A high-strength galvanized steel sheet includes a steel sheet having a chemical composition containing a predetermined component element, a mass ratio of a content of Si to a content of Mn in the steel (Si/Mn) being 0.1 or more and less than 0.2, and the balance: Fe and incidental impurities, and a steel structure in which an average grain size of inclusions containing at least one of Al, Si, Mg, and Ca and existing in an area extending from a surface to a position of ⅓ of a sheet thickness is 50 μm or less, and an average nearest distance between ones of the inclusions is 20 μm or more; and a galvanized layer provided on a surface of the steel sheet, in which an amount of diffusible hydrogen contained in the steel is less than 0.25 mass ppm, and a tensile strength is 1100 MPa or more.

The present disclosure provides a hot-press formed part comprising a plated steel sheet and an aluminum alloy plated layer formed on the plated steel sheet, wherein the aluminum alloy plated layer comprises: an alloying layer (I) formed on the plated steel sheet and containing, by weight %, 5-30% of Al; an alloying layer (II) formed on the alloying layer (I) and containing, by weight %, 30 to 60% of Al; an alloying layer (III) formed on the alloying layer (II) and containing, by weight %, 20-50% of Al and 5-20% of Si; and an alloying layer (IV) formed continuously or discontinuously on at least a part of the surface of the alloying layer (III), and containing 30-60% of Al, wherein the rate of the alloying layer (III) exposed on the outermost surface of the aluminum alloy plated layer is 10% or more.

The present disclosure relates to a process for producing a surface-treated and surface-finished sheet steel. A sheet steel having a zinc-based coating is provided, wherein zinc grains are distributed within the coating. The surface-treated sheet steel are skin-pass rolled to form embossed regions and unembossed regions on the surface of the sheet steel provided with a zinc-based coating. Skin-pass rolling is performed with a degree of skin-pass greater than 1% in such a way that due to the force exerted by the skin-pass rolling the zinc grains in the embossed region are altered in dimension relative to the zinc grains in the unembossed region.

A hot-dipped galvanized steel sheet having excellent bending workability and corrosion resistance and a manufacturing method therefor are provided. A hot-dipped galvanized steel sheet of the present invention comprises: a base steel sheet; a Zn—Mg—Al based plating layer provided on at least one surface of the base steel sheet and including, in wt %, with respect to components other than iron (Fe) diffused from the base steel sheet, 5.1 to 25% of Al and 4.0-10% of Mg, and the remainder of Zn and other inevitable impurities; and an interfacial alloy layer having a Fe—Al—Zn composition formed between the base steel sheet and the plating layer, wherein the interfacial alloy layer has a thickness of 0.5-2 μm and has a dendritic form, the Zn—Mg—Al based plating layer has a Zn—Al—MgZn.sub.2 ternary eutectic structure, a Zn—MgZn.sub.2 binary eutectic structure, and a structure including one or more of an Al single-phase structure having solid-solubilized Zn and a Zn single-phase structure, and agglomerated Al is included in a MgZn.sub.2 structure.

A hot-dipped galvanized steel sheet having excellent bending workability and corrosion resistance and a manufacturing method therefor are provided. A hot-dipped galvanized steel sheet of the present invention comprises: a base steel sheet; a Zn—Mg—Al based plating layer provided on at least one surface of the base steel sheet and including, in wt %, with respect to components other than iron (Fe) diffused from the base steel sheet, 5.1 to 25% of Al and 4.0-10% of Mg, and the remainder of Zn and other inevitable impurities; and an interfacial alloy layer having a Fe—Al—Zn composition formed between the base steel sheet and the plating layer, wherein the interfacial alloy layer has a thickness of 0.5-2 μm and has a dendritic form, the Zn—Mg—Al based plating layer has a Zn—Al—MgZn.sub.2 ternary eutectic structure, a Zn—MgZn.sub.2 binary eutectic structure, and a structure including one or more of an Al single-phase structure having solid-solubilized Zn and a Zn single-phase structure, and agglomerated Al is included in a MgZn.sub.2 structure.

The present disclosure relates to an aluminum alloy-plated steel sheet having excellent workability and corrosion resistance and a method for manufacturing the same, and more particularly, to an aluminum alloy-plated steel sheet preventing microcracks generated during hot forming and has excellent seizure resistance and corrosion resistance, and a method for manufacturing the same.

A coated steel sheet has a coating film on at least one side of a plated steel sheet. The coating film contains a binder resin, non-oxide ceramic particles containing V (excluding VC particles), and doped zinc oxide particles. The respective contents of the non-oxide ceramic particles containing V and the doped zinc oxide particles relative to the coating film satisfy the expressions: [(1) C.sub.Zn≥10.0, (2) C.sub.V≤0.5.Math.C.sub.Zn, (3) C.sub.V≤70−C.sub.Zn, (4) C.sub.V≥0.125.Math.C.sub.Zn, and (5) C.sub.V≥2.0], where C.sub.V represents the content (mass %) of the non-oxide ceramic particles containing V, and C.sub.Zn represents the content (mass %) of the doped zinc oxide particles. The coated steel sheet is excellent in both corrosion resistance before electrodeposition coating, and weldability.

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 MgZn.sub.2 phase is from 45 to 75%, a total area fraction of MgZn.sub.2 and Al phases is not less than 70%, and an area fraction of Zn—Al—MgZn.sub.2 ternary eutectic structure is from 0 to 5%; and the plating layer has a predetermined chemical composition.

This Zn-plated hot stamped product includes a steel, a Zn-based plating layer, and an oxide layer, in which an upper layer which is a region on a surface side of the Zn-based plating layer has a two-phase structure of a Γ phase and an Fe—Zn solid solution, and a lower layer which is a region of the Zn-based plating layer excluding the upper layer has a single-phase structure of an Fe—Zn solid solution, an upper layer thickness and a lower layer thickness satisfy the following expression, a Mn content ratio of Max. Mn/Min. Mn, which is a ratio of a maximum value Max. Mn to a minimum value Min. Mn of an Mn content on a surface of the Zn-plated hot stamped product, is 10.0 or less, and an average value Ave. Mn is 0.5 to 7.5% by mass %.

0.20≤upper layer thickness/(upper layer thickness+lower layer thickness)≤0.80

A plated steel includes: a steel; and a plating layer that is provided on a surface of the steel, in which the plating layer includes, by mass %, Al: 5.00% to 35.00%, Mg: 2.50% to 13.00%, Fe: 5.00% to 40.00%, Si: 0% to 2.00%, Ca: 0% to 2.00%, and a remainder of Zn and impurities, and in a cross section of the plating layer, the area fraction of a Zn solid-solution Fe.sub.2Al.sub.5 phase in which 5% or more of Zn is solid-soluted is 10% to 60% and the area fraction of a MgZn.sub.2 phase is 10% to 90%.