A method of producing a ferritic stainless steel sheet comprises subjecting an Al vapor deposited layer-equipped stainless steel sheet to a heat treatment at 600° C. to 1300° C. for 1 minute or more. The Al vapor deposited layer-equipped stainless steel sheet comprises a ferritic stainless steel and an Al vapor deposited layer thereon. The ferritic stainless steel sheet has a thickness of 100 μm or less and a chemical composition containing, in mass %, C: ≤0.030%, Si: ≤1.0%, Mn: ≤1.0%, P: ≤0.040%, S: ≤0.010%, Cr: 11.0-30.0%, Al: 4.0-6.5%, Ni: 0.05-0.50%, Mo: 0.01-6.0%, N: ≤0.020% s, and Zr: 0.01-0.20% and/or Hf: 0.01-0.20%, with a balance consisting of Fe and inevitable impurities. A thickness of the Al vapor deposited layer per one side is 0.5-10.0 μm.

Disclosed is an ultra-high-strength steel having excellent plasticity, comprising in mass percent the chemical elements: C: 0.26-0.30 wt %; Si: 0.8-1.00 wt %; Mn: 2.80-3.30 wt %; Al: 0.04-0.08 wt %; with the balance being Fe and other inevitable impurities. Also disclosed is a manufacturing method for manufacturing the ultra-high-strength steel having excellent plasticity, comprising the following steps: (1) smelting and thin slab continuous casting; (2) heating; (3) hot rolling, wherein an oxide scale on the surface of a hot-rolled steel strip has a thickness of ≤6 μm, and (FeO+Fe.sub.3O.sub.4)≤40 wt % in the oxide scale on the surface of the hot-rolled strip steel; (4) acid pickling or acid pickling and cold rolling; and (5) continuous annealing: annealing at 800-920° C. and performing slow cooling at 3-10° C./s to 690-760° C.; performing fast cooling to 250-350° C. at 50-100° C.; and then heating to 360-460° C., maintaining the temperature for 100-400s and cooling to room temperature.

The present invention discloses a gold-colored steel sheet capable of expressing color without peeling of a modified layer and the gold-colored steel sheet capable of forming a color-modified layer through a conventional annealing process without expensive facilities. A method of manufacturing the gold-colored steel sheet according to an embodiment of the present invention can form a TiN modified layer on a surface of a steel sheet comprising 0.3 to 1.5 wt % of titanium (Ti) by an annealing treatment in a nitrogen (N.sub.2) atmosphere at 900 to 1,200° C. for 30 to 300 seconds.

Disclosed are a ferritic stainless steel capable of inhibiting high temperature oxidation through generation of an effective oxide scale, and manufacturing method thereof. The ferritic stainless steel excellent in oxidation resistance at high temperature according to an embodiment of the present disclosure includes, in percent (%) by weight of the entire composition, Cr: 10 to 30%, Si: 0.2 to 1.0%, Mn: 0.1 to 2.0%, W: 0.3 to 2.5%, Ti: 0.001 to 0.15%, Al: 0.001 to 0.1%, the remainder of iron (Fe) and other inevitable impurities, and satisfies a following equation (1).
W/(Ti+Al)≥10  (1)

The device has a short production line, and all components are reasonably configured. A multifunctional cooling control device is adopted to integrate high-pressure water descaling and intermediate billet cooling functions, which is simpler and more efficient. Layout of a 4R+(3−4)F rolling mill, four thermos-detectors and short-distance underground coilers are use. The method includes the steps: carrying out continuous casting to manufacture a slab, high-pressure water rotating descaling, rough rolling by a four-stand high reduction rough rolling unit, machining by a drum shear, cooling after high-pressure water descaling in the multifunctional cooling control device, finish rolling by a three-stand or four-stand finish rolling unit, air cooling, dividing coils by a high-speed flying shear, and coiling by underground coilers, wherein temperature monitoring is respectively carried out after rough rolling, before finish rolling, after finish rolling, and before coiling by the underground coiler.

One aspect of the present invention relates to a plated steel sheet for hot press forming, having an excellent impact property.

A metal plate includes a surface including a longitudinal direction of the metal plate and a width direction orthogonal to the longitudinal direction. A surface reflectance by regular reflection of a light is 8% or more and 25% or less. The surface reflectance is measured when the light is incident on the surface at an angle of 45°±0.2°. The light is in at least one plane orthogonal to the surface.

A method for manufacturing a metal plate, the metal plate including a first surface and a second surface positioned on the opposite side of the first surface, may include a step of rolling a base metal having an iron alloy containing nickel to produce the metal plate. The metal plate may include particles containing as a main component an element other than iron and nickel. In a sample including the first surface and the second surface of the metal plate, the following conditions (1) and (2) regarding the particles may be satisfied: (1) The number of the particles having an equivalent circle diameter of 1 μm or more is 50 or more and 3000 or less per 1 mm.sup.3 in the sample, and (2) The number of the particles having an equivalent circle diameter of 3 μm or more is 50 or less per 1 mm.sup.3 in the sample.

The present invention relates to a manufacturing method of a steel strip, a steel strip with controlled decarburized depth, a spot welded joint and the use of said steel strip or said spot welded joint. This invention is particularly well suited for the automotive industry due to the improvement of the Liquid Metal Embrittlement (LME) resistance along with target mechanical properties.

Low-density hot dip galvanized steel, comprising a steel substrate (1) located at a core portion and a coating layer (3) located on the surface. An interface layer is disposed between the steel substrate (1) and the coating layer (3), the interface layer comprises an iron particle layer (4), iron particles dispersed on the steel substrate (1) and covering the steel substrate (1) are disposed in the iron particle layer (4), and the iron particles are covered by a first inhibition layer (5). The low-density hot dip galvanized steel contains element Al in a mass percentage of 3.0% to 7.0%. Correspondingly, the present invention also comprises a manufacturing method for the low-density hot dip galvanized steel. The low-density hot dip galvanized steel has a low density, a high strength and high galvanizability and coating layer adhesion.