| abstract |
The invention concerns a process for the passivating post-treatment of phosphatised metal surfaces of iron, steel, galvanised steel, zinc, aluminium and their alloys, in which the phosphatised metal surfaces are brought into contact at temperatures in the range from 10 to 60 DEG C with chromium-free, acid, silicate-containing aqueous solutions having a pH in the region of 2 to 5 and 0.5 to 50 g/l SiO2 and 0.5 to 100 g/l of an acid. |