Kawasaki Steel Corporation

Jfe Steel Corporation

Other

Dai Nippon Toryo Co., Ltd.

Shigeru Umino

Hiroyuki Ogata

Koji Yamato

Hajime Kimura

Chiyoko Tada

Toshio Ichida

Chiaki Kato

Kenji Takao

Hideo Ogishi

Kei Sakata

Kazuhiro Seto

Kazuo Mochizuki

Hiroki Nakamaru

Akio Tosaka

Yoichi Tobiyama

Toshiyuki Kato

Nobuyuki Morito

Kazuaki Kyono

Keiji Nishimura

Sachiko Suzuki

Hideo Sasaoka

Kazuhiko Higai

Fuminori Mukaihara

Yoshinori Gotou

Kazuo Wakasa

Hiromasa Hayashi

Yuuzo Ootuka

Takeshi Sakuma

A black galvanized steel sheet including a composite coating layer formed on a surface of a blackened galvanized steel sheet by applying a treatment solution containing a phosphate ion, a vanadate ion, a metal ion, an &#x3b1;,&#x3b2;-unsaturated carboxylic acid and a glycoluril resin; and an organic resin layer formed on the composite coating layer, is provided. The black galvanized steel sheet is excellent in heat absorption and heat dissipation, electrical conductance, and corrosion resistance in a worked portion. Furthermore, the black galvanized steel sheet does not include hexavalent chromium.

Black zinc-plated steel sheet

In the present application, a steel sheet having surface-treated zinc-based plating is provided which comprises a zinc-based plating layer, a chromium-free conductive intermediate layer and an organic resin layer, all of the layers being superimposed one on another in the order mentioned. Even though it is of a so-called chromium-free surface-treated steel sheet, the steel sheet is more conductive and more highly resistant to corrosion than conventional chromium-free steel sheets, the likelihood of water pollution is reduced, and the steel sheet can be used in various applications as a replacement for conventional chromate-treated steel sheets.

Surface treated zinc-based metal plated steel sheet

The coating composition includes a methacrylic resin prepared by copolymerization of styrene or a substituted styrene (A), a methacrylic ester obtained from an alcohol having at least two carbon atoms and methacrylic acid (B), and an olefinic compound having at least one carboxylic group (C), in which the molar ratio thereof is 1:(0.05 to 44.5):(0.12 to 13). A metal sheet lubricated with the coating composition has superior characteristics of dissolution of the film in an alkaline solution, chemical processing, paint dryness, blocking resistance, corrosion resistance, stability of coating composition, and press formability (powdering resistance and galling resistance).

Coating composition and lubricated metal sheets

A composition for metal surface treatment which comprises an aluminum ion, a magnesium ion, a manganese ion, a water-soluble organic resin, an acid and water; and a surface treated metal material which has been treated with the composition. The resultant surface treated metal material is free from the danger of water contamination owing to chromium, since the composition is free of chromium, and also is excellent in both electrical conductivity and corrosion resistance. Accordingly, the metal material can be used in a wide variety of applications in place of a conventional chromate-treated steel sheet and the like.

Composition for metal surface treatment and surface treated metallic material

This invention can form a sufficiently internal oxide layer in a surface layer portion of an iron matrix of a steel sheet by hot rolling a base steel and subjecting to a heat treatment at a temperature range of 650-950&deg; C. in an atmosphere substantially not causing reduction while being adhered with a black skin scale irrespectively of a chemical steel composition or production history, or even when a radiation type heating of a radial tube or the like is used in a recrystallization annealing before a hot dipping treatment, and hence excellent hot-dipping property and conversion treating property can be given to a steel sheet for hot dipping.

