abstract |
A method for the treatment or pre-treatment of surfaces of metal objects by means of an acidic, aqueous solution containing zinc and phosphate. The phosphating solution contains between 0.1-10 g/L, zinc, 4-50 g/L phosphate calculated as PO4, between 0.03-3 g/L, of at least one guanidine compound comprising at least one nitro group calculated as nitroguanidine, and between 0.001-0.9 g/L hydrogen peroxide and has a temperature of less than 80° C. The corresponding acidic, aqueous composition and finished products are also disclosed. |