| 摘要 |
Determination (M1) and optionally regulation of accelerator concentration in zinc phosphonating solution containing steel, steel plated with zinc (Zn) (alloy) and/or aluminum (alloy) with a solution containing Zn ions, phosphate ions and specified accelerator(s) (I) comprising determining the (I) concentration using a biochemical hydrogen peroxide sensor that gives an electrical signal with a magnitude, is new. Phosphation of metal surfaces, comprising steel, steel plated with zinc (Zn) or Zn alloy, aluminum (Al) and/or Al alloy involves spraying or dipping for 3 seconds to 8 minutes with a solution containing 0.2-3 g/l Zn ions and 3-50 g/l phosphate ions, such that the weight ratio of phosphate ions to Zn ions is >= 3.7, and accelerator(s) (I). (I) comprises 0.3-4 g/l chlorate ions, 0.01-0.2 g/l nitrite ions, 0.05-2 g/l m-nitrobenzene sulfonate ions, 0.05-2 g/l m-nitrobenzoate ions, 0.05-2 g/l p-nitrophenol, 0.005-0.15 g/l free or combined hydrogen peroxide, 0.1-10 g/l free or combined hydroxylamine, 0.1-10 g/l reducing sugar, 0.05-4 g/l organic N-oxide, preferably N-methylmorpholine, and/or 0.5-5 g/l organic nitro compound selected from nitroguanidine, nitroarginine, its (m)ethyl and propyl esters and nitrofurfurylidene diacetate. The novelty is that the (I) concentration is determined using a biochemical hydrogen peroxide sensor that gives an electrical signal with a magnitude from which the (I) concentration can be determined.
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