A method of producing a high performance stainless steel exhibiting corrosion resistance even under a very severe corrosion environment at temperatures of equal to or higher than 180° C., for example, 220° C., while maintaining strength and toughness by improving the corrosion resistance of a conventional martensitic stainless steel with high strength. The martensitic stainless steel includes, in mass %, C: 0.005% to 0.05%, Si: equal to or less than 1.0%, Mn: equal to or less than 2.0%, Cr: 16 to 18%, Ni: 2.5 to 6.5%, Mo: 1.5 to 3.5%, W: equal to or less than 3.5%, Cu: equal to or less than 3.5%, V: 0.01 to 0.08%, Sol.Al: 0.005 to 0.10%, N: equal to or less than 0.05%, and Ta: 0.01 to 0.06%, and the balance Fe with inevitable impurities.

A high-strength cold-rolled steel sheet and a hot-dipped galvanized steel sheet with low deviation of material properties and excellent formability, and a method for manufacturing same are provided. The present invention relates to a low-yield-ratio high-strength cold-rolled steel sheet with low deviation of directional material and excellent formability, comprising 0.05-0.15 wt % of C, 0.2-1.5 wt % of Si, 2.2-3.0 wt % of Mn, 0.001-0.10 wt % of P, 0.010 wt % or less of S, 0.01-0.10 wt % of sol.Al, 0.010 wt % or less of N, and the balance of Fe and impurities, satisfying Si/(Mn+Si)≦0.5, wherein the microstructure of the steel sheet includes 40% or more of ferrite, 10% or less of bainite, 3% or less of residual austenite, and a balance of martensite, and the area fraction of a Mn band present in the martensite phase is 5% or less.

A high-strength cold-rolled steel sheet and a hot-dipped galvanized steel sheet with low deviation of material properties and excellent formability, and a method for manufacturing same are provided. The present invention relates to a low-yield-ratio high-strength cold-rolled steel sheet with low deviation of directional material and excellent formability, comprising 0.05-0.15 wt % of C, 0.2-1.5 wt % of Si, 2.2-3.0 wt % of Mn, 0.001-0.10 wt % of P, 0.010 wt % or less of S, 0.01-0.10 wt % of sol.Al, 0.010 wt % or less of N, and the balance of Fe and impurities, satisfying Si/(Mn+Si)≦0.5, wherein the microstructure of the steel sheet includes 40% or more of ferrite, 10% or less of bainite, 3% or less of residual austenite, and a balance of martensite, and the area fraction of a Mn band present in the martensite phase is 5% or less.

A system for the hot stamping of workpieces having a furnace installation, in which workpieces can be heated to a forming temperature, and a forming installation, in which the heated workpieces can undergo forming. A transfer device is provided for transferring workpieces from the furnace installation to the forming installation. The transfer device is arranged in a transfer space, which is delimited at least in certain regions by a housing and largely bridges the space between the furnace installation and the forming installation. Also provided is a method for the hot stamping of workpieces.

A system for the hot stamping of workpieces having a furnace installation, in which workpieces can be heated to a forming temperature, and a forming installation, in which the heated workpieces can undergo forming. A transfer device is provided for transferring workpieces from the furnace installation to the forming installation. The transfer device is arranged in a transfer space, which is delimited at least in certain regions by a housing and largely bridges the space between the furnace installation and the forming installation. Also provided is a method for the hot stamping of workpieces.

The present invention relates to a formed product used in vehicle components and the like, and to a method for manufacturing the same. The present invention provides heat treatable steel, a formed product using the same having ultra-high strength and excellent durability, and a method for manufacturing the same, wherein the heat treatable steel contains, in wt %, C (0.22-0.42%), Si (0.05-0.3%), Mn (1.0-1.5%), Al (0.01-0.1%), P (0.01% or less (including 0), S (0.005% or less), Mo (0.05-0.3%), Ti (0.01-0.1%), Cr (0.05-0.5%), B (0.0005-0.005%), N (0.01% or less), the balance Fe, and other inevitable impurities, Mn and Si satisfying Relationship formula (1), below, Mo/p satisfying Relationship formula (2), below: [Relationship formula 1] Mn/Si≧5 [Relationship formula 2] Mo/P≧15.

A high strength galvanized steel sheet having excellent surface qualities, plating adhesion, and formability is provided, wherein a galvanized layer is formed on a cold-rolled steel sheet comprising 0.1-0.3 wt % of C, 1-2.5 wt % of Si, 2.5-8 wt % of Mn, 0.001-0.5 wt % of sol. Al, at most 0.04 wt % of P, at most 0.015 wt % of S, at most 0.02 wt % of N (excluding 0 wt %), 0.1-0.7 wt % of Cr, at most 0.1 wt % of Mo, (48/14)*[N] to 0.1 wt % of Ti, 0.005-0.5 wt % of Ni, 0.01-0.07 wt % of Sb, at most 0.1 wt % of Nb, and at most 0.005 wt % of B, with the remainder being Fe and other inevitable impurities.

A high strength galvanized steel sheet having excellent surface qualities, plating adhesion, and formability is provided, wherein a galvanized layer is formed on a cold-rolled steel sheet comprising 0.1-0.3 wt % of C, 1-2.5 wt % of Si, 2.5-8 wt % of Mn, 0.001-0.5 wt % of sol. Al, at most 0.04 wt % of P, at most 0.015 wt % of S, at most 0.02 wt % of N (excluding 0 wt %), 0.1-0.7 wt % of Cr, at most 0.1 wt % of Mo, (48/14)*[N] to 0.1 wt % of Ti, 0.005-0.5 wt % of Ni, 0.01-0.07 wt % of Sb, at most 0.1 wt % of Nb, and at most 0.005 wt % of B, with the remainder being Fe and other inevitable impurities.

Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 30% or more of a ferrite phase, 40% to 65% of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 μm from the surface in the thickness direction, the area ratio of a ferrite phase is 40% to 55% and the total area ratio of a bainite phase having a grain diameter of more than 5 μm and/or a martensite phase having a grain diameter of more than 5 μm is 20% or less, and a tensile strength is 980 MPa or more.

Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 25% or less of a ferrite phase, 75% or more of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 μm from the surface in the thickness direction, the area ratio of a ferrite phase is 5% to 20%, and a tensile strength is 1180 MPa or more.