Abstract: A method for producing a molded article includes the steps of: preparing a first steel plate and a second steel plate. The first steel plate and the second steel plate are joined to each other, thereby preparing a joined steel plate. The joined steel plate is heated at a temperature between 910° C. and 950° C. The heated joined steel plate is then subjected to hot-press molding, thereby preparing an intermediate molded article; and cooling the intermediate molded article, wherein the first steel plate has a tensile strength (TS) higher than that of the second steel plate.

Abstract: A collector nozzle for continuous casting may include: a nozzle body extended toward a shroud nozzle, and having an internal movement path through which molten steel is moved; a first case covering a side surface of the nozzle body; and a second case including a second metal component, connected to the first case, and covering an exit surface of the nozzle body facing the shroud nozzle. The first case can include a first metal component, and the first and second cases may be connected through welding or formed as one body.

Abstract: A method for manufacturing a hot-stamped part includes reheating a steel slab at a temperature of 1,200° C. to 1,250° C., the steel slab including, by wt %, 0.20 to 0.50% carbon (C), 0.05 to 1.00% silicon (Si), 0.10 to 2.50% manganese (Mn), more than 0% and not more than 0.015% phosphorus (P), more than 0% and not more than 0.005% sulfur (S), 0.05 to 1.00% chromium (Cr), 0.001 to 0.009% boron (B), 0.01 to 0.09% titanium (Ti), and a balance of iron (Fe) and inevitable impurities; finish-rolling the reheated steel slab at a temperature of 880° C. to 950° C.; cooling the hot-rolled steel plate without using water, and coiling the cooled steel plate at a temperature of 680° C. to 800° C. to form a hot-rolled decarburized layer on a surface of the steel plate; pickling the coiled steel plate, followed by cold rolling; annealing the cold-rolled steel plate in a reducing atmosphere; plating the annealed steel plate; and hot-stamping the plated steel plate.

Abstract: Carbon steel for a rack bar contains 0.50 to 0.55% by weight of carbon (C), 0.15 to 0.35% by weight of silicon (Si), 0.75 to 0.95% by weight of manganese (Mn), 0.025% by weight or less of phosphorus (P), 0.025% by weight or less of sulfur (S), 0.65 to 0.85% by weight of chrome (Cr), 0.20% by weight or less of molybdenum (Mo), 0.001 to 0.02% by weight of aluminum (Al), 5 to 50 ppm of boron (B), and iron (Fe) as a remainder and unavoidable impurities. A method for manufacturing the rack bar includes quenching, tempering, and drawing the carbon steel and warm forging the drawn carbon steel.

Abstract: Provided is a material for hot stamping including: a steel sheet including carbon (C) in an amount of 0.19 wt % to 0.25 wt %, silicon (Si) in an amount of 0.1 wt % to 0.6 wt %, manganese (Mn) in an amount of 0.8 wt % to 1.6 wt %, phosphorus (P) in an amount less than or equal to 0.03 wt %, sulfur (S) in an amount less than or equal to 0.015 wt %, chromium (Cr) in an amount of 0.1 wt % to 0.6 wt %, boron (B) in an amount of 0.001 wt % to 0.005 wt %, balance iron (Fe), and other inevitable impurities; and fine precipitates distributed in the steel sheet, wherein the fine precipitates include nitride or carbide of at least one of titanium (Ti), niobium (Nb), and vanadium (V), and trap hydrogen.

Abstract: Steel for a crankshaft includes 0.37 to 0.42 wt % of carbon (C), 0.55 to 0.70 wt % of silicon (Si), 1.45 to 1.65 wt % of manganese (Mn), 0.025 wt % or less (excluding 0 wt %) of phosphorus (P), 0.020 to 0.035 wt % of sulfur (S), 0.15 to 0.30 wt % of chromium (Cr), 0.035 to 0.055% of vanadium (V), and the remainder of Fe and other inevitable impurities. The steel for a crankshaft has strength that is maintained high even when reducing the amount of vanadium.

Abstract: An impact beam having a bent structure is provided. The impact beam is mounted at a lateral portion of each door in a vertical direction of a vehicle body and supports the door in the vertical direction. An upper end of the impact beam extends to support a roof panel and a lower end of the impact beam extends to a lower roller mounting portion. The impact beam is bent in an L shape and a T shape based on a curvature of the door.

