Nippon Kokan Kabushiki Kaisha

Kazuo Matsudo

Takayoshi Shimomura

Tsutomu Watanabe

Takeshi Adaniya

Masaru Ohmura

Teruo Kurokawa

Masahiro Shoji

Takao Arayama

In an acidic zinc sulfate and iron sulfate electro-galvanizing bath, of which a pH value has been adjusted to under 1.5, containing iron from 20 to 90 wt. % relative to the total amount of metals capable of being electro-deposited in said acidic electro-galvanizing bath, a steel sheet is subjected to an electro-galvanizing treatment, with an electric current having a current density of from 10 to 40 A/dm.sup.2 to form on said steel sheet an electro-galvanized layer in a weight of from 1 to 50 g/m.sup.2, containing iron from 5 to 35 wt. % relative to the total weight of the electro-galvanized layer.

Process for manufacturing electro-galvanized steel sheet excellent in

An electro-galvanized steel sheet for coating excellent in bare corrosion resistance, corrosion resistance after coating and formability, which comprises: a steel sheet; a first electro-galvanized layer, as a lower layer, in an amount of from 5 to 120 g/m.sup.2 per side, formed on at least one surface of said steel sheet, said first electro-galvanized layer comprising either an electro-galvanized layer consisting essentially of zinc or a compound electro-galvanized layer consisting essentially of zinc, cobalt and at least one of chromium, indium and zirconium; and a second electro-galvanized layer, as an upper layer, in an amount of from 0.2 to 10 g/m.sup.2 per side, formed on said first electro-galvanized layer, said second electro-galvanized layer consisting essentially of an alloy layer of zinc and from 1 to 60 wt. % iron. Said electro-galvanized steel sheet for coating is adapted to serve particularly for external, underside and closed structures of an automobile.

Dual layer-coated electro-galvanized steel sheet for coating with

An enameling steel sheet characterized by a manganese content of 0.50 wt.% or under and the elimination of annealing after the final cold rolling. A satisfactory enamel adhesive property can be obtained by enameling and baking said enameling steel sheet in as-cold-rolled state after only degreasing and drying.

Enameled cold rolled sheet

An enameling cold rolled steel sheet with a high enamel adhesive property which requires no pickling step before enameling, characterized by an Mn content kept within 0.05 to 0.20%, and the relation between the surface roughness and the Mn content of said steel sheet satisfying at least one of the following two equations:

Enameling cold rolled steel sheet with a high enamel adhesive property

In a two stage cold reducing process, Al-stabilized steel is subjected to a decarburizing treatment as intermediate annealing between the first and second cold reducing, to impart unexpectedly high drawability to Al-stabilized steel, the drawability being more than 2.00 r (Lankford value). Such Lankford value shows that the steel is capable of sustaining any severe press forming.

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Fukuyama, Japan

Kazuo Matsudo