Method for treating organs subject to erosion by liquids and anti-erosion coating alloy

Abstract

The present invention relates to a method for treating organs subject to erosion by liquids, in particular vapour turbine components, which contemplates laser plating with a cobalt-based alloy comprising chromium from 28 to 32% by weight; tungsten from 5 to 7% by weight; silicon from 0.1 to 2% by weight; carbon from 1.2 to 1.7% by weight; nickel from 0.5 to 3% by weight; iron from 0.01 to 1% by weight; manganese from 0.01 to 1% by weight; molybdenum from 0.2 to 1% by weight; possible impurities or other elements from 0 to 0.5% by weight and cobalt the complement to 100%.

1 . A method for the treatment of organs subject to erosion by liquids, comprising the application of a cobalt-based alloy on the surface of said organs to form a layer of anti-erosion coating, wherein said alloy comprises:  
     
       
         
               
               
               
             
                   
                   
               
                   
                   
               
                   
                 chromium 
                 from 28 to 32% by weight 
               
                   
                 tungsten 
                 from 5 to 7% by weight 
               
                   
                 silicon 
                 from 0.1 to 2% by weight 
               
                   
                 carbon 
                 from 1.2 to 1.7% by weight 
               
                   
                 nickel 
                 from 0.5 to 3% by weight 
               
                   
                 iron 
                 from 0.01 to 1% by weight; 
               
                   
                 manganese 
                 from 0.01 to 1% by weight; 
               
                   
                 molybdenum 
                 from 0.2 to 1% bby weight 
               
                   
                 cobalt 
                 the complement to balance. 
               
                   
                   
               
                   
                   
               
           
              
              
             
             
              
              
              
              
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       2 . The method according to  claim 1 , characterized in that said application is effected by means of laser plating (laser cladding).  
   
   
       3 . The method according to  claim 1 , characterized in that said organs comprise the components of a vapour turbine.  
   
   
       4 . The method according to  claim 3 , characterized in that said components are vapour turbine blades.  
   
   
       5 . The method according to  claim 2 , characterized in that said laser plating is effected with a CO 2  or YAG laser.  
   
   
       6 . The method according to  claim 1 , characterized in that the layer of coating applied has a thickness ranging from 0.1 to 5 mm.  
   
   
       7 . The method according to  claim 1 , characterized in that it also comprises a preliminary heating phase of the surface of the organ to be treated.  
   
   
       8 . The method according to  claim 1 , characterized in that it comprises a series of application passages of said alloy.  
   
   
       9 . (canceled)  
   
   
       10 . The cobalt-based alloy according to  claim 9 , characterized in that it has the following composition:  
     
       
         
               
               
               
               
             
                   
                   
               
                   
                   
               
                   
                 Cr 
                 30 
                 g 
               
                   
                 W 
                 6 
                 g 
               
                   
                 Si 
                 1 
                 g 
               
                   
                 C 
                 1.5 
                 g 
               
                   
                 Ni 
                 1.5 
                 g 
               
                   
                 Fe 
                 <0.3 
                 g 
               
                   
                 Mn 
                 <0.3 
                 g 
               
                   
                 Co 
                 48 
                 g 
               
                   
                 Mo 
                 0.75 
                 g 
               
                   
                 Other 
                 <0.25 
                 g 
               
                   
                 (Imp.) 
               
                   
                   
               
                   
                   
               
           
              
              
             
             
              
              
              
              
              
              
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       11 . The cobalt-based alloy according to  claim 9 , characterized in that it has the following composition:  
     
       
         
               
               
               
             
                   
                   
               
                   
                   
               
                   
                 Cr 
                   30 g 
               
                   
                 W 
                   6 g 
               
                   
                 Si 
                   1 g 
               
                   
                 C 
                  1.5 g 
               
                   
                 Ni 
                  1.5 g 
               
                   
                 Fe 
                 0.20 g 
               
                   
                 Mn 
                 0.20 g 
               
                   
                 Co 
                 Balance 
               
                   
                 Mo 
                 0.75 g 
               
                   
                 Other 
                 0.20 g 
               
                   
                   
               
                   
                   
               
           
              
              
             
             
              
              
              
              
              
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       12 . The cobalt-based alloy according to  claim 9 , characterized in that it has the following composition:  
     
       
         
               
               
               
             
                   
                   
               
                   
                   
               
                   
                 Elem. 
                 Quantity 
               
                   
                   
               
                   
                 Cr 
                  28% 
               
                   
                 W 
                 5.1% 
               
                   
                 Si 
                 0.1% 
               
                   
                 C 
                 1.2% 
               
                   
                 Ni 
                 0.5% 
               
                   
                 Fe 
                 0.01%  
               
                   
                 Mn 
                 0.01%  
               
                   
                 Mo 
                 0.2% 
               
                   
                 Co 
                 Balance 
               
                   
                 Other 
                 0.01%  
               
                   
                 (Imp.) 
               
                   
                   
               
                   
                   
               
           
              
              
              
              
             
             
              
              
              
              
              
              
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       13 . The cobalt-based alloy according to  claim 9 , characterized in that it has the following composition:  
     
       
         
               
               
               
             
                   
                   
               
                   
                   
               
                   
                 Elem. 
                 Quantity 
               
                   
                   
               
                   
                 Cr 
                 31.5%  
               
                   
                 W 
                 6.5% 
               
                   
                 Si 
                 1.8% 
               
                   
                 C 
                 1.6% 
               
                   
                 Ni 
                 2.8% 
               
                   
                 Fe 
                 0.9% 
               
                   
                 Mn 
                 0.8% 
               
                   
                 Mo 
                 0.9% 
               
                   
                 Co 
                 Balance 
               
                   
                 Other 
                 0.005%  
               
                   
                 (Imp.) 
               
                   
                   
               
                   
                   
               
           
              
              
              
              
             
             
              
              
              
              
              
              
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       14 . The cobalt-based alloy according to  claim 9 , characterized in that it has the following composition:  
     
       
         
               
               
               
             
                   
                   
               
                   
                   
               
                   
                 Elem. 
                 Quantity 
               
                   
                   
               
                   
                 Cr 
                  30% 
               
                   
                 W 
                   6% 
               
                   
                 Si 
                   1% 
               
                   
                 C 
                 1.5% 
               
                   
                 Ni 
                 1.8% 
               
                   
                 Fe 
                 0.5% 
               
                   
                 Mn 
                 0.3% 
               
                   
                 Mo 
                 0.3% 
               
                   
                 Co 
                 Balance 
               
                   
                 Other 
                 0.05%  
               
                   
                 (Imp.) 
               
                   
                   
               
                   
                   
               
           
              
              
              
              
             
             
              
              
              
              
              
              
              
              
              
              
              
              
              
             
          
         
       
     
   
   
       15 - 18 . (canceled)