Niobium and chromium low alloy carbon steel for high wear resistant automotive chain link plates

Abstract

Niobium chromium low allow carbon steel for automotive chain link plates has improved wear resistance. In one preferred embodiment, the steel composition includes niobium, chromium, carbon, iron, and any impurities. One preferred composition including these components includes, by weight percentage, approximately 0.25% to 0.75% carbon, approximately 0.20% to 2.0% chromium, approximately 0.26% to 1.5% niobium, and the remaining component of the composition is iron. Trace amounts of impurities may also be present. In another embodiment, a steel composition includes, by weight percentage, approximately 0.25% to 0.75% carbon, approximately 0.2% to 1.0% manganese, approximately 0.05% to 0.60% silicon, approximately 0.26% to 1.5% niobium, approximately 0.20% to 2.0% chromium, up to approximately 0.30% aluminum, up to approximately 0.03% phosphorus, up to approximately 0.03% sulfur, and a remainder of the composition being iron and any other impurities.

1 .- 10 . (canceled) 
     
     
         11 . A chain link comprising a steel composition comprising, by weight percentage, approximately 0.25% to 0.75% carbon, approximately 0.26% to 1.5% niobium, approximately 0.20% to 2.0% chromium, iron and any impurities. 
     
     
         12 . The chain link of  claim 11 , wherein the chain link has a hardness of HRc 50 to 60. 
     
     
         13 . The chain link of  claim 12 , wherein the chain link has a hardness of HRc 52 to 58. 
     
     
         14 . The chain link of  claim 11 , wherein the weight percentage of carbon in the composition ranges from approximately 0.5% to 0.6%. 
     
     
         15 . The chain link of  claim 11 , wherein the weight percentage of chromium in the composition ranges from approximately 0.4% to 0.6%. 
     
     
         16 . The chain link of  claim 11 , wherein the weight percentage of niobium in the composition is greater than 0.5%. 
     
     
         17 . The chain link of  claim 11 , wherein the weight percentage of niobium in the composition ranges from approximately 0.26% to 0.8%. 
     
     
         18 . The chain link of  claim 11 , wherein the composition further comprises, by weight percentage, approximately 0.2% to 1.0% manganese. 
     
     
         19 . The chain link of  claim 11 , wherein the composition further comprises, by weight percentage, approximately 0.05% to 0.60% silicon. 
     
     
         20 . The chain link of  claim 11 , wherein the composition further comprises at least one impurity, by weight percentage, selected from the group consisting of:
 a) up to approximately 0.3% aluminum;   b) up to approximately 0.03% phosphorus;   c) up to approximately 0.03% sulfur; and   d) any combination of up to approximately 0.3% aluminum, up to approximately 0.03% phosphorus and up to approximately 0.03% sulfur.   
     
     
         21 . The chain link of  claim 11 , wherein the composition further comprises approximately 0.2% to 1.0% manganese and approximately 0.05% to 0.60% silicon. 
     
     
         22 .- 36 . (canceled) 
     
     
         37 . A chain link comprising a composition comprising, by weight percentage, approximately 0.25% to 0.75% carbon, approximately 0.2% to 1.0% manganese, approximately 0.05% to 0.60% silicon, approximately 0.26% to 1.5% niobium, approximately 0.20% to 2.0% chromium, up to approximately 0.30% aluminum, up to approximately 0.03% phosphorus, up to approximately 0.03% sulfur, and a remainder of the composition being iron and any other impurities. 
     
     
         38 . The chain link of  claim 37 , wherein the chain link has a hardness of HRc 50 to 60. 
     
     
         39 . The chain link of  claim 38 , wherein the chain link has a hardness of HRc 52 to 58. 
     
     
         40 . A chain that includes a plurality of links, each link comprising a steel composition comprising, by weight percentage, approximately 0.25% to 0.75% carbon, approximately 0.2% to 1.0% manganese, approximately 0.05% to 0.60% silicon, approximately 0.26% to 1.5% niobium, approximately 0.20% to 2.0% chromium, up to approximately 0.30% aluminum, up to approximately 0.03% phosphorus, up to approximately 0.03% sulfur, and a remainder of the composition being iron and any other impurities. 
     
     
         41 . The chain of  claim 40 , wherein the links have a hardness of HRc 50 to 60. 
     
     
         42 . The chain of  claim 41 , wherein the links have a hardness of HRc 52 to 58. 
     
     
         43 . A method of producing a chain link, comprising the step of heat treating a steel composition comprising by weight percentage, approximately 0.25% to 0.75% carbon, approximately 0.2% to 1.0% manganese, approximately 0.05 to 0.60% silicon, approximately 0.26% to 1.5% niobium, approximately 0.20 to 2.0% chromium, up to approximately 0.30% aluminum, up to approximately 0.03% phosphorus, up to approximately 0.03% sulfur, and a remainder of the composition being iron and any other impurities, to a hardness of HRc 50 to 60. 
     
     
         44 . The method of  claim 43 , wherein the heat treating step uses a method selected from the group consisting of oil quenching and tempering, salt bath austempering, and salt bath martempering.