摘要 |
The invention concerns an acid aqueous phosphating solution which contains zinc ions, phosphate ions, copper ions and hydroxylamine in free form, as a salt or hydroxylamine-cleaving compound, and additionally one or a plurality of hydroxylamine stabilizers selected from organic molecules having at least two heteroatoms per molecule or, in the case of polymers, at least one heteroatom per four carbon atoms. The invention also concerns an aqueous concentrate and an aqueous supplementary solution for the phosphating solution. |