Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Nihon Parkerizing Co., Ltd.

Soshi Fujita

Jun Maki

Shintaro Yamanaka

Masahiro Fuda

Yuki Suzuki

Hideaki Irikawa

Koichi Sato

Masahiro Kubo

Shinichi Yamaguchi

Naruhiko Nomura

Tatsuya Kubota

Toyomitsu Nakamura

Tatsuya Suzuki

Kenji Kobayashi

Yoshiaki Nakazawa

Toshiya Suzuki

Masahiro Nakata

Takashi Aramaki

Takashi Doi

Takeshi Imai

Masao Kurosaki

Atsushi Morishita

Hiroki Fujimoto

Kazuhisa Kusumi

Hatsuhiko Oikawa

Nobuo Yoshikawa

Taihei Kaneto

Kensuke Mizuno

Takumi Kozaki

Takahiro Kodama

Fumio Eihara

Naomi Inatomi

Michiko Konno

Narihiko Nomura

Hatsushiko Oikawa

Irikawa Hideaki

Kubota Tatsuya

Maki Jun

A hot-stamped product with improved delayed-fracture resistance is provided. The hot-stamped productincludes: a steel substrate; and an Al filmformed on the steel substrate, the Al filmincluding: an interface layerlocated at the interface with the steel substrateand with part of the αFe substituted by Al and Si; an intermediate layerformed on the interface layer; and an oxide layer formed on the intermediate layer, the intermediate layerincluding an Fe—Al—Si phasewith part of the αFe substituted by Al and Si, the Fe—Al—Si phaseincluding one or more elements selected from the group consisting of Zr, Ce, Y, Ta, Ni, Cu, Nb, Cr, Co, V and Ti, the oxide layerincluding one or more elements selected from the group consisting of Be, Mg, Ca, Sr, Ba, Sc and Zn.

Hot-stamped product

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 CeOparticles 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 CeOparticles, then heating it to form a coating containing ZnO particles and CeOparticles 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 CeOparticles having an average particle size smaller than an average particle size of the ZnO particles.

Hot stamped body and method for producing same and Al-plated steel sheet

A manufacturing method includes: heating an overlapped blank; transferring the heated overlapped blank; and a step of performing presswork on the heated overlapped blank by using a die. In the heating step, when sheet-thicknesses of the first and second steel sheets are set, respectively, and an average heating rate at a sheet temperature from 20 to 800° C. of a portion with a total sheet thickness of an overlapped portion, and a non-overlapped portion are set, the total sheet thickness is 2.5 to 5.0 mm, a maximum length of the overlapped portion is 100 to 1100 mm, an area of the first steel sheet, an area of a portion, of the second steel sheet, overlapped with the first steel sheet, and the average heating rates satisfy Expressions (1) to (3), and heating is performed at a temperature and for a time within a specific range on a plane of coordinates.

Method of manufacturing overlapped hot stamp molded body, and overlapped hot stamp molded body

An Al plated electric resistance welded steel pipe for hardening use suppressing the formation of scale to the inside of the plating layer while performing hot forming and an Al plated hollow member using that Al plated electric resistance welded steel pipe, wherein the Al plated electric resistance welded steel pipe for hardening use is comprised of a base material made of a tubular steel plate and having a predetermined chemical composition and an electric resistance welded zone provided at a seam portion of the steel plate and extending in a longitudinal direction of the steel plate, the base material is further provided with an intermetallic compound layer positioned on the surface of the steel plate and including an Al—Fe—Si-based intermetallic compound and an Al plating layer positioned on the surface of the intermetallic compound layer and containing Al and Si, and 70×X/D≤Y/t≤30 is satisfied, wherein X (μm) is a thickness of the intermetallic compound layer, Y (μm) is a thickness of the Al plating layer, t (mm) is a pipe thickness of the steel pipe, and D (mm) is an outside diameter of the steel pipe.

Al plated welded pipe for hardening use and al plated hollow member and method for producing same

This aluminum-plated steel sheet has a steel sheet and a plating layer formed on a surface of the steel sheet, the plating layer contains one or more A group elements selected from a group consisting of Be, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, a remainder of Al, Fe, and impurities, a thickness t of the plating layer is 10 to 60 μm, and an average grain size is 2t/3 or less and 15 μm or less in a thickness range from an outermost surface of the plating layer to a ⅔ thickness t position.

