A method for phosphating metal surfaces in a layer-forming manner using a colloidal aqueous solution as an activation stage containing a dispersed particulate constituent, the particulate constituent containing dispersed inorganic compounds of phosphates of polyvalent metal cations; plus polymeric organic compounds as dispersing agents, which are composed at least partially of styrene and/or an α-olefin having no more than 5 carbon atoms and are composed at least partially of maleic acid, its anhydride and/or its imide, the polymeric organic compounds additionally comprising polyoxyalkylene units. In the activation stage of the method according to the invention, the addition of condensed phosphates can be dispensed with such that the content of dissolved condensed phosphates in the colloidal aqueous solution is less than 0.25, based on the phosphate content in the particulate constituent thereof, in each case based on the element P.

A method for phosphating metal surfaces in a layer-forming manner using a colloidal aqueous solution as an activation stage containing a dispersed particulate constituent, the particulate constituent containing dispersed inorganic compounds of phosphates of polyvalent metal cations; plus polymeric organic compounds as dispersing agents, which are composed at least partially of styrene and/or an α-olefin having no more than 5 carbon atoms and are composed at least partially of maleic acid, its anhydride and/or its imide, the polymeric organic compounds additionally comprising polyoxyalkylene units. In the activation stage of the method according to the invention, the addition of condensed phosphates can be dispensed with such that the content of dissolved condensed phosphates in the colloidal aqueous solution is less than 0.25, based on the phosphate content in the particulate constituent thereof, in each case based on the element P.

A steel sheet wherein a steel structure of an inside of the steel sheet contains, by volume fraction, soft ferrite: 0% to 30%, retained austenite: 3% to 40%, fresh martensite: 0% to 30%, a sum of pearlite and cementite: 0% to 10%, and a remainder including hard ferrite. In the steel sheet, in a ⅛ to ⅜ thickness range, a proportion of retained austenite having an aspect ratio of 2.0 or more is 50% or more, and a soft layer having a thickness of 1 to 100 μm from a surface in a sheet thickness direction is present. When an emission intensity at a wavelength indicating Si is analyzed in the sheet thickness direction from the surface by a radio-frequency glow discharge analysis method, a peak of the emission intensity appears in a range of more than 0.2 μm and 5.0 μm or less from the surface.

A hot stamped steel includes a base material that is formed of steel, a plated layer that is formed on a surface of the base material, and a phosphate coating that is formed on a surface of the plated layer; chemical composition of the plated layer contains 20.00 to 45.00 mass % of Al, 10.00 to 45.00 mass % of Fe, 4.50 to 15.00 mass % of Mg, 0.10 to 3.00 mass % of Si, 0.05 to 3.00 mass % of Ca, 0 to 0.50 mass % of Sb, 0 to 0.50 mass % of Pb, 0 to 1.00 mass % of Cu, 0 to 1.00 mass % of Sn, 0 to 1.00 mass % of Ti, 0 to 0.50 mass % of Sr, 0 to 1.00 mass % of Cr, 0 to 1.00 mass % of Ni, and 0 to 1.00 mass % of Mn with a remainder of Zn and impurities; the phosphate coating consists of zinc phosphate crystals containing 5.0 to 50.0 mass % of Mg and 0.5 to 5.0 mass % of Ca; and the adhesion amount of the phosphate coating per one surface is in a range of 0.1 to 10.0 g/m.sup.2.

Provided are coated metal, the metal having improved properties due to a novel coating, a coating-forming treatment solution for forming the novel coating, and a method for producing the coated metal that has the novel coating. The coated metal includes metal and a coating formed on the metal. The coating includes Si, P, and O, and at least one selected from the group consisting of Mg, Ca, Ba, Sr, Zn, Al, and Mn. The coating includes a compound having a Na Super Ionic Conductor-type (NASICON-type) crystal structure represented by a general formula M.sup.IM.sup.IV.sub.2(M.sup.VO.sub.4).sub.3.

Provided are coated metal, the metal having improved properties due to a novel coating, a coating-forming treatment solution for forming the novel coating, and a method for producing the coated metal that has the novel coating. The coated metal includes metal and a coating formed on the metal. The coating includes Si, P, and O, and at least one selected from the group consisting of Mg, Ca, Ba, Sr, Zn, Al, and Mn. The coating includes a compound having a Na Super Ionic Conductor-type (NASICON-type) crystal structure represented by a general formula M.sup.IM.sup.IV.sub.2(M.sup.VO.sub.4).sub.3.

The threaded connection for pipes includes a pin, a box and a Zn—Ni alloy plating layer. The pin has a pin-side contact surface that includes a pin-side thread part. The box has a box-side contact surface that includes a box-side thread part. The Zn—Ni alloy plating layer is formed on at least one of the pin-side contact surface and the box-side contact surface. The Zn—Ni alloy plating layer is consisting of Zn, Ni, trace amount of Cr and impurities. The trace amount of Cr content of the Zn—Ni alloy plating layer is 5.0×10 counts/sec or more in terms of Cr intensity as measured by secondary ion mass spectrometry using O.sub.2.sup.+ ions as bombarding ions.

An insulating coating treatment liquid for forming a chromium-free insulating coating on a surface of a grain-oriented electrical steel sheet, the insulating coating treatment liquid including at least one phosphate salt selected from phosphate salts of any of Mg, Ca, Ba, Sr, Zn, Al, and Mn and including colloidal silica and particles of a metal-element-containing compound. A content of the colloidal silica in terms of SiO.sub.2, on a solids basis, is 50 to 120 parts by mass, and a content of the particles of a metal-element-containing compound in terms of elemental metal is 5 to 60 parts by mass, per 100 parts by mass of the at least one phosphate salt, and the insulating coating treatment liquid has a thixotropic index (TI) of 1.00 or greater and 10.00 or less.

Disclosed is a method of treating a substrate, comprising contacting at least a portion of the substrate surface with a first composition comprising a lanthanide source and an oxidizing agent. A substrate obtainable by the methods also is disclosed.

A grain-oriented magnetic steel sheet with chromium-free insulating tension coating includes a grain-oriented magnetic steel sheet and an insulating tension coating containing a phosphate salt and silica on a surface of the grain-oriented magnetic steel sheet, the coating further including a crystalline compound represented by the general formula (1): M.sup.II.sub.3M.sup.III.sub.4(X.sup.VO.sub.4).sub.6 . . . (1). A method for producing a grain-oriented magnetic steel sheet with chromium-free insulating tension coating includes applying an insulating tension coating liquid to a surface of a finish annealed grain-oriented magnetic steel sheet, the coating liquid including colloidal silica, a phosphate salt and a metal element M-containing compound in a specific ratio, and heat treating the steel sheet at least one time at a temperature of not less than 900° C. in an atmosphere including a non-oxidizing gas and having a dew point of not more than 0° C.