Nippon Steel Sumitomo Metal Corporation

Nippon Steel Corporation

Sony Corporation

Nihon Parkerizing Co., Ltd.

Shintaro Yamanaka

Soshi Fujita

Jun Maki

Masao Kurosaki

Koichi Sato

Shigeru Hirano

Hiroki Fujimoto

Hirokazu Yokoya

Hatsuhiko Oikawa

Yasuhiko Sato

Kazuhisa Kusumi

Hideaki Irikawa

Morio Yanagihara

Masakazu Noda

Nobuo Nakasone

Tatsuya Suzuki

Shinichi Suzuki

Hiroyuki Tanaka

Kengo Takeda

Satoshi Nishimura

Masayuki Nakamura

Toshimasa Tomokiyo

Yoshifumi Kobayashi

Takashi Imamura

Hiroaki Ando

Tetsuo Yutani

Kazuyuki Kawano

Kensuke Mizuno

Takumi Kozaki

Takahiro Kodama

Yasunori Itoh

Kazutoshi Nagatome

Hatsushiko Oikawa

To provide a Sn-based plated steel sheet excellent in yellowing resistance, coating film adhesiveness, and sulfurization blackening resistance without performing the conventional chromate treatment. A Sn-based plated steel sheet of the present invention includes: a steel sheet; a Sn-based plating layer located on at least one surface of the steel sheet; and a coating layer located on the Sn-based plating layer, wherein: the Sn-based plating layer contains 0.10 to 15.00 g/mof Sn per side in terms of metal Sn; the coating layer contains a Zr oxide and a Mn oxide; a content of the Zr oxide is 0.20 to 50.00 mg/mper side in terms of metal Zr; a content of the Mn oxide in terms of metal Mn is 0.01 to 0.50 times on a mass basis relative to the content of the Zr oxide in terms of metal Zr; and a depth position A where an element concentration of Mn is maximum is located on a side closer to a surface of the coating layer than a depth position B where an element concentration of Zr is maximum, and a distance in a depth direction between the depth position A and the depth position B is 2 nm or more in an element analysis in the depth direction by XPS.

Sn-based plated steel sheet

To provide a Sn-based plated steel sheet capable of exhibiting superior corrosion resistance, yellowing resistance, coating film adhesiveness, and sulphide stain resistance without using a chromate film. A Sn-based plated steel sheet of the present invention includes: a steel sheet; a Sn-based plating layer located on at least one surface of the steel sheet; and a coating layer located on the Sn-based plating layer, wherein the Sn-based plating layer contains 1.0 g/mto 15.0 g/mof Sn per side in terms of metal Sn, the coating layer contains zirconium oxide, and a content of the zirconium oxide is 1.0 mg/mto 10.0 mg/mper side in terms of metal Zr, the zirconium oxide includes zirconium oxide with an amorphous structure, and a crystalline layer whose main component is zirconium oxide with a crystalline structure is present on an upper layer of the zirconium oxide with the amorphous structure.

A Sn-plated steel sheet including a base plated steel sheet having a steel sheet, a Sn-plated layer on at least one surface of the steel sheet, and a film layer containing a zirconium oxide and a tin oxide. An adhesion amount of Sn per surface of the Sn-plated steel sheet is 0.1 g/mor more and 15 g/mor less, an amount of the zirconium oxide in the film layer is in a range of 1 mg/mor more and 30 mg/mor less in terms of an amount of metal Zr, a peak position of a binding energy of Sn3dof the tin oxide is 1.4 eV or more and less than 1.6 eV from a peak position of a binding energy of metal Sn, and a quantity of electricity required for reduction of the tin oxide is more than 5.0 mC/cmand 20 mC/cmor less.

Sn-plated steel sheet and method for manufacturing Sn-plated steel sheet

A Sn-plated steel sheet according to the present invention includes a steel sheet, a Sn-plated layer that is provided on at least one surface of the steel sheet, and a film that is provided on a surface of the Sn-plated layer and includes zirconium oxide and tin oxide, in which an amount of the zirconium oxide in the film is 0.2 mg/mto 50 mg/min terms of metal Zr amount, in a depth direction analysis by X-ray photoelectron spectroscopy, a depth position A at which an element concentration of Zr present as the zirconium oxide is maximum is positioned closer to a surface of the film than a depth position B at which an element concentration of Sn present as the tin oxide is maximum, and a distance between the depth position A and the depth position B in a depth direction is 0.5 nm or more.

The Sn-plated steel sheet of the disclosure is an Sn-plated steel sheet including: a steel sheet; an Sn plating layer formed on at least one side of the steel sheet and containing, based on % by mass, from 0.1 g/mto 15 g/mof metal Sn; and a coating layer formed on the surface of the Sn plating layer and containing zirconium oxide and tin oxide; in which the content of the zirconium oxide in the coating layer is from 0.2 mg/mto 50 mg/min terms of metal Zr amount, and the peak position of binding energy of Sn3daccording to X-ray photoelectron spectroscopy of the tin oxide in the coating layer is 1.6 eV or higher than the peak position of binding energy of the metal Sn.

Sn-plated steel sheet

The Sn-based alloy plated steel sheet of this disclosure includes: a steel sheet; a composite plating layer formed on at least one side of the steel sheet and including an Fe&#x2014;Ni&#x2014;Sn alloy layer and an island-shaped Sn layer located on the Fe&#x2014;Ni&#x2014;Sn alloy layer; and a coating layer formed on the surface of the composite plating layer and containing zirconium oxide and tin oxide, and the composite plating layer contains a predetermined amount of Ni and a predetermined amount of Sn, a content of the zirconium oxide in the coating layer is from 0.2 mg/mto 50 mg/min terms of metal Zr amount, and a peak position of binding energy of Sn3daccording to X-ray photoelectron spectroscopy of the tin oxide in the coating layer is 1.6 eV or higher than a peak position of binding energy of the metal Sn.

