Abstract: The present invention relates to a process for anticorrosion pretreatment of multiple components in series, each component in the series at least partly comprises metal surfaces of zinc, iron and/or aluminum and undergoes a zinc phosphating step in which the component is contacted with an acidic aqueous composition containing an amount of an activating aid sufficient to ensure a layer weight below 5.5 g/m2 on a cleaned, untreated hot-dip galvanized steel surface (Z), wherein the activating aid is based on a water-dispersed particulate constituent at least partly selected from hopeite, phosphophyllite, scholzite and/or hureaulite, and at least one polymeric organic compound; and further relates to acidic aqueous zinc phosphating compositions obtainable by adding a particular amount of a colloidal aqueous solution containing the dispersed particulate constituent to an acidic aqueous composition containing zinc ions, phosphate ions and free fluoride.

Abstract: The invention relates to a method for zinc phosphating components comprising surfaces made of zinc in order to suppress the formation of insoluble phosphation constituents removably adhered to the zinc surfaces and thus further improve the adhesion of dip-paint coatings applied later. In the method, a process is used of activating the zinc surfaces by means of dispersions containing particulate hopeite, phosphophyllite, scholzite, and/or hureaulite, wherein the proportion of particulate phosphates in the activation process must be adapted to the quantity of free fluoride and dissolved silicon in the zinc phosphation.

Abstract: The invention relates to a method for zinc phosphating components so as to form layers, said components comprising surfaces made of steel with a high tolerance against aluminum dissolved in the zinc phosphating bath, wherein the precipitation of poorly soluble aluminum salts can be largely prevented. In the method, a process is used of activating the zinc surfaces by means of dispersions containing particulate hopeite, phosphophyllite, scholzite, and/or hureaulite, wherein the proportion of particulate phosphates in the activation process must be adapted to the quantity of free fluoride and dissolved aluminum in the zinc phosphation.

Abstract: The invention relates to a method for zinc phosphating components comprising surfaces made of zinc in order to suppress the formation of insoluble phosphation constituents removably adhered to the zinc surfaces and thus further improve the adhesion of dip-paint coatings applied later. In the method, a process is used of activating the zinc surfaces by means of dispersions containing particulate hopeite, phosphophyllite, scholzite, and/or hureaulite, wherein the proportion of particulate phosphates in the activation process must be adapted to the quantity of free fluoride and dissolved silicon in the zinc phosphation.

Abstract: The invention relates to a method for zinc phosphating components so as to form layers, said components comprising surfaces made of steel with a high tolerance against aluminum dissolved in the zinc phosphating bath, wherein the precipitation of poorly soluble aluminum salts can be largely prevented. In the method, a process is used of activating the zinc surfaces by means of dispersions containing particulate hopeite, phosphophyllite, scholzite, and/or hureaulite, wherein the proportion of particulate phosphates in the activation process must be adapted to the quantity of free fluoride and dissolved aluminum in the zinc phosphation.

Abstract: A multistage method for treatment of composite metal structures containing metallic surfaces of aluminum, zinc and optionally iron, is provide wherein in a first step, selective zinc phosphating of zinc and ferrous surfaces proceeds using a phosphating solution containing a quantity of water-soluble inorganic silicon compounds sufficient to suppress white spot formation on zinc, but less than the quantity where zinc phosphating loses selectivity. In a following second step, aluminum surfaces are passivated with an acidic treatment solution. Also provided is a zinc phosphating solution suitable for said method containing at least 0.025 g/l, but less than 1 g/l of silicon as water-soluble inorganic compounds calculated as SiF6, wherein the product (Si/mM)·(F/mM) of the concentration of silicon [Si in mM] in the form of water-soluble inorganic compounds and the concentration of free fluoride [F in mM] divided by the free acid point number is no greater than 5.

Abstract: The invention relates to an aqueous composition and to a method for the anticorrosion conversion treatment of metallic surfaces, particularly metallic materials which are assembled into composite structures, comprising steel or galvanized or alloy-galvanized steel and any combinations thereof, the composite structure being composed at least in part of aluminum or the alloys thereof. The aqueous composition according to the invention is based on a phosphating solution and contains, in addition to water-soluble compounds of zirconium and titanium, a quantity of free fluoride in a ratio that both permits phosphating of the steel and galvanized and/or alloy-galvanized steel surfaces and determines low pickling rates of the aluminum substrate with simultaneous passivation of the aluminum.

Abstract: The present invention relates to an aqueous composition and to a method for the anticorrosion conversion treatment of metallic surfaces, particularly metallic materials which are assembled into composite structures, comprising steel or galvanized or alloy-galvanized steel and any combinations of these materials, the composite structure being composed at least in part of aluminum or the alloys thereof. The aqueous composition according to the invention is based on a phosphating solution and contains, in addition to water-soluble compounds of zirconium and titanium, a quantity of free fluoride in a ratio that both permits phosphating of the steel and galvanized and/or alloy-galvanized steel surfaces and determines low pickling rates with regard to the aluminum substrate with simultaneous passivation of the aluminum.

