Disclosed herein are embodiments of a molybdate-based composition and a conversion coating obtained therefrom that can replace conventional and toxic chromate-based conversion coatings in a variety of applications and industries. The molybdate-based composition provides conversion coatings that exhibit anodic inhibition and rapid repassivation when applied to objects, such as metal-based objects, and do not contain hexavalent chromium. The molybdate-based composition and conversion coating can be used to reduce corrosion. Embodiments of methods of protecting objects, such as metal surfaces, with the molybdate-based conversion coating also are disclosed.

Disclosed herein are embodiments of a molybdate-based composition and a conversion coating obtained therefrom that can replace conventional and toxic chromate-based conversion coatings in a variety of applications and industries. The molybdate-based composition provides conversion coatings that exhibit anodic inhibition and rapid repassivation when applied to objects, such as metal-based objects, and do not contain hexavalent chromium. The molybdate-based composition and conversion coating can be used to reduce corrosion. Embodiments of methods of protecting objects, such as metal surfaces, with the molybdate-based conversion coating also are disclosed.

Disclosed are pretreatment compositions and associated methods for treating metal substrates with pretreatment compositions, including ferrous substrates, such as cold rolled steel and electrogalvanized steel. The pretreatment composition includes: a Group IIIB and/or IVB metal; free fluoride; and molybdenum. The methods include contacting the metal substrates with the pretreatment composition.

Disclosed are pretreatment compositions and associated methods for treating metal substrates with pretreatment compositions, including ferrous substrates, such as cold rolled steel and electrogalvanized steel. The pretreatment composition includes: a Group IIIB and/or IVB metal; free fluoride; and molybdenum. The methods include contacting the metal substrates with the pretreatment composition.

The present disclosure relates to a method of chemical pretreatment and selective phosphation of a composite metal construction comprising at least a portion made of aluminum and at least a portion made of zinc and optionally a further portion made of iron, which includes (I) treating the composite metal construction with an aqueous zinc phosphation composition that results in the formation of a surface-covering crystalline zinc phosphate layer and thenwith an intervening water rinse operation (II) applying an aqueous acidic passivation composition,

The present disclosure also relates to a corresponding zinc phosphation composition, to a concentrate for production thereof, to a corresponding composite metal construction and to a method of using thereof.

The present invention relates to a method for adjusting a passivation composition by determining the redox potential of a passivation composition as well as to a method for passivating metallic substrates by treatment with a passivation composition.

Disclosed herein are embodiments of a molybdate-based composition and a conversion coating obtained therefrom that can replace conventional and toxic chromate-based conversion coatings in a variety of applications and industries. The molybdate-based composition provides conversion coatings that exhibit anodic inhibition and rapid repassivation when applied to objects, such as metal-based objects, and do not contain hexavalent chromium. The molybdate-based composition and conversion coating can be used to reduce corrosion. Embodiments of methods of protecting objects, such as metal surfaces, with the molybdate-based conversion coating also are disclosed.

Disclosed herein are embodiments of a molybdate-based composition and a conversion coating obtained therefrom that can replace conventional and toxic chromate-based conversion coatings in a variety of applications and industries. The molybdate-based composition provides conversion coatings that exhibit anodic inhibition and rapid repassivation when applied to objects, such as metal-based objects, and do not contain hexavalent chromium. The molybdate-based composition and conversion coating can be used to reduce corrosion. Embodiments of methods of protecting objects, such as metal surfaces, with the molybdate-based conversion coating also are disclosed.

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 is a surface treated steel sheet for a fuel tank, the surface treated steel sheet including: a Zn plated layer or a ZnNi alloy plated layer which is formed on at least a surface of the steel sheet to be an inner surface of the fuel tank; and a chromate-free chemical conversion coating layer containing a water-and-oil repellent, the chromate-free chemical conversion coating layer being placed over the Zn plated layer or the ZnNi alloy plated layer on the surface to be the inner surface of the fuel tank. A water contact angle on a surface of the chromate-free chemical conversion coating layer is more than or equal to 70 degrees and an n-hexadecane contact angle on the surface of the chromate-free chemical conversion coating layer is more than or equal to 30 degrees and less than or equal to 70 degrees.