Abstract: An electrical steel sheet provided with an insulating coating wherein the insulating coating is formed by a method includes forming an insulating coating on an electrical steel sheet, including: preparing a treatment solution that does not contain an Fe compound by adding an Si compound to water; applying the treatment solution to a surface of the electrical steel sheet; leaving the treatment solution on the surface of the electrical steel sheet to allow Fe in the electrical steel sheet to be dissolved in the treatment solution; and baking the treatment solution to form the insulating film such that a coating weight of Si in the insulating coating in terms of SiO2 is 50% to 99% of the total coating weight, and a ratio (Fe/Si) of content of Fe to content of Si in the insulating coating is 0.01 to 0.6 on a molar basis.

Abstract: A method for forming an insulating coating on an electrical steel sheet is provided. The method includes preparing a treatment solution by adding a Si compound to water and applying the treatment solution to a surface of the electrical steel sheet. Fe in the electrical steel sheet dissolves in the treatment solution and, thereafter, the electrical steel sheet and treatment solution are baked to form the insulating film. In the insulating film, a coating weight of Si in terms of SiO2 is 50% to 99% of the total coating weight, and a ratio (Fe/Si) of content of Fe to content of Si in the insulating coating is 0.01 to 0.6 on a molar basis.

Abstract: A method for forming an insulating coating on an electrical steel sheet is provided. The method includes preparing a treatment solution by adding a Si compound to water and applying the treatment solution to a surface of the electrical steel sheet. Fe in the electrical steel sheet dissolves in the treatment solution and, thereafter, the electrical steel sheet and treatment solution are baked to form the insulating film. In the insulating film, a coating weight of Si in terms of SiO2 is 50% to 99% of the total coating weight, and a ratio (Fe/Si) of content of Fe to content of Si in the insulating coating is 0.01 to 0.6 on a molar basis.

Abstract: An electrical steel sheet is provided with insulating coating. The insulating coating contains Si and Fe. The coating weight of Si in the insulating coating in terms of SiO2 is 50% to 99% of the total coating weight. The ratio (Fe/Si) of the content of Fe to the content of Si in the insulating coating is 0.01 to 0.6 on a molar basis. The ratio (C (the organic resin+the lubricant)/(Fe2O3+SiO2)) of the coating weight of the organic resin and/or the lubricant in terms of C to the sum of the coating weight of Fe in terms of Fe2O3 and the coating weight of Si in terms of SiO2 preferably is 0.05 to 0.8.

Abstract: An electrical steel sheet is provided with insulating coating. The insulating coating contains Si and Fe. The coating weight of Si in the insulating coating in terms of SiO2 is 50% to 99% of the total coating weight. The ratio (Fe/Si) of the content of Fe to the content of Si in the insulating coating is 0.01 to 0.6 on a molar basis. The ratio (C (the organic resin+the lubricant)/(Fe2O3+SiO2)) of the coating weight of the organic resin and/or the lubricant in terms of C to the sum of the coating weight of Fe in terms of Fe2O3 and the coating weight of Si in terms of SiO2 preferably is 0.05 to 0.8.

Abstract: A semi-organic insulation coating includes an inorganic component and an organic resin, a Zr compound and an Si compound contains a plate-like silica as an inorganic component and are included in a ratio in a dry coating of 20 to 70 mass % of Zr compound (converted to ZrO2) and 10 to 50 mass % of Si compound containing plate-like silica (converted to SiO2), and the remainder is substantially an organic resin, whereby a magnetic steel sheet with a semi-organic insulation coating has no deterioration of corrosion resistance and water resistance without containing a chromium compound and being excellent in powdering resistance, scratch resistance, sticking resistance, TIG weldability, punchability and coating appearance.

