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: The present disclosure relates to a manufacturing method of a negative active material for a battery, a negative active material manufactured therefrom, and a lithium secondary battery including the negative electrode, including: the steps of coating a base material for a negative active material with a coating material; and heating the obtained coating product; wherein, the coating material is graphitizable carbon, the softening point is 50° C. or less, and the coating material is included so that the residual carbon amount is 1 to 5 parts by weight with respect to 100 parts by weight of the base material for the negative active material.

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: 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: 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: 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: 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.

Abstract: An aspect of the present disclosure is to provide a gas shielded arc welding wire capable of imparting excellent fatigue resistance characteristics and resistance to deformation due to residual stress to a weld zone. Another aspect of the present disclosure is to provide a welding member having excellent fatigue resistance characteristics and resistance to deformation due to residual stress of a weld zone, and a method for manufacturing the same.

Abstract: A plating steel sheet for hot press forming includes: a base steel sheet; an Al—Zn-based plating layer formed on at least one surface of the base steel sheet; and an Fe—Al-based surface alloy layer formed between the base steel sheet and the Al—Zn-based plating layer, wherein the Al—Zn-based plating layer can include 10-30 wt % of Zn, 1 wt % or less of Fe, and the balance of Al and impurities.

Abstract: The hot-rolled coated steel sheet comprising: in wt %, C: 0.05-0.14%, Si: 0.1-1.0%, Mn: 1.0-2.0%, P: 0.001-0.05%, S: 0.001-0.01%, AI: 0.01-0.1%, Cr: 0.005-1.0%, Ti: 0.005-0.13%, Nb: 0.005-0.03%, N: 0.001-0.01%, Fe residues, and other inevitable impurities; a mixed structure of ferrite and bainite as a main phase; and as a remaining structure, one or more selected from the group consisting of martensite, austenite, and phase martensite (MA), wherein a fraction of the ferrite and bainite is 95-99 area % and Equation 1 is satisfied. [Equation 1] FCO{110}<112>+FCO{112}<111>?10 where, FCO{110}<112> and FCO{112}<111>, each representing an area fraction occupied by a structure having ac crystal orientation of {110}<112> and {112}<111>.

Abstract: A plated steel wire, according to one aspect of the present invention, comprises: a base steel wire; and a zinc alloy plated layer. The zinc alloy plated layer comprises, in percentage by weight: 1.0% to 3.0% of Al; 1.0% to 2.0% of Mg; 0.5% to 5.0% of Fe; and the balance being Zn and unavoidable impurities, and includes a Zn/MgZn2/Al ternary eutectic structure, a Zn single-phase structure, and an Fe—Zn—Al-based crystal structure, wherein the Fe—Zn—Al-based crystal structure is formed adjacent to the base steel wire, and can have an average thickness of ? to ½ with respect to an average thickness of the zinc alloy plated layer.

Abstract: Provided are plated steel sheets for hot press forming, hot press formed parts, and manufacturing methods thereof, the plated steel sheets comprising: a base steel sheet comprising, in weight %, C: 0.07 to 0.5%, Si: 0.05 to 1%, Mn: 0.5 to 5%, P: 0.001 to 0.015%, S: 0.0001 to 0.02%, Al: 0.01 to 0.1%, Cr: 0.01 to 1%, N: 0.001 to 0.02%, Ti: 0.1% or less, B: 0.01% or less, Sn: 0.01 to 0.1%, and a balance of Fe and inevitable impurities; an aluminum or aluminum alloy plating layer disposed on at least one surface of the base steel sheet; and an Sn-enriched layer provided between the base steel sheet and the plating layer, wherein the Sn-enriched layer satisfies a specific relationship.

Abstract: Provided is a hot press-formed member having excellent crack propagation resistance and ductility. The hot press-formed member includes: a base steel sheet and a zinc or zinc alloy plating layer on at least one surface of the base steel sheet. The base steel sheet contains, by wt %, carbon (C): 0.08-0.30%, silicon (Si): 0.01-2.0%, manganese (Mn): 3.1-8.0%, aluminum (Al): 0.001-0.5%, phosphorus (P): 0.001-0.05%, sulfur (S): 0.0001-0.02%, nitrogen (N): 0.02% or less, and a balance of iron (Fe) and other impurities. The hot press-formed member comprises 1-30 area % of retained austenite as a microstructure, and a Mn(wt %)/Zn(wt %) content ratio in an oxide layer of 0.5-1.2 ?m in a thickness direction from a surface layer of the plating layer is 0.1 or more.

Abstract: A method for preparing a cathode active material precursor for a secondary battery, including: moving a co-precipitation filtrate generated after a co-precipitation reaction to a co-precipitation filtrate storage tank; removing a metal hydroxide by passing the co-precipitation filtrate through a filter; reacting the co-precipitation filtrate from which the metal hydroxide is removed with sulfuric acid or nitric acid to produce an ammonium sulfate or an ammonium nitrate while removing ammonia from the co-precipitation filtrate from which the metal hydroxide is removed; cooling and crystallizing the co-precipitation filtrate from which the metal hydroxide and ammonia are removed to precipitate a sodium sulfate; filtering the precipitated sodium sulfate to separate the precipitated sodium sulfate from the co-precipitation filtrate from which the metal hydroxide and ammonia are removed; drying the sodium sulfate separated from the co-precipitation filtrate and moving the co-precipitation filtrate separated from t

Abstract: Provided is a method of manufacturing a high strength steel sheet having excellent workability, including: reheating a steel slab; hot-rolling the reheated steel slab at an Ar3 transformation point or higher; coiling in a temperature range of 400 to 700° C.; primary cooling at a cooling rate of 0.1° C./s or less to room temperature; producing a cold rolled steel sheet at a cold reduction ratio of 40 to 70%; continuously annealing the cold rolled steel sheet in a temperature range of Ac1+30° C. to Ac3?20° C.; secondary cooling at a cooling rate of 10° C./s or less to 630 to 670° C.; third cooling to 400 to 500° C. at a cooling rate of 5° C./s or more in a hydrogen; maintaining for 70 seconds or more; hot-dip galvanizing; and performing a final cooling to Ms or less at a cooling rate of 1° C./s or more.

Abstract: The present invention relates to a side frame for a battery case, which can achieve lightweight and cost reduction simultaneously while sufficiently protecting battery cells against the external shock, and the side frame for a battery case according to an embodiment comprises: a first frame unit formed to have an open end surface; and a second frame unit which is arranged in the first frame unit to close the open end surface of the first frame unit and is coupled to the first frame unit, wherein the first frame unit and the second frame unit may be formed of different materials from each other.

Abstract: The present invention relates to a sulfide-based solid electrolyte for an all-solid lithium secondary battery, and to a method for preparing the sulfide-based solid electrolyte. The present invention has an effect of providing a sulfide-based solid electrolyte that has excellent stability with respect to lithium metal and has excellent ion conductivity, while having high crystallinity. The present invention has an effect of providing a method for preparing a sulfide-based solid electrolyte that has excellent stability with respect to lithium metal and has excellent ion conductivity, while having high crystallinity even when heat-treated at a low temperature.