An electrical steel sheet (1) includes a base material (2) of electrical steel, and an insulating film (3) formed on a surface of the base material (2). The insulating film (3) contains a phosphates of one or more selected from the group consisting of Al, Zn, Mg and Ca. The phosphate exhibits a specific peak having a top within a range of 26 ppm to 16 ppm in a solid .sup.31P-NMR spectrum, and a proportion of an integrated intensity of the specific peak relative to an integrated intensity of all peaks in the solid .sup.31P-NMR spectrum is 30% or more.

An electrical steel sheet (1) includes a base material (2) of electrical steel, and an insulating film (3) formed on a surface of the base material (2). The insulating film (3) contains a phosphates of one or more selected from the group consisting of Al, Zn, Mg and Ca. The phosphate exhibits a specific peak having a top within a range of 26 ppm to 16 ppm in a solid .sup.31P-NMR spectrum, and a proportion of an integrated intensity of the specific peak relative to an integrated intensity of all peaks in the solid .sup.31P-NMR spectrum is 30% or more.

A treatment device for single-stage treatment of a metal object to be treated by at least the steps of pickling and phosphating. The treatment device comprises at least the following: a treatment container for receiving the object to be treated and for receiving a flowable treatment substance; and a pump device for exchanging at least a fraction of the treatment substance. The treatment substance is flowable around at least one part of the object to be treated. The treatment substance comprises a phosphor- or phosphate-containing solution, in particular phosphoric acid. The phosphor- or phosphate-containing solution consists partly of water and partly of a reaction substance, and the reaction substance consists of phosphor or a phosphate and an additional treatment effect-improving substance. The proportion of the phosphor or phosphate in the reaction substance is at least 95%, and the reaction substance does not have a salt acid or sulfuric acid content.

A treatment device for single-stage treatment of a metal object to be treated by at least the steps of pickling and phosphating. The treatment device comprises at least the following: a treatment container for receiving the object to be treated and for receiving a flowable treatment substance; and a pump device for exchanging at least a fraction of the treatment substance. The treatment substance is flowable around at least one part of the object to be treated. The treatment substance comprises a phosphor- or phosphate-containing solution, in particular phosphoric acid. The phosphor- or phosphate-containing solution consists partly of water and partly of a reaction substance, and the reaction substance consists of phosphor or a phosphate and an additional treatment effect-improving substance. The proportion of the phosphor or phosphate in the reaction substance is at least 95%, and the reaction substance does not have a salt acid or sulfuric acid content.

A treatment device is provided for single-stage treatment of a metal object, wherein the treatment comprises at least pickling and phosphating of the object. The treatment device comprises a treatment container for holding the object to be treated and for holding a flowable treatment substance, and a pumping apparatus for circulating at least a portion of the treatment substance. The treatment substance is flowable around at least part of the object to be treated, and the treatment substance is a phosphorus- or phosphate-containing solution. The phosphorus- or phosphate-containing solution consists of water and a reaction substance, and the reaction substance consists of phosphorus or of a phosphate and at least one additional substance that improves the treatment effect. The fraction of the phosphorous or the phosphate in the reaction substance is between 75 vol % to 94 vol %, and the reaction substance has no fractions of hydrochloric acid and sulfuric acid.

A treatment device is provided for single-stage treatment of a metal object, wherein the treatment comprises at least pickling and phosphating of the object. The treatment device comprises a treatment container for holding the object to be treated and for holding a flowable treatment substance, and a pumping apparatus for circulating at least a portion of the treatment substance. The treatment substance is flowable around at least part of the object to be treated, and the treatment substance is a phosphorus- or phosphate-containing solution. The phosphorus- or phosphate-containing solution consists of water and a reaction substance, and the reaction substance consists of phosphorus or of a phosphate and at least one additional substance that improves the treatment effect. The fraction of the phosphorous or the phosphate in the reaction substance is between 75 vol % to 94 vol %, and the reaction substance has no fractions of hydrochloric acid and sulfuric acid.

The grain-oriented electrical steel sheet according to the present invention is a grain-oriented electrical steel sheet having a base steel sheet (1), an intermediate layer (4) disposed to be in contact with the base steel sheet (1), and an insulation coating (3) disposed to be in contact with the intermediate layer (4), and the grain-oriented electrical steel sheet includes a surface of the base steel sheet (1) having a groove (G) which extends in a direction intersecting a rolling direction of the base steel sheet (1), in which in a cross-sectional view of a plane parallel to the rolling direction and a sheet thickness direction of the base steel sheet (1), when a region between end portions of the groove (G) is defined as a groove part (R.sub.G), an average thickness of the intermediate layer (4) of the groove part (R.sub.G) is 0.5 times or more and 3.0 times or less an average thickness of the intermediate layer (4) other than the groove part (R.sub.G), and an area ratio of voids in the insulation coating (3) of the groove part (R.sub.G) is 15% or less.

Provided is a grain-oriented electrical steel sheet including a base steel sheet, an intermediate layer which is disposed in contact with the base steel sheet and mainly includes silicon oxide, and an insulation coating which is disposed in contact with the intermediate layer and mainly includes phosphate and colloidal silica, in which the base steel sheet contains predetermined chemical composition, BN having an average particle size of 50 to 300 nm is present, when an emission intensity of B is measured using glow discharge emission analysis, predetermined conditions are satisfied, and a ratio of a major axis to a minor axis of BN is 1.5 or less.

To further improve, even under OT bending with the use of a ZnAlMg-based alloy plated steel sheet as a base sheet, corrosion resistance regarding corrosion under paint film at a OT bent portion and a periphery thereof, without causing occurrence of cracks and peeling in the paint film.

A pre-coated plated steel sheet according to the present invention includes: a plating layer composed of ZnAlMg-based alloy plating, the plating layer being positioned on one side or both sides of a steel sheet; a chemical treatment film layer positioned on the plating layer; and a paint film layer positioned on the chemical treatment film, in which the paint film layer includes a primer paint film layer, and an upper paint film layer positioned on the primer paint film layer, and at least any of the following is satisfied: both a condition (a-1) and a condition (a-2); a condition (b); and a condition (c).

Provided is an aluminum-resin bonded body that expresses excellent bonding strength and does not show a reduction in the strength after a durability test, thus being able to keep the excellent bonding strength over a long period of time. The aluminum-resin bonded body includes: an aluminum substrate formed of aluminum or an aluminum alloy; an oxygen-containing film containing oxygen, the oxygen-containing film being formed on a surface of the aluminum substrate; and a resin molded body formed of a thermoplastic resin composition containing a thermoplastic resin and an additive, the resin molded body being bonded onto the oxygen-containing film, in which the thermoplastic resin composition contains any one or both of: a thermoplastic resin containing an element having an unshared electron pair in a repeat unit and/or at an end; and an additive containing an element having an unshared electron pair.