Heat treatment of rene 95 die inserts

Abstract

A rigid die insert for forming and shaping a working material. The rigid die insert comprises a nickel-base superalloy, preferably Rene 95. A plurality of gamma prime particles are uniformly distributed throughout the rigid die insert, which has a Rockwell hardness Rc of between about 48 and about 52. The invention also includes a method of treating a rigid die insert comprising a nickel-base superalloy to reduce crack propagation and raise yield stress. The method comprises the steps of: providing the rigid die insert; dissolving larger gamma-prime particles in the rigid die insert; and growing additional gamma-prime particles of smaller particle size in the rigid die insert, whereby the particle size of each of the plurality of gamma-prime particles is refined, thereby reducing crack propagation and raising the yield stress of the rigid die insert. A method of refining the particle size of gamma-prime particles in a Rene 95 superalloy is also disclosed.

What is claimed is:  
     
         1 . A rigid die insert for forming and shaping a working material, said rigid die insert comprising a nickel-base superalloy, wherein a plurality of gamma prime particles are uniformly distributed throughout said rigid die insert, and wherein said rigid die insert has a Rockwell hardness, R c , of between about 48 and about 52.  
     
     
         2 . The rigid die insert according to  claim 1 , wherein said nickel-base superalloy is Rene 95.  
     
     
         3 . A nickel-base superalloy for forming a rigid die insert, said nickel-base superalloy comprising a Rene 95 alloy and being formed by heating said Rene 95 alloy to a sub-solvus temperature in an inert atmosphere for a first predetermined hold time, quenching said Rene 95 in a room temperature bath, and heating said Rene 95 alloy to a second predetermined temperature for a second predetermined hold time in an inert atmosphere, wherein said nickel-base superalloy has a plurality of gamma prime particles uniformly distributed throughout, and wherein said nickel-base superalloy has a Rockwell hardness, R c , of between about 48 and about 52.  
     
     
         4 . The nickel-base superalloy of  claim 3 , wherein said sub-solvus temperature is about 2050° F., and wherein said first predetermined hold time is about two hours.  
     
     
         5 . The nickel-base superalloy of  claim 3 , wherein said second predetermined temperature is about 1400° F., and wherein said second predetermined hold time is about 16 hours.  
     
     
         6 . A rigid die insert for forming and shaping a working material, said rigid die insert comprising a Rene 95 superalloy, wherein said rigid die insert is heated in an inert atmosphere to a sub-solvus temperature of said Rene 95 superalloy for a first predetermined hold time, quenched in a room temperature bath, and heated in an inert atmosphere to a second predetermined temperature for a second predetermined hold time, wherein said rigid die insert has a plurality of gamma prime particles uniformly distributed throughout, and wherein said rigid die insert has a Rockwell hardness, R c , of between about 48 and about 52.  
     
     
         7 . The rigid die insert of  claim 6 , wherein said sub-solvus temperature is about 2050° F., and wherein said first predetermined hold time is about two hours.  
     
     
         8 . The rigid die insert of  claim 6 , wherein said second predetermined temperature is about 1400° F., and wherein said second predetermined hold time is about 16 hours.  
     
     
         9 . A method of treating a rigid die insert to reduce crack propagation and raise yield stress therein, the rigid die insert comprising a nickel-base superalloy having a plurality of gamma-prime particles, each of the gamma-prime particles having a particle size, the method comprising the steps of: 
 a) providing the rigid die insert;    b) dissolving larger gamma-prime particles in the rigid die insert; and    c) growing additional gamma-prime particles of smaller particle size in the rigid die insert,    whereby the particle size of each of the plurality of gamma-prime particles is refined, thereby reducing crack propagation and raising the yield stress of the rigid die insert.    
     
     
         10 . The method of  claim 9 , wherein the step of dissolving larger gamma-prime particles comprises the steps of: 
 a) heat treating the rigid die insert in an inert atmosphere to a first predetermined temperature for a first predetermined hold time, said first predetermined temperature being a sub-solvus temperature; and    b) quenching the rigid die insert in a room temperature bath.    
     
