Abstract: In a steel sheet for plating, according to one aspect of the present invention, the CBS profile of an Mn element, which is observed in the direction of surface to depth, sequentially comprises local maximum points and local minimum points, difference of converted concentration of Mn can be 10% or higher, and difference of converted concentration of Si can be 10% or higher.

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: The present invention is to provide a steel material having low surface hardness and excellent low temperature impact toughness, and a method for manufacturing same.

Abstract: The present invention provides a steel material for a seismic damper, and a manufacturing method for same. The steel material comprises, in wt %, at most 0.006% of C, at most 0.05% of Si, at most 0.3% of Mn, at most 0.02% of P, at most 0.01% of S, 0.005 to 0.05% of Al, at most 0.005% of N, 48/14×[N] to 0.05% of Ti (here, [N] is the nitrogen content in wt %), 0.04 to 0.15% of Nb, and the remainder in Fe and other unavoidable impurities, and has a ferrite single structure, and has a ferrite grain average particle size of 150 to 500 ?m in a region of a surface layer part, corresponding to 30% of the total thickness from the surface thereof.

Abstract: The present invention relates to a battery case that can effectively handle side impacts in, for example, an electric vehicle or the like, and thereby minimize battery deformation. The battery case comprises: a case body for accommodating a battery cell; and a cover coupled to the case body. The case body includes: a bottom plate; a side frame coupled to the bottom plate so as to surround the battery cell and including an inner wall and an outer wall; a mounting frame coupled to the outer wall of the side frame; and at least one reinforcement material which is disposed on the bottom plate and of which both ends in the longitudinal direction are inserted into the side frame. The ends of the reinforcement material can pass through the inner wall and the outer wall of the side frame and come into contact with the mounting frame.

Abstract: The present invention relates to a front side member for a vehicle, which can effectively support a collision load on the front side and can improve the rigidity of a vehicle body, the front side member for a vehicle, comprising: an outer wall; an inner wall positioned to face the outer wall; an outer bead which is formed, along the lengthwise direction of a vehicle body, from the outer wall and has a first groove surface; and an inner bead which is formed, along the lengthwise direction of the vehicle body, from the inner wall and has a second groove surface, wherein the outer bead comprises an area in which a bead depth that is the distance between the outer wall and the first groove surface changes along the lengthwise direction of the vehicle body, and the inner bead comprises an area in which a bead depth that is the distance between the inner wall and the second groove surface changes along the lengthwise direction of the vehicle body.

Abstract: Disclosed is a stainless steel for a fuel cell separator having excellent surface hydrophilicity and electrical conductivity. According to an embodiment of a stainless steel for a fuel cell separator having excellent surface hydrophilicity and electrical conductivity, the surface oxide element ratio (1) value below may be 0.2 or more and the contact angle may be 80° or less as measured for the surface of a stainless steel containing 15 wt % or more of Cr by X-ray angle-resolved photoemission spectroscopy using an Al-K? X-ray source under the condition where a take-off angle of photoelectrons is from 120 to 85°.

Abstract: A hot-rolled steel sheet comprises, by wt %, 0.1-0.25% of carbon (C), 0.2-2.0% of manganese (Mn), 0.3% or less of silicon (Si), 0.05% or less of aluminum (Al), 0.05% or less of phosphorous (P), 0.03% or less of sulfur (S), 0.01% or less of nitrogen (N), 0.005 to 0.05% of titanium (Ti), 0.0005 to 0.005% of boron (B), 0.01% or less of niobium (Nb), 0.1% or less of molybdenum (Mo), 0.1% or less of vanadium (V), and the balance of iron (Fe) and inevitable impurities, comprises, in a microstructure, 55-90% of bainite and 10-45% of ferrite by volume fraction, the number per unit area of carbides having a major axis length of 25-500 nm from among carbides present in the bainite is 3*106/mm2 or more, and the average aspect ratio (major axis/minor axis) of the carbides present in the bainite can be 2.0 or less.

Abstract: Provided are a hot rolled steel having small compressive strength loss after being processed into a steel pipe, and a manufacturing method therefor. The hot rolled steel of the present invention comprises, by wt %, 0.15% or less of carbon (C), 2.5% or less of silicon (Si), 2.0% or less of manganese (Mn), 0.05% or less of aluminum (Al), nitrogen (N) and boron (B) in a sum of 0.002 to 0.008%, and a balance of Fe and inevitable impurities, wherein 250<450C+95Si+70Mn is satisfied, a microstructure is a mixed structure of ferrite and pearlite, the average grain size of the ferrite is 8 to 25 ?m, and a value defined by relation 1 is less than 20%.

Abstract: An aspect of the present invention relates to a cold-rolled steel plate for hot forming, which is excellent in corrosion-resistance and spot-weldability, contains, by weight %, C: 0.1-0.4%, Si: 0.5-2.0%, Mn: 0.01-4.0%, Al: 0.001-0.4%, P: 0.001-0.05%, S: 0.0001-0.02%, Cr: 0.5% to less than 3.0%, N: 0.001-0.02%, and a balance of Fe and inevitable impurities, satisfying formula (1) below, and includes an Si amorphous oxidation layer continuously or discontinuously formed at a thickness of 1 nm-100 nm on the surface thereof. Formula (1): 1.4?0.4*Cr+Si?3.2 (wherein element symbols denote measurements of respective element contents by weight %).

