The present invention has as its object the provision of a coated steel member and coated steel sheet excellent in hydrogen embrittlement resistance in a corrosive environment and methods for manufacturing the same. The coated steel member of the present invention is provided on its surface with an Al—Fe-based coating containing Cu and one or more of Mo, Ni, Mn, and Cr in a total by mass % of 0.12% or more by heating, cooling, and manufacturing a coated steel sheet having a layer containing Cu on its surface under predetermined conditions.

A steel-strip production apparatus adapted to produce a hot-dip-plated steel strip and a cold-rolled steel strip includes a continuous annealing furnace, a snout connected to the continuous annealing furnace, a contact-type seal plate device and a noncontact-type seal roll device, a hot-dip-plating tank that is movable, and a roll configured to turn the path direction of the steel strip after passing through the snout, wherein a hot-dip-plated steel strip production unit configured to produce a hot-dip-plated steel strip by bringing the steel strip continuously annealed in the continuous annealing furnace into the hot-dip-plating tank; and a cold-rolled steel strip production unit configured to produce a cold-rolled steel strip by transferring the steel strip continuously annealed in the continuous annealing furnace without causing the steel strip to pass through the hot-dip-plating tank, are configured to be switchable with one another.

The invention relates to a method for the production of carbon fiber reinforced aluminum matrix composite wires by drawing carbon fibers through molten salt and molten aluminum in such a way that the molten aluminum and the molten salt are spatially separated, and the carbon fibers are drawn through first the molten salt, then the molten aluminum separated from it. The invention further relates to an apparatus for the implementation of the method.

Zn alloy plated steel material having excellent weldability and processed-part corrosion resistance and a method for production of Zn alloy plated steel material are provided. In the Zn alloy plated steel material comprising base steel material and a Zn alloy plating layer, the Zn alloy plating layer includes, by wt %, Al: 0.1-5.0%, Mg: 0.1-5.0%, as well as a remainder of Zn and inevitable impurities. The Zn alloy plated steel material includes a lower interface layer and an upper interface layer between the base steel material and the Zn alloy plating layer, wherein the lower interface layer is formed on the base steel material and has a dense structure, and the upper interface layer is formed on the lower interface layer and has a network-type or island-type structure.

A surface-finished steel sheet, in some examples cold-rolled thin steel sheet, includes a metallic corrosion-resistant layer that may comprise more than 40% by weight aluminum and iron. So that that corrosion-resistant layer has high formability, especially cold formability, and hence significantly improved adhesion on forming, the corrosion-resistant layer may comprises nickel, wherein nickel-containing phases are located at a transition from the corrosion-resistant layer to a base material of the steel sheet. The nickel content of the corrosion resistant layer may be in a range from 5 to 30% by weight. Further, a method for producing a surface-finished steel sheet of this kind is also disclosed. In some examples, a nickel layer may be applied to a steel sheet, preferably cold-rolled thin steel sheet in the form of flat steel product, prior to hot-dip coating the steel sheet with a liquid aluminum melt or with a liquid melt of aluminum-based alloy.

Provided is a hot-rolled steel sheet having a composition containing 0.04 mass percent to 0.20 mass percent C, 0.7 mass percent to 2.3 mass percent Si, 0.8 mass percent to 2.8 mass percent Mn, 0.1 mass percent or less P, 0.01 mass percent or less S, 0.1 mass percent or less Al, and 0.008 mass percent or less N, the remainder being Fe and inevitable impurities. Internal oxides containing one or more selected from the group consisting of Si, Mn, and Fe are present at grain boundaries and in grains in a base metal. The internal oxides present at the grain boundaries in the base metal are located within 5 μm from the surface of the base metal. The difference between the depths at which the internal oxides are formed in the cross direction of the steel sheet is 2 μm or less.

A continuous annealing furnace for annealing steel strips that is a vertical-type annealing furnace is configured so that part of gas inside the furnace is drawn and introduced to a refiner disposed outside the furnace including an oxygen removing apparatus and a dehumidifying apparatus, oxygen and moisture contained in the gas are removed to lower the dew point of the gas, and the gas having a lowered dew point is put back into the furnace. At least one gas inlet through which gas is drawn from the furnace into the refiner is disposed in the vicinity of the entry side of the furnace at a distance of 6 m or less in the vertical direction and 3 m or less in the furnace-length direction from the steel-strip-introduction section located at the lower part of the heating zone.

Disclosed is a steel sheet for hot press forming, which includes: a base steel sheet; and a plating layer disposed on the base steel sheet and including a diffusion layer and a surface layer that are sequentially laminated, wherein the diffusion layer includes an Fe—Al alloy layer and an Fe—Al intermetallic compound layer that are sequentially disposed on the base steel sheet and each include silicon, and an area fraction of the Fe—Al intermetallic compound layer with respect to the diffusion layer is 84.5% to 98.0%.

A hot-dip-coated, non-skin-passed, cold-rolled metal strip is provided. The metal coating of the metal strip includes a waviness Wa.sub.0.8 of less than or equal to 0.70 μm, 0.2 to 8% by weight of aluminum and magnesium, and up to 0.3% by weight of additional elements, the balance being zinc and inevitable impurities. Metal parts are also provided.

A hot-dip Sn—Zn-based alloy-plated steel sheet according to an aspect of the present invention includes: a steel sheet having a predetermined chemical composition; a diffusion alloy layer provided on one surface or both surfaces of the steel sheet; and a Sn—Zn-plated layer provided on the diffusion alloy layer, in which the diffusion alloy layer contains Fe, Sn, Zn, Cr, and Ni, an area ratio of a Sn—Fe—Cr—Zn phase to a Sn—Fe—Ni—Zn phase in the diffusion alloy layer is 0.01 or more and less than 2.5, the diffusion alloy layer has a coverage of 98% or more with respect to the one surface, the Sn—Zn-plated layer contains 1% to 20% of Zn by mass % and a remainder consisting of Sn and impurities, and an adhesion amount of the Sn—Zn-plated layer is 10 to 80 g/m.sup.2 per one surface.