摘要 |
The phosphate concentration, and therefore the pollution potential, of conventional high quality phosphating compositions containing zinc, manganese, and, optionally, nickel or copper cations, can be reduced without loss of corrosion protective value of the phosphate coatings formed by maintaining concentrations of active ingredients within prescribed ranges. Under the most preferred conditions, the corrosion resistance of phosphated and then painted cold rolled steel and the paint adhesion to phosphated and then painted electrogalvanized steel are improved over values obtained with the now most commonly used commercial high quality low zinc phosphating processes.
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