| abstract |
Described is a method of phosphatizing steel, aluminium or galvanized or alloy-plated steel or aluminium surfaces by spraying the surface with, or dipping the surface in, a zinc-containing phosphatization solution for between 3 seconds and 8 minutes. The method is characterized in that the phosphatization solution contains 0.2 to 3 g/l of zinc ions, 3 to 50 g/l of phosphate ions, 1 to 100 mg/l of nickel or cobalt ions, as well as one or more accelerators and not more than 0.5 g/l of nitrate ions. Optional additives are lithium, copper and/or manganese. |