A grain-oriented electrical steel sheet is a grain-oriented electrical steel sheet which does not have an inorganic coating containing forsterite as a main component and which includes: a base steel sheet containing a prescribed chemical component; a silicon-containing oxide layer provided on the base steel sheet; an iron-based oxide layer provided on the silicon-containing oxide layer; and a tension-insulation coating provided on the iron-based oxide layer, having a thickness of 1 to 3 μm, and containing phosphate and colloidal silica as main components. When the tension-insulation coating undergoes elemental analysis using a glow discharge optical emission spectrometry in a sheet thickness direction from a surface of the tension-insulation coating, a peak Si emission intensity satisfies a prescribed requirement.

A grain-oriented electrical steel sheet according to the present invention includes a silicon steel sheet as a base steel sheet, and when an average value of amplitudes in a wavelength range of 20 to 100 μm among wavelength components obtained by performing Fourier analysis on a measured cross-sectional curve parallel to a sheet width direction of the silicon steel sheet is set as ave-AMP.sub.C100, ave-AMP.sub.C100 is 0.0001 to 0.050 μm.

A composition for washing a pickled steel plate and a method for washing a pickled steel plate using the same are provided. The composition for washing a pickled steel plate includes a phosphoric acid ester compound, an amine-based compound, sodium carbonate, ammonium acetate, ethylene diamine tetraacetic acid (EDTA) and a remainder of water, and the method for washing a pickled steel plate is performed using the same.

A composition for washing a pickled steel plate and a method for washing a pickled steel plate using the same are provided. The composition for washing a pickled steel plate includes a phosphoric acid ester compound, an amine-based compound, sodium carbonate, ammonium acetate, ethylene diamine tetraacetic acid (EDTA) and a remainder of water, and the method for washing a pickled steel plate is performed using the same.

A stainless steel sheet for fuel cell separators comprises: a predetermined chemical composition; and Cr-containing fine precipitates at a steel sheet surface, wherein an average equivalent circular diameter of the fine precipitates is 20 nm or more and 500 nm or less, and a number of the fine precipitates existing per 1 m.sup.2 at the steel sheet surface is three or more.

An insulating coating-attached electrical steel sheet has, on at least one surface, an insulating coating including an insulating tensile coating layer A. A tension applied to the steel sheet by an insulating tensile coating layer having a coating weight of M/2 from a surface of the insulating tensile coating layer A is 0.80.sub.A or more, where M is a weight of the insulating tensile coating layer A, and .sub.A is the tension applied to the steel sheet by the insulating tensile coating layer A. The insulating coating-attached electrical steel sheet has excellent adhesion of the insulating coating. A method for manufacturing the insulating coating-attached electrical steel sheet is also provided.

A surface treatment agent capable of forming a hexavalent chromium-free chemical conversion coating that can provide an excellent corrosion-resistant coating on various metallic materials; a metallic material having a surface treatment coating obtained therefrom; and a method of producing the same. A free fluorine ion-containing surface treatment agent for surface-treating a metallic material, which is obtained by mixing at least one supply source (A) of trivalent chromium-containing ions A; a supply source (B) of ions B that are at least one selected from titanium-containing ions and zirconium-containing ions; a water-soluble or water-dispersible compound (C) containing an alkoxysilyl group, an aromatic ring, a hydroxy group directly bonded to the aromatic ring, and at least one of primary, secondary, tertiary and quaternary amino groups, wherein the alkoxysilyl group is bonded to the nitrogen atom of the amino group directly or via an alkylene group; and a fluorine-containing compound (D) providing fluorine-containing ions.

Provided are: an oriented electrical steel sheet having a high tension applied to a steel sheet and excellent adhesion to a film; and a method for producing the same. This oriented electrical steel sheet includes: a steel sheet; a film A containing a crystalline material disposed on the steel sheet; and a film B containing a vitreous material disposed on the film A, wherein an element profile, which is obtained by using a high-frequency glow discharge light-emission surface analysis method, in the direction from the film B to the steel sheet satisfies formulae (1) and (2). 0.35(t.sub.A/t.sub.Fe/2)0.75 . . . (1), 0.25(t.sub.A/2/t.sub.Fe/2)1.00 . . . (2), where t.sub.A represents the peak time of an alkali metal element profile, t.sub.A/2 represents the half time of an alkali metal.

A composition for washing a pickled steel plate and a method for washing a pickled steel plate using the same are provided. The composition for washing a pickled steel plate includes a phosphoric acid ester compound, an amine-based compound, sodium carbonate, ammonium acetate, ethylene diamine tetraacetic acid (EDTA) and a remainder of water, and the method for washing a pickled steel plate is performed using the same.

A method for manufacturing a high-strength galvanized steel sheet having excellent strength-elongation balance, coating adhesiveness, and surface appearance. The method includes: (i) a first heating process of heating a steel sheet having a predetermined chemical composition, (ii) a first pickling process of pickling the steel sheet which was subjected to the first heating process in an oxidizing acidic aqueous solution, (iii) a second pickling process of pickling the steel sheet which was subjected to the first pickling process in a non-oxidizing acidic aqueous solution, (iv) a second heating process of holding the steel sheet, which was subjected to the second pickling process, at a temperature range of 700 C. or higher and 900 C. or lower in a hydrogen-containing atmosphere for 20 seconds or more and 300 seconds or less, and (v) performing a galvanizing treatment on the steel sheet which was subjected to the second heating process.