process for corrosion protection of stahblech, einsetig beschichted with zn ni alloy

摘要

Corrosion inhibitor for a metallic material such as steel, of the type consisting of an aqueous solution containing an alkali metal nitrite, characterised in that the said solution contains 0.01 to 0.3 mol/l of an alkali metal nitrite, 0.01 to 0.3 mol/l of an alkali metal phosphate and phosphoric acid in the proportion of a quantity sufficient to maintain the pH of the said solution, measured at ambient temperature, between 6.9 and 7.2.