Nkk Corporation

Jfe Steel Corporation

Nihon Parkerizing Co., Ltd.

Takafumi Yamaji

Masaaki Yamashita

Akira Matsuzaki

Yuichi Fukushima

Keiji Yoshida

Kenji Morita

Tatsuya Miyoshi

Satoru Ando

Junichi Inagaki

Takahiro Kubota

Naoto Yoshimi

Masaru Sagiyama

Kazuhisa Okai

Yasuhiko Haruta

Akihiko Furuta

Etsuo Hamada

Nobuyuki Ishida

Toshihiko Ooi

Toshiyuki Okuma

Hiroyasu Matsuki

Yoshio Nagae

Yasuo Okumura

Norio Inoue

Yasuhisa Tajiri

Yasuo Tanizawa

Yasuhiro Majima

Yuichiro Tanaka

Shinji Hori

Kenichi Tomita

Reiko Yamaji, Legal Representative

The present invention provides a surface treated steel sheet including a steel sheet; a plating layer containing at least one metal selected from the group consisting of zinc and aluminum on a surface of the steel sheet; and a film on the plating layer, the film containing at least one metal selected from the group consisting of Al, Mg, and Zn, a tetravalent vanadium compound, and a phosphoric acid group. This surface treated steel sheet exhibits excellent corrosion resistance and excellent surface appearance without containing hazardous substances, such as hexavalent chromium, in the film.

Surface-treated steel sheet and method for manufacturing the same

A surface-treated steel sheet includes a steel sheet, an Al&mdash;Zn-base alloy plating layer formed on the steel sheet, a chemical conversion film provided on the alloy plating layer, and a concentric layer of a Cr compound that is formed on the alloy plating layer of the chemical conversion film. The surface-treated steel sheet may include a steel sheet, an zinc-base plating layer formed on the steel sheet, and a film that contains chromium and calcium and that is formed on the zinc-base plating layer.

Surface-treated steel sheet and production method therefor

The method for manufacturing coated steel sheet has the steps of: immersing a steel sheet in a hot-dip coating bath to form an Al&mdash;Zn base coating layer containing 20 to 95 mass % Al on the steel sheet, forming a passivated layer on the coating layer; and applying thermal history to the coating layer. The thermal history is applied immediately after the steel sheet left the hot-dip coating bath or in a temperature range of from T(&deg; C.) between 130&deg; C. and 300&deg; C. to 100&deg; C.

Coated steel sheet and method for manufacturing the same

A coated steel sheet having excellent corrosion resistance comprises: a zinc or a zinc alloy plated steel sheet or an aluminum or an aluminum alloy plated steel sheet; a composite oxide coating formed on the surface of the plated steel sheet; and an organic coating formed on the composite oxide coating. The composite oxide coating contains a fine particle oxide and a phosphoric acid and/or a phosphoric acid compound. The organic coating has thickness of from 0.1 to 5 &mgr;m.

Coated steel sheet having excellent corrosion resistance and method for producing the same

A lubricant composition effectively enhancing the press-formability, and corrosion-resistance of a zinc-plated steel material and providing a superior, anti-powdering property and degreasing comprises (A) 70 -97% by weight of a lubricant component comprising the sub-components of (a) a succinate of a C.sub.12-18 aliphatic alcohol, (b) a paraffin wax with a melting point of 45.degree. C. -55.degree. C. and (c) a C.sub.12-18 fatty acid ester of C.sub.6-10 aliphatic alcohol and/or a mineral oil, the weight ratio ((a)+(b))/(c) being 1/3 to 1/1 and the weight ratio (a)/(b) being 1/3 to 4/1, and (B) 3 to 30% by weight of a rust-inhibiting component comprising a sulfonates with C.sub.16 or more, a carboxylic acid with C.sub.12 or more and/or a salt of the carboxylic acid, and has a melting point of 25.degree. C. to 40.degree. C. and an acid value of less than 2.0.

Rust-preventive lubricant composition for zinc-plated steel material

Growing community of inventors

Kawasaki, Japan

Takafumi Yamaji