Abstract: A method for removing ferric ions contained in a sulfate-based iron electroplating solution comprises a step of regeneration for reduction of the ferric ions by circulating a ferric ion-containing sulfate-based iron electroplating solution in a solution bath containing ferrous metal charged therein, wherein the ferrous metal is charged in an amount that satisfies the following formula (1): S?0.01 Iconv/Cmax (1). In formula (1), S indicates a total surface (m2) of ferrous metal, Cmax indicates a maximum permissible ion concentration level (g/L) of the ferric ions in the solution, and Iconv indicates, as represented by the following formula (2), converted current (A) obtained by dividing the sum of current (I) applied to an electroplated cell during the plating time (tp, sec) by the regeneration time (tr, sec) for reduction of the ferric ions in an electrolyte.

Abstract: According to one aspect of the present invention, it is possible to provide a tailor welded blank, a hot press formed part, and a method for manufacturing same, the tailor welded blank having a weld part that can effectively prevent deterioration of properties after hot press forming.

Abstract: A method for preparing hydrogen from ammonia by using pressure swing adsorption (PSA) is provided. The method for preparing hydrogen from ammonia, of the present invention, comprises the steps of: generating hydrogen and nitrogen from ammonia gas through a high-temperature reaction by using a catalyst; performing purification by selectively adsorbing unreacted ammonia gas from a gas containing unreacted ammonia and low-purity hydrogen and nitrogen, which are supplied through the high-temperature reaction and cooled; and performing purification by separating high-purity hydrogen from the gas consisting of low-purity hydrogen and nitrogen, wherein purification is carried out by using a carbon molecular sieve (CMS) adsorbent so as to desorb the unreacted ammonia gas through PSA.

Abstract: It is related to a positive active material for lithium secondary battery, a manufacturing method thereof, and a lithium secondary battery containing the same, provides that a positive active material for lithium secondary battery, wherein, it is a layered lithium metal compound comprises nickel, cobalt, and manganese, and aluminum, zirconium, and boron are doped.

Abstract: Provided is a method of manufacturing a hot rolled steel sheet having excellent formability and fatigue properties, including: preparing a slab including, by weight %, 0.3 to 0.8% of carbon C, 13 to 25% of manganese (Mn), 0.1 to 1.0% of vanadium (V), 0.005 to 2.0% of silicon (Si), 0.01 to 2.5% of aluminum (Al), 0.03% or less of phosphorus (P), 0.03% or less of sulfur (S), 0.04% or less (excluding 0%) of nitrogen (N), and a remainder of iron (Fe) and inevitable impurities; heating the slab to 1050 to 1250° C.; finish rolling, the slab heated in the heating, at a temperature of not lower than a recrystallization temperature of a region having an average V concentration and not higher than a recrystallization temperature of a region having twice the average V concentration, to obtain a hot rolled steel sheet; and coiling the hot-rolled steel sheet at 50 to 700° C.

Abstract: A positive electrode active material for a lithium secondary battery, a manufacturing method thereof, and it is provided a positive electrode active material for a lithium secondary battery, comprising: a core containing a lithium nickel-based compound having a Ni content of 80 mol % or more; and a coating material positioned on at least a portion of the core surface; wherein, the coating material includes a first coating material containing at least one of group 5 elements and group 6 elements; and S; and a second coating material including B, LiOH, Li2CO3 and Li2SO4.

Abstract: A positive electrode active material for a lithium secondary battery, a manufacturing method thereof, and a lithium secondary battery including the same, wherein the positive electrode active material is a lithium nickel-based compound particle having a Ni content of 75 mol % or more, and a difference in concentration of Al between the center and the surface in the lithium nickel-based compound particle is less than 1 mol %.

Abstract: The austenitic stainless steel that does not cause defects such as aging crack or delayed fracture even after the expansion and curling process of 5 steps or more is disclosed. In accordance with an aspect of the present disclosure, an austenitic stainless steel with excellent pipe expanding workability and aging crack resistance includes, in percent (%) by weight of the entire composition, C: 0.01 to 0.04%, Si: 0.1 to 1.0%, Mn: 0.1 to 2.0%, Cr: 16 to 20%, Ni: 6 to 10%, Cu: 0.1 to 2.0%, Mo: 0.2% or less, N: 0.035 to 0.07%, the remainder of iron (Fe) and other inevitable impurities, and the C+N satisfies 0.1% or less, the product of the Md30 (° C.) value and average grain size (?m) satisfies less than ?500.

Abstract: A steel wire with improved drawability, and a manufacturing method therefor are disclosed. A steel wire according to the present invention comprises, by wt %, 0.52-0.69% of C, 0.3-0.8% of Mn, 0.1-0.5% of Si, and the balance of Fe and inevitable impurities, wherein the carbon content of cementite in pearlite is 7 at. % or more, and the following formula (1) is satsified. [TS]+exp(?)*10<1500??(1) In Expression (1), [TS] means the tensile strength (MPa) of a wire before drawing, and e means draw strain.

