Abstract: A method of forming an Al—Zn—Si—Mg alloy coating on a steel strip includes dipping steel strip into a bath of molten Al—Zn—Si—Mg alloy and forming a coating of the alloy on exposed surfaces of the steel strip. The method also includes controlling conditions in the molten coating bath and downstream of the coating bath so that there is a uniform Al/Zn ratio across the surface of the coating formed on the steel strip. An Al—Zn—Mg—Si coated steel strip includes a uniform Al/Zn ratio on the surface or the outermost 1-2 ?m of the Al—Zn—Si—Mg alloy coating.

Abstract: Provided is a metallic coated steel product which is less likely to experience LME and blowhole formation and is likely to exhibit an improved corrosion resistance at welding heat affected zones. The metallic coated steel product is a hot-dip metallic coated steel product including a steel product and a plating layer that is provided on a surface of the steel product and includes a Zn—Al—Mg alloy layer. In a cross-section of the Zn—Al—Mg alloy layer an area fraction of MgZn2 phase is from 45 to 75%, a total area fraction of MgZn2 and Al phases is not less than 70%, and an area fraction of Zn—Al—MgZn2 ternary eutectic structure is from 0 to 5%; and the plating layer has a predetermined chemical composition.

Abstract: The present invention provides a coated steel product including: a steel product; a coating layer that is coated on the surface of the steel product and that includes from 8 to 50% by mass of Mg, from 2.5 to 70.0% by mass of Al, and from 0.30 to 5.00% by mass of Ca, with the balance consisting of Zn and impurities; and an intermediate layer interposed between the steel product and the coating layer, in which the intermediate layer has a sea-island structure constituted by a sea portion composed of an Al—Fe alloy phase, and island portions including a Zn—Mg—Al alloy phase having a Mg content of 8% by mass or more, and in which the sea portion composed of the Al—Fe alloy phase has an area fraction of from 55 to 90%.

Abstract: A method of forming an Al—Zn—Si—Mg alloy coating on a steel strip includes dipping steel strip into a bath of molten Al—Zn—Si—Mg alloy and forming a coating of the alloy on exposed surfaces of the steel strip. The method also includes controlling conditions in the molten coating bath and downstream of the coating bath so that there is a uniform Al/Zn ratio across the surface of the coating formed on the steel strip. An Al—Zn—Mg—Si coated steel strip includes a uniform Al/Zn ratio on the surface or the outermost 1-2 ?m of the Al—Zn—Si—Mg alloy coating.

Abstract: A method of forming an Al—Zn—Si—Mg alloy coating on a steel strip includes dipping steel strip into a bath of molten Al—Zn—Si—Mg alloy and forming a coating of the alloy on exposed surfaces of the steel strip. The method also includes controlling conditions in the molten coating bath and downstream of the coating bath so that there is a uniform Al/Zn ratio across the surface of the coating formed on the steel strip. An Al—Zn—Mg—Si coated steel strip includes a uniform Al/Zn ratio on the surface or the outermost 1-2 ?m of the Al—Zn—Si—Mg alloy coating.

Abstract: A Zn—Al—Mg-based plated steel sheet has, an alloy layer formed on a surface of a steel sheet and contains Fe and Si, and a plated layer formed on a surface of the alloy layer opposite to the steel sheet, in which the plated layer and the alloy layer include, in mass %, Al: 45.0 to 65.0%, Si: 0.50 to 5.00%, Mg: 1.00 to 10.00%, and a balance of Zn, Fe, and impurities, the plated layer contains 0.1 to 20.0% of a Mg—Si phase in terms of volume fraction, an average equivalent circle diameter of the Mg—Si phase in the surface layer area is 0.1 to 15.0 ?m, and an integrated value of a Si content from the surface to thickness center of the plated layer is 0.55 times or more of an integrated value of the Si content from the surface to an interface.

Abstract: This Zn—Al—Mg-based plated steel sheet has a steel sheet, an alloy layer which is formed on a surface of the steel sheet and contains Fe and Si, and a plated layer which is formed on a surface of the alloy layer opposite to the steel sheet, in which an average composition of the plated layer and the alloy layer includes, in mass %, Al: 45.0 to 65.0%, Si: 0.50 to 5.00%, Mg: 1.00 to 10.00%, and a balance of Zn, Fe, and impurities, the plated layer contains 0.1 to 20.0% of a Mg-Si phase in terms of volume fraction, in a case where a 1 ?m range from a surface of the plated layer in a thickness direction of the plated layer is defined as a surface layer area of the plated layer, an average equivalent circle diameter of the Mg-Si phase in the surface layer area in a direction in which the plated layer is overserved in a plane view is 0.1 to 15.0 ?m, and an integrated value of a Si content from the surface of the plated layer to thickness center of the plated layer is 0.

