Abstract: A black colored steel sheet has a Zn—Ni plating steel sheet which is processed by blackening treatment and a coating film formed on a surface of the Zn—Ni plating steel sheet by applying a paint composition which contains (a) metal ions, (b) a water soluble organic resin, (c) a water dispersible organic resin, (d) a glycoluril resin, and (e) an acid.

Abstract: 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 ?,?-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.

Abstract: 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 ?,?-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.

Abstract: 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.

Abstract: A surface treated metal sheet having an organic coating comprising an epoxy resin, a glycoluril resin, and a metal compound (which is not a chromium compound) on at least one surface of the metal sheet; or a surface treated metal sheet having an intermediate layer comprising a metal (which is not chromium) on at least one surface of the metal sheet, and an organic coating comprising an epoxy resin and a glycoluril resin on the intermediate layer. A surface treating agent comprising an epoxy resin, a glycoluril resin, and a metal compound (which is not a chromium compound).

Abstract: 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).

Abstract: The present invention is a highly corrosion-resistant steel sheet for a fuel tank, in which zinc-based plating layers 2a and 2b and chromate layers 3a and 3b are formed in order by lamination on both surfaces of the steel sheet 1 containing C: 0.0007 to 0.0050 mass %, Si: 0.5 mass % or less, Mn: 2.0 mass % or less, P: 0.10 mass % or less, S: 0.015 mass % or less, Al: 0.01 to 0.20 mass %, N: 0.01 mass % or less, Ti: 0.005 to 0.08 mass %, and B: 0.001 to 0.01 mass %, a first composite coating 4 comprising metal powders of Al and Ni and an amine-modified epoxy resin is formed on one chromate layer 3a, and a second composite coating 5 comprising silica, a lubricant, a particle having conductivity, and at least one kind of organic resin having at least one functional group selected from the group consisting of a hydroxyl group, an isocyanate group, a carboxyl group, a glycidyl group, and an amino group is formed on the other chromate layer 3b.

Abstract: 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.

Abstract: 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° 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.

Abstract: The invention is a high-strength hot dip galvannealed steel sheet having excellent press formability and plating properties by utilizing Si as a strengthening component, specifying an interrelation between Si and Mn and further specifying an alloying ratio of hot dip galvannealed layer, which comprises C: 0.0005-0.0050%, Si: 0.1-2.5%, Mn: 0.1-2.5%, Ti: 0.003-010%, Nb: 0.003-0.10%, B: 0.005-0.0080%, P: 0.040-0.18%, S: not more than 0.008%, Al: 0.005-0.10%, and N: not more than 0.0060 wt %, provided that Si and Mn satisfy the following equation, and the remainder being Fe and incidental impurities, and has a hot dip galvannealed layer formed on a surface of the steel sheet and having a Fe content of 9-12%, wherein said equation is:1.5 (% Mn)-2.ltoreq.(% Si).ltoreq.2(% Mn) (1).

Abstract: In connection with a process of implementing galvanizing and galvannealing on steel strips containing highly oxidizable elements such as Si, Mn, P, Ti, Nb, Al, Ni, Cu, Mo, V, Cr, and B, after annealing in a continuous line or implementing electroplating after annealing, the present invention provides a method for restraining non-plating at low cost in a stable manner and a surface treated steel strip having minimal non-plating. By applying on at least one surface of a steel strip a Fe plating having a coating weight of 0.1-10 g/m.sup.2 and an oxygen content of 0.1-10 wt %, followed by annealing and then zinc or zinc alloy plating, there is obtained a surface treated steel strip having minimal plating defects which includes a Fe plating layer immediately below a zinc or zinc alloy plating layer and a steel alloying element concentrated stratum immediately below the Fe plating layer. The Fe plating may be formed using an electroplating bath which contains 0.1-10 g/l of Fe.sup.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.