This electrical steel sheet is an electrical steel sheet in which at least part of either or both surfaces of a base steel sheet is coated with an insulation coating having an adhesive ability, wherein a logarithmic decrement of the insulation coating in a temperature range of 25 to 100° C. is 0.3 or less.

This electrical steel sheet is an electrical steel sheet in which at least part of either or both surfaces of a base steel sheet is coated with an insulation coating having an adhesive ability, wherein a logarithmic decrement of the insulation coating in a temperature range of 25 to 100° C. is 0.3 or less.

Described are methods of treating surfaces of metal alloy substrates and associated metal alloy products. The methods may include providing an aluminum alloy product having a bulk and a surface and scanning abeam of high energy across the surface. The method may further include applying a liquid layer onto the surface prior to scanning a beam of high energy. The beam of high energy may interact with the surface and/or the liquid layer to form a treated surface. The beam of high energy may interact with the surface and/or the liquid layer to physically modify the at least a portion of the aluminum alloy product to form a treated sub-surface layer.

A steel sheet for a fuel tank includes: a Zn—Ni alloy plated layer which is placed on one surface or each of both surfaces of a base metal and formed on at least one surface; and an inorganic chromate-free chemical conversion coating film which is placed over the Zn—Ni alloy plated layer. The Zn—Ni alloy plated layer has a crack starting from an interface between the Zn—Ni alloy plated layer and the inorganic chromate-free chemical conversion coating film and reaching an interface between the Zn—Ni alloy plated layer and the steel sheet, and a water contact angle on a surface of the inorganic chromate-free chemical conversion coating film is more than or equal to 50 degrees.

A steel sheet for a fuel tank includes: a Zn—Ni alloy plated layer which is placed on one surface or each of both surfaces of a base metal and formed on at least one surface; and an inorganic chromate-free chemical conversion coating film which is placed over the Zn—Ni alloy plated layer. The Zn—Ni alloy plated layer has a crack starting from an interface between the Zn—Ni alloy plated layer and the inorganic chromate-free chemical conversion coating film and reaching an interface between the Zn—Ni alloy plated layer and the steel sheet, and a water contact angle on a surface of the inorganic chromate-free chemical conversion coating film is more than or equal to 50 degrees.

Provided are an insulation coating composition for an oriented electrical steel sheet, an oriented electrical steel sheet having an insulation coating formed on the surface thereof by using the same, and a manufacturing method thereof, and specifically, it is possible to provide an insulation coating composition for an oriented electrical steel sheet, including 0.1 to 7 wt % of hollow nanoparticles, 0.1 to 5 wt % of ceramic nanofibers, 0.1 to 5 wt % of mesoporous nanoparticles, 30 to 60 wt % of colloidal silica nanoparticles, and 30 to 60 wt % of phosphate, and to provide an oriented electrical steel sheet including an insulation coating produced by the composition on the surface of the oriented electrical steel sheet, including 0.005 to 0.05 wt % of any one element selected from boron (B), vanadium (V), or a combination thereof, 2.6 to 4.3 wt % of silicon (Si), 0.020 to 0.040 wt % of aluminum (Al), 0.01 to 0.20 wt % of manganese (Mn), in which the balance is composed of Fe and other inevitable impurities, and a manufacturing method thereof.

Aqueous compositions useful as pretreatments prior to painting and to prevent the formation of white rust in the uncoated condition include an organopolyphosphonic acid or salt thereof, an organosilane, and a trivalent chromium compound. A method for treating a surface of a zinc-containing metal includes contacting the surface with an aqueous composition including an organopolyphosphonic acid or salt thereof, an organosilane, and a trivalent chromium compound. The composition may also include an agent for reducing hydrophilicity, such as a polyacrylic acid. The aqueous composition has been found to be particularly well-suited for treating a zinc-containing metal to passivate the surface, improve paint adhesion, and/or improve corrosion resistance.

Aqueous compositions useful as pretreatments prior to painting and to prevent the formation of white rust in the uncoated condition include an organopolyphosphonic acid or salt thereof, an organosilane, and a trivalent chromium compound. A method for treating a surface of a zinc-containing metal includes contacting the surface with an aqueous composition including an organopolyphosphonic acid or salt thereof, an organosilane, and a trivalent chromium compound. The composition may also include an agent for reducing hydrophilicity, such as a polyacrylic acid. The aqueous composition has been found to be particularly well-suited for treating a zinc-containing metal to passivate the surface, improve paint adhesion, and/or improve corrosion resistance.

A manufacturing method for steel sheets for containers produces steel sheets with excellent film adhesion qualities. This steel sheet for containers has, on a steel sheet, a chemical conversion coating with a metal Zr content of 1-100 mg/m.sup.2, a P content of 0.1-50 mg/m.sup.2, and an F content of no more than 0.1 mg/m.sup.2, upon which is formed a phenolic resin layer with a C content of 0.1-50 mg/m.sup.2. Moreover, the manufacturing method for steel sheets for containers is a method for obtaining the steel sheet for containers wherein the chemical conversion coating is formed on the steel sheet by subjecting the steel sheet to immersion in or electrolytic treatment with a treatment solution containing Zr ions, phosphoric acid ions, and F ions; and subsequently, the steel sheet upon which the chemical conversion coating has been formed is immersed in, or undergoes topical application of, an aqueous solution containing phenolic resin, then dried.

A manufacturing method for steel sheets for containers produces steel sheets with excellent film adhesion qualities. This steel sheet for containers has, on a steel sheet, a chemical conversion coating with a metal Zr content of 1-100 mg/m.sup.2, a P content of 0.1-50 mg/m.sup.2, and an F content of no more than 0.1 mg/m.sup.2, upon which is formed a phenolic resin layer with a C content of 0.1-50 mg/m.sup.2. Moreover, the manufacturing method for steel sheets for containers is a method for obtaining the steel sheet for containers wherein the chemical conversion coating is formed on the steel sheet by subjecting the steel sheet to immersion in or electrolytic treatment with a treatment solution containing Zr ions, phosphoric acid ions, and F ions; and subsequently, the steel sheet upon which the chemical conversion coating has been formed is immersed in, or undergoes topical application of, an aqueous solution containing phenolic resin, then dried.