A process of preventing crack formation in chemical conversion coating comprising providing a substrate; introducing a chemical conversion coating material; adding an additive containing a binder to the conversion coating material; and coating the substrate with the chemical conversion coating and the additive.

A steel sheet for a container according to the present invention includes: a base steel sheet; a metal chromium layer; and a chromium-containing layer, in which the metal chromium layer is located on at least one surface of the base steel sheet, the chromium-containing layer is located on the metal chromium layer and contains a granular trivalent chromium compound, or contains a granular trivalent chromium compound and granular metal chromium, the metal chromium layer and the chromium-containing layer are separately disposed in two layers on the base steel sheet, in the chromium-containing layer, an average particle size of the trivalent chromium compound and the metal chromium is 10 nm or more and 100 nm or less, and an adhesion amount of the chromium-containing layer is 1.0 mg/m.sup.2 or more and 100 mg/m.sup.2 or less in terms of a Cr content.

The present inventions refers to a passivation composition for depositing a chromium-comprising passivation layer on a zinc or zinc-nickel coated substrate, the composition comprising: (i) trivalent chromium ions, (ii) at least one complexing agent for the trivalent chromium ions, being different from the at least one corrosion-inhibiting agent, and (iii) at least one corrosion-inhibiting agent, which is (A) one or more than one substituted azole compound and/or salts thereof, together in a total concentration below 10 mg/L, based on the total volume of the passivation composition, and/or (B) one or more than one unsubstituted or substituted aliphatic organic acid with at least one mercapto-group and/or salts thereof, together in a total concentration in a range from 0.001 mg/L to 100 mg/L, based on the total volume of the passivation composition.

An object is to provide a trivalent chromium chemical conversion treatment liquid for a zinc or zinc alloy base capable of forming an environmentally-friendly chemical conversion coating with high corrosion resistance. The present invention provides a hexavalent chromium-free trivalent chromium chemical conversion treatment liquid for zinc or zinc alloy, the liquid comprising trivalent chromium ions, zirconium ions, nitrate ions, and chain colloidal silica, in which the pH of the treatment liquid is 2.5 to 5.0.

A corrosion resistant coating including a matrix, corrosion resistant particles dispersed throughout the matrix, and a glass-forming additive is disclosed. The glass-forming additive and one or more materials in the matrix form a glassy-phase when cured. Coated gas turbine engine components and methods for coating components are also 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 solution composition for steel sheet surface treatment, comprising 30 wt % to 60 wt % of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B); 0.2 wt % to 0.4 wt % of a rust-inhibiting and corrosion-resisting agent; 0.1 wt % to 0.3 wt % of a molybdenum-based compound; 5 wt % to 10 wt % of a water-soluble cationic urethane resin; 0.5 wt % to 2.0 wt % of a silane coupling agent; and 27.3 wt % to 64.2 wt % of water, a zinc-based plated steel sheet surface-treated with the same, and a manufacturing method therefor, the zinc-based plated steel sheet surface-treated with the solution composition for steel sheet surface treatment containing trivalent chromium may have an excellent effect on corrosion resistance, blackening resistance, fingerprint resistance, oil resistance, and alkali resistance.

A surface treatment solution composition for forming an inorganic film, comprising: 10 to 30% by weight of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B) and satisfying a content ratio A/(A+B) of 0.3 to 0.6; 5 to 50% by weight of a silane compound; 0.2 to 3% by weight of a vanadium-based rust-inhibiting and corrosion-resisting agent; 0.5 to 5% by weight of a cobalt-based rust-inhibiting and corrosion-resisting agent; and 12 to 84.3% by weight of water, an alloyed hot-dip galvanized steel sheet surface-treated using the composition, and a method for manufacturing the alloyed hot-dip galvanized steel sheet, are provided, and the surface treatment solution composition containing the trivalent chromium compound has an excellent effect on corrosion resistance, blackening resistance, fuel resistance, weldability, and alkali resistance.

In certain aspects, a coated steel substrate comprises a single or multiple-layer electroplated aluminum coating over a steel substrate. The multiple-layer electroplated aluminum coating comprises one or more porous layers and one or more compact layers. The one or more porous layers comprise a material selected from a group consisting of aluminum and aluminum alloys. The one or more compact layers comprise a material selected from a group consisting of aluminum and aluminum alloys. In certain aspects, a method of depositing a multiple-layer aluminum coating over a steel substrate includes electroplating one or more porous aluminum layers over the steel substrate. The one or more porous aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys. One or more compact aluminum layers are electroplated over the steel substrate. The one or more compact aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys.

The present invention relates to a method for forming a black-passivation layer on a zinc-iron alloy of a substrate, a black-passivation composition for depositing a black-passivation layer on such, in which the black-passivation composition includes one or more than one blackening agent selected from the group consisting of formula (I) and formula (II) as described hereinafter, and a respective use of said blackening agents for blackening a zinc-iron alloy.