Kawasaki Steel Corporation

Toyota Motor Corporation

Furukawa Aluminum Co., Ltd.

Nobuyuki Morito

Chiaki Kato

Kazuo Mochizuki

Yoichi Tobiyama

Kiyoshi Shibuya

Hajime Kimura

Toru Sato

Yasuji Uesugi

Teruo Hiramatsu

Akira Yasuda

Seiji Nakajima

Hisatada Nakakoji

Nobuo Totsuka

Shuji Gomi

Shigeko Sujita

Seiko Nara

Toshitomo Sugiyama

Kouichi Yasuda

Hiroki Nakamaru

Toshio Ichida

Masao Yukumoto

Takaaki Hira

Koichi Hashiguchi

Kazuaki Kyono

Kyoko Hamahara

Shigeru Umino

Nobue Fujibayashi

Motohiro Nabae

Yoshihiro Matsumoto

Makoto Isobe

Yasuo Yokoyama

Makoto Imanaka

Tomokatsu Katagiri

Shigeo Kurokawa

Ryoichi Muko

Kazuhiro Hasegawa

Hiroaki Ohnuma

Yoshio Obata

Michio Katayama

Tohru Fujimura

Shinji Kobayashi

A Zn or part-Zn plated steel sheet has an MgO coating free of metallic Mg thereon which increases corrosion resistance and plating adherence. The MgO coating is formed by coating according to the sol-gel method or by dipping or treating by cathodic electrolysis a Zn or part-Zn plated steel sheet in a molten salt bath mainly containing a magnesium salt.

Corrosion resistant Zn or part-Zn plated steel sheet with MgO coating

Method for hot dip galvanizing high tensile steel strip with minimal

The improved organic composite coated steel plate includes a zinc or zinc alloy plated steel plate as a substrate that has on its surface a chromate film the Cr.sup.6+ content of which is no more than 70% of the total Cr content and which is deposited in an amount of 5-500 mg/m.sup.2 in terms of metallic chromium, the chromate film being overlaid with a resin layer that is deposited in an amount of 0.1-3 g/m.sup.2 on a dry weight basis and which is formed primarily of water-dispersed silica and one organic resin member as selected from the group consisting of an anionic aqueous resin, a nonionic aqueous resin and an anionic aqueous urethane resin. This steel plate is adapted for not contaminating the environment of the earth in the process of its manufacture.

Organic composite coated steel plates having improved corrosion

Corrosion resistant steel sheets improved in corrosion resistance and

A method of manufacturing a galvanized steel sheet with high press formability, the sheet having an inorganic compound on a metallic galvanized-layer thereof. The method includes the step of effecting a galvanization on a steel sheet followed by an alloying treatment. The sheet of galvanized steel is immersed in a bath of an aqueous solution containing 0.1 wt % or more of borate of an alkali metal, and then taking the steel sheet out of the bath and effecting such control as to make the amount of deposition of the water-containing borate film on the steel sheet surface to range from 10 to 1,000 mg/m.sup.2, and then heating the steel sheet at a temperature ranging from 60.degree. to 400.degree. C. Thereafter, the steel sheet is cooled to a normal temperature.

Method of manufacturing of galvanized steel sheet having high press

An organic composite coated steel strip having well-balanced corrosion resistance, coating properties including adaptability to electrophoretic coating and water resistant secondary coating adherence, and spot weldability is provided. The organic composite coated strip comprises a zinc or zinc base alloy plated steel substrate; a chromate later on the substrate containing up to 70% by weight of Cr.sup.6+ based on the total chromium quantity, the chromate layer being coated in a weight of 5 to 500 mg/m.sup.2 in terms of elemental chromium; and an organic composite layer on the chromate layer mainly comprising silica and an organic high molecular weight resin. In the organic composite coated steel strip, (a) silica has an average primary particle diameter of 5 to 30 nm; (b) silica is agglomerated into agglomerates of an average thickness of 0.2 to 2 .mu.m and an average apparent diameter of 5 to 300 .mu.m; and (c) the organic composite layer has been coated to a dry weight of 0.1 to 3 g/m.sup.2. The organic composite coated steel strip of the invention has various uses including automobile bodies.

