Abstract: The invention provides a method for producing a coated steel sheet for a can. A film of aluminum, aluminum alloy, titanium or titanium alloy 0.005 to 5 .mu.m thick is plated on one surface of a steel sheet by means of a dry process. A metal film is also plated on the other surface of the steel sheet by means of a dry process.

Abstract: This invention relates to a highly corrosion-resistant, multi-layer coated steel sheet, and includes an undercoat film obtained by galvanization or zinc-alloy plating and a chromate coated film thereon, on which a resin-composition film is further applied, comprising an organic high-molecular weight resin having a glass transision temperature of 343.degree. to 423.degree. K. and soluble in organic solvent and hydrophobic silica.For the purpose of improvement of corrosion preventiveness, a sparingly water soluble Cr compound may be contained in this resin composition film. Together with this sparingly water soluble Cr compound, a di- or tri-alkoxysilane compound may be also contained in the resin composition film.

Abstract: Plated steel sheet for a can comprises: a steel sheet; an Al or Al alloy plated film of 0.005 to 5 .mu.m in thickness on one surface of the steel sheet; and a plated film of 0.005 to 5 .mu.m in thickness on the other surface of the steel sheet, the plated film comprising a metal selected from the group consisting of Ti, Zn, Ni, Co, Cr, Mo and Sn; and furthermore, Plated steel sheet for a can comprises: a steel sheet; a Ti or Ti alloy plated film of 0.005 to 5 .mu.m in thickness on one surface of the steel sheet; and a plated film of 0.005 to 5 .mu.m in thickness on the other surface of the steel sheet, the plated film comprising a metal selected from the group consisting of Al, Zn, Co, Mo and Sn.

Abstract: The present invention relates to a highly corrosion resistant surface-treated steel plate. The steel plate of the invention comprises a zinc deposition or zinc alloy deposition film as the undercoat deposition layer, a chromate film formed on the undercoat deposition layer and a film of a resin composition formed on the chromate film. This resin composition comprises a substrate resin formed by adding at least one basic nitogen atom and at least two primary hydrogen groups to terminal of an epoxy resin, silica and sparingly water soluble Cr compound. The resin composition may comprise a polyisocyanate compound as the curing agent. Moreover, the resin composition may comprise a silane compound as the crosslinking agent for the substrate resin and silica.

Abstract: A composite zinc-silica electro-galvanized steel sheet excellent in corrosion resistance, having on at least one surface thereof a zinciferous plating layer, preferably in an amount of from 5 to 100 g/m.sup.2 per side thereof, into which silica particles are dispersed. The above-mentioned plating layer consists essentially of:silica particles: from 0.1 to 20 wt. %,nitrogen compounds: from 0.0005 to 0.5 wt. % as converted into nitrogen,and the balance being zinc and incidental impurities.The above-mentioned plating layer further additionally contains as required at least one element selected from the group consisting of:iron: from 2 to 80 wt. %,nickel: from 2 to 25 wt. %,cobalt: from 0.1 to 5 wt. %, andchromium: from 0.5 to 20 wt. %.The total amount of the above-mentioned at least one element thus additionally contained is limited to up to 80 wt. %.

Abstract: The present invention relates to a highly corrosion-resistant surface-treated steel plate. The steel plate of the present invention comprises a zinc deposition or zinc alloy deposition film as the undercoat deposition layer, a chromate film formed on the undercoat deposition layer and a film of a resin composition formed on the chromate film. This resin composition comprises a base resin formed by adding at least one basic nitrogen atom and at least two primary hydroxyl groups to terminals of an epoxy resin. The resin composition may comprise a polyisocyanate compound as the curing agent. Furthermore, the resin composition may comprise silica or a hardly soluble chromium compound as the additive for improving the corrosion resistance. Moreover, the resin composition may comprise a silane compound as the crosslinking agent for the base resin and silica.

Abstract: The present invention relates to a process for the preparation of a highly anticorrosive surface-treated steel plate. This process comprises the steps of subjecting a surface of a steel plate having a plating layer of the zinc or aluminum type deposited thereon to a chromate treatment to form a chromate film, treating the steel plate with an organic composite silica solution comprising an epoxy resin in an amount exceeding a certain level as an indispensable component and a curing agent optionally incorporated therein to form an organic composite silicate film comprising colloidal silica, organic resin and silane formed on the chromate film, and heat-treating the steel plate at a specific temperature.