Abstract: The invention provides a coated steel including a steel, a coated metal layer coated on a surface of the steel, and an interfacial alloy layer formed at the boundary between the steel and the coated metal layer, in which the coated metal layer has a predetermined composition and structure, and in which the thickness of the coated metal layer is 0.1 ?m or more, and the thickness of the interfacial alloy layer is 500 nm or less.

Abstract: Provided is a metallic coated steel product which is less likely to experience LME and blowhole formation and is likely to exhibit an improved corrosion resistance at welding heat affected zones. The metallic coated steel product is a hot-dip metallic coated steel product including a steel product and a plating layer that is provided on a surface of the steel product and includes a Zn—Al—Mg alloy layer. In a cross-section of the Zn—Al—Mg alloy layer an area fraction of MgZn2 phase is from 45 to 75%, a total area fraction of MgZn2 and Al phases is not less than 70%, and an area fraction of Zn—Al—MgZn2 ternary eutectic structure is from 0 to 5%; and the plating layer has a predetermined chemical composition.

Abstract: The present invention provides a coated steel product including: a steel product; a coating layer that is coated on the surface of the steel product and that includes from 8 to 50% by mass of Mg, from 2.5 to 70.0% by mass of Al, and from 0.30 to 5.00% by mass of Ca, with the balance consisting of Zn and impurities; and an intermediate layer interposed between the steel product and the coating layer, in which the intermediate layer has a sea-island structure constituted by a sea portion composed of an Al—Fe alloy phase, and island portions including a Zn—Mg—Al alloy phase having a Mg content of 8% by mass or more, and in which the sea portion composed of the Al—Fe alloy phase has an area fraction of from 55 to 90%.

Abstract: A Mg-containing Zn alloy coated steel including a steel and a metallic coating layer placed on a surface of the steel, in which the metallic coating layer is a layered structure of plural flat-form metal particles having a particle diameter of from 5 to 100 ?m, and a thickness of from 0.5 to 30 ?m, the composition of the metal particles include Zn from 11 to 80 mass %, Al from 3 to 80 mass %, Mg from 8 to 45 mass %, and Ca from 1 to 5 mass %, and the Zn, Al, and Mg content satisfy Zn+Al>Mg, and in which the metal particles include a quasicrystalline phase, an MgZn2 phase, and optionally a balance structure.

Abstract: A Mg-containing Zn alloy coated steel including a steel and a metallic coating layer placed on a surface of the steel, in which the metallic coating layer is a layered structure of plural flat-form metal particles having a particle diameter of from 5 to 100 ?m, and a thickness of from 0.5 to 30 ?m, the composition of the metal particles include Zn from 11 to 80 mass %, Al from 3 to 80 mass %, Mg from 8 to 45 mass %, and Ca from 1 to 5 mass %, and the Zn, Al, and Mg content satisfy Zn+Al>Mg, and in which the metal particles include a quasicrystalline phase, an MgZn2 phase, and optionally a balance structure.

Abstract: An Mg-containing Zn alloy coated steel including a steel and a metallic coating layer placed on a surface of the steel, in which the metallic coating layer is a layered structure of a flat-form metal particle having a particle diameter of from 5 to 100 ?m, and a thickness of from 0.5 to 30 ?m, the composition of the metal particles include, in terms of % by mass, Zn from 11 to 80%, Al from 3 to 80%, Mg from 8 to 45%, and Ca from 1 to 5%, while the balance is impurities, and the Zn content, the Al content, and the Mg content in terms of % by mass satisfy Zn+Al>Mg, and in which the metal particles include a quasicrystalline phase, an MgZn2 phase, and a balance structure, in which the total area fraction of the quasicrystalline phase and the MgZn2 phase is 45% or more, the area fraction of the balance structure is from 0 to 55%, the area fraction of the quasicrystalline phase is 20% or more, and the area fraction of the MgZn2 phase is 3% or more.