Organic composite coated steel strip having improved corrosion

Surface treated steel strip with minimal plating defects and method for

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 process for the manufacture of tinplates comprising electroplating a substrate in a fused-chloride tin plating bath at a temperature of about 150.degree. to 350.degree. C., a current density of about 100 to 500 A/dm.sup.2 in an atmosphere of a non-oxidizing gas. This process may be converted to a process for the manufacture of reflow type tinplates by only changing the bath temperature, and vice versa. For the manufacture of no-reflow type tinplates, the bath is kept at 150.degree. to 232.degree. C., while for the manufacture of reflow type tinplates, the bath is kept at 233.degree. to 350.degree. C. In these cases, the bath includes SnCl.sub.2 and at least one member selected from the group consisting of KCl, NaCl, LiCl and AlCl.sub.3, and may preferably be operated while flowing the bath at a flow rate of about 0.1 m/sec higher. There is provided equipment for the manufacture of tin-plated steel strip comprising a pretreating apparatus for cold rolling steel strip, an annealing apparatus, a skin pass rolling apparatus, a fused-salt tin-electroplating apparatus with the above bath including chlorides, and an aftertreating apparatus, these apparatus being continuously integrated into the equipment by use of a fused-salt bath.

Process for the manufacture of tinplate using a fused tin chloride

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

The present invention provides a method of producing a zinc-chromium alloy-plated steel sheet having excellent properties such as bare corrosion resistance, corrosion resistance after coating, plating adhesiveness and weldability. The method is characterized by plating the surface of the steel sheet using an acid plating bath containing zinc ion (Zn.sup.2+) and chromium ion (Cr.sup.3+) at a molar concentration ratio of about 0.1.ltoreq.Cr.sup.3+ /(Zn.sup.3+ +Cr.sup.3+).ltoreq.0.9 in a total amount of at least about 0.5 mol/1 within the dissolution range, and about 0.1 to 30 g/1 of at least one nonionic organic additive having at least a triple bond, at a bath temperature of about 25.degree. to 70.degree. C. and a pH of about 1.0 to 4.0 with a current density of about 50 to 200 A/dm.sup.2.

Method of producing zinc-chromium alloy plated steel sheet with

A method of guiding and transferring a rapidly quenched metallic tape includes steps of peeling the rapidly quenched metallic tape produced by solidification through rapid quenching on a circumferential surface of a single cooling roll rotating at a high speed, introducing the metallic tape into a cylindrical transfer guide to a pinch roll unit arranged at a terminal end of the transfer guide to catch the metallic tape by the pinch roll unit, and moving the pinch roll unit to a winder for the metal tape. The metallic tape is fed in the transfer guide substantially without being in contact with the transfer guide. An apparatus for guiding and transferring a rapidly quenched metallic tape includes a cylindrical transfer guide arranged on a normal line of a single cooling roll for introducing and guiding the metallic tape, a pinch roll unit arranged at a terminal end of the transfer guide for catching the metallic tape, and a transfer trolley for transferring the pinch roll unit to a winder for the metallic tape.

Apparatus for transferring rapidly quenched metallic tapes

An apparatus for transferring a rapidly quenched metallic tape, which is produced by solidification through rapid quenching on a circumferential surface of a single cooling roll rotating at a high speed, from the cooling roll into a winder, comprises a transfer means provided with a pinch roll unit for catching and feeding out the peeled metallic tape, a fan for breaking and discharging the metallic tape fed out from the pinch roll unit, and a dust device for recovering metallic pieces and powder generated in the breakage of the metallic tape by the fan.

A method and an apparatus for transporting a rapidly quenched ribbon from a cooling roll to a winding reel by a pinch roll are disclosed. The pinch roll comprises a brush roll and a solid roll for transporting the ribbon such as to maintain an adequate tension in the ribbon without any transversal displacement and breakdown of ribbon. The tension is controlled within a range of 2.about.8 kgf by adjusting at least one of an amount of pressing of the brush roll against the solid roll, a pressing force on the brush roll and a ratio between circumferential speeds of the pinch roll and the cooling roll.

Method of transporting rapidly quenched ribbon and apparatus therefor

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Chiba, Japan

Nobuyuki Morito