Corrosion-resistant alloy

Abstract

The invention relates to metallurgic engineering, to nickel-based alloys intended for use in aggressive oxidizing environments. The invention obtains an alloy with a high level of plastic properties for operation in the temperature range 550° C. to 625° C. and increased corrosion cracking resistance. The alloy contains carbon, silicon, manganese, chromium, molybdenum, phosphorus, sulphur, iron, nickel and unavoidable impurities, titanium, aluminium, niobium, magnesium with specified components amounts.

1 . A corrosion-resistant nickel-based alloy containing carbon, silicon, manganese, chromium, molybdenum, phosphorus, sulphur, iron, nickel and unavoidable impurities, wherein it additionally contains titanium, aluminium, niobium, magnesium with the following components ratio, wt. %: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Carbon 
                   ≤0.006 
                 
                     
                   Silicon 
                   ≤0.1  
                 
                     
                   Manganese 
                   ≤1.0  
                 
                     
                   Chromium 
                   22.8-24.0 
                 
                     
                   Iron 
                   ≤0.75  
                 
                     
                   Molybdenum 
                   12.0-14.0 
                 
                     
                   Niobium 
                   0.01-0.03 
                 
                     
                   Titanium 
                   0.01-0.06 
                 
                     
                   Aluminium 
                   0.1-0.2 
                 
                     
                   Magnesium 
                   0.005-0.01  
                 
                     
                   Phosphorus 
                   ≤0.015 
                 
                     
                   Sulphur 
                   ≤0.012 
                 
                     
                   Nickel and unavoidable impurities 
                   balance 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         2 . The alloy according to  claim 1 , wherein the content of chromium, molybdenum and iron is related by the ratio: 
       
         
           
             
               
                 
                   
                     
                       [ 
                       Cr 
                       ] 
                     
                     + 
                     
                       [ 
                       
                         
                           I 
                           ′ 
                         
                          
                         
                           i 
                           ^ 
                         
                       
                       ] 
                     
                   
                   
                     [ 
                     Fe 
                     ] 
                   
                 
                 ≥ 
                 46 
               
               , 
               4. 
             
           
         
       
     
     
         3 . The alloy according to  claim 1 , wherein the content of niobium and carbon is related by the ratio: 
       
         
           
             
               
                 
                   
                     [ 
                     Nb 
                     ] 
                   
                   
                     [ 
                     C 
                     ] 
                   
                 
                 ≥ 
                 1 
               
               , 
               66. 
             
           
         
       
     
     
         4 . The alloy according to  claim 1 , wherein the content of chromium, molybdenum and iron is related by the ratio: 
       
         
           
             
               
                 
                   
                     
                       [ 
                       Cr 
                       ] 
                     
                     + 
                     
                       [ 
                       
                         
                           I 
                           ′ 
                         
                          
                         
                           i 
                           ^ 
                         
                       
                       ] 
                     
                   
                   
                     [ 
                     Fe 
                     ] 
                   
                 
                 ≥ 
                 46 
               
               , 
               4 
             
           
         
         and the content of niobium and carbon is related by the ratio: 
       
       
         
           
             
               
                 
                   
                     [ 
                     Nb 
                     ] 
                   
                   
                     [ 
                     C 
                     ] 
                   
                 
                 ≥ 
                 1 
               
               , 
               66.