Abstract: The invention provides a coated steel including a steel, a coated metal layer coated on a surface of the steel, and an interfacial alloy layer formed at the boundary between the steel and the coated metal layer, in which the composition of the coated metal layer includes in terms of % by mass Zn from 20 to 83%, and Al from 2.5 to 46.5% as well as Mg and impurities as the balance, in which the Mg content is 10% or more, in which the structure of the coated metal layer includes a quasicrystalline phase, a MgZn2 phase, and a balance structure, in which the area fraction of the quasicrystalline phase is from 30 to 60%, and not less than 90 number-% of the quasicrystalline phases are a quasicrystalline phase having a particle diameter in the major axis direction of from 0.05 to 1.0 ?m, and in which the thickness of the coated metal layer is 0.1 ?m or more, and the thickness of the interfacial alloy layer is 500 nm or less.

Abstract: The aluminum-zinc plated steel sheet according to the present invention includes a plated steel sheet and a covering film that covers the plated steel sheet. The covering film contains a basic compound of transition metal other than cobalt and chromium, and metallic cobalt, or metallic cobalt and a cobalt compound. An amount of the covering film per one side is within a range of 0.01 to 0.8 g/m2. An amount in terms of mass of transition metal other than cobalt in the covering film per one side of the plated steel sheet is within a range of 4 to 400 mg/m2. An amount in terms of mass of cobalt in the covering film per one side of the plated steel sheet is within a range of 0.1 to 20 mg/m2.

Abstract: A method of forming an Al—Zn—Si—Mg alloy coating on a steel strip includes dipping steel strip into a bath of molten Al—Zn—Si—Mg alloy and forming a coating of the alloy on exposed surfaces of the steel strip. The method also includes controlling conditions in the molten coating bath and downstream of the coating bath so that there is a uniform Al/Zn ratio across the surface of the coating formed on the steel strip. An Al—Zn—Mg—Si coated steel strip includes a uniform Al/Zn ratio on the surface or the outermost 1-2 ?m of the Al—Zn—Si—Mg alloy coating.

Abstract: Disclosed is a high-strength Zn—Al coated steel wire for bridges with excellent corrosion resistance and fatigue properties, the Zn—Al coated steel wire includes: a steel wire; and a Zn—Al coating having a coating body layer and an Fe—Al alloy layer formed in an interface between a surface layer of the steel wire and the coating body layer, wherein a chemical composition of a core material of the steel wire includes, by mass %: C: 0.70% to 1.2%; Si: 0.01% to 2.5%; Mn: 0.01% to 0.9%; P: limited to 0.02% or less; S: limited to 0.02% or less; N: limited to 0.01% or less; and the balance including Fe and unavoidable impurities, wherein wire-drawn pearlite is most abundant microstructure among microstructures of the core material of the steel wire; wherein an average composition of the Zn—Al coating includes, by mass %, Al: 3.0 to 15.0%; and Fe: limited to 3.0% or less, and wherein the Fe—Al alloy layer has a thickness of 5 ?m or less.

Abstract: The aluminum-zinc plated steel sheet according to the present invention includes a plated steel sheet and a covering film that covers the plated steel sheet. The covering film contains a basic compound of transition metal other than cobalt and chromium, and metallic cobalt, or metallic cobalt and a cobalt compound. An amount of the covering film per one side is within a range of 0.01 to 0.8 g/m2. An amount in terms of mass of transition metal other than cobalt in the covering film per one side of the plated steel sheet is within a range of 4 to 400 mg/m2. An amount in terms of mass of cobalt in the covering film per one side of the plated steel sheet is within a range of 0.1 to 20 mg/m2.

Abstract: A surface-coated aluminum and zinc plated steel sheet in accordance with the present invention includes: a plated steel sheet; a composite coating film formed by applying an aqueous surface treatment agent on the plated steel sheet and drying the aqueous surface treatment agent. The aqueous surface treatment agent contains a water dispersible resin (A), a cobalt compound (B), and water, and has a pH within a range of 7.5 to 10. The composite coating film contains the water dispersible resin (A) and the cobalt compound (B). A percentage by mass of the water dispersible resin (A) in the composite coating film is 90% or more. A mass of the composite coating film per one surface of the plated steel sheet falls within a range of 0.5 to 3.5 g/m2.

Abstract: The present invention provides a hot-dipped steel 1 that demonstrates favorable corrosion resistance and formability, and has a favorable appearance of a plating layer. The hot-dipped steel of the present invention includes a steel substrate formed thereon with an aluminum-zinc alloy plating layer. The aluminum-zinc alloy plating layer contains Al, Zn, Si and Mg as constituent elements thereof and the Mg content is 0.1% to 10% by weight. The aluminum-zinc alloy plating layer contains 0.2% to 15% by volume of an Si—Mg phase, and the weight ratio of Mg in the Si—Mg phase to the total weight of Mg is 3% or more.