IMPROVED COMPOSITION CONTAINING TRIVALENT CHROMIUM USED IN CORROSION RESISTANT COATING ON METAL SURFACE Russian patent published in 2011 - IPC C23C22/48 

FIELD: metallurgy.

SUBSTANCE: procedure for manufacture of item consists in coating and/or finishing surface with at least one region of bare metal and/or at least one region of coating on underlying metal of substrate. The procedure consists in: (1) coating covered and/or finished surface with a layer of liquid composition stable at storage and free from hexavalent chromium containing: (A) component of fluoro-metallate anions, also, each of then consists of: (i) at least four atoms of fluorine; and (ii) at least one atom of elements chosen from group consisting of titanium, zirconium, hafnium, silicon, aluminium and boron and not necessarily one or both from: (iii) at least one ionised atom of hydrogen; and (iv) at least one atom of oxygen; (B) component of water solved fluoride of chromium; and (II) drying liquid layer formed at stage (I) with formation of open surface.

EFFECT: fabrication of coating resistant to influence of salt fog formed at contact of metal surface with composition containing trivalent chromium.

19 cl, 4 tbl, 2 ex