IMPROVED METHOD FOR NICKEL-FREE PHOSPHATING METAL SURFACES

摘要

The present invention relates to a method for substantially nickel-free phosphating of a metallic surface, wherein a metallic surface is treated one after the other with the following compositions:i) with an alkaline, aqueous cleaner composition which comprises at least one water-soluble silicate, andii) with an acidic, aqueous, substantially nickel-free phosphating composition which comprises zinc ions, manganese ions and phosphate ions.;The invention also relates to the above cleaner composition itself and also to a metallic surface phosphate-coated by the above method, and to the use of said surface.