Aluminum-plated steel sheet, hot-stamped member, and method for manufacturing hot-stamped member

A method of producing a hot press-formed product includes subjecting an Al-plated steel sheet having a zinc compound layer or a metallic zinc layer, as an outermost layer, provided on an Al plating layer to hot press forming using a die. The die includes a hard layer having a skewness (Rsk), as measured in a direction from the outside of a die hole toward the inside of the die hole, of 1.3 or less and a hardness Hv_Die of HV 2,000 or more, over the entirety of a region of a steel sheet contact surface that is adjacent to a die shoulder portion. The steel sheet contact surface is a surface located outside of the die hole and configured to contact the Al-plated steel sheet that is to be subjected to the hot press forming.

Production method for hot press molded articles, press molded article, die mold, and mold set

This manufacturing method of a hot press-formed article includes a heating step of heating an Al-plated steel sheet and a forming step of obtaining a hot press-formed article using a die after the heating step, the Al-plated steel sheet has a base steel sheet, an Al plating layer, and a coating layer, the coating layer is a metal layer containing at least one metal of Mg, Ca, V, Ti, and Zn, a metal oxide layer containing an oxide of one or more of Mg, Ca, V, Ti, and Zn, or a mixed layer including the metal layer and the metal oxide layer, the die has a hard layer on a surface, HVthat is a surface hardness of the die at a position of the hard layer is HV1500 or more and HV3800 or less, and a temperature Tm of the Al-plated steel sheet at a start of forming and an average movement velocity V of the die in the forming step satisfy 800−(HV/40)≤Tm≤850−(V/4)−(HV/100).

Method for manufacturing hot-press-formed article, and hot-press-formed article

A plated steel sheet for hot stamping according to one aspect of the present invention includes a steel sheet, a plating layer formed on either surface or both surfaces of the steel sheet and having an Al content of 60 mass % or more, and a surface film layer formed on the plating layer. A thickness t of the plating layer is 10 to 60 μm. An average crystal grain diameter of the plating layer in a thickness range from an interface between the plating layer and the surface film layer to a position at ⅔ of the thickness t is 2t/3 or less and 15.0 μm or less. A surface film layer contains particles containing one or more elements selected from A group elements consisting of Sc, V, Mn, Fe, Co, Ce, Nb, Mo, and W. A total content of the A group elements is 0.01 to 10.0 g/m. An average grain diameter of the particles containing the A group elements is 0.05 to 3.0 μm.

Plated steel sheet for hot stamping and hot-stamped member

Provided is an Al-plated hot stamped steel material comprising a steel base material, an Al-plating layer formed on at least one surface of the steel base material, and a chemical conversion coating formed on the Al-plating layer and containing zinc phosphate-based crystals and Ce-based compounds deposited on the surfaces of the zinc phosphate-based crystals, wherein an amount of deposition of the zinc phosphate-based crystals in the chemical conversion coating is, converted to metal Zn, 0.3 to 4.0 g/mand an area ratio of the Ce-based compounds in the chemical conversion coating is 0.5 to 25%.

Al-plated hot stamped steel material

An Al plated electric resistance welded steel pipe for hardening use suppressing the formation of scale to the inside of the plating layer while performing hot forming and an Al plated hollow member using that Al plated electric resistance welded steel pipe, wherein the Al plated electric resistance welded steel pipe for hardening use is comprised of a base material made of a tubular steel plate and having a predetermined chemical composition and an electric resistance welded zone provided at a seam portion of the steel plate and extending in a longitudinal direction of the steel plate, the base material is further provided with an intermetallic compound layer positioned on the surface of the steel plate and including an Al&#x2014;Fe&#x2014;Si-based intermetallic compound and an Al plating layer positioned on the surface of the intermetallic compound layer and containing Al and Si, and 70&#xd7;X/D&#x2264;Y/t&#x2264;30 is satisfied, wherein X (&#x3bc;m) is a thickness of the intermetallic compound layer, Y (&#x3bc;m) is a thickness of the Al plating layer, t (mm) is a pipe thickness of the steel pipe, and D (mm) is an outside diameter of the steel pipe.

