Patent ID: 8663443

Claim:
A method for corrosion-protective pretreatment of metal components, comprising: contacting a metal component at least partially comprised of metal surfaces made of iron, with a chromium-free aqueous treatment solution comprising: (i) no less than 50 ppm and no more than 1000 ppm zirconium and/or titanium in the form of their fluoro complexes, and (ii) no less than 10 ppm and no more than 1000 ppm phosphate ions, (iii) a non-zero amount less than 50 ppm of oxo anions of vanadium, tungsten and/or molybdenum; and said treatment solution having a pH of no less than 3.5 and no greater than 6.0 and a molar ratio of zirconium and/or titanium to phosphate ions in a range no greater than 10:1 and no less than 1:10; and wherein the method is carried out without addition of organic polymers other than organic polymers based on homo- or copolymers of vinylpyrrolidone.