Nippon Steel Corporation

Nippon Paint Compnay, Ltd.

Hidetoshi Shindo

Kiyokazu Ishizuka

Ikuo Kikuchi

Jun Maki

Yasuto Goto

Kohei Tokuda

Masao Kurosaki

Atsushi Morishita

Koichi Saito

Mamoru Saito

Kenichiro Matsumura

Motohiro Sasaki

Atsuhiko Tounaka

Kimitaka Hayashi

Fumiaki Nakamura

Koji Kawanishi

Hiroaki Uramoto

Yuto Fukuda

Akira Takahashi

Hiroshi Sakai

Riki Okamoto

Noriyuki Maekawa

Shinichi Yamaguchi

Takuya Mitsunobu

Kohei Ueda

Hiroshi Takebayashi

Hiroshi Kanai

Takeshi Toyoda

Kazuhiko Honda

Satoru Tanaka

Seiji Sugiyama

Kazumi Nishimura

Teruaki Izaki

Yasuhide Morimoto

Hiroyasu Furukawa

Yoshihiro Suemune

Hiromasa Nomura

Fumio Shibao

Daisuke Ito

Takashi Futaba

Masaaki Sugiyama

Yoshio Kimata

Hisaaki Sato

Takayuki Kuwagaki

Naoyuki Yamato

Yasuhiro Majima

Keita Katsumaru

Ryohei Mimura

Ryohta Niiya

Toshikazu Amemiya

A plated steel sheet comprises a plated layer on a surface of a steel sheet, in which in the plated layer, the total amount ΣA of Sn, Bi, and In is less than 0.75%, the total amount ΣB of Ca, Y, La, and Ce is 0.03 to 0.60%, the total amount ΣC of Cr, Ti, Ni, Co, V, Nb, Cu, and Mn is 0 to 1.00%, Sn≤Si, and 20.0≤Mg/Si are satisfied, and in an X-ray diffraction pattern of a surface of the plated layer, an X-ray diffraction peak of AlZnCa, an X-ray diffraction peak of CaZn, and an X-ray diffraction peak of η'-MgZnsatisfy a predetermined relationship.

Plated steel sheet

A plated steel including a plated layer on a surface of a steel, in which Expression 1 of 0&#x2264;Cr+Ti+Ni+Co+V+Nb+Cu+Mn&#x2264;0.25 and Expression 2 of 0&#x2264;Sr+Sb+Pb+B+Li+Zr+Mo+W+Ag+P&#x2264;0.50 are satisfied, and Expression 3 of I(MgZn(41.31&#xb0;))/I&#x3a3;(MgZn)&#x2264;0.265 and Expression 6 of 0.150&#x2264;{I(MgZn(20.79&#xb0;))+I(MgZn(42.24&#xb0;))}/I&#x3a3;(MgZn) are further satisfied in an X-ray diffraction pattern of a surface of the plated layer measured using Cu-K&#x3b1; rays under a condition that an X-ray output is 40 kV and 150 mA.

Plated steel

A plated steel includes: a steel; a zinc based electroplated layer formed on a surface of the steel; and an organic resin coating layer formed on a surface of the zinc based electroplated layer, in which the surface of the zinc based electroplated layer has hairline extending in a predetermined direction, Ra (ML) measured on the surface of the zinc based electroplated layer is 0.10 to 0.70 &#x3bc;m, on the surface of the zinc based electroplated layer, a peak number PPI measured in a hairline orthogonal direction with a reference level of 10 &#x3bc;inch satisfies PPI&#x2265;350&#xd7;Ra (MC) with respect to Ra (MC), on a surface of the organic resin coating layer, Ra (CC) satisfies Ra (CC)/Ra (CL)&#x2265;1.10 with respect to Ra (CL), and Ra (CC) satisfies Ra (CC)&#x3c;Ra (MC) with respect to Ra (MC).

Provided is a surface treated steel sheet for a fuel tank, the surface treated steel sheet including: a Zn plated layer or a Zn&#x2014;Ni alloy plated layer which is formed on at least a surface of the steel sheet to be an inner surface of the fuel tank; and a chromate-free chemical conversion coating layer containing a water-and-oil repellent, the chromate-free chemical conversion coating layer being placed over the Zn plated layer or the Zn&#x2014;Ni alloy plated layer on the surface to be the inner surface of the fuel tank. A water contact angle on a surface of the chromate-free chemical conversion coating layer is more than or equal to 70 degrees and an n-hexadecane contact angle on the surface of the chromate-free chemical conversion coating layer is more than or equal to 30 degrees and less than or equal to 70 degrees.

Surface treated steel sheet for fuel tank

A hot-rolled steel sheet has predetermined chemical composition, a sum of a Si content and an Al content is higher than 0.20% and lower than 0.81%, a microstructure includes, by area fraction, 90% to 99% of a ferrite, 1% to 10% of a martensite, and a bainite limited to 5% or less, the grain size of the martensite is 1 to 10 &#x3bc;m, the X-ray random intensity ratio of a {211}&#x3c;011&#x3e; orientation which is parallel to a rolled surface of the steel sheet and is parallel to a rolling direction is 3.0 or less.

