Disclosed herein is a high-strength plated steel sheet having a plated layer on the surface of a base steel sheet and containing predetermined steel components. The steel sheet includes, in the order from the interface of the base steel sheet and the plated layer towards the base steel sheet: a soft layer having a Vickers hardness that is 90% or less of the Vickers hardness at a portion t/4 of the base steel sheet, where t is a sheet thickness of the base steel sheet; and a hard layer consisting of a structure which is mainly composed of martensite and bainite and in which the average grain size of prior austenite is 20 μm or less. The average depth D of the soft layer is 20 μm or greater, and the average depth d of an internal oxide layer is 4 μm or greater and smaller than D.

The high-strength plated steel sheet of the present invention has a plated layer on the surface of a base steel sheet and contains predetermined steel components. The steel sheet includes, in the order from the interface of the base steel sheet and the plated layer towards the base steel sheet: a soft layer having a Vickers hardness that is 90% or less of the Vickers hardness at a portion t/4 of the base steel sheet, where t is a sheet thickness of the base steel sheet: and a hard layer containing martensite, bainite, and ferrite in predetermined ranges. The average depth D of the soft layer is 20 μm or greater, and the average depth d of an internal oxide layer is 4 μm or greater and smaller than D.

The high-strength plated steel sheet of the present invention has a plated layer on the surface of a base steel sheet and contains predetermined steel components. The steel sheet includes, in the order from the interface of the base steel sheet and the plated layer towards the base steel sheet: a soft layer having a Vickers hardness that is 90% or less of the Vickers hardness at a portion t/4 of the base steel sheet, where t is a sheet thickness of the base steel sheet: and a hard layer containing martensite, bainite, and ferrite in predetermined ranges. The average depth D of the soft layer is 20 μm or greater, and the average depth d of an internal oxide layer is 4 μm or greater and smaller than D.

Method of hot press forming an article from zinc or zinc alloy coated steel, wherein the steel is a product obtained by: casting the molten steel into slabs; reheating the slabs; hot rolling the steel into a strip, preferably with an FRT above Ar3; coiling the hot rolled steel strip; pickling the hot rolled steel strip; continuous annealing the strip; hot dip coating the steel strip with the zinc or zinc alloy whilst: using a dipping time of 3 seconds or more; maintaining in the hot dip bath a bath temperature of 420° C. to 500° C.; wherein the zinc bath contains essentially zinc, at least 0.1% Al, and optionally up to 5% Al and optionally up to 4% Mg, the rest of the bath including further elements all individually less than 0.3%, and unavoidable impurities; hot press forming the article.

This hot-dip Zn—Al—Mg-based plated steel includes: a steel; and a plating layer formed on a surface of the steel, in which the plating layer contains, as an average composition, Mg: 1 to 10 mass %, Al: 4 to 22 mass %, and a remainder consisting of Zn and impurities, the plating layer includes an (Al—Zn mixed structure) in an area ratio of 10% to 70% in a cross section of the plating layer in a matrix of an (Al/Zn/MgZn.sub.2 ternary eutectic structure), the (Al—Zn mixed structure) includes a first region that has a Zn concentration in a range of 75 mass % or more and less than 85 mass % and a second region that is present inside the first region and has a Zn concentration in a range of 67 mass % or more and less than 75 mass %, and an area ratio of the second region in the (Al—Zn mixed structure) in the cross section of the plating layer is more than 0% and 40% or less.

Provided are a plated steel sheet and a method for manufacturing same, the plated steel sheet comprising: a base steel sheet; a Zn—Mg—Al based steel sheet plating layer provided on at least one surface of the base steel sheet; and an Fe—Al based inhibition layer provided between the base steel sheet and the Zn—Mg—Al based plating layer, wherein the plating layer comprises, in wt %: 4% or more of Mg; 2.1 times or more of Mg content and 14.2% or less of Al; 0.2% or less (including 0%) of Si; 0.1% or less (including 0%) of Sn; the remainder Zn; and unavoidable impurities.

A high-performance thermoformed component provided with a coating, and a manufacturing method therefor. The thermoformed component comprises a substrate and a coating thereon. The substrate comprises the following ingredients in percentage by weight: 0.01-0.8% of C, 0.05-1.0% of Si, 0.1-5% of Mn, 0.001-0.3% of P, 0.001-0.1% of S, 0.001-0.3% of Al, 0.001-0.5% of Ti, 0.0005-0.1% of B, 0.001-0.5% of Nb, 0.001-0.5% of V, and the remainder being Fe and other unavoidable impurities. The appearance of the thermoformed component has no color difference and no mottling. The surface oxygen content of the thermoformed component is 0.1-20 wt. %, and the ratio of the standard deviation to the average value of the surface oxygen content satisfies: 0<standard deviation of oxygen content/average value of oxygen content ≤0.3. In the manufacturing method, a coated steel plate that has undergone heat treatment, transfer processing, and hot stamping is not treated with oil.

The present disclosure relates to a zinc plated steel sheet having excellent fatigue strength of electrical resistance spot welds and a method for manufacturing the same. According to an aspect of the present disclosure, a zinc plated steel sheet includes a base steel sheet and a zinc-based plating layer formed on a surface of the base steel sheet, wherein a concentration profile of one or two of oxygen, and silicon and manganese measured in a depth direction from the surface of the base steel sheet has a maximum point in the depth direction from the surface, and an absolute value of a difference between a depth at which the maximum point of the concentration profile of oxygen is formed and a depth at which the maximum point of the concentration profile of one of silicon and manganese is formed is 0.5 μm or less.

The present disclosure relates to a zinc plated steel sheet having excellent fatigue strength of electrical resistance spot welds and a method for manufacturing the same. According to an aspect of the present disclosure, a zinc plated steel sheet includes a base steel sheet and a zinc-based plating layer formed on a surface of the base steel sheet, wherein a concentration profile of one or two of oxygen, and silicon and manganese measured in a depth direction from the surface of the base steel sheet has a maximum point in the depth direction from the surface, and an absolute value of a difference between a depth at which the maximum point of the concentration profile of oxygen is formed and a depth at which the maximum point of the concentration profile of one of silicon and manganese is formed is 0.5 μm or less.

This steel sheet has a specific chemical composition, the tensile strength is 1300 MPa or more, the ratio (R/t) of the limit bend radius to the sheet thickness is less than 3.5, when a depth position of 30 μm from the surface in the sheet thickness direction is defined as a position A and a depth position of ¼ of the sheet thickness from the surface in the sheet thickness direction is defined as a position B, the number density of AIN at the position A is 3000 pieces/mm.sup.2 or more and 6000 pieces/mm.sup.2 or less, a metallographic structure at the position B includes 90% or more of martensite by volume percentage, and the hardness at the position A is 1.20 times or higher than the hardness at the position B.