A method for post-treatment of a chromium finish surface to improve corrosion resistance comprising a) providing a substrate having a chromium finish surface, and at least one intermediate layer between the chromium finish surface and the substrate, selected from the group consisting of nickel, nickel alloys, copper and copper alloys, wherein the chromium finish surface is a surface of a trivalent chromium plated layer, obtained by electroplating the substrate, having the at least one intermediate layer, in a plating bath, the plating bath comprising chromium (III) ions; b) contacting the chromium finish surface with an aqueous solution, comprising a permanganate, at least one compound which is selected from a phosphorus-oxygen compound, a hydroxide, a nitrate, a borate, boric acid, a silicate, or a mixture of two or more of these compounds; c) forming a transparent corrosion protection layer onto the chromium finish surface during step b.

A method for electrolytically depositing a chromium oxide layer onto i) blackplate or onto ii) blackplate coated with a chromium electrodeposited coating produced based on chromium(III) technology electroplating, and to the coated product obtained thereby.

A method for electrolytically depositing a chromium oxide layer onto i) blackplate or onto ii) blackplate coated with a chromium electrodeposited coating produced based on chromium(III) technology electroplating, and to the coated product obtained thereby.

An aqueous electroplating bath is disclosed. The aqueous trivalent chromium bath comprises:—trivalent chromium cations in an amount of 0.12-0.276 mol/l,—ammonium ions in an amount of 4.0-6.0 mol/l, and—carboxylate ions in an amount of 2.0-7.4 mol/l, and the molar ratio of trivalent chromium cations to the carboxylate ions is 0.016-0.099, and the pH of the aqueous trivalent chromium bath is 2-6.

An aqueous electroplating bath is disclosed. The aqueous trivalent chromium bath comprises:—trivalent chromium cations in an amount of 0.12-0.276 mol/l,—ammonium ions in an amount of 4.0-6.0 mol/l, and—carboxylate ions in an amount of 2.0-7.4 mol/l, and the molar ratio of trivalent chromium cations to the carboxylate ions is 0.016-0.099, and the pH of the aqueous trivalent chromium bath is 2-6.

Provided is a shock absorber in which trivalent chromium is used to achieve both high hardness and low frictional force at a high level without using hexavalent chromium which is suspected of causing damage to the human body and the environment, and a method for manufacturing the shock absorber.

A shock absorber (100) of the present invention includes: a cylinder (1) which is filled with hydraulic oil (3); a piston rod (2) which is movable in the cylinder (1); and an oil seal (8) which is fixed to the cylinder (1) and slides on the piston rod (2), in which a hard layer mainly containing chromium obtained from a trivalent chromium plating bath is provided on a surface of the piston rod (2), and the hard layer contains both a crystalline material and an amorphous material, and also contains an additive other than chromium.

Provided is a shock absorber in which trivalent chromium is used to achieve both high hardness and low frictional force at a high level without using hexavalent chromium which is suspected of causing damage to the human body and the environment, and a method for manufacturing the shock absorber.

A shock absorber (100) of the present invention includes: a cylinder (1) which is filled with hydraulic oil (3); a piston rod (2) which is movable in the cylinder (1); and an oil seal (8) which is fixed to the cylinder (1) and slides on the piston rod (2), in which a hard layer mainly containing chromium obtained from a trivalent chromium plating bath is provided on a surface of the piston rod (2), and the hard layer contains both a crystalline material and an amorphous material, and also contains an additive other than chromium.

An electrode for electrolytic processes, in particular to an anode suitable for oxygen evolution having a valve metal substrate, a catalytic layer, a protection layer consisting of oxides of valve metals interposed between the substrate and the catalytic layer and an outer coating of oxides of valve metals. The electrode is particularly suitable for processes of cathodic electrodeposition of chromium from an aqueous solution containing Cr (III).

An electrode for electrolytic processes, in particular to an anode suitable for oxygen evolution having a valve metal substrate, a catalytic layer, a protection layer consisting of oxides of valve metals interposed between the substrate and the catalytic layer and an outer coating of oxides of valve metals. The electrode is particularly suitable for processes of cathodic electrodeposition of chromium from an aqueous solution containing Cr (III).

The present invention relates to an aqueous passivation solution having a pH in the range from 5.4 to 7.2, the solution including trivalent chromium ions, and formate anions and/or oxalate anions as complexing agents for said trivalent chromium ions, in which the trivalent chromium ions with respect to all formate anions together with all oxalate anions form a molar ratio in the range from 1:15 to 1:400.