Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Nippon Paint Compnay, Ltd.

Other

Mitsui Chemicals, Inc.

Nippon Steel & Sumikin Stainless Steel Corporation

Mitsui Takeda Chemicals, Inc.

Masahiro Fuda

Soshi Fujita

Yuki Suzuki

Jun Maki

Hideaki Irikawa

Atsushi Morishita

Hiroshi Kanai

Teruaki Izaki

Taihei Kaneto

Masahiro Kubo

Noriyuki Maekawa

Yuji Yamaguchi

Kiyokazu Ishizuka

Natsuko Sugiura

Koichi Saito

Hironori Sato

Naruhiko Nomura

Kazuhisa Kusumi

Tatsuya Kubota

Kenichiro Matsumura

Akira Takahashi

Motohiro Sasaki

Yasuaki Naito

Ikuro Yamaoka

Toshinori Mizuguchi

Tsutomu Tawa

Nobuyoshi Okada

Hiroaki Uramoto

Takayuki Ohmori

Junji Nakano

Kenji Kobayashi

Yoshiaki Nakazawa

Masahiro Nakata

Takashi Aramaki

Takashi Doi

Takeshi Imai

Masao Kurosaki

Yoshiharu Inoue

Hiromasa Shoji

Yashichi Oyagi

Mitsuru Nakamura

Nobuo Yoshikawa

Yoichiro Mori

Kimitaka Hayashi

Ryousuke Wake

Fumio Shibao

Tetsurou Takeshita

Yoshio Kimata

Kensuke Mizuno

Katsuyuki Kawakami

Chikako Kouda

Makoto Yamasaki

Kensei Yuasa

Naomi Inatomi

Junpei Karoji

Hiroshi Kosuge

Ryosuke Wake

Fumiaki Hirata

Nobyoshi Okada

Ken Sawada

Takayuki Omori

Akiyoshi Inoue

Fumio Eihara

Irikawa Hideaki

Kubota Tatsuya

Maki Jun

Makoto Yamazaki

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

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

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

A fuel tank () includes: a lower panel () made of steel and an upper panel () made of steel; and at least one pillar () made of steel which is disposed in an interior space (V) formed by the lower panel () and the upper panel () facing each other and of which a first end portion is fixed to the lower panel () and a second end portion is fixed to the upper panel () in a state where the second end portion is disposed in a hole formed in the upper panel ().

Fuel tank with support pillar

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

A hot-dip Sn&#x2014;Zn-based alloy-plated steel sheet according to an aspect of the present invention includes: a steel sheet having a predetermined chemical composition; a diffusion alloy layer provided on one surface or both surfaces of the steel sheet; and a Sn&#x2014;Zn-plated layer provided on the diffusion alloy layer, in which the diffusion alloy layer contains Fe, Sn, Zn, Cr, and Ni, an area ratio of a Sn&#x2014;Fe&#x2014;Cr&#x2014;Zn phase to a Sn&#x2014;Fe&#x2014;Ni&#x2014;Zn phase in the diffusion alloy layer is 0.01 or more and less than 2.5, the diffusion alloy layer has a coverage of 98% or more with respect to the one surface, the Sn&#x2014;Zn-plated layer contains 1% to 20% of Zn by mass % and a remainder consisting of Sn and impurities, and an adhesion amount of the Sn&#x2014;Zn-plated layer is 10 to 80 g/mper one surface.

Hot-dip Sn&#x2014;Zn-based alloy-plated steel sheet

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-treated steel sheet for fuel tanks, including a Zn&#x2014;Ni alloy plating layer on one surface or both surfaces of a steel sheet; and a trivalent chromate covering layer or a chromate-free covering layer on the Zn&#x2014;Ni alloy plating layer, wherein, in a surface outermost layer of the trivalent chromate covering layer or the chromate-free covering layer, concavities, of which a depth from an arithmetic average height of a cross-sectional curve of the surface outermost layer is more than or equal to 0.1 &#x3bc;m, exist in a proportion of 50 to 1000 concavities/mm2 and at an area ratio of 20 to 80% to a surface area of the steel sheet.

Surface-treated steel sheet for fuel tanks

A steel sheet for a fuel tank according to the present invention includes: a Zn&#x2014;Ni alloy plated layer placed on one surface or each of both surfaces of a base metal; and a chromate-free chemical conversion coating film which is placed over the Zn&#x2014;Ni alloy plated layer. The Zn&#x2014;Ni alloy plated layer has a crack starting from an interface with the chromate-free chemical conversion coating film and reaching an interface with the steel sheet, the chromate-free chemical conversion coating film consists of an organosilicon compound consisting of a condensation polymer of a silane coupling agent, a phosphoric acid compound and/or a phosphonic acid compound, a vanadium compound, and a titanium compound and/or a zirconium compound, and a concentration of a total of amounts in terms of metal, per surface, of the phosphoric acid compound and/or the phosphonic acid compound+the vanadium compound+the titanium compound and/or the zirconium compound, is 5 mass % to 20 mass %.

Steel sheet for a fuel tank

A steel sheet for a fuel tank includes: a Zn&#x2014;Ni alloy plated layer which is placed on one surface or each of both surfaces of a base metal and formed on at least one surface; and an inorganic chromate-free chemical conversion coating film which is placed over the Zn&#x2014;Ni alloy plated layer. The Zn&#x2014;Ni alloy plated layer has a crack starting from an interface between the Zn&#x2014;Ni alloy plated layer and the inorganic chromate-free chemical conversion coating film and reaching an interface between the Zn&#x2014;Ni alloy plated layer and the steel sheet, and a water contact angle on a surface of the inorganic chromate-free chemical conversion coating film is more than or equal to 50 degrees.

A steel sheet for electroplating includes, by mass %, C: 0.0005% to 0.0050%, Si: 0.20% to 1.0%, Mn: 0.40% to 2.5%, P: 0.05% or less, Ti: 0.010% to 0.050%, Nb: 0.010% to 0.040%, B: 0.0005% to 0.0030%, S: 0.02% or less, Al: 0.01% to 0.30%, N: 0.0010% to 0.01%, and the balance including Fe and impurities, in which when Si content is represented by [Si] and Mn content is represented by [Mn], '[Mn]+5[Si]' is 2.0 to 7.0, and the steel sheet has surface property in which an average of displacements of a measurement point obtained based on a moving average of continuous 31 points in total including 15 front points and 15 back points in a cross-sectional profile of a surface obtained by measuring the average of displacements in an evaluation length of 10 &#x3bc;m or more at an interval of 0.07 &#x3bc;m, is 0.005 &#x3bc;m to 0.10 &#x3bc;m.

Steel sheet for electroplating, electroplated steel sheet, and methods for producing the same

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Tokyo, Japan

Masahiro Fuda