Posco Co., Ltd

Posco

Tae-Jin Song

Min-Seo Koo

Chang-Sik Choi

Won-Tae Cho

Jeong-Eun Kim

Sung-Il Kim

Kwang-Geun Chin

Sung-Kyu Kim

Young-Ha Kim

Sun-Ho Jeon

Man-Young Park

Tai-Ho Kim

Provided is a method of manufacturing a clad steel sheet. The method includes: preparing a base material including 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; preparing a cladding material including C: 0.1 to 0.45%, Mn: 0.1 to 3.0%, and a remainder of Fe and inevitable impurities; disposing the base material between two of the cladding material to obtain a laminate; welding an edge of the laminate; heating the welded laminate between 1050 and 1350° C.; finish-rolling the heated laminate between 750 and 1050° C. with a rolling reduction ratio of 30% or more in a first pass; coiling the hot-rolled steel sheet between 400 and 700° C.; pickling the coiled hot-rolled steel sheet, and applying a cold-reduction ratio of 35 to 90%; and annealing the cold-rolled steel sheet between 550° C. and A3+200° C. of the cladding material.

Method of manufacturing clad steel sheet having excellent formability and fatigue property

Provided are a hot rolled steel sheet having excellent crashworthiness and a method for manufacturing same. The hot rolled steel sheet of the present invention contains, in weight %, 0.05-0.13% of carbon (C), 0.2-2.0% of silicon (Si), 1.3-3.0% of manganese (Mn), 0.01-0.1% of aluminum (Al), 0.001-0.05% of phosphor (P), 0.001-0.05% of sulfur (S), 0.001-0.02% of nitrogen (N), and the balance being Fe and other inevitable impurities, and has a steel microstructure comprising, in area %, 55% or more of bainitic ferrite, 10% or more of a martensite/austenite composite phase (MA), the sum of the bainitic ferrite and the martensite/austenite composite phase (MA) being 95% or more, and the remaining total being less than 5% of granular ferrite, retained austenite, and carbides.

Hot rolled steel sheet having excellent crashworthiness and method for manufacturing same

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.

Hot rolled steel sheet having excellent formability and fatigue properties and manufacturing method therefor

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.

Low-density clad steel sheet having excellent strength and plateability, and manufacturing method therefor

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.

Low-density clad steel sheet having excellent formability and fatigue property

Provided is a hot rolled steel sheet having excellent formability and fatigue properties comprising, in percentage by weight: 0.3-0.8% of C; 13-25% of Mn; 0.1-1.0% of V; 0.005-2.0% of Si; 0.01-2.5% of Al; 0.03% or less of P; 0.03% or less of S; 0.04% or less (excluding 0%) of N; and the balance being Fe and inevitable impurities, wherein, when viewed in a cross section in the thickness direction, the hot rolled steel sheet comprises, by area fraction, 20-70% of a non-recrystallized structure and 30-80% of a recrystallized structure.

A clad steel plate, having excellent strength and formability, may include a base material; and a cladding material provided on both side surfaces of the base material, wherein the base material is austenitic high-manganese steel comprising, by weight, 0.3% to 1.4% of C, 12% to 25% of Mn, and a remainder of Fe and inevitable impurities, the cladding material is a martensitic carbon steel comprising, by weight, 0.09% to 0.4% of C, 0.3% to 4.5% of Mn, and a remainder of Fe and inevitable impurities.

Clad steel plate having excellent strength and formability, and production method therefor

The present invention relates to a high-strength and high-manganese steel sheet suitable for an outer panel or a vehicle body of a transport vehicle and, more specifically, to a high-strength and high-manganese steel sheet having excellent vibration-proof properties and a method for producing the same.

Growing community of inventors

Gwangyang-si, South Korea

Tae-Jin Song