FIELD: protective coatings. SUBSTANCE: to protect metal surface from corrosion, a new aqueous liquid composition is provided containing simple and complex fluorides, iron-chelating reagent, phosphate ion, hydroxylamine source, and oxidant selected from the group including water-soluble nitroaromatic compounds and molybdates. High-quality protective phosphate conversion coatings are obtained for iron, zinc-containing, aluminum, and magnesium metal surfaces and also for magnesium alloy surfaces. Method does not require cations of two- or more-valence metals which are commonly used when manufacturing such coatings. If composition contains surfactants, preliminary chemical treatment of metal is unnecessary. EFFECT: simplified method and improved quality of coatings. 14 cl, 3 tbl, 6 ex
