The present invention provides a method for manufacturing more beautiful black coated steel sheets by uniformly blackening the coating layer. Specifically, the present invention provides a method for manufacturing black coated steel sheets, which brings Zn—Al—Mg alloy coated steel sheets (1) into contact with steam in a closed container (10), wherein said closed container (10) can maintain a predefined internal pressure through variable control of the amount of steam flowing into said closed container (10) and/or the amount of steam flowing out of said closed container (10), and in said closed container (10) that can maintain said predefined pressure, said Zn—Al—Mg alloy coated steel sheets (1) have contact with the steam introduced into said closed container (10).

The present invention provides a method for manufacturing more beautiful black coated steel sheets by uniformly blackening the coating layer. Specifically, the present invention provides a method for manufacturing black coated steel sheets, which brings Zn—Al—Mg alloy coated steel sheets (1) into contact with steam in a closed container (10), wherein said closed container (10) can maintain a predefined internal pressure through variable control of the amount of steam flowing into said closed container (10) and/or the amount of steam flowing out of said closed container (10), and in said closed container (10) that can maintain said predefined pressure, said Zn—Al—Mg alloy coated steel sheets (1) have contact with the steam introduced into said closed container (10).

Embodiments of the present disclosure provides an aluminum alloy-plated steel sheet having high surface quality and weldability, a hot-formed member, and methods for manufacturing the aluminum alloy-plated steel sheet and the hot-formed member. The aluminum alloy-plated steel sheet includes: a base steel sheet; and an aluminum alloy plating layer formed on the base steel sheet, wherein the aluminum alloy plating layer includes, by weight %, Zn: 21% to 35%, Si: 1% to 6.9%, Fe: 2% to 12%, and the balance of Al and inevitable impurities.

Embodiments of the present disclosure provides an aluminum alloy-plated steel sheet having high surface quality and weldability, a hot-formed member, and methods for manufacturing the aluminum alloy-plated steel sheet and the hot-formed member. The aluminum alloy-plated steel sheet includes: a base steel sheet; and an aluminum alloy plating layer formed on the base steel sheet, wherein the aluminum alloy plating layer includes, by weight %, Zn: 21% to 35%, Si: 1% to 6.9%, Fe: 2% to 12%, and the balance of Al and inevitable impurities.

The present invention relates to a method for the manufacture of a hot-dip coated steel sheet coated with a zinc or an aluminum based coating including the provision of a specific steel sheet, a recrystallization annealing with specific heating, soaking and cooling sub-steps using an inert gas and a hot-dip coating; the hot dip coated steel sheet and the use of the hot-dip coated steel sheet.

The present invention relates to a method for the manufacture of a hot-dip coated steel sheet coated with a zinc or an aluminum based coating including the provision of a specific steel sheet, a recrystallization annealing with specific heating, soaking and cooling sub-steps using an inert gas and a hot-dip coating; the hot dip coated steel sheet and the use of the hot-dip coated steel sheet.

An aluminum alloy according to the present invention includes 1.2% by mass to 4.0% by mass of copper, 4.0% by mass to 14.0% by mass of zinc, 0.5% by mass to 4.0% by mass of magnesium, 0.01% or less of silicon, and 0.01% or less of iron, with the balance containing aluminum and inevitable impurities, and has an average equivalent circle crystal grain size of 500 nm or less.

An aluminum alloy according to the present invention includes 1.2% by mass to 4.0% by mass of copper, 4.0% by mass to 14.0% by mass of zinc, 0.5% by mass to 4.0% by mass of magnesium, 0.01% or less of silicon, and 0.01% or less of iron, with the balance containing aluminum and inevitable impurities, and has an average equivalent circle crystal grain size of 500 nm or less.

The present invention relates to the technical field of manufacturing of metal materials, and in particular to a 7000-series aluminum alloy wire for additive manufacturing and a preparation method thereof. The wire was prepared by subjecting an Al—Ti—B intermediate alloy containing TiB.sub.2 particles generated in situ to severe plastic deformation to obtain an intermediate alloy containing TiB.sub.2 nanoparticles having a particle size of 50-1,000 nm or a mixture of two different particles; using the intermediate alloy containing TiB.sub.2 nanoparticles as a matrix raw material, adding other metal or intermediate alloy for smelting to obtain an alloy melt; preparing a wire blank with the alloy melt; subjecting the wire blank to hot rolling, drawing, intermediate annealing and surface treatment to obtain an Al—Zn—Mg—Cu alloy wire reinforced by particles at nano scale or submicron scale.

The present invention relates to the technical field of manufacturing of metal materials, and in particular to a 7000-series aluminum alloy wire for additive manufacturing and a preparation method thereof. The wire was prepared by subjecting an Al—Ti—B intermediate alloy containing TiB.sub.2 particles generated in situ to severe plastic deformation to obtain an intermediate alloy containing TiB.sub.2 nanoparticles having a particle size of 50-1,000 nm or a mixture of two different particles; using the intermediate alloy containing TiB.sub.2 nanoparticles as a matrix raw material, adding other metal or intermediate alloy for smelting to obtain an alloy melt; preparing a wire blank with the alloy melt; subjecting the wire blank to hot rolling, drawing, intermediate annealing and surface treatment to obtain an Al—Zn—Mg—Cu alloy wire reinforced by particles at nano scale or submicron scale.