Abstract: Provided is an ultra-high strength cold-rolled steel sheet having excellent hole expandability and a method for manufacturing same and, more specifically, to an ultra-high strength cold-rolled steel sheet having excellent hole expandability which can be mainly used for structural members and to ensure safety in the event of an automobile collision, and to a method for manufacturing same.

Abstract: Provided is a steel sheet and a method for manufacturing same, the steel sheet, which can be used for automobile parts and the like, having superb bendability, and excellent balance of strength and ductility and of strength and hole expansion ratio. The steel sheet includes: by wt %, C: 0.25 to 0.75%, Si: 4.0% or less, Mn: 0.9 to 5.0%, Al: 5.0% or less, P: 0.15% or less, S: 0.03% or less, N: 0.03% or less, a balance of Fe, and unavoidable impurities; and as microstructures, ferrite which is a soft structure, and tempered martensite, bainite, and retained austenite which are hard structures.

Abstract: The present invention relates to an ultra-high strength cold-rolled steel sheet and a manufacturing method thereof and, more specifically, to a cold-rolled steel sheet and a manufacturing method thereof, wherein the cold-rolled steel sheet has a tensile strength of 1.5 GPa and exhibits an excellent elongation rate, and as such, can be suitably used for cold stamping.

Abstract: A method of manufacturing a low-density clad steel sheet, including: preparing a base material, a lightweight steel sheet including C: 0.3 to 1.0%, Mn: 4.0 to 16.0%, Al: 4.5 to 9.0%, and Fe; preparing cladding materials, each being martensitic carbon steel including C: 0.1 to 0.45%, Mn: 0.1 to 3.0%, and Fe; disposing the base material between the cladding materials to obtain a laminate; welding an edge of the laminate, and heating the welded laminate to 1050 to 1350° C.; finish-rolling the heated laminate to 750 to 1050° C. with a rolling reduction ratio of 30% or more in a first pass, to obtain a hot-rolled steel sheet; coiling the hot-rolled steel sheet at 400 to 700° C.; applying a cold-reduction ratio of 35 to 90% to obtain a cold-rolled steel sheet; and annealing the cold-rolled steel sheet at 550° C. or higher and A3+200° C. or lower of the cladding materials.

Abstract: Provided is an ultrahigh-strength steel sheet with excellent bendability and stretch flangeability, and a manufacturing method therefor and, more specifically, to: a steel sheet having excellent bendability and stretch flangeability by using rapid low-temperature tempering, and having a high yield ratio and ultrahigh strength; and a manufacturing method therefor.

Abstract: Provided is an ultra high strength steel sheet having a high yield ratio, and a method for manufacturing same and, more specifically, to a steel sheet having ultra high strength, a high yield ratio and excellent bendability, and a method for manufacturing same.

Abstract: Provided is a density clad steel sheet having excellent strength and plateability, the clad steel sheet including a base metal, and a clad material provided at both sides of the base metal, wherein the base metal is a ferrite-austenitic duplex lightweight steel sheet comprising, by wt %, 0.3-0.7% of C, 2.0-9.0% of Mn, 4.5-8.0% of Al and the balance of Fe and inevitable impurities, and the clad material is a ferrite carbon steel comprising, by wt %, 0.0005-0.2% of C, 0.05-2.5% of Mn and the balance of Fe and inevitable impurities.

Abstract: Provided is a method of manufacturing a high-strength cold rolled steel sheet. The method includes: preparing a slab; heating the slab to 1,150° C. to 1,250° C.; finish hot rolling the heated slab within 900° C. to 980° C.; cooling the slab at an average cooling rate of 10° C./sec to 100° C./sec; winding the slab in 500° C. to 700° C.; cold rolling the slab at a cold-rolling reduction ratio of 30% to 60% to obtain a cold rolled steel sheet; continuously annealing the cold rolled steel sheet at Ae3+30° C. to Ae3+80° C.; primarily cooling the continuously annealed steel sheet at an average cooling rate of 10° C./s or less to 560° C. to 700° C. and secondarily cooling the steel sheet at an average cooling rate of 10° C./s or more to 270° C. to 330° C.; and reheating the cooled steel sheet at a temperature increase rate of 5° C./s or lower to a temperature in a range of 380° C. to 460° C.

