High Nitrogen, Multi-Principal Element, High Entropy Corrosion Resistant Alloy

Abstract

A multi-principal element, corrosion resistant alloy is disclosed. The alloy has the following composition in weight percent: Co about 13 to about 28 Ni about 13 to about 28 Fe+Mn about 13 to about 28 Cr about 13 to about 37 Mo about 8 to about 28 N about 0.10 to about 1.00. The alloy also includes the usual impurities found in corrosion resistant alloys intended for the same or similar use. In addition, one or both of W and V may be substituted for some or all of the Mo. The alloy provides a solid solution that is substantially all FCC phase, but may include minor amounts of secondary phases that do not adversely affect the corrosion resistance and mechanical properties provided by the alloy.

1 . A multi-principal element, high entropy, corrosion resistant alloy having a solid solution phase and wherein the alloy comprises, in weight percent: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Co 
                   about 13 to about 28 
                 
                     
                   Ni 
                   about 13 to about 35 
                 
                     
                   Fe + Mn 
                   about 13 to about 28 
                 
                     
                   Cr 
                   about 13 to about 37 
                 
                     
                   Mo 
                   about 8 to about 28 
                 
                     
                   N 
                   about 0.10 to about 1.00 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
                
               
            
           
         
         and the usual impurities, wherein one or both of W and V may be substituted for some or all of the Mo. 
       
     
     
         2 . The multi-principal element, corrosion resistant alloy claimed in  claim 1  wherein the solid solution phase consists essentially of a face-centered-cubic crystalline structure. 
     
     
         3 . The multi-principal element, corrosion resistant alloy claimed in  claim 1  wherein the alloy has the following characteristics:
   −6 kJ/mol<Δ H   mix <0 kJ/mol,
 
   Δ S   mix >12 J/(K mol),
 
   2.00%<δ<4.5%, and
 
 the valence electron concentration of the alloy is greater than about 7.80. 
 
     
     
         4 . A high entropy, corrosion resistant alloy that forms a single phase solid solution, said alloy having the formula (Fe, Mn) a Co b Ni c Cr x (Mo, W, V) y  wherein a, b, c, x, and y are as follows in atomic percent,
   12≤ a≤ 35,
     12≤ b≤ 35,
     12≤ c≤ 40,
     12≤ x≤ 40,
     4≤ y≤ 20,
   wherein W and V may be substituted for some or all of Mo on an equiatomic basis, and wherein the alloy comprises from at least about 0.10% N up to the solubility limit.   
     
     
         5 . The high entropy, corrosion resistant alloy claimed in  claim 4  wherein the solid solution phase consists essentially of a face centered cubic crystalline structure. 
     
     
         6 . The high entropy, corrosion resistant alloy claimed in  claim 4  wherein the alloy has the following characteristics:
   −6 kJ/mol≤Δ H   mix ≤0 kJ/mol,
 
   Δ S   mix >12 J/(K mol),
 
   2.00%<δ<4.5%, and
 
 the valence electron concentration of the alloying elements is greater than about 7.80. 
 
     
     
         7 . A high entropy, corrosion resistant alloy having a solid solution phase and wherein the alloy comprises, in weight percent: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Co 
                   about 13 to about 28 
                 
                     
                   Ni 
                   about 13 to about 35 
                 
                     
                   Cu 
                   about 13 to about 28 
                 
                     
                   Fe + Mn 
                   about 13 to about 28 
                 
                     
                   Cr 
                   about 13 to about 37 
                 
                     
                   Mo 
                   about 8 to about 28 
                 
                     
                   N 
                   about 0.10 to about 1.00 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
                
                
               
            
           
         
         and the usual impurities, wherein one or both of W and V may be substituted for some or all of the Mo. 
       
     
     
         8 . The high entropy, corrosion resistant alloy claimed in  claim 7  wherein the solid solution phase consists essentially of a face centered cubic crystalline structure. 
     
     
         9 . The high entropy, corrosion resistant alloy claimed in  claim 7  wherein the alloy has the following characteristics:
   −6 kJ/mol<Δ H   mix ≤0 kJ/mol,
 
   Δ S   mix >12 J/(K mol),
 
   2.00%<δ<4.5%, and
 
 the valence electron concentration of the alloy is greater than about 7.80. 
 
     
     
         10 . A high entropy, corrosion resistant alloy that forms a single phase solid solution, said alloy having the formula (Fe, Mn) a Co b Ni c Cu d Cr x (Mo, W, V) y  wherein a, b, c, x, and y are as follows, in atomic percent,
   10≤ a≤ 30,
     10≤ b≤ 30,
     10≤ c≤ 30,
     10≤ d≤ 30
     10≤ x≤ 30,
     4≤ y≤ 18,
   wherein W and V may be substituted for some or all of Mo on an equiatomic basis, and wherein the alloy comprises from at least about 0.10% N up to the solubility limit.   
     
     
         11 . The high entropy, corrosion resistant alloy claimed in  claim 10  wherein the solid solution phase consists essentially of a face centered cubic crystalline structure. 
     
     
         12 . The high entropy, corrosion resistant alloy claimed in  claim 10  wherein the alloy has the following characteristics:
   −6 kJ/mol≤Δ H   mix ≤0 kJ/mol,
 
   Δ S   mix >12 J/(K mol),
 
   2.00%<δ<4.5%, and
 
 the valence electron concentration of the alloying elements is greater than about 7.80.