Alloy steel composition

Abstract

An alloy steel composition which includes the following constituents by weight: 0.5-3.5% carbon, 0.2-0.8% silicon, 0.5-1.5% manganese, 0.1-2.0% nickel, 1.0-3.0% chromium, 0.1-0.5% molybdenum and 0.1-2.0% copper.

1 . An alloy steel composition which includes the following constituents by weight:  
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                     
                 
                     
                   carbon 
                   0.5-3.5% 
                 
                     
                   silicon 
                   0.2-0.8% 
                 
                     
                   manganese 
                   0.5-1.5% 
                 
                     
                   nickel 
                   0.1-2.0% 
                 
                     
                   chromium 
                   1.0-3.0% 
                 
                     
                   molybdenum 
                   0.1-0.5% 
                 
                     
                   copper 
                   0.1-2.0%. 
                 
                     
                     
                 
                     
                     
                 
             
                
                
               
               
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         2 . An alloy steel composition according to  claim 1  wherein the percentage composition of nickel is 0.10-0.45% by weight.  
     
     
         3 . An alloy steel composition according to  claim 1  wherein the percentage composition of copper is 0.10-0.45% by weight.  
     
     
         4 . A metal casting produced from an alloy steel composition which includes the following constituents by weight:  
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                     
                 
                     
                   carbon 
                   0.5-3.5% 
                 
                     
                   silicon 
                   0.2-0.8% 
                 
                     
                   manganese 
                   0.5-1.5% 
                 
                     
                   nickel 
                   0.1-2.0% 
                 
                     
                   chromium 
                   1.0-3.0% 
                 
                     
                   molybdenum 
                   0.1-0.5% 
                 
                     
                   copper 
                   0.1-2.0%. 
                 
                     
                     
                 
                     
                     
                 
             
                
                
               
               
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         5 . A metal casting according to  claim 4  which has a substantially pearlitic microstructure throughout its entirety.  
     
     
         6 . A metal casting according to  claim 4  wherein the hardness of the casting is greater than 310 HB.  
     
     
         7 . A metal casting according to  claim 4  wherein the hardness of the casting is greater than 335 HB.  
     
     
         8 . A metal casting according to  claim 4  for use in applications, which result in high wear upon the casting.  
     
     
         9 . A metal casting according to  claim 8  for use as components in autogenous grinding mills, semi-autogenous grinding mills or ball mills.  
     
     
         10 . A metal casting according to  claim 9  wherein the component is any component subject to wear.  
     
     
         11 . A metal casting according to  claim 9  wherein the components are lifter bars, liners, pulp lifters and/or grates.  
     
     
         12 . A metal casting according to  claim 8  wherein, after about 50 to 100 mm of wear has occurred on the casting, the hardness of the casting is greater than 310 HB and preferably greater than 330 HB.  
     
     
         13 . A method of producing a metal casting composed of the alloy steel composition according to  claim 1  characterised by the steps of: 
 i. pouring the molten alloy composition into a metal casting mould;    ii. cooling the metal casting at ambient temperature; and    iii. grind casting and gauge to profile.    
     
     
         14 . A method according to  claim 13  which includes the step of air blasting when the metal casting is greater than 300 mm in thickness.  
     
     
         15 . A method according to  claim 14  which includes the step of tempering at about 580° C.  
     
     
         16 . An alloy steel composition which includes the following constituents by weight: 
 carbon 0.80-0.85%    silicon 0.42-0.48%    manganese 0.85-0.95%    nickel 0.32-0.38%    chromium 2.05-2.25%    molybdenum 0.30-0.37%    copper 0.32-0.38%.