Heat resistant super alloy and its use

Abstract

A heat resistant super alloy suffices the following conditions: carbon 0.01-0.2 percent in weight chromium 8-10 percent in weight aluminum 4-6 percent in weight titanium 2-4 percent in weight molybdenum 1.5-2.8 percent in weight tungsten 10-13.5 percent in weight niobium 1.5-2.5 percent in weight boron 0 < B ≦ 0.04 percent in weight zircon 0 < Zr ≦ 0.15 percent in weight the contents of hafnium and lanthanum together amounts to 0 < Hf + La ≦ 1.5 percent in weight, optionally traces of tantalum, the remainder being nickel. Such an alloy is preferably used for turbine wheels and particularly for turbochargers.

1 . The heat resistant super alloy suffices comprises the following conditions:  
       
         
           
                 
                 
                 
                 
               
                     
                     
                 
                     
                     
                 
                     
                   carbon 
                   0.01-0.2 
                   percent in weight 
                 
                     
                   chromium 
                   8-10 
                   percent in weight 
                 
                     
                   aluminum 
                   4-6 
                   percent in weight 
                 
                     
                   titanium 
                   2-4 
                   percent in weight 
                 
                     
                   molybdenum 
                   1.5-2.8 
                   percent in weight 
                 
                     
                   tungsten 
                   10-13.5 
                   percent in weight 
                 
                     
                   niobium 
                   1.5-2.5 
                   percent in weight 
                 
                     
                   boron 
                   0 < B ≦ 0.04 
                   percent in weight 
                 
                     
                   zircon 
                   0 < Zr ≦ 0.15 
                   percent in weight 
                 
                     
                     
                 
                     
                     the contents of hafnium and lanthanum together amounts to 0 < Hf + La ≦ 1.5 percent in weight,    
                 
                     
                     optionally traces of tantalum,    
                 
                     
                     the remainder being nickel.    
                 
                     
                     
                 
             
                
                
               
               
                
                
                
                
                
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         2 . A heat resistant super alloy as claimed in  claim 1 , wherein the contents of boron suffices at least one of the following conditions: 
 (a) it amounts to at least 0.01 percent in weight;    (b) it amounts to 0.035 percent in weight in maximum.    
     
     
         3 . A heat resistant super alloy as claimed in  claim 1 , wherein the contents of zircon suffices at least one of the following conditions: 
 (a) it amounts to at least 0.02 percent in weight;    (b) it amounts to 0.08 percent in weight in maximum.    
     
     
         4 . A heat resistant super alloy as claimed in  claim 1 , wherein the contents of lanthanum suffices at least one of the following conditions: 
 (a) it amounts to at least 0.0035 percent in weight;    (b) it amounts to 0.015 percent in weight in maximum, preferably 0.01 percent in weight in maximum.    
     
     
         5 . A heat resistant super alloy as claimed in  claim 1 , wherein the contents of hafnium and lanthanum together amounts to 0.7 percent in weight in maximum, preferably the following additional conditions being met: 
 (a) the contents of hafnium amounts at least to 0.3 percent in weight;    (b) the contents of hafnium amounts 0.7 percent in weight in maximum, preferably 0.6 percent in weight in maximum.    
     
     
         6 . A heat resistant super alloy as claimed in  claim 1 , wherein the contents of tungsten and molybdenum together is greater than or equals to 14 percent in weight.  
     
     
         7 . A heat resistant super alloy as claimed in  claim 1 , wherein the contents of aluminum and titanium together is greater than or equals to 7 percent in weight.  
     
     
         8 . A heat resistant super alloy as claimed in  claim 1 , wherein the contents of titanium, niobium and aluminum together is greater than or equals to 9.5 percent in weight.  
     
     
         9 . A heat resistant super alloy as claimed in  claim 1 , wherein the contents of tantalum is below 2 percent in weight, preferably below 1.5 percent in weight, and more particularly below 1 percent in weight.  
     
     
         10 . Use of an alloy as claimed in  claim 1  for casting a turbine wheel, particularly of a turbocharger.