METALLIZING PRELIMINARY TREATMENT OF ZINC SURFACES Russian patent published in 2013 - IPC C23C18/54 C23C28/00 

FIELD: metallurgy.

SUBSTANCE: in the method contact is provided between the specified surface with an agent (1) on water basis, having the pH value not exceeding 9 and containing cations and/or compounds of a metal (A), selected from cations and/or compounds of metals from the group, which includes iron, molybdenum, tungsten, cobalt, nickel, lead and/or tin in concentration of at least 0.001 M, and an acceleration agent selected from the group, which includes the group, including oxoacids of phosphorus or nitrogen, and their salts, besides, there is at least one atom of phosphorus or nitrogen with average extent of oxidation. Molar ratio of the acceleration agent and cations and/or compounds of the metal (A) in the specified agent makes at least 1:5, and oxidation-reduction potential E_Redox of cations and/or compounds of the metal (A), being measured on the metal electrode of the electrode of the metal (A) at the specified temperature of the process and concentration of cations and/or compounds of the metal (A) in the agent (1) on water basis, turns out to be more anode than the electrode potential E_zn of steel surface galvanised or coated with zinc alloy, being in contact with the agent (2) on water basis, besides, the last agent differs from the agent (1) only by the fact that it does not contain cations and/compounds of the metal (A).

EFFECT: improved adhesion of a surface and elimination of varnish peeling caused by defects in a zinc shell of strip steel.

20 cl, 7 dwg, 4 tbl