Abstract: The present invention provides a chromium-free surface treatment agent, comprising: a resin compound having a specific bisphenol skeleton; cationic urethane resin emulsion; silane coupling agent; an organic titanium chelate compound; a quadrivalent vanadyl compound; a molybdic acid compound; and water, wherein these components are blended at predetermined ratios such that pH value of the surface treatment agent is in the range of 4 to 5. The one-pack type chromium-free surface treatment agent of the present invention exhibits good stability during storage and is capable of forming on a metal material surface a coating film excellent in corrosion resistance at a bending-processed portion of a steel sheet, solvent resistance and paintability after alkali degreasing.

Abstract: A method of producing a hot-dip galvanized steel sheet includes applying, to a hot-dip galvanized steel sheet having a Ra of 0.5 to 2.0 ?m and a PPI of 150 or more, a predetermined surface treatment agent, i.e., a surface treatment agent containing a specified resin compound, a specified urethane resin having cationy, a specified silane coupling agent having a functional group, a specified organic Ti chelate compound, and a tetravalent vanadyl compound at a specified ratio; and drying the surface treatment agent at a ultimate sheet temperature of 50° C. to 180° C. to form a surface treatment coating film with a coating weight of 0.2 to 1.0 g/m2 on the surface of the steel sheet.

Abstract: There is provided an electrical steel sheet provided with an insulating coating which has high corrosion resistance and high adhesion. The electrical steel sheet provided with an insulating coating includes an electrical steel sheet and an insulating coating disposed on the electrical steel sheet. The insulating coating includes Zr and Fe. The content of Zr in the insulating coating is in the range of 0.05 to 1.50 g/m2 in terms of ZrO2. The compositional ratio between Zr and Fe is such that the molar ratio of Fe to Zr, that is, the ratio of the amount (moles) of Fe included in the insulating coating to the amount (moles) of Zr included in the insulating coating, is in the range of 0.10 to 2.00.

Abstract: An electrical steel sheet with an insulation coating excellent in punchability, coating adhesion property and coating film property after annealing, even without containing any chromium compound in the insulation coating. The insulation coating is formed by applying a surface-treatment agent to at least one side of the electrical steel sheet and drying the surface-treatment agent. The surface-treatment agent contains trialkoxysilane and/or dialkoxysilane (A) in which a substituent bound to Si is constituted only by at least one non-reactive substituent selected from the group consisting of hydrogen, an alkyl group, and a phenyl group; and a silane coupling agent (B), at a mass ratio (A/B) of 0.05 to 1.0.

Abstract: A surface-treatment agent contains a resin compound having a specific bisphenol skeleton, a cationic urethane resin emulsion, a silane coupling agent, an organic titanium chelate compound, a tetravalent vanadyl compound, and water, with predetermined proportions and having a pH of 4 to 5; a method for producing a coated steel sheet using the surface-treatment agent; and a coated steel sheet.

Abstract: A method of producing a hot-dip galvanized steel sheet includes applying, to a hot-dip galvanized steel sheet having a Ra of 0.5 to 2.0 ?m and a PPI of 150 or more, a predetermined surface treatment agent, i.e., a surface treatment agent containing a specified resin compound, a specified urethane resin having cationy, a specified silane coupling agent having a functional group, a specified organic Ti chelate compound, and a tetravalent vanadyl compound at a specified ratio; and drying the surface treatment agent at a ultimate sheet temperature of 50° C. to 180° C. to form a surface treatment coating film with a coating weight of 0.2 to 1.0 g/m2 on the surface of the steel sheet.

Abstract: A semi-organic insulation coating includes an inorganic component and an organic resin, a Zr compound and an Si compound contains a plate-like silica as an inorganic component and are included in a ratio in a dry coating of 20 to 70 mass % of Zr compound (converted to ZrO2) and 10 to 50 mass % of Si compound containing plate-like silica (converted to SiO2), and the remainder is substantially an organic resin, whereby a magnetic steel sheet with a semi-organic insulation coating has no deterioration of corrosion resistance and water resistance without containing a chromium compound and being excellent in powdering resistance, scratch resistance, sticking resistance, TIG weldability, punchability and coating appearance.

