Kawasaki Steel Corporation

Furukawa Aluminum Co., Ltd.

The Furukawa Electric Co., Ltd.

Toyota Motor Corporation

Yasuji Uesugi

Nobuyuki Morito

Motohiro Nabae

Akira Yasuda

Chiaki Kato

Hajime Kimura

Koichi Hashiguchi

Nobuo Totsuka

Yoshihiro Matsumoto

Rinsei Ikeda

Naoki Nishiyama

Kouichi Yasuda

Yoichi Tobiyama

Masaaki Kurihara

Takaaki Hira

Koji Yamato

Makoto Imanaka

Masaki Mabuchi

Kouichi Hashiguchi

An aluminum alloy sheet combining excellent press formability and spot weldability is disclosed. A chromate film of about 1.0 to 50.0 mg/m.sup.2 expressed in terms of metallic chromium is formed as a first layer on an aluminum alloy sheet, and an organic resin film containing about 60-95% by weight of organic lubricant and having a thickness of 0.02 to 0.90 .mu.m in terms of dry thickness is formed as a second layer on the chromate film. As the organic lubricant, a high-density polyethylene having a mean molecular weight of about 900 to 15,000 and a density of about 0.93 g/ml or more is preferable. This aluminum alloy sheet can be effectively used for automobile body applications.

Aluminum alloy sheet having excellent press formability and spot

A zinc or zinc-alloy plated steel sheet having an improved weldability and plating properties, as well as a method for making the same is provided. Even when the substrate steel sheet is the one which is difficult to deposit a zinc or zinc-alloy layer by conventional methods, such as an extra low carbon steel sheet, the present invention enables a reliable production of a galvanized steel sheet suffering from no plating failure of insufficient adhesion as well as a reliable production of a galvanized steel sheet suffering from no plating failure or streaking of the alloyed layer. The zinc or zinc-alloy plated steel sheet having improved weldability comprises an extra low carbon steel sheet, an iron-carbon plated layer or a carbon-rich layer generated by diffusion of the iron-carbon plated layer on at least one major surface of the extra low carbon steel sheet, and a zinc or zinc-alloy plated layer on the iron-carbon plated layer or the carbon-rich layer. The zinc or zinc-alloy plated steel sheet having improved weldability and/or plating properties is produced by depositing on the steel sheet an iron-carbon plated layer having a carbon content of from 0.01% by weight to 10% by weight to a coating weight of from 0.01 g/m.sup.2 to 10 g/m.sup.2, optionally annealing the iron-carbon plated steel sheet, and depositing a zinc or zinc-alloy plated layer, preferably by galvanizing or galvannealing, on the annealed steel sheet.

Surface-treated steel sheet having improved weldability and plating

A surface-treated aluminum material comprising an aluminum or aluminum alloy substrate, a chromate film deposited on the substrate, and an organic resin mixture film deposited on the chromate film is provided. The chromate film is deposited to a coating weight of from 5 to 100 mg/m.sup.2 calculated in terms of elementary chromium on the aluminum substrate. The organic resin mixture film is deposited to a dry film thickness of from 0.05 to 3.0 .mu.m, and comprises (a) 100 parts by weight of an organic resin, (b) 0.5 to 40 parts by weight of a powder lubricant having an average particle size of from 0.05 to 20 .mu.m, said average particle size being in the range of from 1.0 to 10 folds of the dry film thickness, and (c) 1.0 to 40 parts by weight of electroconductive finely divided particles having an average particle size in the range of from 0.05 to 5 .mu.m, said average particle size being in the range of from 1.0 to 2 folds of the dry film thickness. The organic surface-treated aluminum material has remarkable weldability, workability as well as corrosion resistance.

Surface-treated aluminum material having improved spot resistance

A zinc or zinc-alloy plated steel sheet having an improved weldability and plating properties, as well as a method for making the same is provided. Even when the substrate steel sheet is the one which is difficult to deposit a zinc or zinc-alloy layer by conventional methods, such as an extra low carbon steel sheet, the present invention enable a reliable production of a galvanized steel sheet suffering from no plating failure or insufficient adhesion as well as a reliable production of a galvannealed steel sheet suffering from no plating failure or streaking of the alloyed layer. The zinc or zinc-alloy plated steel sheet having improved weldability comprises an extra low carbon steel sheet, an iron-carbon plated layer or a carbon-rich layer generated by diffusion of the iron-carbon plated layer on at least one major surface of the extra low carbon steel sheet, and a zinc or zinc-alloy plated layer on the iron-carbon plated layer or the carbon-rich layer. The zinc or zinc-alloy plated steel sheet having improved weldability and/or plating properties is produced by depositing on the steel sheet an iron-carbon plated layer having a carbon content of from 0.01% by weight to 10% by weight to a coating weight of from 0 01 g/m.sup.2 to 10 g/m.sup.2, optionally annealing the iron-carbon plated steel sheet, and depositing a zinc or zinc-alloy plated layer, preferably by galvanizing or galvannealing, on the annealed steel sheet.

Aluminum alloy sheet with improved formability and method of production

Growing community of inventors

Chiba, Japan

Yasuji Uesugi