Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Other

Nihon Parkerizing Co., Ltd.

Nippon Steel & Sumikin Materials Co., Ltd.

Nippon Steel Stainless Steel Corporation

Nippon Stell & Sumikin Materials Co., Ltd.

Nippon Steel & Sumikin Coated Sheet Corporation

Masayuki Abe

Jun Maki

Hironori Sato

Yuzo Takahashi

Masahiro Oogami

Kunio Hayashi

Shinya Nakajima

Masao Kurosaki

Takuya Mitsunobu

Soshi Fujita

Kazuhisa Kusumi

Takehiro Takahashi

Shintaro Yamanaka

Hiroshi Takebayashi

Masahiro Fuda

Kohei Tokuda

Shinichi Yamaguchi

Yuki Suzuki

Yasuto Goto

Kazutoshi Takeda

Hiroyasu Fujii

Seiji Sugiyama

Teruaki Izaki

Takayuki Kobayashi

Hiroyuki Tanaka

Yoshitaka Nishiyama

Shinichi Terashima

Hideya Kaminaka

Tatsuya Kubota

Hidetoshi Shindo

Toyomitsu Nakamura

Masamoto Tanaka

Shuji Nagasaki

Tatsuya Suzuki

Noriyuki Suzuki

Masahiro Nakata

Kengo Takeda

Hiroyuki Kawata

Takashi Aramaki

Nobuhiro Fujita

Shuichi Yamazaki

Koichi Nose

Manabu Takahashi

Osamu Goto

Yuji Ogawa

Kohei Ueda

Hiroshi Kanai

Hiroki Fujimoto

Mamoru Saito

Hideaki Irikawa

Keitaro Matsuda

Takayuki Ohmori

Hiroyuki Mimura

Kazumi Nishimura

Yasuhide Morimoto

Junko Imamura

Nobuyoshi Okada

Masaaki Uranaka

Akira Akagi

Masami Fujishima

Hideaki Suda

Naruhiko Nomura

Kazuhiko Honda

Hidekuni Murakami

Satoru Tanaka

Hatsuhiko Oikawa

Hiroyasu Furukawa

Yoshihiro Suemune

Yasuhiro Masaki

Nobuo Yoshikawa

Hiroyuki Tanahashi

Hiromasa Nomura

Yasushi Tsukano

Masahiro Ohgami

Tetsurou Takeshita

Haruhiko Eguchi

Masaaki Sugiyama

Shunsuke Taniguchi

Kunio Nishimura

Hisaaki Sato

Kensuke Mizuno

Yusho Oyama

Takumi Kozaki

Takahiro Kodama

Shintaroh Yamanaka

Norihiro Fujita

Toshiyuki Kanda

Nobyoshi Okada

Yu Ando

Masaaki Yamamoto

Masaaki Enjuji

Yuya Fujii

Michiko Konno

Yusuke Kanto

Kohei Maejima

Yuya Takashima

A steel welded member comprising a plurality of Zn-based plated steel materials, each having a Zn-based plating layer on a surface of a steel material, joined together through at least one spot weld, wherein the steel material contains, by mass %, C: 0.05 to 0.40%, Si: 0.2 to 3.0%, and Mn: 0.1 to 5.0%, the steel welded member includes, by area ratio, 20 to 80% of a Γ phase (FeZn) and at least one oxide with a long axis of 0.5 μm or more in a region up to 0.5 mm from an end part of a pressure weld of the spot weld.

Steel welded member

A galvanized steel sheet comprising a steel sheet containing C: 0.05 to 0.30%, Si: 0.01 to 3.00%, Mn: 0.80 to 3.00%, and Al: 0.010 to 2.000% and having a thickness of 0.10 to 0.95 mm, and a galvanized layer on the steel sheet, wherein a tensile strength is 550 to 1500 MPa, and, when defining a thickness of an internal oxide layer per surface of the steel sheet as 'A' (μm), a thickness of a decarburized layer per surface of the steel sheet as “B” (μm), and a thickness of the steel sheet as “t” (μm), A/B: 0.01 to 0.50 and B/t: 0.001 to 0.200.

Galvanized steel sheet

High strength plated steel sheet having high hydrogen embrittlement resistance, that is, alloyed hot dip galvannealed steel sheet including steel sheet containing C: 0.05 to 0.40%, Si: 0.2 to 3.0%, Mn: 0.1 to 5.0%, and sol. Al: 0.4 to 1.50% and a alloyed hot dip galvannealed layer deposited on at least one surface of the steel sheet to 10 to 100 g/mand containing Fe: 5.0 to 15.0% and Al: 0.01 to 1.0%, having an internal oxidation layer including grain boundary oxides in a surface layer of the steel sheet, when examining a cross-section of a surface layer of the steel sheet, a Ratio A of the length of the grain boundary oxides projected an interface of the steel sheet and the alloyed hot dip galvannealed layer to the length of interface is 50% or more and 100% or less, and a surface depleted layer with a steel composition not including the grain boundary oxides which satisfies, by mass %, Si≤0.6% and Al≥0.05% is included at a depth of ½ of the average depth of the internal oxidation layer.