Abstract: An iron-zinc alloy electro-galvanized steel sheet having a plurality of iron-zinc alloy coatings, which comprises: at least one iron-zinc alloy coating as the lower layer, formed on the surface of a steel sheet, and at least two iron-zinc alloy coatings as the upper layer, formed on the at least one iron-zinc alloy coating as the lower layer. The ratio of iron content to the coating weight of each of the at least one iron-zinc alloy coating as the lower layer is within the range of from 1 to 15 wt. %, and the total coating weight of the at least one iron-zinc alloy coating as the lower layer is within the range of from 1 to 50 g/m.sup.2 per side of the steel sheet. The ratio of iron content to the coating weight of each of the at least two iron-zinc alloy coatings as the upper layer is over 15 wt.

Abstract: A strip horizontally travels within an electroplating apparatus while the plating solution is applied between the strip and anode, in which relative speed of the solution to the strip and/or current density are varied, whereby an outer plated layer on the strip is provided with Fe-Zn alloy of high Fe content while an inner plated layer on the strip is provided with Fe-Zn alloy of low Fe content.

Abstract: In a process for manufacturing an electro-galvanized steel strip, which comprises: moving a steel strip in an acidic electro-galvanizing bath containing cobalt and chrominum in parallel with the plane of at least one anode plate to subject said steel strip to an electro-galvanizing treatment, thereby forming, on at least one surface of said steel strip, an electro-galvanized layer excellent in bare corrosion resistance and corrosion resistance after chromating; the improvement characterized by: keeping the cobalt content in said electro-galvanizing bath within the range of from 8 to 30 g/l, as converted into metallic cobalt, the chromium content in said electro-galvanizing bath within the range of from 0.1 to 1.5 g/l, as converted into metallic chromium, and the temperature of said electro-galvanizing bath within the range of from 35.degree. to 60.degree. C.; and, flowing said electro-galvanizing bath between said steel strip and said anode plate at a flow velocity of at least 0.

Abstract: 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.

Abstract: 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.

Abstract: A chromated electro-galvanized steel sheet is manufactured by electro-galvanizing a steel sheet in an acidic galvanizing bath containing zinc with or without specified amounts of cobalt, or with specified amounts of cobalt and with at least one of chromium (Cr.sup.+3, Cr.sup.+6 or Cr.sup.+3 and Cr.sup.+6) and zirconium; then electro-galvanizing in a zinc-based galvanizing bath containing specified amounts of at least one of chromium (Cr.sup.+3, Cr.sup.+6 or Cr.sup.+3 and Cr.sup.+6), tin and indium; and chromating the resulting steel sheet.

Abstract: In a Zn-ion based acidic galvanizing bath containing at least one additive selected from the group consisting of:______________________________________ (a) Cr.sup.3.sup.+ 50 - 700 ppm, (b) Cr.sup.6.sup.+ 50 - 500 ppm, (c) Cr.sup.3.sup.+ and Cr.sup.6.sup.+ 50 - 700 ppm, in which Cr.sup.6.sup.+ being 500 ppm at the maximum, (d) In ion 10 - 3,000 ppm, and (e) Zr ion 10 - 2,500 ppm; and: (f) Co ion 50 - 10,000 ppm, ______________________________________A steel sheet is subjected to an electro-galvanizing treatment to form a first galvanizing layer on the surface thereof; and then, said electro-galvanized steel sheet with said first galvanizing layer formed thereon to a conventional chromate treatment.

Abstract: In a Zn-ion based acidic galvanizing bath containing one additive selected from the group consisting of:______________________________________ (a) Cr.sup.3.sup.+ 50 - 700ppm, (b) Cr.sup.6.sup.+ 50 - 500ppm, and (c) Cr.sup.3.sup.+ and Cr.sup.6.sup.+ 50 - 700 ppm, in which Cr.sup.6.sup.+ being 500ppm at the maximum; ______________________________________And at least one additive selected from the group consisting of: ______________________________________ (d) Sn ion 10 - 5,000ppm, and (e) In ion 10 - 3,000ppm, ______________________________________A steel sheet is subjected to an electro-galvanizing treatment, and then, said electro-galvanized steel sheet is subjected to a conventional chromate treatment.

Abstract: There is provided a molten metal plating method and apparatus wherein at each of the strip feeding and discharging ends of a horizontal molten metal plating tank arranged in a horizontal strip pass line, each of a current and a magnetic field which intersect each other at right angles is applied in a direction perpendicular to the direction of travel of a steel strip to apply to the molten metal at each end an electromagnetic force which is directed toward the inside of the plating tank, whereby by adjusting the intensity of the magnetic field or the amount of the current, the run-out or leakage of the molten metal from the strip feeding and discharging ends of the plating path is reduced to zero or controlled to a desired value.