at ?5O ° C., and a method of manufacturing the same can be provided.

Abstract: There are provided a steel for deep drawing, and a method for manufacturing the steel and a high pressure container. The steel for deep drawing includes, by weight: C: 0.25 to 0.40%, Si: 0.15 to 0.40%, Mn: 0.4 to 1.0%, Al: 0.001 to 0.05%, Cr: 0.8 to 1.2%, Mo: 0.15 to 0.8%, Ni: 1.0% or less, P: 0.015% or less, S: 0.015% or less, Ca: 0.0005 to 0.002%, Ti: 0.005 to 0.025%, B: 0.0005 to 0.0020% and the balance of Fe and inevitable impurities, wherein a microstructure of the steel has a triphase structure of ferrite, bainite and martensite. The steel for deep drawing may be useful to further improve the strength without the deterioration of the toughness by adding a trace of Ti and B, compared to the conventional steels having a strength of approximately 1100 MPa.