As a rust prevention member that has excellent corrosion resistance, while being provided with a coating film that contains Si, a rust prevention member which is provided with a base material, a zinc-based plating layer that is provided on the base material, and a chemical conversion coating film that contains Si and is provided on the zinc-based plating layer is described. This rust prevention member is characterized in that the chemical conversion coating film has an Si-rich region on the surface side, said Si-rich region having an atomic ratio of the Si content to the Zn content of 1 or more, while having a thickness of 100 nm or more.

The present invention provides a metal sheet including a steel substrate coated on at least one face with a coating including from 0.1 to 20% by weight of magnesium, optionally from 0.1 to 20% by weight of aluminum, the balance being zinc, potential impurities linked to the method and optionally one or more additional elements selected from among Si, Sb, Pb, Ti, Ca, Mn, Sn, La, Ce, Cr, Ni, Zr and Bi, the content by weight of each additional element being less than 0.3%. The coating itself is covered by a layer, based on zinc hydroxychloride, having a chlorine coating weight of at least 1 mg/m.sup.2. The layer does not include hydrozincite or mixed hydroxycarbonates of zinc and aluminum or water-soluble compounds of sodium or potassium. The present invention also provides a method to obtain the metal sheet.

The present invention provides a metal sheet including a steel substrate coated on at least one face with a coating including from 0.1 to 20% by weight of magnesium, optionally from 0.1 to 20% by weight of aluminum, the balance being zinc, potential impurities linked to the method and optionally one or more additional elements selected from among Si, Sb, Pb, Ti, Ca, Mn, Sn, La, Ce, Cr, Ni, Zr and Bi, the content by weight of each additional element being less than 0.3%. The coating itself is covered by a layer, based on zinc hydroxychloride, having a chlorine coating weight of at least 1 mg/m.sup.2. The layer does not include hydrozincite or mixed hydroxycarbonates of zinc and aluminum or water-soluble compounds of sodium or potassium. The present invention also provides a method to obtain the metal sheet.

A ternary zinc-nickel-iron alloy and aqueous alkaline electrolyte for electroplating the alloy includes zinc, nickel, and a complex of an iron salt.

A ternary zinc-nickel-iron alloy and aqueous alkaline electrolyte for electroplating the alloy includes zinc, nickel, and a complex of an iron salt.

The invention is directed to a conversion coating composition for coating a metal surface including a water soluble dye, at least one metal compound selected from the group consisting of a zirconium-containing compound, titanium-containing compound and silicon-containing compound; and water, wherein the provides for qualitative characterization of the conversion coating uniformity and thickness by the naked human eye or visible light detecting device; and, a method for coating the metal surfaces using the conversion coating composition.

The invention is directed to a conversion coating composition for coating a metal surface including a water soluble dye, at least one metal compound selected from the group consisting of a zirconium-containing compound, titanium-containing compound and silicon-containing compound; and water, wherein the provides for qualitative characterization of the conversion coating uniformity and thickness by the naked human eye or visible light detecting device; and, a method for coating the metal surfaces using the conversion coating composition.

An aqueous acidic composition for treating metal surfaces, the composition including the following components: a) at least one water soluble or water dispersable anionic polyelectrolyte; b) at least one organofunctional silane including one or more reactive functional groups selected from the group including amino, mercapto, methacryloxy, epoxy and vinyl; c) at least one water dispersible solid wax wherein the weight ratio between components a:b is in the range of 1:2-4:1, based on dry matter; the weight ratio between components (a+b):c is in the range of 1:3-3:1, based on dry matter, and wherein components a and b may be presentat least partiallyas their graft reaction product. Another aspect is a treating method using this composition and use of the thus treated metal surface.

An aqueous acidic composition for treating metal surfaces, the composition including the following components: a) at least one water soluble or water dispersable anionic polyelectrolyte; b) at least one organofunctional silane including one or more reactive functional groups selected from the group including amino, mercapto, methacryloxy, epoxy and vinyl; c) at least one water dispersible solid wax wherein the weight ratio between components a:b is in the range of 1:2-4:1, based on dry matter; the weight ratio between components (a+b):c is in the range of 1:3-3:1, based on dry matter, and wherein components a and b may be presentat least partiallyas their graft reaction product. Another aspect is a treating method using this composition and use of the thus treated metal surface.

There is provided a high-strength galvanized steel sheet and a relatively low-strength galvanized steel sheet that undergoes complex forming, a galvanized steel sheet that exhibits consistently excellent press formability and that generates no hazardous fumes during welding as well as a manufacturing method therefor. The galvanized steel sheet has an oxide layer on the surface, where the oxide layer has an average thickness of 20 nm or more, and the oxide layer contains 30 mg/m.sup.2 or more of Zn, 1.0 mg/m.sup.2 or more of S, and 50 mg/m.sup.2 or more and 1,000 mg/m.sup.2 or less of polyethylene particles having an average particle size of 5.0 m or less.