Abstract: Provided is a low-density clad steel sheet having excellent formability and fatigue properties, including a base material; and cladding materials provided on both side surfaces of the base material, wherein the base material is a lightweight steel sheet including, by weight, C: 0.3 to 1.0%, Mn: 4.0 to 16.0%, Al: 4.5 to 9.0%, and a remainder of Fe and inevitable impurities, and each of the cladding materials is martensitic carbon steel including, by weight, C: 0.1 to 0.45%, Mn: 1.0 to 3.0%, and a remainder of Fe and inevitable impurities.

Abstract: Provided is a high-strength cold rolled steel sheet, a high-strength hot-dip galvanized steel sheet manufactured using the cold rolled steel sheet, and manufacturing methods therefor, the high-strength cold rolled steel sheet comprising, by wt %, 0.17-0.21% of carbon (C), 0.3-0.8% of silicon (Si), 2.7-3.3% of manganese (Mn), 0.3-0.7% of chromium (Cr), 0.01-0.3% of aluminum (Al), 0.01-0.03% of titanium (Ti), 0.001-0.003% of boron (B), 0.04% or less of phosphorus (P), 0.02% or less of sulfur (S), 0.01% or less of nitrogen (N) and the balance of iron (Fe) and other inevitable impurities, wherein the amounts of carbon (C), silicon (Si) and aluminum (Al) satisfy the following mathematical relation (1). [Mathematical relation (1)] [C]+([Si]+[Al])/5?0.35% (wherein [C], [Si] and [Al] respectively mean the wt % of C, Si and Al.

Abstract: Provided is a steel sheet and a method for manufacturing same, the steel sheet, which can be used for automobile parts and the like, having superb bendability, and excellent balance of strength and ductility and of strength and hole expansion ratio. The steel sheet includes: by wt %, C: 0.25 to 0.75%, Si: 4.0% or less, Mn: 0.9 to 5.0%, Al: 5.0% or less, P: 0.15% or less, S: 0.03% or less, N: 0.03% or less, a balance of Fe, and unavoidable impurities; and as microstructures, ferrite which is a soft structure, and tempered martensite, bainite, and retained austenite which are hard structures.

Abstract: Provided is a steel sheet and a method for manufacturing same, the steel sheet which can be used for automobile parts and the like, having excellent bending workability, and excellent balance of strength and ductility and of strength and hole expansibility.

Abstract: Provided are a high-strength steel sheet and a method for manufacturing same, the high-strength steel sheet including: an alloy system having C, Si, Mn, Cr, Al, Nb, Ti, B, P, S, N, and the remainder of Fe and other inevitable impurities. The contents of C, Si, and Al satisfy equation (1) below. The microstructure includes, by an area fraction, greater than 50% to 70% or less of tempered martensite, and the remainder of residual austenite, fresh martensite, ferrite, and bainite, in which a cementite phase as a second phase is precipitated and distributed in an area fraction of 1-3% between bainite laths, or at a lath on the tempered martensite or grain boundaries. [Equation (1)] [C]+([Si]+[Al])/5?0.35 wt. % (wherein [C], [Si], and [Al] denote wt % of C, Si, and Al, respectively.

Abstract: Provided is a high-strength cold rolled steel sheet, a high-strength hot-dip galvanized steel sheet manufactured using the cold rolled steel sheet, and manufacturing methods therefor, the high-strength cold rolled steel sheet comprising, by wt %, 0.17-0.21% of carbon (C), 0.3-0.8% of silicon (Si), 2.7-3.3% of manganese (Mn), 0.3-0.7% of chromium (Cr), 0.01-0.3% of aluminum (Al), 0.01-0.03% of titanium (Ti), 0.001-0.003% of boron (B), 0.04% or less of phosphorus (P), 0.02% or less of sulfur (S), 0.01% or less of nitrogen (N) and the balance of iron (Fe) and other inevitable impurities, wherein the amounts of carbon (C), silicon (Si) and aluminum (Al) satisfy the following mathematical relation (1). [Mathematical relation (1)] [C]+([Si]+[Al])/5?0.35% (wherein [C], [Si] and [Al] respectively mean the wt % of C, Si and Al.