Hot-rolled steel sheet and production method of therefor

The present invention provides a composite coated zinc-containing plated steel material different from the plated steel materials treated by conventional chromate replacement technologies and superior in all of corrosion resistance, blackening resistance, coating adhesion, and alkali resistance. The composite coated zinc-containing plated steel material of the present invention is characterized by having a composite coating formed by coating and drying on the surface of a plated steel material a treatment solution containing a basic zirconium compound, vanadyl (VO)-containing compound, phosphoric acid compound, cobalt compound, organic acid, and water and having a pH 7 to 14, the composite coating containing, with respect to the Zr element as 100 parts by mass, V in an amount of 10 to 45 parts by mass, P in 5 to 100 parts by mass, Co in 0.1 to 20 parts by mass, and an organic acid in 10 to 90 parts by mass.

Composite coated zinc-containing plated steel material superior in corrosion resistance, blackening resistance, coating adhesion, and alkali resistance

The present invention provides an inorganic-organic composite-treated zinc-plated steel sheet whose treated coatings do not contain any chromium and which is excellent in corrosion resistance after degreasing, coating adhesion and electrodeposition coating performance. The inorganic-organic composite-treated zinc-plated steel sheet, which is obtained by forming a zinc phosphate coating, in a coating weight of 0.3 to 5 g/m, on the zinc-plated steel sheet surface and forming thereon a post-treatment coating, in a coating weight of 0.01 to 1 g/m, by using a post-treatment composition containing at least one compound (A) selected from the group consisting of thiocarbonyl group-containing compounds, sulfide group-containing compounds and guanidyl group-containing compounds, an organic resin (B), a crosslinking agent (C) and an inorganic corrosion inhibitor (D).

Inorganic-organic composite-treated zinc-plated steel sheet

The present invention is intended to provide an inorganic-organic composite-treated zinc-plated steel sheet whose treated coatings do not contain any hazardous chromate and which is excellent in corrosion resistance after alkaline degreasing and coating adhesion. An inorganic-organic composite-treated zinc-plated steel sheet

A tin-plating or aluminum-plating surface treated steel material with excellent corrosion resistance containing an intermetallic compound composed of one or more Group IIa (alkaline earth metal) elements and one or more Group IVb elements in a tin-based plating layer or aluminum-based plating layer on the surface of a steel material. For a tin-based plating layer, the long diameter of the intermetallic compound massive bodies is 1 82 m or greater and the short diameter/long diameter ratio is at least 0.4. For an aluminum-based plating layer, the long diameter of the intermetallic compound massive bodies is 10 &mgr;m or greater and the short diameter/long diameter ratio is at least 0.4.

Surface treated steel product prepared by tin-based plating or aluminum-based plating

A zinc phosphate treated galvanized steel sheet capable of securing sufficient white rust resistance and non-uniform dew condensation resistance without requiring a sealing chromate treatment has high white color and is excellent in color tone uniformity. The galvanized steel sheet has a zinc phosphate film containing at least 2% of Mg and 0.01 to 1% of at least one element selected from the group consisting of Ni, Co and Cu, and the adhesion value of the zinc phosphate film is at least 0.7 g/m .

Zinc phosphate-treated galvanized steel sheet excellent in corrosion resistance and color tone

Phosphate-treated galvanized steel sheet excellent in corrosion resistance and paintability

A coated steel material excellent in corrosion resistance and a method of producing the same, wherein a coated steel material has on the surface of the steel sheet a Zn-alloy coating layer containing 1-10 wt % of Mg, 2-19 wt % of Al and 0.01-2 wt % of Si, where Mg and Al satisfy Mg (%)&plus;Al (%)&lE;20%, the balance being Zn and unavoidable impurities, and has a coating layer structure of a Mg intermetallic compound or the like. As a base metal treatment, it is preferably provided with a Ni coating layer. The coated Zn-alloy coated steel sheet may have provided on the coating layer, as an intermediate layer, a chromate film layer, and, as an upper layer, an organic coating layer. The Zn-alloy coating layer may further contain one or more of 0.01-1 wt % of In, 0.01-1 wt % of Bi and 1-10 wt % of Sn. The coated steel material may be painted.

-Zn coated steel material, ZN coated steel sheet and painted steel sheet excellent in corrosion resistance, and method of producing the same

The present invention has an object to provide a surface-treated steel sheet which has highly balanced corrosion resistance and formability, and satisfies fundamental properties required mainly for steel sheets for automobile body, and a manufacturing method thereof. The surface-treated steel sheet of the invention is excellent in corrosion resistance and formability, comprising an amorphous inorganic film containing at least 5% magnesium and having a weight within a range of from 0.1 to 2.0 g/m , formed on the surface of a zinc or zinc alloy plated steel sheet; wherein the inorganic film is soluble in an acidic solution and hardly soluble in a neutral or alkaline solution, and a manufacturing method thereof is provided. A zinc phosphate film may be provided between the galvanized steel sheet and the amorphous inorganic film. The inorganic film should preferably comprise one or more selected from the group consisting of phosphoric acid, phosphates, biphosphates, various condensed phosphoric acids, various condensed phosphates, organic phosphoric acid, and organic phosphates.

Surface-treated steel sheet and manufacturing method thereof

Growing community of inventors

Himeji, Japan

Hidetoshi Shindo