ONE-STAGE PROCESS FOR ZINC PHOSPHATING

• Main Authors: Angenendt, Christina, Brouwer, Jan-Willem, Balzer, Marc, Posner, Ralf, Wapner, Kristof, Hamacher, Matthias
• Format: Patent
• Language: English
• Published: 13.07.2023
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

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.