Abstract: The present invention relates to a Doherty combiner used in a Doherty power amplifier, the Doherty combiner comprising: a phase shift section connected to one end of a carrier amplifier so as to change a phase of an RF signal output from the carrier amplifier; a matching section connected to an output terminal of the Doherty power amplifier so as to impedance-match an output of the Doherty power amplifier; and a bandwidth improvement section connected to one end of a peaking amplifier so as to change at least one of a phase bandwidth and an amplitude bandwidth of the Doherty power amplifier.

Abstract: Provided is an ultra-high strength steel sheet used as a material of a vehicle and, more specifically, to an ultra-high strength steel sheet having excellent bendability and a manufacturing method therefor. There is an effect of providing a steel sheet by utilizing a continuous annealing furnace without having water quenching equipment, thereby simultaneously ensuring a tensile strength of 1200 MPa or greater compared with that of conventional super high strength martensite steel and having excellent shape and bending properties.

Abstract: Provided is a density clad steel sheet having excellent strength and plateability, the clad steel sheet including a base metal, and a clad material provided at both sides of the base metal, wherein the base metal is a ferrite-austenitic duplex lightweight steel sheet comprising, by wt %, 0.3-0.7% of C, 2.0-9.0% of Mn, 4.5-8.0% of Al and the balance of Fe and inevitable impurities, and the clad material is a ferrite carbon steel comprising, by wt %, 0.0005-0.2% of C, 0.05-2.5% of Mn and the balance of Fe and inevitable impurities.

Abstract: The present invention provides an apparatus and a method for detecting the presence of and/or determining the amount of a label-free microRNA using an atomic force microscope. The method is extremely selective and/or ultrasensitive. In particular, the present invention provides a cantilever comprising a probe that selectively binds to a double strand of DNA/RNA hybrid complex. The probe comprises a hybrid binding domain (HBD) or a variant thereof.

Abstract: Provided is a cold-rolled steel sheet manufactured by a cold-rolled steel sheet manufacturing method comprising a continuous annealing step, which has a composition comprising, by weight %: C: 0.1-0.15%; Si: 0.2% or less (including 0%); Mn: 2.3-3.0%; P: 0.001-0.10%; S: 0.010% or less (including 0%); Sol.Al: 0.01-0.10%; N: 0.010% or less (excluding 0%); Cr: 0.3-0.9%; B: 0.0010-0.0030%; Ti: 0.01-0.03%; Nb:0.01-0.03%; the balance being Fe and other impurities, and satisfies following relationship 1. [relationship 1] 1650?5541.4C+239Mn+169.1Cr+0.74SS-1.36RCS?1688, in which microstructure comprises, in area %, at least 90% of martensite and tempered martensite; and 10% or less of ferrite and bainite, in which the fraction of the tempered martensite in the martensite and the tempered martensite is 90% or more, in area %, and the ratio (b/a) of the C+Mn concentration (a) in the martensite to the C+Mn concentration (b) in the ferrite and the bainite is 0.65 or more.

Abstract: Provided is a low-density clad steel sheet having excellent formability and fatigue properties, including a base material; and cladding materials provided on both side surfaces of the base material, wherein the base material is a lightweight steel sheet including, by weight, C: 0.3 to 1.0%, Mn: 4.0 to 16.0%, Al: 4.5 to 9.0%, and a remainder of Fe and inevitable impurities, and each of the cladding materials is martensitic carbon steel including, by weight, C: 0.1 to 0.45%, Mn: 1.0 to 3.0%, and a remainder of Fe and inevitable impurities.