摘要:
A process for phosphating a galvanized surface of a steel strip electrolytically galvanized on one side by contacting the galvanized surface of the steel strip with a phosphating solution containing 1.0 to 6 g/l zinc, 0.5 to 5.0 g/l nickel and 14 to 25 g/l phosphate at a temperature of 40.degree. to 70.degree. C. for from 2 to 20 seconds. The ungalvanized surface remains metal bright.
摘要:
A process for the corrosion protection of steel strips coated with zinc or zinc alloy, characterised in that the steel strips coated with zinc or zinc alloy are brought into contact with an aqueous treatment solution having a pH within the range of from 1.5 to 3.5, which contains 1 to 20 g/l manganese(II) ions and 1 to 150 g/l phosphate ions, and the solution is dried without intermediate rinsing. Optionally the solution may contain in addition: up to 10 g/l zinc ions, up to 10 g/l nickel ions, up to 20 g/l titanium ions, up to 50 g/l silicon ions in the form of silicon compounds, up to 30 g/l fluoride ions, up to 150 g/l of one or more polymers or copolymers of polymerisable carboxylic acids selected from acrylic acid, methacrylic acid and maleic acid, and esters thereof with alcohols having 1 to 6 carbon atoms. The present invention also relates to the correspondingly-treated metal strips.
摘要:
A process for controlling the layer weight during the phosphating of steel strip zinc-coated on one or both sides, using a phosphating solution which contains 1 to 6 g/l zinc ions and 10 to 30 g/l phosphate ions, characterized in that a Fe(II) ion content within the range of 3 to 100 mg/l is established in the phosphating solution. The higher the Fe(II) content, the lower is the layer weight. An alteration in the Fe(II) content of 3 to 20 mg/l results in an alteration in the layer weight of about 0.1 g/m2.
摘要:
The invention concerns a process, not using chlorate or nitrite, for the production of nickel and manganese containing zinc phosphate films on steel, zinc, and/or zinc alloys by spraying, spray-dipping, and/or dipping, using an aqueous solution. An organic oxidizing agent is added, primarily to depolarize the nascent hydrogen produced.
摘要:
Activation of metal surfaces prior to phosphating can be improved by using aqueous dispersions of polymeric titanium(IV) phosphates in which at least 95% by weight of the polymeric particles have a particle diameter of less than 200 nm. This low particle diameter is attained by adding a titanium(IV)-complexing agent before or during an otherwise conventional reaction between a titanium(IV) compound, acid or phosphate, and water. The complexing agent is used in an amount of less than the stoichiometric amount, based on the titanium(IV) content. The best complexing agents are poly(aldehydocarboxylic acids), 1,1-diphosphonic acids, and/or the alkali metal salts of these types of acids.
摘要:
Process for the alkaline passivation of galvanized and alloy-galvanized steel surfaces and of aluminum in strip lines, wherein the metal surfaces are brought into contact with an alkaline aqueous solution that contains complexing agents and iron, which has a free alkalinity in the range of 5 to 20 points and a total alkalinity in the range of 7 to 30 points and contains: 0.1 to 1 g/l magnesium ions, 0.1 to 1 g/l iron (III) ions and 0.5 to 5 g/l amino or hydroxy carboxylate ions. This may be followed by a chrome-containing or chrome-free secondary passivation.
摘要:
A process for phosphating metal surfaces by treatment with an acidic zinc- and phosphathe-containing solution which does not require rinsing. The metal substrate is contacted with a phosphating solution containing 2 to 25 g/l of zinc ions, 2 to 25 g/l of manganese ions and 50 to 300 g/l of phosphate ions. The solution has a pH value of 1 to 3.6, a free acid content of 0 to 100 points, a total acid content of 40 to 400 points and a ratio of free acid to total acid of 1:4 to 1:20.
摘要:
In a process for phosphatizing electrolytically and/or hot-dip galvanized steel strip, the steel strip is briefly treated with acidic phosphatizing solutions which contain, in addition to zinc and phosphate ions, manganese and nickel cations and anions of oxygen-containing acids with an accelerator effect. The weight ratio of nickel cations to nitrate anions is adjusted to between 1:10 and 1:60 and the weight ratio of manganese cations nitrate anions is adjusted to between 1:1 and 1:40.