Process for preparing high carbon martensitic stainless steel

Abstract

A process for preparing a high carbon martensitic stainless steel is disclosed. Said process for preparing said high-carbon martensitic stainless steel comprises: providing a steel composition comprising 1.7 to 1.9% by weight C, 17 to 18% by weight Cr, 1.6 to 2.0% by weight Mo, 2.9 to 3.5% by weight V, 0.40 to 0.60% by weight Nb, and Fe as main constituent; melting the steel composition; transferring the molten steel composition to a die casting mold; demolding the steel composition at a temperature in a range of 850 to 950° C. followed by forced air cooling; preparing the steel composition for open die forging; subjecting the steel composition to open die forging, subjecting the steel composition to anti-flaking heat treatment, followed by hardening and tempering to obtain the high carbon martensitic stainless steel.

1 . A process for preparing a high carbon martensitic stainless steel, the process comprising:
 providing a steel composition comprising 1.7 to 1.9% by weight C, 17 to 18% by weight Cr, 1.6 to 2.0% by weight Mo, 2.9 to 3.5% by weight V, 0.40 to 0.60% by weight Nb, and Fe as main constituent;   melting the steel composition;   transferring the molten steel composition to a die casting mold;   demolding the steel composition at a temperature in a range of 850 to 950° C. followed by forced air cooling;   preparing and subjecting the demolded steel composition to open die forging; and   subjecting the forged steel composition to anti-flaking heat treatment, followed by hardening and tempering thereof to obtain the high carbon martensitic stainless steel.   
     
     
         2 . The process as claimed in  claim 1 , wherein the melting of the steel composition is carried at a temperature ranging between 1470 to 1520° C., for a time ranging between 60 to 90 minutes. 
     
     
         3 . The process as claimed in  claim 1 , wherein, before demolding, the steel composition is allowed to cool to a temperature in the range of 850 to 950° C. in the die casting mold for up to 5 minutes. 
     
     
         4 . The process as claimed in  claim 1 , wherein the demolded steel composition is prepared for open die forging by heating the material at a temperature in a range of 1100 to 1200° C. for a time of 30 to 50 minutes/inch soak with the minimum forging temperature of 950° C. 
     
     
         5 . The process as claimed in  claim 1 , wherein the anti-flaking heat treatment is carried out at a temperature between 760 to 800° C., for a time ranging between 15 to 25 hours. 
     
     
         6 . The process as claimed in  claim 1 , wherein the hardening is carried out at a temperature ranging between 1080 to 1130° C., for a time of 30 to 60 minutes/inch soak. 
     
     
         7 . The process as claimed in  claim 1 , wherein the quenched steel composition is subjected to tempering at a temperature between 320 to 370° C., for a time of 60 to 90 minutes/inch.