Abstract: A stainless steel with a yield strength of 2,200 MPa or more is disclosed through the generation of the strain-induced martensite phase and the increase of the martensite phase strength. A high strength stainless steel according to an embodiment of present disclosure includes, in percent (%) by weight of the entire composition, C: 0.14 to 0.20%, Si: 0.8 to 1.0%, Mn: more than 0 and 0.5% or less, Cr: 15.0 to 17.0%, Ni: 4.0 to 5.0%, Mo: 0.6 to 0.8%, Cu: 0.5% or less, N: 0.05 to 0.11%, the remainder of iron (Fe) and other inevitable impurities, and C+N: 0.25% or more and Md30 value satisfies 40° C. or more.

Abstract: Provided is a method of manufacturing a zinc-plated steel sheet. The method includes: coating a metal on the steel sheet on a steel sheet; annealing the metal coated steel sheet; and zinc plating the annealed steel sheet by dipping in a molten zinc plating bath. Further provided is a method of manufacturing a hot-press part including: coating a metal on the steel sheet on a steel sheet; annealing the metal coated steel sheet; zinc plating the annealed steel sheet by dipping in a molten zinc plating bath; heating the zinc-plated steel sheet; and press forming the heated steel sheet.

Abstract: The present invention relates to a steel material for pressure vessels, offshore structures and the like and, more specifically, to a high-strength steel material having excellent low-temperature strain aging impact properties and a method for manufacturing same.

Abstract: A ferritic stainless steel with improved mechanical properties of weld zone is disclosed. The ferritic stainless steel includes, in percent (%) by weight of the entire composition, C: 0.005 to 0.02%, N: 0.005 to 0.02%, Cr: 11.0 to 13.0%, Ti: 0.16 to 0.3%, Nb: 0.1 to 0.3%, Al: 0.005 to 0.05%, the remainder of iron (Fe) and other inevitable impurities, and the ferritic stainless steel has a texture maximum strength of 30 or less in the {001} direction after welding.

Abstract: Provided is an annealing separating agent composition for a grain-oriented electrical steel sheet, a grain-oriented electrical steel sheet and a method for manufacturing a grain-oriented electrical steel sheet. The annealing separating agent composition for a grain-oriented electrical steel sheet according to an embodiment of the present invention contains 30 to 70% by weight of a calcium compound, and the remainder of magnesium oxide or magnesium hydroxide on a solid basis.

Abstract: Provided are chromium steel having excellent high-temperature oxidation resistance and high-temperature strength, and a method of manufacturing same. The present invention relates to chromium steel, having excellent high-temperature oxidation resistance and high-temperature strength, which comprises, by weight %, 0.1% or less of C (not including 0%), 0.7% or less of Si (not including 0%), 0.1% or less of Mn (not including 0%), 0.01% or less of S (not including 0%), 0.03% or less of P (not including 0%), 27-33% of Cr, 3.5% or less of Al (not including 0%), 2.5% or less of Nb (not including 0%), 6.5% or less of W (not including 0%), 0.5% or less of Mo (not including 0%), 0.3% or less of Ti (not including 0%), 0.015% or less of N (not including 0%) and the remainder being Fe and unavoidable impurities, and satisfies relational expression (1).

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: Provided is an Al—Fe-alloy plated steel sheet for hot forming, having excellent TWB welding characteristics since excellent hardness uniformity of a TWB weld zone after hot forming is obtained by suitably controlling a batch annealing condition, after plating Al, such that an Al—Fe-alloy layer is formed; a hot forming member; and manufacturing methods therefor.

Abstract: Provided is a composition for surface treatment of a steel sheet, the composition having excellent resistance to an acid, such as sulfuric acid, and to a coated steel sheet to which the composition for surface treatment is applied, wherein the composition for surface treatment comprises 30-50% wt % of colloidal silica containing 5-20 nm-sized silica, 40-60% wt % of silane containing three or more alkoxy groups, 5-15 wt % of an acrylate-based organic monomer, 0.01-1 wt % of an acid, and 1-15 wt % of a solvent.

Abstract: A preferable aspect of the present invention provides: an ultra-high-strength hot-rolled steel sheet containing, by weight, one or two of 0.40-0.60% of C, 0.7-1.5% of Mn, 0.3% or less (excluding 0%) of Si, 0.03% or less (including 0%) of P, 0.004% or less (including 0%) of S, 0.04% or less (excluding 0%) of Al, 0.3% or less (excluding 0%) of Cr, 0.3% or less (excluding 0%) of Mo, 0.9-1.5% of Ni, and 0.9-1.5% of Cu, 1.1% or more of Cu+Ni, 0.04% or less (excluding 0%) of Ti, 0.005% or less (excluding 0%) of B, 0.006% or less (excluding 0%) of N, and the balance Fe and other impurities, the alloy elements satisfying relational formulas 1 and 2 below, wherein a microstructure of the hot-rolled steel sheet comprises, by volume, 7% or more of ferrite and 93% or less of perlite; a steel pipe and a member each using the same; and manufacturing methods therefor.

Abstract: Provided is an unconstrained vibration damping metal sheet with foam pores. The unconstrained vibration damping metal sheet of the present invention comprises: a metal sheet; an organic-inorganic pretreatment layer containing an acrylic resin formed on the metal sheet; and a foam resin layer formed on the pretreatment layer, the foam resin layer containing, based on weight % thereof, a thermoplastic polyvinyl chloride resin: 40-80%, a plasticizer: 5-40%, a foaming agent: 0.1-10%, an oxide-based crosslinker: 1-4%, and spherical silica: 1-10%.