Al plated welded pipe for hardening use and Al plated hollow member and method for producing same

An aluminum-based plated steel sheet according to an aspect of the present invention includes: a base material; an aluminum-based plating layer located above the base material; and an intermetallic compound layer that is located between the base material and the aluminum-based plating layer and contains an intermetallic compound of Al and Fe, in which the base material has a chemical component within a predetermined range, the aluminum-based plating layer contains, on average, 80 mass % or more and 97 mass % or less of Al, 3 mass % or more and 15 mass % or less of Si, 0 mass % or more and 5 mass % or less of Zn, 0 mass % or more and 5 mass % or less of Fe, 0 mass % or more and 3 mass % or less in total of one or more selected from the group consisting of Mg and Ca, and impurities so that a total amount thereof is 100 mass %, an average value of a thickness of the intermetallic compound layer is 2 &#x3bc;m or more and 10 &#x3bc;m or less, a maximum value of the thickness of the intermetallic compound layer is 10 &#x3bc;m or more and 25 &#x3bc;m or less, and a standard deviation of the thickness of the intermetallic compound layer is 2 &#x3bc;m or more and 10 &#x3bc;m or less.

Aluminum-based plated steel sheet, method of manufacturing aluminum-based plated steel sheet, and method of manufacturing component for vehicle

Fe-Al-based plated hot-stamped member exhibiting excellent formed part corrosion resistance and post-coating corrosion resistance and manufacturing method. The hot-stamping member includes Fe-Al-based plated layer on one or both surfaces of a base material, the base material has a predetermined steel component, Fe-Al-based plated layer has a thickness of 10 &#x3bc;m or more and 60 &#x3bc;m or less, formed by A, B, C and D layers sequentially from a surface toward the base material, and each of the four layers is a Fe-Al-based intermetallic compound containing Al, Fe, Si, Mn and Cr for predetermined contents with the balance made up of impurities, the D layer further contains Kirkendall voids each of which cross-sectional area is 3 &#x3bc;m-30 &#x3bc;mfor 10 pieces/6000 &#x3bc;mor more and 40 pieces/6000 &#x3bc;mor less.

Fe&#x2014;Al-based plated hot-stamped member and manufacturing method of Fe&#x2014;Al-based plated hot-stamped member

To solve the problem about the difference in temperature increasing rate between an overlapped part and a one-sheet part so as to further improve the corrosion resistance of plating after hot stamping. An overlapped blank for hot stamping includes: a first steel sheet; and at least one second steel sheet connected to a surface of the first steel sheet via a welding point and smaller in area than the first steel sheet, wherein: the first steel sheet is a plated steel sheet having an aluminum-based plated layer on both faces of the first steel sheet, and the second steel sheet is a plated steel sheet having an aluminum-based plated layer on both faces of the second steel sheet; a coating weight of the aluminum-based plated layer on the first steel sheet is W1 (g/m) in terms of an average coating weight on both the faces; a coating weight of the aluminum-based plated layer on a surface on a side not in contact with the first steel sheet in the second steel sheet is W2 (g/m); and each of the W1 and the W2 is within a range of 20 g/mor more and 120 g/mor less, and satisfies relationships of Expression (1) and Expression (2).

Overlapped blank for hot stamping, method of manufacturing overlapped hot stamp molded body, and overlapped hot stamp molded body

A surface treatment solution for a plated steel sheet to be hot-pressed comprising a ZnO aqueous dispersion (A) and a water dispersible organic resin (B), wherein the ZnO aqueous dispersion (A) comprises water and ZnO particle size having 50 to 300 nm particles, the water dispersible organic resin (B) has a 5 to 45 mgKOH/g acid value and 5 to 300 nm emulsion particle size, and a mass ratio (W/W) of a mass of ZnO particles in the ZnO aqueous dispersion (W) to a mass of solid content of the water dispersible organic resin (W) is 30/70 to 95/5.

Surface treatment solution for plated steel sheet to be hot-pressed

Provided is an alloyed hot-dip galvanized steel sheet including a base steel sheet, the base steel sheet containing a given amount of C, Si, Mn, and other elements. The alloyed hot-dip galvanized steel sheet is provided with an alloyed hot-dip galvanized layer on a surface of the base steel sheet, the alloyed hot-dip galvanized layer containing, in mass %, Fe: more than or equal to 5% and less than or equal to 15%, and having a thickness of more than or equal to 3 &#x3bc;m and less than or equal to 30 &#x3bc;m. The alloyed hot-dip galvanized steel sheet includes an A layer immediately under the surface of the base steel sheet, the A layer being formed in the base steel sheet and having a thickness of more than or equal to 2 &#x3bc;m and less than or equal to 20 &#x3bc;m from the surface of the base steel sheet, containing more than or equal to 50 vol % of a ferrite structure, and containing more than or equal to 90 mass % of unoxidized Fe, less than or equal to 10 mass % of a total of contents of oxides of Fe, Si, Mn, P, S, and Al, and less than 0.05 mass % of C.

Growing community of inventors

Tokyo, Japan

Soshi Fujita