Metal strip product

Abstract

A coated steel strip product with a dense and hard abrasion resistant coating on one side or both sides of said strip. The thickness of said coating is in total maximally 25 μm, the hardness of said coating is at least 600 HV and the tensile strength of the steel strip substrate is at least 1200 MPa. The coating is preferably applied by electron beam evaporation and the coating may be, e.g., of Al 2 O 3 . The coated metal strip is useful for the manufacturing of doctor and coater blades for paper and printing industry.

1 . A coated steel strip product, comprising: 
 a steel strip substrate; and    a dense and hard abrasion resistant coating on one side or both sides of the strip substrate, the coating comprising a mixture including Al 2 O 3  and ZrO 2 ,    wherein the mixture has a main ingredient of Al 2 O 3 ,    wherein the coating is directly applied onto the steel strip substrate, and    wherein a thickness of the coating is in total maximally 25 μm.    
   
   
       2 . The product according to  claim 1 , wherein the mixture includes TiO 2 .  
   
   
       3 . The product according to  claim 1 , wherein a hardness of the coating is at least 600 HV and a tensile strength of the steel strip substrate is at least 1200 MPa.  
   
   
       4 . The product according to  claim 1 , wherein the thickness of the strip substrate is between 0.015 mm and 5.0 mm.  
   
   
       5 . The product according to  claim 1 , wherein the strip substrate is made of hardenable carbon steel, hardenable stainless chromium steel, or precipitation hardenable strip steel.  
   
   
       6 . The product according to  claim 1 , wherein the coating has a multi-layer structure of a plurality of individual layers.  
   
   
       7 . The product according to  claim 6 , wherein the multilayer structure has up to 10 individual layers.  
   
   
       8 . The product according to  claim 6 , wherein each individual layer of the multi-layer structure has a thickness of between 0.1 to 15 μm.  
   
   
       9 . The product according to  claim 6 , wherein the coating includes at least one layer of TiO 2 .  
   
   
       10 . The product according to  claim 6 , wherein layers of the coating include nitrides or carbides.  
   
   
       11 . The product according to  claim 10 , wherein the nitrides include TiN and the carbides include TiC.  
   
   
       12 . The product according to  claim 10 , wherein the coating includes at least one layer of a metal.  
   
   
       13 . The product according to  claim 12 , wherein the metal is Cr.  
   
   
       14 . The product according to  claim 6 , wherein the coating includes a transition metal carbide, a transition metal nitride, or a mixture thereof.  
   
   
       15 . The product according to  claim 14 , wherein the coating includes TiN, TiC, CrN, or mixtures thereof.  
   
   
       16 . The product according to  claim 1 , wherein the coating includes at least one layer of nickel having a thickness up to 2 μm, the at least one layer not being adjacent the strip substrate.  
   
   
       17 . A doctor or coater blade, comprising a coated steel strip product as in any one of claims  1 ,  6  and  16 .  
   
   
       18 . A doctor or coater blade according to  claim 17 , wherein a lateral scraping side and/or a cutting side is coated with the same coating composition as a main side.  
   
   
       19 . A method of manufacturing a coated steel strip product, the coated steel strip product having a steel strip substrate and a dense and hard abrasion resistant coating on one side or both sides of the strip substrate, wherein the coating includes a mixture including Al 2 O 3  and ZrO 2 , the coating is directly applied on to the steel strip substrate, and a thickness of the coating is in total maximally 25 μm, the method comprising: 
 operating a continuous roll-to-roll process of a strip production line at a feed rate of at least 2.5 m/min to feed the strip substrate;    removing a thin oxide layer from the strip substrate by ion assisted etching in an etch chamber to form a clean strip substrate; and 
 depositing the coating directly on the cleaned strip substrate by a physical vapor deposition technique in a deposition chamber,  
   wherein both the etch chamber and the deposition chamber are integrated into the continuous roll-to-roll process.    
   
   
       20 . The method according to  claim 19 , wherein a hardness of the coating is at least 600 HV and a tensile strength of the steel strip substrate is at least 1200 MPa  
   
   
       21 . The method according to  claim 19 , comprising forming the coated strip substrate into a final dimension by slitting or edge treatment.  
   
   
       22 . The method according to  claim 19 , wherein the physical vapor deposition technique is electron beam evaporation in an electron beam deposition chamber.  
   
   
       23 . The method according to  claim 22 , wherein electron beam evaporation is plasma activated.  
   
   
       24 . The method according to  claim 19 , wherein the mixture has a main ingredient of Al 2 O 3 .