0301 Steel for making pipe molds

Abstract

A low alloy steel, designated 0301 (Khare IV) steel, that may be used for making pipe molds with high hardenability, high ductility and high toughness are described, the steel consisting essentially of from about 0.16% to about 0.22% carbon, about 0.60% to about 0.90% manganese, about 0.50% to about 0.65% silicon, about 0.015% maximum phosphorus, about 0.015% maximum sulfur, about 2.25% to about 2.55% chromium, about 0.40% to about 0.50% molybdenum, about 0.55% to about 0.65% nickel, about 0.03% to about 0.08% vanadium, and balance essentially iron.

What is claimed is:  
     
         1 . A ferritic alloy steel in weight percentage consisting essentially of from about 0.16-0.22% carbon, 0.60-0.90% manganese, 0.50-0.65% silicon, 0.015% maximum phosphorus, 0.015% maximum sulfur, 2.25-2.55% chromium, 0.40-0.50% molybdenum, 0.55-0.65% nickel, 0.03-0.08% vanadium, and balance essentially iron.  
     
     
         2 . The steel recited in  claim 1 , consisting essentially of from about 0.18% carbon, 0.75% manganese, 0.56% silicon, 0.005% maximum phosphorus, 0.005% maximum sulfur, 2.40% chromium, 0.45% molybdenum, 0.50% nickel, 0.05% vanadium, and balance essentially iron.  
     
     
         3 . A pipe mold steel for centrifugally casting pipe formed from a ferritic alloy steel in weight percentage in weight percentage consisting essentially of from about 0.16-0.22% carbon, 0.60-0.90% manganese, 0.50-0.65% silicon, 0.015% maximum phosphorus, 0.015% maximum sulfur, 2.25-2.55% chromium, 0.40-0.50% molybdenum, 0.55-0.65% nickel, 0.03-0.08% vanadium, and balance essentially iron.  
     
     
         4 . The pipe mold steel recited in  claim 3 , consisting essentially of from about 0.18% carbon, 0.75% manganese, 0.56% silicon, 0.005% maximum phosphorus, 0.005% maximum sulfur, 2.40% chromium, 0.45% molybdenum, 0.50% nickel, 0.05% vanadium, and balance essentially iron.  
     
     
         5 . A pipe mold steel for centrifugally casting pipe formed from a ferritic alloy steel comprising vanadium.  
     
     
         6 . The pipe mold steel recited in  claim 5 , comprising vanadium in a weight percentage of from about 0.03-0.08%.  
     
     
         7 . The pipe mold steel recited in  claim 6 , comprising vanadium in a weight percentage of from about 0.05%.