     
         11 . The method of  claim 10 , further including the step of forced-air cooling the rigid die insert after the step of heat treating the rigid die insert to a first predetermined temperature.  
     
     
         12 . The method of  claim 10 , wherein the inert atmosphere is an argon atmosphere.  
     
     
         13 . The method of  claim 10 , wherein the step of quenching the rigid die insert in a room temperature bath comprises quenching the rigid die insert in a room temperature oil bath.  
     
     
         14 . The method of  claim 9 , wherein the step of growing additional gamma-prime particles of smaller particle size comprises aging the rigid die insert in an inert atmosphere to a second predetermined temperature for a second predetermined hold time.  
     
     
         15 . The method of  claim 14 , wherein the inert atmosphere is an argon atmosphere.  
     
     
         16 . A method of refining the particle size of gamma-prime particles in a Rene 95 superalloy, the method comprising the steps of: 
 a) providing a Rene 95 superalloy;    b) heating the Rene 95 superalloy in an inert atmosphere to a first temperature, the first temperature being a temperature below a solvus temperature of the Rene 95 superalloy;    c) quenching the Rene 95 superalloy at room temperature in a bath, thereby dissolving larger gamma-prime particles; and    d) aging the Rene 95 superalloy in an inert atmosphere at a second predetermined temperature for a second predetermined hold time, thereby growing additional gamma-prime particles of smaller particle size, whereby a more uniform size distribution of gamma-prime particles is created.    
     
     
         17 . The method of  claim 16 , wherein the step of heating the Rene 95 superalloy in an inert atmosphere to a first temperature comprises heating the Rene 95 superalloy to about 2050° F. for about two hours.  
     
     
         18 . The method of  claim 16 , wherein the step of quenching the Rene 95 superalloy at room temperature in a bath comprises quenching the Rene 95 superalloy in a room temperature oil bath.  
     
     
         19 . The method of  claim 16 , wherein the step of aging the Rene 95 superalloy in an inert atmosphere at a second predetermined temperature for a second predetermined hold time comprises heating the Rene 95 into about 1400° F. for about 16 hours.  
     
     
         20 . The method of  claim 16 , wherein the inert atmosphere is an argon atmosphere.  
     
     
         21 . A method of treating a rigid die insert to reduce crack propagation and raise yield stress, the rigid die insert comprising a Rene 95 superalloy having a plurality of gamma-prime particles, each of the gamma-prime particles having a particle size, the method comprising the steps of: 
 a) providing the rigid die insert;    b) heating the rigid die insert in an inert atmosphere to a first temperature for a first predetermined hold time, the first temperature being a temperature below a solvus temperature of the Rene 95 superalloy;    c) forced-air cooling the rigid die insert;    d) quenching the rigid die insert at room temperature in a bath, thereby dissolving larger gamma-prime particles; and    e) aging the rigid die insert in an inert atmosphere at a second predetermined temperature for a second predetermined hold time,    whereby the particle size of each of the plurality of gamma-prime particles is refined, thereby reducing crack propagation and raising the yield stress of the rigid die insert.    
     
     
         22 . The method of  claim 21 , wherein the step of quenching the rigid die insert in a room temperature bath comprises quenching the rigid die insert in a room temperature oil bath.  
     
     
         23 . The method of  claim 21 , wherein the step of heating the rigid die insert in an inert atmosphere to a first temperature for a first predetermined hold time comprises heating the rigid die insert to about 2050° F. for about two hours.  
     
     
         24 . The method of  claim 21 , wherein the step of aging the rigid die insert in an inert atmosphere at a second predetermined temperature for a second predetermined hold time comprises heating the rigid die insert into about 1400° F. for about 16 hours.  
     
     
         25 . The method of  claim 21 , wherein the inert atmosphere is an argon atmosphere.