Abstract: Disclosed is an austenitic stainless steel for a fuel cell separator with improved contact resistance. The austenitic stainless steel for a fuel cell separator with improved contact resistance according to an embodiment of the present disclosure includes, in percent by weight (wt %), at most of C (excluding 0), at most 3.0% of Si (excluding 0), at most 3.0% of Mn (excluding 0), 20 to 30% of Cr, 8 to 20% of Ni, at most 0.003% of S, at most 0.03% of P, at most 0.6% of Mo (excluding 0), at most 0.8% of Cu (excluding 0), 0.1 to 0.3% of N, at most 2.0% of W (excluding and the remainder being Fe and other inevitable impurities.

Abstract: Disclosed is a ferritic stainless steel with improved strength, workability, and corrosion resistance, which may be applied to various industrial fields, such as washing machines, refrigerators, and all kinds of electric home appliances. An embodiment of the disclosed ferritic stainless steel comprises, in percent by weight (wt %), 0.0005 to 0.02% of C, 0.005 to 0.02% of N, 0.7 to 1.0% of Si, 16.0 to 17.0% of Cr, 0.05 to 0.3% of Ti, and the balance being Fe and inevitable impurities, wherein the ferritic stainless steel has a value of Formula (1) below satisfying 21 to 25, a tensile strength of 470 MPa or more, and an elongation of 27% or more. 7*Si+Cr??(1) In Formula (1), Si and Cr represent the contents (wt %) of the respective elements.

Abstract: The present invention relates to steel used for a sash component and the like of a vehicle and, more specifically, to a hot-rolled steel sheet for a high-strength electric resistance welded steel pipe having excellent expandability and a method for manufacturing same, the hot-rolled steel sheet having a smaller decrease in the strength of a welding heat-affected zone (HAZ) formed during electric resistance welding, in comparison with a base material.

Abstract: A grain-oriented electrical steel sheet according to an embodiment of the present invention includes: a groove on a line formed on one surface of an electrical steel sheet in a direction crossing a rolling direction; and a thermal shock portion on a line formed on one surface of the electrical steel sheet in the direction crossing the rolling direction, wherein a distance between the groove and the thermal shock portion is 1 mm or less.

Abstract: Disclosed is a high-strength austenitic stainless steel having excellent hot workability. The high-strength austenitic stainless steel having excellent hot workability according to the present disclosure includes, in percent by weight (wt %), 0.01 to 0.035% of C, 0.5% or less of Si, 0.5 to 1.5% of Mn, 17 to 22% of Cr, 6 to 11% of Ni, 1% or less of Mo, 1% or less of Cu, 0.1 to 0.22% of N, and the balance of Fe and inevitable impurities, wherein a value of Formula (1) below 1.9 or more, or a precipitation temperature of chromium nitride satisfies a value represented by Formula (2) below or less.

Abstract: An embodiment of the present invention provides a wire rod and a steel wire which are for springs and have excellent corrosion fatigue resistance properties, and a method for producing same, the wire rod and steel wire containing, in wt %, 0.40-0.70% of C, 1.20-2.30% of Si, 0.20-0.80% of Mn, 0.20-0.80% of Cr, 0.015% or less of P, 0.015% or less of S, and 0.010% or less of N, with the remainder comprising Fe and other unavoidable impurities, along with at least one among 0.01-0.20% of V and 0.01-0.10% of Nb, wherein the V and Nb satisfy relational expression 1 below, the average grain size of prior austenite is no greater than 20 ?m, and the surface decarburization depth is no greater than 0.1 mm. [Relational expression 1] [V]+[Nb]?0.

Abstract: The present invention provides an annealing separator composition, a grain-oriented electrical steel sheet and a method for manufacturing a grain-oriented electrical steel sheet. An annealing separator composition for a grain-oriented electrical steel sheet according to an embodiment of present invention comprising: on the basis of total solid 100 wt %, 5 to 70 wt % of mullite; and the remainder being magnesium oxide or magnesium hydroxide.

Abstract: An embodiment of the present invention provides an electrical steel sheet laminate, including: a plurality of electrical steel sheets; and a fusion layer disposed between the electrical steel sheets, wherein the fusion layer includes an olefin-based semi-crystalline polymer and at least one inorganic metal compound of a metal phosphate and a metal chromate.

Abstract: An insulation film composition for a grain-oriented electrical steel sheet according to an exemplary embodiment of the present invention includes 10-50 parts by weight of metal silicate or organic silicate, 20-70 parts by weight of inorganic nanoparticles and 0.1-20 parts by weight of cobalt hydroxide. The insulation film composition can further include 10-50 parts by weight of metal phosphate, and/or 5-30 parts by weight of inorganic nanoparticles having a particle diameter of 1 nm to less than 10 nm, and/or inorganic nanoparticles having a particle diameter of 10 to 100 nm and/or 0.1-20 parts by weight of chromium oxide.

Abstract: The present invention relates to an apparatus for preventing welding distortion and a method for welding a pipe and a flange using same, the apparatus being capable of effectively reducing welding distortion of a flange, which occurs during welding with a pipe and improving economic efficiency and productivity. The apparatus for preventing the welding distortion comprises: at least one counterweight which is arranged to be in contact with one side of a flange that is to be welded to a pipe, and has a hollow portion therein; and a fastening tool which fixes the counterweight to the flange, wherein the hollow portion of the counterweight may accommodate a refrigerant.