METHOD OF COATING METAL SURFACES, BASES COATED WITH SUCH METHOD, AND THEIR USE Russian patent published in 2019 - IPC C23C22/34 C23C22/36 C23C22/44 C23C22/83 

FIELD: technological processes.

SUBSTANCE: invention relates to a method of producing a conversion coating on a metal surface. Method comprises treating a base with a metal surface with an acidic aqueous conversion composition which contains 0.01 to 1 g/l of TiF₆^2-, ZrF₆^2- and/or HfF₆^2- in form of ions calculated as ZrF₆^2-, from 0.01 to 1 g/l Fe²⁺-, Mn- and/or Zn-ions, of which at least one type of said ions is contained in range of 0.01 to 1 g/l, and content of molybdate, calculated as MoO₄^2-, and/or content of phosphorus-containing oxyanions, calculated as PO₄^3-, is correspondingly less than 0.1 g/l, wherein said acidic aqueous composition has a pH in range of 2.5 to 6.5, and the obtained coating has a layer thickness of 0.3 to 3 mcm.

EFFECT: inventions are excellent for replacement of alkaline phosphating on metal surfaces of bases of various types, and metal surfaces of various types can be processed simultaneously or successively in the same bath.

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