Sn-based alloy plated steel sheet

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.

Alloyed hot-dip galvanized steel sheet and method of manufacturing the same

A high-strength hot-dip galvanized steel sheet that is a steel sheet that includes major components and that contains at least 40 vol. % the sum of bainite and martensite, 8-60 vol. % retained austenite, and less than 40 vol. % ferrite, with the remainder comprising an incidental structure. The hot-dip galvanized steel sheet has, at the interface between the deposit layer formed by hot-dip galvanization and the base steel sheet, an intermetallic compound constituted of Fe, Al, Zn, and incidental impurities and having an average thickness of 0.1-2 &#x3bc;m, the intermetallic compound having a crystal grain diameter of 0.01-1 &#x3bc;m. After the deposit layer formed by hot-dip galvanization was removed, the surface of the base steel sheet has an arithmetic average roughness Ra of 0.1-2.0 &#x3bc;m and gives a roughness curve in which the contour elements have an average length RSm of 5-300 &#x3bc;m.

High-strength hot-dip galvanized steel sheet

By superposing a plurality of steel sheets including a high tensile steel sheet and performing pulsation conduction by an inverter DC type spot welding power supply and controlling the conduction time of the current pulses, intervals of the current pulses, that is, conduction idle time, and weld current applied at the current pulses in a variable manner, the optimum weld conditions are obtained. For resistance spot welding of the hot stamped steel sheet, resistance spot welding with a minimum weld current of a second pulsation step higher than the maximum weld current at a first pulsation step is used to suppress the occurrence of outer spatter and inner spatter and secure a broad suitable current range even if using an inverter DC power supply.

Resistance spot welding method

A high-strength hot-dip galvanized steel sheet containing a main component, the steel sheet having at least 40 wt. % of ferrite as a main phase in terms of the volumetric ratio, and 8-60% inclusive of residual austenite, the remaining structure comprising one or more of bainite, martensite, or pearlite. Austenite particles within a range where the average residual stress (sigmaR) thereof satisfies the expression &#x2212;400 MPa&#x3c;=sigmaR&#x3c;=200 MPa (formula (1)) are present in an amount of 50% or more in the hot-dip galvanized steel sheet. The surface of the steel sheet has a hot-dip galvanized layer containing less than 7 wt. % of Fe, the remainder comprising Zn, Al and inevitable impurities.

High-strength hot-dip galvanized steel sheet and process for producing the same

A resistance spot welding method including: a pulsation process of clamping a sheet assembly of two or more overlapped steel sheets including at least one high tensile steel sheet using a pair of welding electrodes that are connected to a spot welding power source employing an inverter direct current method, and performing plural repetitions of current passing and current pass stopping, while pressing the steel sheets with the welding electrodes; and a continuous current pass process in which, after the pulsation process, current is passed continuously for a longer period of time than a maximum current pass time of the pulsation process, while pressing the steel sheets with the welding electrodes.

[Object] There are provided automobile parts and a method for manufacturing the automobile parts. The automobile parts have an excellent corrosion resistance after coated with a electrodeposition paint with smaller thickness, improve formability and productivity in hot pressing, and also improve chemical conversion treatability after hot press-forming. [Solution] An automobile part according to the present invention includes: a formed steel sheet having an intermetallic compound layer formed on a surface of the steel sheet, the intermetallic compound layer being formed of Al&#x2014;Fe intermetallic compound having a thickness of 10 &#x3bc;m or more and 50 &#x3bc;m or less, the intermetallic compound layer including a diffusion layer positioned in closest proximity to the steel sheet, the diffusion layer having a thickness of 10 &#x3bc;m or less; a surface coating layer provided on a surface of the intermetallic compound layer, the surface coating layer including a coating containing ZnO and a zinc phosphate coating and having a surface roughness of 3 &#x3bc;m or more and 20 &#x3bc;m or less as a maximum profile height Rt in accordance with JIS B0601 (2001); and an electrodeposition paint film provided on a surface of the surface coating layer and having a thickness of 6 &#x3bc;m or more and less than 15 &#x3bc;m.

Automobile part and method for manufacturing automobile part

To provide a plated steel sheet for hot pressing, a hot pressing method for the plated steel sheet, and an automobile part made by the hot pressing method that has an excellent lubricity with less deposition amount and can improve formability and productivity in hot pressing work and also can improve chemical conversion treatability after hot press forming, there is provided an Al plating layer formed on one side or both sides of the steel sheet, the Al plating layer containing at least Al, and further containing one or more elements, at a total content of 0.02 to 2 mass %, selected from Mg, Ca, Sr, Li, Na, and K; and a surface coating layer laminated on the Al plating layer and containing at least ZnO.

Plated steel sheet for hot pressing, hot pressing method for plated steel sheet, and automobile part

An Al-based alloy plated steel material includes: a steel material and a coating layer formed on a surface of the steel material, wherein the coating layer includes an Al-based alloy plating layer containing, in mass %, not less than 10% nor more than 50% Fe and not less than 3% nor more than 15% Si, and formed on the surface of the steel material; a layer containing ZnO and formed above a surface of the Al alloy plating layer; and a ZnAlOlayer with a thickness of not less than 0.05 &#x3bc;m nor more than 2 &#x3bc;m, formed between the Al alloy plating layer and the layer containing ZnO.

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Tokyo, Japan

Shintaro Yamanaka