| 摘要 |
The present invention relates to a multistage method for the corrosion-protective and adhesion-promoting treatment of metal surfaces, comprising a first method step for passivating pretreatment using an acidic aqueous composition (A) containing water-soluble compounds of Zr and/or Ti and fluoride ions, a subsequent method step for post-treatment using an aqueous composition (B) containing at least one organic compound having at least one aromatic heterocyclic compound, wherein the aromatic heterocyclic compound has at least one nitrogen atom. The invention further relates to a metal surface treated according to the method according to the invention and the use of said treated metal surface for subsequent coating with an organic binding agent system. |
