Method for phosphatizing zinc or aluminium surfaces

摘要

The invention relates to a method for phosphatizing zinc or aluminium surfaces with a phosphatizing solution containing 0.5 to 2.0 g/l Zn<2+>, 0.3 to 2.0 g/l Ni<2+>, 0.1 to 0.4 g/l NH2OH, at least 3.0 g/l NO3<-> and 10.0 to 20.0 g/l phosphate (calculated as P2O5). Said solution is applied to the surfaces by immersion or spraying at 35 to 75 DEG C, the immersion time being 0.5 to 10 minutes and the spraying time being 3 seconds to 5 minutes.