Abstract: Disclosed is a steel sheet for hot press forming, which includes: a base steel sheet; and a plating layer disposed on the base steel sheet and including a diffusion layer and a surface layer that are sequentially laminated, wherein the diffusion layer includes an Fe—Al alloy layer and an Fe—Al intermetallic compound layer that are sequentially disposed on the base steel sheet and each include silicon, and an area fraction of the Fe—Al intermetallic compound layer with respect to the diffusion layer is 84.5% to 98.0%.

Abstract: Disclosed is a method for manufacturing high-carbon bearing steel, which include: heating a billet at a temperature of about 950 to 1,050° C. for about 70 to 120 minutes, rolling the billet to manufacture a wire rod, winding the wire rod to manufacture a wire rod coil, cooling the wire rod coil, and subsequently heat treating the wire rod coil for spheroidizing and carbonitriding, respectively. The bearing steel may include an amount of about 0.9 to 1.3 wt % of carbon (C), an amount of about 1.1 to 1.6 wt % of silicon (Si), an amount of about 1.0 to 1.5 wt % of manganese (Mn), an amount of about 1.5 to 1.9 wt % of chromium (Cr), an amount of about 0.2 to 0.6 wt % of nickel (Ni), an amount of about 0.1 to 0.3 wt % of molybdenum (Mo), and the balance iron (Fe) based on the total weight thereof.

Abstract: A method for manufacturing a high-strength steel bar can include the steps of: reheating a steel slab at a temperature ranging from 1000° C. to 1100° C., the steel slab including a certain amount of carbon (C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S), chromium (Cr), copper (Cu), nickel (Ni), molybdenum (Mo), aluminum (Al), vanadium (V), nitrogen (N), antimony (Sb), tin (Sn), and iron (Fe) and other inevitable impurities, The method can further include finish hot-rolling the reheated steel slab at a temperature of 850° C. to 1000° C., and cooling the hot-rolled steel to a martensite transformation start temperature (Ms (° C.)) through a tempcore process.

Abstract: A forming method for a vehicle body member may include a tube making process of forming a steel pipe by welding a steel plate coil; a non-circular tube making process of primary preforming the steel pipe formed in the tube making process so as to have a cross section of a predetermined shape; a bending process of bending and secondarily preforming the steel pipe preformed firstly in the non-circular tube making process; and a hot stamping process of heating the secondarily preformed steel pipe, inserting the heated steel pipe into a mold to form a desired shape, and then, quenching the heated steel pipe to form a vehicle body member, thereby easily forming a vehicle body member having high rigidity.

Abstract: A method for manufacturing a high-strength cold-rolled steel sheet according to an embodiment includes the steps of: reheating a steel slab, which includes 0.10 wt % to 0.13 wt % carbon (C), 0.9 wt % to 1.1 wt % silicon (Si), 2.2 wt % to 2.3 wt % manganese (Mn), 0.35 wt % to 0.45 wt % chromium (Cr), 0.04 wt % to 0.07 wt % molybdenum (Mo), 0.02 wt % to 0.05 wt % antimony (Sb), and the remainder being iron (Fe) and inevitable impurities, at a temperature of 1150° C. to 1250° C.; hot-rolling the reheated slab in such a manner as to reach a finishing mill delivery temperature of 800° C. to 900° C.; cooling the hot-rolled slab to a temperature of 600° C. to 700° C. and coiling the cooled slab, thereby obtaining a hot-rolled steel sheet; pickling the hot-rolled steel sheet, followed by cold rolling; annealing the cold-rolled steel sheet in a two-phase region of ? and ? phases; and cooling the annealed steel sheet to the martensite temperature range, followed by overaging.

Abstract: A method for producing a coated steel sheet by reheating a steel slab containing 0.15-0.25 wt % of carbon (C), more than 0 wt % but not more than 1.5 wt % of silicon (Si), 1.5-2.5 wt % of manganese (Mn), more than 0 wt % but not more than 1.8 wt % of aluminum (Al), 0.3-1.0 wt % of chromium (Cr), more than 0 wt % but not more than 0.03 wt % of titanium (Ti), more than 0 wt % but not more than 0.03 wt % of niobium (Nb), and the balance of iron (Fe) and unavoidable impurities. Hot-rolling, cooling and coiling the steel slab, thereby producing a hot-rolled steel sheet. Pickling the hot-rolled steel sheet, then cold rolling. Annealing the cold-rolled steel sheet at a temperature between 820° C. and 870° C., followed by cooling at a finish-cooling temperature between 350° C. and 450° C.; tempering the cooled steel sheet at a temperature between 450° C. and 550° C.; and hot-dip galvanizing the tempered steel sheet.