Abstract: A process for the anticorrosive treatment of metal components that have been heat-treated at a temperature of at least 100° C. and at least partially comprise zinc surfaces, wherein the surfaces of the component that consist of zinc already partially have a crystalline zinc phosphate layer, wherein the cleaned component is given an activating pretreatment with an acidic aqueous dispersion of insoluble phosphates having a pH of not less than 4 and the component is subsequently subjected to a phosphating conversion treatment before electrocoating is applied. The invention also comprises the use of metal components that have been treated in such a process, for the application of multilayer systems and in particular for the manufacture of bodies in automobile production.

Abstract: The invention relates to an aqueous composition and to a method for the anticorrosion conversion treatment of metallic surfaces, particularly metallic materials which are assembled into composite structures, comprising steel or galvanized or alloy-galvanized steel and any combinations thereof, the composite structure being composed at least in part of aluminum or the alloys thereof. The aqueous composition according to the invention is based on a phosphating solution and contains, in addition to water-soluble compounds of zirconium and titanium, a quantity of free fluoride in a ratio that both permits phosphating of the steel and galvanized and/or alloy-galvanized steel surfaces and determines low pickling rates of the aluminum substrate with simultaneous passivation of the aluminum.

Abstract: A process for the anticorrosive treatment of metal components that have been heat-treated at a temperature of at least 100° C. and at least partially comprise zinc surfaces, wherein the surfaces of the component that consist of zinc already partially have a crystalline zinc phosphate layer, wherein the cleaned component is given an activating pretreatment with an acidic aqueous dispersion of insoluble phosphates having a pH of not less than 4 and the component is subsequently subjected to a phosphating conversion treatment before electrocoating is applied. The invention also comprises the use of metal components that have been treated in such a process, for the application of multilayer systems and in particular for the manufacture of bodies in automobile production.

Abstract: The present invention relates to an aqueous composition and to a method for the anticorrosion conversion treatment of metallic surfaces, particularly metallic materials which are assembled into composite structures, comprising steel or galvanized or alloy-galvanized steel and any combinations of these materials, the composite structure being composed at least in part of aluminum or the alloys thereof. The aqueous composition according to the invention is based on a phosphating solution and contains, in addition to water-soluble compounds of zirconium and titanium, a quantity of free fluoride in a ratio that both permits phosphating of the steel and galvanized and/or alloy-galvanized steel surfaces and determines low pickling rates with regard to the aluminum substrate with simultaneous passivation of the aluminum.

Abstract: In a process for the chemical pretreatment before painting of composite metal structures that contain aluminum or aluminum alloy portions together with steel, galvanized steel and/or alloy-galvanized steel portions, in a first step the metal structure is treated with a zinc phosphating solution that forms a surface-covering crystalline zinc phosphate layer on steel and on galvanized or alloy-galvanized steel, but without forming a zinc phosphate layer on the aluminum portions, and then in a second step the metal structure is brought into contact with a treatment solution that does not excessively dissolve the crystalline zinc phosphate layer on steel, galvanized and/or alloy-galvanized steel, but forms a conversion layer on the aluminum portions.

Abstract: The invention is a process for applying a nickel-free, copper-containing phosphate coating to a metal surface by contacting the metal surface with a phosphate solution containing 0.2 to 2.0 g/l zinc ions, 0.5 to 25 mg/l copper ions, and 5-30 g/l phosphate ions.

Abstract: Metal surfaces are contacted with a solution of a process bath (1), for example a phosphating or pickling solution, which comprises several components in aqueous solution, the composition of the process bath (1) being maintained within a given range by addition of solutions or gases, in particular air. The profitability is improved considerably if the solution of the process bath (1) is circulated via a first line (2) and a circulating pump (3) and the solution to be added and/or the gas to be added is fed to the process bath where, as a consequence of the ending of the line (2), vigorous thorough mixing prevails, or if the solution to be added or the gas to be added is fed to a suction pump (4), the solution to be added or the gas to be added mixing with the circulated solution.

Abstract: A method for stabilizing the electrolyte content of latex composition baths in which, preferably, the bath is flowingly contacted with the outside of a tubular filtration membrane having pores smaller than the latex micelles, and partly deioized water flows through the center of the tubular membrane at a rate sufficient to cause a pressure differential and thus effect ultrafiltration removal of electrolytes.

Abstract: A process for increasing the anticorrosive properties of an autodeposited coating wherein after the bath but before the curing, metallic chromate salts are formed in situ by first rinsing with metallic non-chromate water soluble salts and then rinsing with a chromium compound.