Method for coating a metal surface with an ultra-fine layer

Abstract

The present invention relates to a method for continuously coating a substrate in motion such as a metal strip made of steel, the coating formed being an ultra-fine film of a thickness between 10 and 100 nm, deposited on the substrate: from a solution containing nanoparticles of oxides, in conditions of controlled pH, said substrate being at a temperature higher than 120° C., the total duration of the deposition being less than 5 seconds and preferably less than 1 second, characterised in that at least one chemical additive, called a “refiner”, is incorporated into said solution, said refiner having, mutatis mutandis, the effect of restricting the formation of said coating.

1 - 32 . (canceled) 
     
     
         33 . A flat or long metallurgical product coated with an ultra-fine protective layer, said protective layer comprising nanoparticles of oxides or a mixture of these oxides. 
     
     
         34 . The product according to  claim 33 , wherein the oxides are Al 2 O 3 , Y 2 O 3 , SiO 2 , SnO 2 , TiO 2 , ZnO, S 2 O 5 , ZrO 2  or CeO 2 . 
     
     
         35 . The product according to  claim 33 , wherein the protective layer has a thickness of less than 100 nm. 
     
     
         36 . The product according to  claim 33 , wherein the product is a strip, wire, profiled section or tube. 
     
     
         37 . The product according to  claim 33 , wherein an initial thickness of the product prior to being coated with the protective layer is between 0.15 and 5 mm. 
     
     
         38 . A flat or long metallurgical product coated with an ultra-fine protective layer, said protective layer comprising nanoparticles of oxides or a mixture of these oxides, wherein the oxides are Al 2 O 3 , Y 2 O 3 , SiO 2 , SnO 2 , TiO 2 , ZnO, S 2 O 5 , ZrO 2  or CeO 2 ; wherein the protective layer has a thickness of less than 100 nm; wherein the product is a strip, wire, profiled section or tube; and wherein an initial thickness of the product prior to being coated with the protective layer is between 0.15 and 5 mm.