Alloyed hot dip galvannealed steel sheet

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 non-oriented electrical steel sheet according to one embodiment of the present invention includes a base metal steel sheet, and a composite coating film composed of a Zn-containing phosphate and an organic resin, the composite coating film being formed on a surface of the base metal steel sheet, wherein: a content of Zn in the composite coating film is 10 mg/mor more per side; and the product of an amount of oxygen in the base metal steel sheet and a sheet thickness of the base metal steel sheet is 50 ppm·mm or less.

Non-oriented electrical steel sheet and method for producing same

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

A non-oriented electrical steel sheet according to one embodiment of this invention includes a base metal steel sheet and a composite coating film composed of a Zn-containing phosphate and an organic resin, the composite coating film being formed on a surface of the base metal steel sheet. A molar ratio of Zn to all metal components in the composite coating film is 10 mol % or more, and after the non-oriented electrical steel sheet is boiled for 20 minutes in boiled distilled water, an amount of soluble Zn in the distilled water is 1.0 mg/mor more. The method for determining the amount of soluble Zn is in accordance with JIS K 0102: 2016 'Testing Methods for Industrial Wastewater', 53.3 “ICP Emission Spectroscopy”.

High strength steel sheet and plated steel sheet having high plateability, LME resistance, and hydrogen embrittlement resistance, that is, steel sheet containing C: 0.05 to 0.40%, Si: 0.2 to 3.0%, Mn: 0.1 to 5.0%, and sol. Al: 0.4 to 1.50%, having an internal oxidation layer including fine granular oxides, coarse granular oxides, and grain boundary oxides in a surface layer of the steel sheet, a number density of fine granular oxides in the internal oxidation layer being 4.0/μmor more, a number density of coarse granular oxides in the internal oxidation layer being 4.0/25 μmor more, having a Ratio A of the length of the grain boundary oxides projected on the surface of the steel sheet to the length of the surface of the steel sheet when examining a cross-section of the surface layer of the steel sheet being 50% or more and 100% or less, and including a surface depleted layer with a steel composition not including oxides which satisfies, by mass %, Si≤0.6% and Al≥0.05% at a depth of ½ of the average depth of the internal oxidation layer calculated from the cross-sectional SEM image of the steel sheet, and a plated steel sheet using the same.

Steel sheet and plated steel sheet

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 hot stamped body comprising a steel base material and an Al—Zn—Mg-based plating layer formed on a surface of the steel base material, wherein the plating layer has a predetermined chemical composition, the plating layer comprises an interfacial layer positioned at an interface with the steel base material and containing Fe and Al and a main layer positioned on the interfacial layer, the main layer comprises, by area ratio, 10.0 to 90.0% of an Mg—Zn containing phase, 5.0 to less than 30.0% of an Fe—Al containing phase, and 2.0 to 25.0% of an Al—Si containing oxide phase, the Mg—Zn containing phase comprises at least one selected from the group consisting of an MgZn phase, MgZnphase, and MgZnphase, and the Fe—Al containing phase comprises at least one of an FeAl phase and Fe—Al—Zn phase.

Hot stamped body

A non-oriented electrical steel sheet according to an embodiment of the present invention is a non-oriented electrical steel sheet including a base metal steel sheet and a composite coating film that is formed on surfaces of the base metal steel sheet and includes Zn-containing phosphate and an organic resin, wherein the non-oriented electrical steel sheet contains crystalline aluminum phosphate showing diffraction lines belonging to ICDD No. 01-074-3256 when the composite coating film is measured by a wide-angle X-ray diffraction method.

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

A plated steel material comprising a steel base material and an Al&#x2014;Zn&#x2014;Mg-based plating layer formed on a surface of the steel base material, wherein the plating layer has a predetermined chemical composition, and in a surface structure of the plating layer, there is, by area ratio, 2.0% or more of an acicular Al&#x2014;Zn&#x2014;Si&#x2014;Ca phase.

Plated steel material

A plated steel sheet having excellent chemical convertibility 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 35.00%, Si: 0% to 2.00%, Ca: 0.03% to 2.00%, and a remainder consisting of Zn and impurities, and in a surface of the plating layer, the area fraction of a Fe&#x2014;Al phase is 0% to 30%, the area fraction of a rod-like lamellar structure of Zn and MgZnis 5% to 90%, the area fraction of a massive MgZnphase is 10% to 70%, and the area fraction of a remainder is 10% or less.

Plated steel sheet

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Tokyo, Japan

Jun Maki