Nippon Steel Corporation

Dainippon Ink and Chemicals, Incorporated

Hisao Odashima

Minoru Kitayama

Kazumi Nishimura

Susumu Yamaguchi

Shin'ichi Kuwamura

Ryohei Mizoguchi

Yoshihiko Hirano

Kiyoshi Ohnishi

Masahide Amemoto

Shigeto Fujii

Atsushi Miyagaki

Keitaro Shibata

Akihiro Kasuya

Kiyoshi Ohmori

Tetsuya Ohara

Takao Saito

Teruyoshi Hiraoka

Akimi Umezono

The present invention comprises an improved organic composite-plated steel plate which is obtained by applying a thermosetting resin to a chromate-coated alloy-plated steel plate and curing this, wherein, various aqueous resin compositions having the form of basic coating film formation components, such as, for example, aqueous vinyl modified epoxy ester resins, or aqueous vinyl modified epoxy ester resin / blocked isocyanate compound-types, or aqueous vinyl modified epoxy ester resin / blocked isocyanate compounds / colloidal silica-types, are used as the thermosetting resin described above. In accordance with the present invention, it is possible to provide an organic composite-plated steel plate which is novel and has extremely high applicability in a form in which an aqueous resin (composition) for organic composite coating, which has superior adhesion with adhesives, superior continuous welding properties, superior post-working corrosion resistance, and superior electro-deposition coating properties, and moreover, has superior coating material adhesion and corrosion resistance, and the coated surface of which, after electro-deposition coating, has particularly superior shininess (smoothness), and which furthermore has superior rust resistance and does not use large amounts of organic solvent, is pre-coated onto a metallic material.

Organic composite-plated steel plate and resin composition for coating

Process for manufacturing a galvanized steel sheet, comprising steps of coating a steel sheet with nickel in an amount of from 0.2 to 2 g/m.sup.2, heating the steel sheet thus coated to a temperature within the range of from 420.degree. C. to 500.degree. C. in a non-oxidative atmosphere, and dipping the nickel coated steel sheet into a molten zinc bath containing aluminum at a content of from 0.1 to 1% without contact with air, wherein the steel sheet is dipped into the molten zinc bath within 15 seconds after the temperature of the steel sheet exceeds 350.degree. C. in the heating step. An apparatus for performing the process comprises a nickel electroplating apparatus, a non-oxidative atmosphere-heating apparatus, and a galvanizing apparatus equipped with a molten zinc adhering amount-controlling device at the outlet side thereof, arranged sequentially in the steel sheet delivery direction, said non-oxidative atmosphere-heating apparatus comprising a ring transformer having a space for steel sheet delivery, a conductor roll provided at the inlet side of the ring transformer and being connected by use of an electroconductive member to a molten zinc bath of the galvanizing installation, thus a secondary coil of the transformer being formed from the conductor roll, the electroconductive member and the delivered steel sheet between the entering point in the molten zinc bath and the conductor roll contact point, and an atmospheric gas-feeding device for feeding a non-oxidative gas to the atmospheric chamber.

Process for manufacturing galvanized steel sheet by nickel pre-coating

Process for manufacturing a galvanized steel sheet, comprising steps of coating a steel sheet with nickel in an amount of from 0.2 to 2 g/m.sup.2, heating the steel sheet thus coated to a temperature within the range of from 420.degree. C. to 500.degree. C. in a non-oxidative atmosphere, and dipping the nickel coated steel sheet into a molten zinc bath containing aluminum at a content of from 0.1 to 1% without contract with air, wherein the steel sheet is dipped into the molten zinc bath within 15 seconds after the temperature of the steel sheet extends 350.degree. C. in the heating step. And apparatus for performing the process comprises a nickel electroplating apparatus, a non-oxidative atmosphere-heating apparatus, and a galvanizing apparatus equipped with a molten zinc adhering amount-controlling device at the outlet side, arranged sequentially in the steel sheet delivery direction, thereof said non-oxidative atmosphere-heating apparatus comprising a ring transformer having a space for steel sheet delivery, a conductor roll provided at the inlet side of the ring transformer and being connected by use of an electroconductive member to a molten zinc bath of the galvanizing installation, thus a secondary coil of the transformer being formed from the conductor roll, the electroconductive member and the delivered steel sheet between the entering point in the molten zinc bath and the conductor roll contact point, and an atmospheric gas-feeding device for feeding a non-oxidative as to the atmospheric chamber.

A multiple coated composite steel strip having an excellent corrosion (rust) resistance, weldability and paint adhesion, and thus useful for car bodies, comprises a steel strip substrate, a first metal coating layer, a second chlorate coating layer formed by an electrolytic chromate treatment method, containing 40 to 120 mg/m.sup.2 of chromium and having a content of Cr.sub.2 O.sub.3 of 45% by weight or more, and a third resinous coating layer comprising a homopolymer or copolymer of acrylic acid, methacrylic acid, acrylic acid ester or methacrylic acid ester and 15% to 40% of colloidal silica particles having a very small size of 1 to 12 m .mu.m.

Multiple coated composite steel strip

A cold rolled steel strip having an excellent conversion coating property is produced by a process comprising:

Process for producing cold rolled steel strip highly susceptible to

Oxidation inhibitor

A method for preventing decarburization of a steel material comprising applying a mixture of SiC powder and metallic Al powder on the steel material, further applying an oxidation inhibitor thereon, and heating thus coated steel material, so as to give 30 to 500 g/m.sup.2 SiC on the steel material. The present method is particularly useful for preventing the lowering in strength of steel materials due to the surfacial decarburization.

Method for preventing decarburization of steel materials

A scale inhibitor composition comprising Cr.sub.2 O.sub.3, reducing agent, refractory or clay, SiO.sub.2 and water glass, and a method of inhibiting the formation of scale on the surfaces of metal substrates to be heated in high temperature atmosphere by application of a coating of the scale inhibitor composition either on the metal surface, or on a subbing layer of a parting agent previously applied on the metal surfaces are disclosed, wherein improvements are effected particularly in both yield and prevention of surface scars.

Scale inhibitor compositions for application onto metal substrates to be

A process of treating metals with coatings capable, upon heating, of providing and maintaining a controlled atmosphere around the surfaces of said metals which process comprises coating the surfaces of said metals with base coating composition capable, upon heating, of providing a gas, and then with an over-coating composition capable of maintaining the gas around the surfaces of the metals at high temperatures while excluding an environmental oxidizing atmosphere therefrom, and thereafter heating the coated metals in the oxidizing atmosphere.

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Himeji, Japan

Hisao Odashima