Abstract: Disclosed is a coil width control method including: a step in which a control unit generates a prediction model for predicting the width shrinkage of a coil, which occurs in the heat-treatment process and post-treatment process of a cold-rolled steel sheet production process, on the basis of historical operating results; a step in which the control unit receives the input width of the coil entering the heat-treatment process; and a step in which the control unit predicts the output width of the coil after the post-treatment process on the basis of the received input width and the conditions of the cold-rolled steel sheet production process, and controls in-furnace temperature and in-furnace tension of the heat-treatment process and elongation of the post-treatment process.

Abstract: An ultra-high-strength spring steel for an engine valve spring steel comprises, by weight: 0.5-0.7% of carbon (C), 1.3-2.3% of silicon (Si), 0.6-1.2% of manganese (Mn), 0.6-1.2% of chrome (Cr), 0.1-0.5% of molybdenum (Mo), 0.05-0.8% of nickel (Ni), 0.05-0.5% of vanadium (V), 0.05-0.5% of niobium (Nb), 0.05-0.3% of titanium (Ti), 0.001-0.01% of boron (B), 0.01-0.52% of tungsten (W), 0.3% or less (0% exclusive) of copper (Cu), 0.3% or less (0% exclusive) of aluminum (Al), 0.03% or less (0% exclusive) of nitrogen (N), 0.003% or less (0% exclusive) of oxygen (O), and a remainder of Fe and other inevitable impurities, based on 100% by weight of the ultra-high-strength spring steel.

Abstract: A low-alloy and corrosion-resistant steel for a vehicle, may include about 0.001 wt % to about 0.1 wt % of C, about 0.01 wt % to about 0.5 wt % of Si, about 0.1 wt % to about 0.6 wt % of Mn, more than 0 wt % and about 0.18 wt % or less of P, more than 0 wt % and less than about 0.02 wt % of S, about 0.001 wt % to about 0.03 wt % of Nb, more than 0 wt % and about 0.03 wt % or less of Cr, about 0.05 wt % to about 0.3 wt % of Cu, about 0.05 wt % to about 0.2 wt % of Ni, and more than 0 wt % and about 0.2 wt % or less of a combined weight of Sn and Sb, and the balance iron and inevitable impurities.

Abstract: Disclosed herein are a steel sheet having excellent aging resistance and low yield ratio properties, and a method for producing the same. The disclosed sheet comprises, by weight, 0.005-0.06% carbon (C), 0.2% or less silicon (Si), 1.0-2.0% manganese (Mn), 0.08% or less phosphorus (P), 0.01% or less sulfur (S), 0.2-2.0% aluminum (Al), one or more of chromium (Cr) and molybdenum (Mo) in an amount satisfying 0.3?[Cr wt %]+0.3[Mo wt %]?2.0, and 0.008% or less nitrogen (N), with the remainder being iron (Fe) and inevitable impurities, and has a single-phase structure of ferrite in a hot-rolled state, and a two-phase structure of ferrite and martensite in a cold-rolled state.

Abstract: Disclosed is a hot stamping device and method for preventing plating from sticking to a die. The hot stamping device may include a die that receives a heated plating material, presses the received plating material, and rapidly cools the pressed plating material in a constrained state. Before the plating material is pressed, an anti-sticking layer may be formed on the surface of the die disposed in contact with the plating material.

Abstract: A steel composition is provided and includes carbon of about 0.5 to 0.7 wt %; silicon of about 1.3 to 2.3 wt %; manganese of about 0.6 to 1.2%; chromium of about 0.6 to 1.2 wt %; molybdenum of about 0.1 to 0.5 wt %; nickel of about 0.05 to 0.8 wt %; vanadium of about 0.05 to 0.5 wt %; niobium of about 0.05 to 0.5 wt %; titanium of about 0.05 to 0.3 wt %; cobalt of about 0.01 to 3 wt %; zirconium of about 0.001 to 0.2 wt %; yttrium of about 0.01 to 1.5 wt %; copper of about 0.3% or less but greater than 0 wt %; aluminum of about 0.3% or less but greater than 0 wt %; nitrogen of about 0.03% or less but greater than 0 wt %; oxygen of about 0.003% or less but greater than 0 wt %. Additionally, a balance iron, based on the total weight is included.

Abstract: A door impact beam that is disposed across a door frame of a vehicle and a method of manufacturing the door impact beam may include a body formed in a pipe shape and concaved on a side facing an external side of the vehicle; and coupling portions integrally extending from first and second end portions of the body to be coupled to the door frame through spot welding.