Provided is a hot stamped body comprising a steel base material, an Al-plating layer formed on at least one surface of the steel base material, a coating formed on the Al-plating layer and containing ZnO particles and CeO.sub.2 particles having an average particle size smaller than an average particle size of the ZnO particles, and a Zn- and Al-containing complex oxide layer formed between the Al-plating layer and the coating. Further, provided is a method for producing a hot stamped body comprising forming an Al-plating layer on at least one side of a steel sheet, coating a surface of the Al-plating layer with an aqueous solution containing ZnO particles and CeO.sub.2 particles, then heating it to form a coating containing ZnO particles and CeO.sub.2 particles on the Al-plating layer, and hot pressing the steel sheet. Further, provided is an Al-plated steel sheet comprising a steel base material, an Al-plating layer formed on at least one surface of the steel base material, and a coating formed on the Al-plating layer and containing ZnO particles and CeO.sub.2 particles having an average particle size smaller than an average particle size of the ZnO particles.

An embodiment of the present invention provides a steel sheet for hot press, including carbon (C) in an amount of 0.03 to 0.15 wt%, silicon (Si) in an amount of 0.1 to 1.5 wt%, manganese (Mn) in an amount of 1.0 to 2.0 wt%, phosphorus (P) in an amount of 0.1 wt% or less, sulfur (S) in an amount of 0.01 wt% or less, boron (B) in an amount of 0.0005 to 0.005 wt%, a sum of one or more of titanium (Ti), niobium (Nb), and vanadium (V) in an amount of 0.01 to 1.0 wt%, chromium (Cr) in an amount of 0.01 to 0.5 wt%, the balance of iron (Fe), and other unavoidable impurities. The steel sheet for hot press includes MnS-based inclusions, and an area fraction of the MnS-based inclusions is 5 % or less.

The present disclosure relates to an aluminum-based plated steel that is provided for vehicles by hot forming, an aluminum-based alloy plated steel manufactured using the same, and method of manufacturing thereof.

This joint component is a joint component including a first steel member, a second steel member, and a spot-welded portion that joins the first steel member and the second steel member, in which the first steel member includes a steel sheet substrate having a predetermined chemical composition and a coating that is formed on a surface of the steel sheet substrate, contains Al and Fe, and has a thickness of 25 μm or more, in a cross section in a thickness direction of the first steel member and the second steel member including the spot-welded portion, a filled metal containing Al and Fe is present in a gap between the first steel member and the second steel member in a periphery of the spot-welded portion, in the cross section, the filled metal has a cross-sectional area of 3.0×10.sup.4 μm.sup.2 or more, and has a filling ratio of 80% or more in the gap in a range of 100 μm from an end portion of a corona bond formed in the periphery of the spot-welded portion, and includes a first region and a second region.

A steel sheet has a hot-dip Zn—Al—Mg-based coating film, the coating film containing 1 mass % to 22 mass % of Al and 0.1 mass % to 10 mass % of Mg on a surface of the steel sheet, in which an X-ray diffraction peak intensity ratio of a Mg—Zn compound phase in the coating film, that is, MgZn.sub.2/Mg.sub.2Zn.sub.11, is 0.2 or less.

A steel sheet has a hot-dip Zn—Al—Mg-based coating film, the coating film containing 1 mass % to 22 mass % of Al and 0.1 mass % to 10 mass % of Mg on a surface of the steel sheet, in which an X-ray diffraction peak intensity ratio of a Mg—Zn compound phase in the coating film, that is, MgZn.sub.2/Mg.sub.2Zn.sub.11, is 0.2 or less.

Provided is a galvanized steel sheet having excellent plating adhesion, having a plated layer with improved friction characteristics by means of a predetermined level of Fe elution, and having excellent corrosion resistance; and a manufacturing method therefor.

Provided is a galvanized steel sheet having excellent plating adhesion, having a plated layer with improved friction characteristics by means of a predetermined level of Fe elution, and having excellent corrosion resistance; and a manufacturing method therefor.

A method for producing a zinc or zinc-alloy coated steel sheet with a tensile strength higher than 900 MPa, for the fabrication of resistance spot welds containing in average not more than two Liquid Metal Embrittlement cracks per weld having a depth of 100 μm or more, with steps of providing a cold-rolled steel sheet, heating cold-rolled steel sheet up to a temperature T1 between 550° C. and Ac1+50° C. in a furnace zone with an atmosphere (A1) containing from 2 to 15% hydrogen by volume, so that the iron is not oxidized, then adding in the furnace atmosphere, water steam or oxygen with an injection flow rate Q higher than (0.07%/h×α), α being equal to 1 if said element is water steam or equal to 0.52 if said element is oxygen, at a temperature T≥T1, so to obtain an atmosphere (A2) with a dew point DP2 between −15° C. and the temperature Te of the iron/iron oxide equilibrium dew point, then heating the sheet from temperature T.sub.1 up to a temperature T.sub.2 between 720° C. and 1000° C. in a furnace zone under an atmosphere (A2) of nitrogen containing from 2 to 15% hydrogen and more than 0.1% CO by volume, with an oxygen partial pressure higher than 10.sup.−21 atm., wherein the duration t.sub.D of heating of the sheet from temperature T.sub.1 up to the end of soaking at temperature T.sub.2 is between 100 and 500 s., soaking the sheet at T.sub.2, then cooling the sheet at a rate between 10 and 400° C./s, then coating the sheet with zinc or zinc-alloy coating.

Provided is a multilayer zinc alloy plated steel material comprising a base steel material and multiple plating layers formed on the base steel material, wherein each of the multiple plating layers includes one of a Zn plating layer, a Mg plating layer, and a Zn—Mg alloy plating layer, and the ratio of the weight of Mg contained in the multiple plating layers to the total weight of the multiple plating layers is from 0.13 to 0.24.