Kawasaki Steel Corporation

Furukawa Aluminum Co., Ltd.

Masaki Mabuchi

Nobuo Totsuka

Yoshihiro Naruse

Koji Yamato

Motohiro Nabae

Yasuji Uesugi

Katsuhei Kikuchi

Rinsei Ikeda

Naoki Nishiyama

Keizou Okuno

Junichi Mano

Kouichi Hashiguchi

Youzou Ogawa

The improved version of a chromated metal sheet has a chromate layer on at least one side of a metal substrate or a plated metal substrate and it is characterized in that the chromate layer has a chromium deposit of 10-200 mg/m.sup.2 per surface in terms of metallic Cr, that the chromate layer contains silica in an amount of 0.1-6.0 in terms of the weight ratio of SiO.sub.2 to Cr, and that the chromate layer contains at least one kind of lubricating particles selected from the group consisting of graphite, MoS.sub.2, BN, calcium stearate and an organic lubricating substance in an amount of 0.1-100 in terms of the weight ratio of the lubricating particles to Cr. The lubricating particles can have a surface layer capable of nonionic surface activating action, and this surface layer accounts for 1-70 wt % of the lubricating particles. The chromated metal sheet has sufficient lubricity to withstand press forming in the absence of lube oil coatings, has high enough electric conductivity to present no problems in spot weldability and groundability, and has sufficiently high corrosion resistance to withstand use in a naked state.

Chromated metal sheet having high corrosion resistance with improved

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 surface-treated metal sheet which excels in workability, electrical conductivity and corrosion resistance has a metal sheet which has been plated as required, a chromate layer as a first layer formed on at least one side of the metal sheet, with a deposition amount of about 5 to 200 mg/m.sup.2 as calculated on the basis of Cr, and a second layer formed on the first layer from organic lubricant particles, with a deposition amount of from about 5 to 1000 mg/m.sup.2, such that the area coated by the organic lubricant particles to the entire area of the metal sheet surface is below about 50%. The second layer is preferably applied with a roll coater, a spin coater or a dip coater, a dispersion liquid or an emulsion containing about 0.1 to 40 wt. % of the organic lubricant particles so as to provide a wet film thickness of about 0.2 to 10 .mu.m.

Surface-treated metal sheet which excels in workability, electrical

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Chiba, Japan

Masaki Mabuchi