Methods of producing steel plate, hot-dip steel plate and alloyed hot-dip steel plate

High-strength hot dip galvannealed steel sheets having excellent plating

Surface treated steel strip with minimal plating defects and method for

The improved corrosion-resistant steel plate with an organic coating comprises a steel plate having a zinc or zinc alloy plate layer which is overlaid with a chromate film which in turn is coated with an organic resin paint film. The organic resin coat comprises an epoxy resin having a dialkanolamine incorporated into its bisphenol A skeleton, an amino resin, and silica. The dialkanolamine combines with the amino resin to provide satisfactory curability at low temperatures; at the same time, it combines with the silica to provide a satisfactory film reinforcing effect. The organic coat formed of this composition can be effectively cured at low temperatures and yet it will neither dissolve nor soften upon swelling under the action of the alkali that is generated during cationic electrodeposition at the interface between the electrodeposited film and the organic coat. Thus, the organic coat has good paint adhesion, high corrosion resistance, as well as good workability and weldability and makes the steel plate suitable for use as an automotive part after painting. If the proportion of trivalent chromium in the chromate film and the amounts of zinc oxide and silica sol to be incorporated as additives are properly adjusted, the organic coating will exhibit satisfactory resistance to chromium dissolution and hence its paint adhesion and corrosion resistance are further improved to make the steel plate more suitable for use as an automotive part after painting.

Steel plate with organic coating having improved corrosion resistance

The improved corrosion-resistant steel plate with an organic coating comprises a steel plate having a zinc or zinc alloy plate layer which is overlaid with a chromate film which in turn is coated with an organic resin paint film. The organic resin coat comprises an epoxy resin which is prepared by reacting with an isocyanate compound and has a dialkanolamine incorporated into its bisphenol A skeleton, and silica. The dialkanolamine combines with a urethane-modified epoxy resin to provide satisfactory curability at low temperatures; at the same time, it combines with the silica to provide a satisfactory film reinforcing effect. The organic coat formed of this composition can be effectively cured at low temperatures and yet it will neither dissolve nor soften upon swelling under the action of the alkali that is generated during cationic electrodeposition at the interface between the electrodeposited film and the organic coat. Thus, the organic coat has good paint adhesion, high corrosion resistance, as well as good workability and as-worked corrosion resistance and makes the steel plate suitable for us an automotovie part after painting.

Steel plate with organic coating having improved corrosion resistance in

Composite plated steel strips comprising a zinc base layer electrodeposited on at least one surface of a steel strip exhibit excellent corrosion resistance with or without painting provided that the zinc base layer contains 0.1 to 10% by weight of cobalt, 0.05 to 5% by weight of chromium, 0.05 to 8% by weight of aluminum, and optionally, 0.05 to 5% by weight of Si, the balance being zinc. Such composite plated steel strips are prepared by subjecting a steel strip to composite electroplating in an acidic zinc plating bath which contains at least one water-soluble compound of Co.sup.2+ in an amount of 0.3 to 60 g/l of metallic cobalt, at least one water-soluble compound of Cr.sup.3+ in an amount of 0.2 to 2.5 g/l of metallic chromium, a pseudo-boehmite like alumina sol in an amount of 0.5 to 20 g/l of alumina, and optionally, colloidal silica in an amount of 0.5 to 20 g/l of silica at pH 1 or higher and a current density of at least 40 A/dm.sup.2.

Method for making high corrosion resistance composite plated steel strip

Composite plated steel strips comprising a zinc base layer electrodeposited on at least one surface of a steel strip exhibit excellent corrosion resistance with or without painting provided that the zinc base layer contains 0.1 to 10% by weight of cobalt, 0.05 to 5% by weight of chromium, 0.05 to 8% by weight of aluminum, and optionally, 0.05 to 5% by weight of Si, the balance being zinc. Such composite plated steel strips are prepared by subjecting a steel strip to composite electroplating in an acidic zinc plating bath which contains at least one water-soluble compound of Co.sup.2+ in an amount of 0.3 to 60 g/l of metallic cobalt, at least one water-soluble compound of Cr.sup.3+ in an amount of 0.2 to 2.5 g/l of metallic chromium, a pseudo-boehmite like alumina sol in an amount of 0.5 to 20 g/l of alumina, and optionally, colloidal silica in an amount of 0.5 to 20 g/l of silica of pH 1 or higher and a current density of at least 40 A/dm.sup.2.

High corrosion resistance composite plated steel strip

Growing community of inventors

Chiba, Japan

Shigeru Umino