Corrosion and cracking resistant high manganese austenitic steels containing passivating elements

Abstract

Improved steel compositions and methods of making the same are provided. The present disclosure provides advantageous corrosion and/or cracking resistant steel. More particularly, the present disclosure provides high manganese (Mn) steel compositions having enhanced corrosion and/or cracking resistance, and methods for fabricating high manganese steel compositions having enhanced corrosion and/or cracking resistance. Methods for fabricating high manganese steel compositions (e.g., via passivation) having enhanced corrosion and/or cracking resistance are also provided.

What is claimed is: 
     
         1 . A method for fabricating a ferrous based component comprising the steps of:
 a. providing a composition having from 8 to 30 weight % manganese, from 11 to 30 weight % chromium, and the balance iron;   b. melting the composition in a controlled environment to produce a liquid alloy steel composition;   c. cooling the liquid alloy steel composition to form an alloy steel composition;   d. hot deforming the alloy steel composition;   e. re-heating the alloy steel composition for a pre-determined time period;   f. cooling the alloy steel composition; and   g. Cold deforming the alloy steel composition.   
     
     
         2 . The method for fabricating a ferrous based component of  claim 1 , wherein step b) includes melting the composition at 1600° C. for 30 minutes. 
     
     
         3 . The method for fabricating a ferrous based component of  claim 1 , wherein step c) includes cooling the liquid alloy steel composition to ambient temperature to form the alloy steel composition. 
     
     
         4 . The method for fabricating a ferrous based component of  claim 1 , wherein step d) includes hot deforming the alloy steel composition at or above 800° C. 
     
     
         5 . The method for fabricating a ferrous based component of  claim 1 , wherein step e) includes re-heating the alloy steel composition at or above 1000° C. for one hour. 
     
     
         6 . The method for fabricating a ferrous based component of  claim 1 , wherein step e) includes re-heating the alloy steel composition at or above 1200° C. for one hour. 
     
     
         7 . The method for fabricating a ferrous based component of  claim 1 , wherein step f) includes cooling the alloy steel composition to below 300° C. 
     
     
         8 . The method for fabricating a ferrous based component of  claim 7 , wherein step f) includes cooling the alloy steel composition at least 10° C. per second until the alloy steel composition is below 300° C. 
     
     
         9 . The method for fabricating a ferrous based component of  claim 1 , wherein the composition further includes one or more alloying elements selected from the group consisting of carbon, aluminum, silicon, nickel, cobalt, molybdenum, niobium, copper, titanium, vanadium, tungsten, nitrogen, boron, zirconium, hafnium and combinations thereof. 
     
     
         10 . The method for fabricating a ferrous based component of  claim 9 ;
 a. wherein each of the nickel or cobalt ranges from 0.5 to 20 weight % of the total composition;   b. wherein the aluminum ranges from 0.1 to 15 weight % of the total composition;   c. wherein each of the molybdenum, niobium, copper, titanium, tungsten or vanadium ranges from 0.2 to 10 weight % of the total composition;   d. wherein the silicon ranges from 0.01 to 10 weight % of the total composition;   e. wherein the nitrogen ranges from 0.01 to 3.0 weight % of the total composition;   f. wherein the boron ranges from 0.001 to 0.1 weight % of the total composition; and   g. wherein each of the zirconium or hafnium ranges from 0.2 to 6 weight % of the total composition.   
     
     
         11 . The method for fabricating a ferrous based component of  claim 1 , wherein the composition comprises of:
 a. from 8 to 30 weight % manganese, from 11 to 30 weight % chromium;   b. one or more of the alloying additions including, from 0.10 to 1.5 weight % carbon, from 0.10 to 1.5 weight % nitrogen, and their combination thereof;   c. from 0.5 to 10 weight % silicon, from 1.0 to 15 weight % aluminum, and their combination thereof; and   d. the balance iron.   
     
     
         12 . A ferrous based component fabricated according to the steps comprising:
 a. providing a composition having from 8 to 30 weight % manganese, from 11 to 30 weight % chromium, and the balance iron;   b. melting the composition in a controlled environment to produce a liquid alloy steel composition;   c. cooling the liquid alloy steel composition to form an alloy steel composition;   d. hot deforming the alloy steel composition;   e. re-heating the alloy steel composition for a pre-determined time period;   f. cooling the alloy steel composition; and   g. cold deforming the alloy steel composition.   
     
     
         13 . The ferrous based component of  claim 12 , wherein step b) includes melting the composition at 1600° C. for 30 minutes. 
     
     
         14 . The ferrous based component of  claim 12 , wherein step c) includes cooling the liquid alloy steel composition to ambient temperature to form the alloy steel composition. 
     
     
         15 . The ferrous based component of  claim 12 , wherein step d) includes hot deforming the alloy steel composition at or above 800° C. 
     
     
         16 . The ferrous based component of  claim 12 , wherein step e) includes re-heating the alloy steel composition at or above 1000° C. for one hour. 
     
     
         17 . The ferrous based component of  claim 12 , wherein step e) includes re-heating the alloy steel composition at or above 1200° C. for one hour. 
     
     
         18 . The ferrous based component of  claim 12 , wherein step f) includes cooling the alloy steel composition to below 300° C. 
     
     
         19 . The ferrous based component of  claim 18 , wherein step f) includes cooling the alloy steel composition at least 10° C. per second until the alloy steel composition is below 300° C. 
     
     
         20 . The ferrous based component of  claim 12 , wherein the composition further includes one or more alloying elements selected from the group consisting of carbon, aluminum, silicon, nickel, cobalt, molybdenum, niobium, copper, titanium, vanadium, tungsten, nitrogen, boron, zirconium, hafnium and combinations thereof. 
     
     
         21 . The ferrous based component of  claim 20 :
 a. wherein each of the nickel or cobalt ranges from 0.5 to 20 weight % of the total composition;   b. wherein the aluminum ranges from 0.1 to 15 weight % of the total composition;   c. wherein each of the molybdenum, niobium, copper, titanium, tungsten or vanadium ranges from 0.2 to 10 weight % of the total composition;   d. wherein the silicon ranges from 0.01 to 10 weight % of the total composition;   e. wherein the nitrogen ranges from 0.01 to 3.0 weight % of the total composition;   f. wherein the boron ranges from 0.001 to 0.1 weight % of the total composition; and   g. wherein each of the zirconium or hafnium ranges from 0.2 to 6 weight % of the total composition.   
     
     
         22 . The ferrous based component of  claim 12 , wherein the composition comprises of:
 a. from 8 to 30 weight % manganese, from 11 to 30 weight % chromium;   b. one or more of the alloying additions including, from 0.10 to 1.5 weight % carbon, from 0.10 to 1.5 weight % nitrogen, and their combination thereof;   c. from 0.5 to 10 weight % silicon, from 1.0 to 15 weight % aluminum; and   d. the balance iron.