Abstract: The present invention provides a chromium-free surface treatment agent, comprising: a resin compound having a specific bisphenol skeleton; cationic urethane resin emulsion; silane coupling agent; an organic titanium chelate compound; a quadrivalent vanadyl compound; a molybdic acid compound; and water, wherein these components are blended at predetermined ratios such that pH value of the surface treatment agent is in the range of 4 to 5. The one-pack type chromium-free surface treatment agent of the present invention exhibits good stability during storage and is capable of forming on a metal material surface a coating film excellent in corrosion resistance at a bending-processed portion of a steel sheet, solvent resistance and paintability after alkali degreasing.

Abstract: An electrical steel sheet is provided with an insulating coating which has inorganic with some organic materials, the insulating coating including inorganic components and an organic resin, the insulating coating contains, as the inorganic components, a Zr compound, a B compound, and a Si compound, specifically, when expressed as percentages in the dry coating, 20% to 70% by mass of the Zr compound (in terms of ZrO2), 0.1% to 5% by mass of the B compound (in terms of B2O3), and 10% to 50% by mass of the Si compound (in terms of SiO2), and the balance containing the organic resin.

Abstract: A surface-treatment agent contains a resin compound having a specific bisphenol skeleton, a cationic urethane resin emulsion, a silane coupling agent, an organic titanium chelate compound, a tetravalent vanadyl compound, and water, with predetermined proportions and having a pH of 4 to 5; a method for producing a coated steel sheet using the surface-treatment agent; and a coated steel sheet.

Abstract: A method for making a phosphate-treated galvanized steel sheet, including forming a phosphate film on the surface of a galvanized layer of a galvanized steel sheet using a phosphate treatment solution containing Zn2+ and Mg2+ so as to satisfy 2.0<Zn2+?5.0 g/L, 2.0?Mg2+?5.0 g/L, and 0.4?Mg2+/Zn2+?2.5, and satisfying 0.020?free acidity/total acidity<0.10. The method allows for the quick formation of a uniform phosphate film, whereby a phosphate-treated galvanized steel sheet having excellent corrosion resistance and blackening resistance is obtained.

Abstract: A method for making a phosphate-treated galvanized steel sheet, including forming a phosphate film on the surface of a galvanized layer of a galvanized steel sheet using a phosphate treatment solution containing Zn2+ and Mg2+ so as to satisfy 2.0<Zn2+?5.0 g/L, 2.0?Mg2+?5.0 g/L, and 0.4?Mg2+/Zn2+?2.5, and satisfying 0.020?free acidity/total acidity<0.10. The making method allows the quick formation of a uniform phosphate film, whereby a phosphate-treated galvanized steel sheet having excellent corrosion resistance and blackening resistance is obtained.

Abstract: A surface-treated steel sheet is disclosed, including a zinc based plated steel sheet having thereon a surface-treated film containing titanium, nickel, aluminum and fluorine and having a film thickness of from 0.05 to 1.0 ?m, the surface-treated film having a titanium deposition amount of from 0.01 to 0.5 g/m2 and containing from 0.01 to 5 parts by mass of nickel, from 0.1 to 25 parts by mass of aluminum and from 1 to 500 parts by mass of fluorine relative to 100 parts by mass of titanium. This surface-treated steel sheet does not contain hexavalent chromium in the film thereof at all and has excellent heat discoloration resistance, corrosion resistance and resistance to blackening.

Abstract: A coated steel sheet that has excellent bending workability, press formability, film adhesiveness after processing, solvent resistance, chemical resistance, stain resistance, weather resistance, electrical conductivity, and corrosion resistance, good surface appearance, and sufficient film hardness is provided. The coated steel sheet is produced by successively forming a galvanized layer and a chemical conversion coating free from chromium on both faces of a steel sheet, and forming a monolayer film on the chemical conversion coating at one face of the steel sheet. The monolayer film contains a polyester resin cured with a cross-linker and resin particles. The resin particles have an average particle size in the range of 3 to 40 ?m, a glass transition temperature in the range of 70° C. to 200° C., and hardness higher than that of the polyester resin.