Method of processing maraging steel

Abstract

A method of processing a workpiece of maraging steel includes receiving a workpiece of maraging steel that has been subjected to thermomechanical processing at an austenite solutionizing temperature and then directly aging the workpiece of maraging steel at an aging temperature to form precipitates within a microstructure of the workpiece of maraging steel, without any intervening heat treatments between the thermomechanical processing and the direct aging.

1 . A method of processing a workpiece of maraging steel, comprising:
 receiving a workpiece of maraging steel having a composition comprising 17wt%-19wt% of nickel, 8wt%-12wt% of cobalt, 3wt%-5wt% of molybdenum, 0.2wt%-1.7wt% of titanium, 0.15wt%-0.15wt% of aluminum, and a balance of iron and that has been subjected to thermomechanical processing at an austenite solutionizing temperature; and   directly aging the workpiece of maraging steel at an aging temperature to form precipitates within a microstructure of the workpiece of maraging steel, without any intervening heat treatments between the thermomechanical processing and the direct aging, wherein the thermomechanical processing and the direct aging provide the workpiece of maraging steel with an average ASTM grain size of 10.   
   
   
       2 . The method as recited in  claim 1 , further including selecting the aging temperature to be about 850° F.-95° F. 
   
   
       3 . The method as recited in  claim 1 , further including selecting the aging temperature to be about 900° F. 
   
   
       4 . The method as recited in  claim 1 , further including cooling the workpiece of maraging steel in air from the aging temperature to a temperature less than 850° F. 
   
   
       5 . (canceled) 
   
   
       6 . The method as recited in  claim 1 , further including selecting the aging temperature to be about 900° F., and subjecting the workpiece of maraging steel to the aging temperature for about nine hours. 
   
   
       7 . A component produced according to the method recited in  claim 1 . 
   
   
       8 . A method of processing a workpiece of maraging steel, comprising:
 thermomechanically processing a workpiece of maraging steel at an austenite solutionizing temperature. the workpiece having a composition comprising 17wt%-19wt% of nickel, 8wt%-12wt% of cobalt, 3wt%-5wt% of molybdenum. 0.2wt%-1.7wt% of titanium, 0.05wt%-0.15wt% of aluminum, and a balance of iron; and   directly aging the workpiece of maraging steel at an aging temperature to form precipitates within a microstructure of the workpiece of maraging steel, without any intervening heat treatments between the thermomechanical processing and the, direct aging, wherein the thermomechanical processing and the direct aging provide the workpiece of maraging steel with an average ASTM grain size of 10.   
   
   
       9 . The method as recited in  claim 8 , wherein the thermomechanical processing includes forging. 
   
   
       10 . The method as recited in  claim 8 , wherein the thermomechanical processing includes rolling. 
   
   
       11 . (canceled) 
   
   
       12 . (canceled) 
   
   
       13 . A method of processing a workpiece of maraging steel, comprising:
 processing a workpiece of maraging steel that has been subjected to thermomechanical processing at an austenite solutionizing temperature, to thereby produce a component of maraging steel, the component having a composition comprising 17wt%-19wt% of nickel, 8wt%-12wt% of cobalt, 3wt%-5wt% of molybdenum, 0.2wt%-1.7wt% of titanium. 0.05wt%-0.15wt% of aluminum, and a balance of iron; and   establishing at a temperature of 850° F.-950° F. an ultimate tensile strength of the component of maraging steel that is greater than 265 ksi by directly aging the workpiece of maraging steel at an aging temperature to form precipitates within a microstructure of the workpiece of maraging steel, without any intervening heat treatments between the thermomechanical processing and the direct aging, wherein the thermornechanical processing and the direct aging provide the workpiece of maraging steel with an average ASTM grain size of 10.   
   
   
       14 . The method as recited in  claim 13 , further including establishing an ultimate tensile strength of at least about 290 ksi. 
   
   
       15 . The method as recited in  claim 13 , further including establishing a % elongation of about 9.5%. 
   
   
       16 . The method as recited in  claim 13 , further including establishing a 0.2% yield strength that is greater than 256 ksi. 
   
   
       17 . The method as recited in  claim 13 , further including establishing a 0.2% yield strength of at least about 279 ksi. 
   
   
       18 . The method as recited in  claim 1 , wherein the ASTM grain size is established according to ASTM E112. 
   
   
       19 . The method as recited in  claim 1 , wherein the direct aging includes forming precipitates of Ni 3 Mo and Ni 3 Ti. 
   
   
       20 . The method as recited in  claim 1 , wherein the direct aging includes establishing a hardness of 56-58 R c . 
   
   
       21 . The method as recited in  claim 1 , wherein the austenite solutionizing temperature is 1500° F.-1750° F., and the aging temperature is about 850° F.-950° F. for a time of about nine hours.