Carburizing alloy steel having improved durability and method of manufacturing the same

Abstract

A carburizing alloy steel includes 0.1 to 0.35 wt % of carbon (C), 0.1 to 2 wt % of silicon (Si), 0.1 to 1.5 wt % of manganese (Mn), 0.5 to 1.5 wt % of chromium (Cr), 0.2 to 0.5 wt % of molybdenum (Mo), 0.1 to 0.6 wt % of nickel (Ni), more than 0 wt % and less than or equal to 0.07 wt % of niobium (Nb), more than 0 wt % and less than or equal to 0.5 wt % of vanadium (V), more than 0 wt % and less than or equal to 0.5 wt % of titanium (Ti), more than 0 wt % and less than or equal to 0.015 wt % of nitrogen (N), 0.00002 to 0.00005 wt % of boron (B), based on the total weight of the alloy steel, iron (Fe) as a main component.

What is claimed is: 
     
         1 . A carburizing alloy steel comprising:
 0.1 to 0.35 wt % of carbon (C), 0.1 to 2.0 wt % of silicon (Si), 0.1 to 1.5 wt % of manganese (Mn), 0.5 to 1.5 wt % of chromium (Cr), 0.2 to 0.5 wt % of molybdenum (Mo), more than 0 wt % and less than or equal to 0.07 wt % of niobium (Nb), 0.1 to 0.6 wt % of nickel (Ni), more than 0 wt % and less than or equal to 0.5 wt % of vanadium (V), more than 0 wt % and less than or equal to 0.5 wt % of titanium (Ti), more than 0 wt % and less than or equal to 0.015 wt % of nitrogen (N), and 0.00002 to 0.00005 wt % of boron (B), based on a total weight of an alloy steel and iron (Fe) as a main component.   
     
     
         2 . The carburizing alloy steel of  claim 1 , further comprising:
 tungsten (W).   
     
     
         3 . The carburizing alloy steel of  claim 2 , wherein a content of tungsten (W) is more than 0 wt % and less than or equal to 0.4 wt % 
     
     
         4 . The carburizing alloy steel of  claim 1 , further comprising:
 zirconium (Zr).   
     
     
         5 . The carburizing alloy steel of  claim 4 , wherein a content of zirconium (Zr) is more than 0 wt % and less than or equal to 0.01 wt %. 
     
     
         6 . The carburizing alloy steel of  claim 1 , further comprising:
 cobalt (Co).   
     
     
         7 . The carburizing alloy steel of  claim 6 , wherein a content of cobalt (Co) is more than 0 wt % and less than or equal to 5 wt %. 
     
     
         8 . The carburizing alloy steel of  claim 1 , further comprising:
 yttrium (Y).   
     
     
         9 . The carburizing alloy steel of  claim 8 , wherein a content of yttrium (Y) is more than 0 wt % and less than or equal to 2 wt %. 
     
     
         10 . The carburizing alloy steel of  claim 1 , further comprising:
 one or more of tungsten (W), zirconium (Zr), cobalt (Co), or yttrium (Y).   
     
     
         11 . The carburizing alloy steel of  claim 10 , wherein a content of tungsten (W) is more than 0 wt % and less than or equal to 0.4 wt %, a content of zirconium (Zr) is more than 0 wt % and less than or equal to 0.01 wt %, a content of cobalt (Co) is more than 0 wt % and less than or equal to 5 wt %, and a content of yttrium (Y) is more than 0 wt % and less than or equal to 2 wt %. 
     
     
         12 . A method of manufacturing a carburizing alloy steel, the method comprising:
 mixing materials of an alloy steel for carburizing an alloy steel;   carburizing the alloy steel at 880 to 940° C. for 1.5 to 2 hours;   oil-quenching the carburized alloy steel at 80 to 120° C.; and   tempering the oil-quenched alloy steel at 170 to 200° C. for 1 to 3 hours,   wherein the carburizing alloy steel comprising: 0.1 to 0.35 wt % of carbon (C), 0.1 to 2.0 wt % of silicon (Si), 0.1 to 1.5 wt % of manganese (Mn), 0.5 to 1.5 wt % of chromium (Cr), 0.2 to 0.5 wt % of molybdenum (Mo), more than 0 wt % and less than or equal to 0.07 wt % of niobium (Nb), 0.1 to 0.6 wt % of nickel (Ni), more than 0 wt % and less than or equal to 0.5 wt % of vanadium (V), more than 0 wt % and less than or equal to 0.5 wt % of titanium (Ti), more than 0 wt % and less than or equal to 0.015 wt % of nitrogen (N), and 0.00002 to 0.00005 wt % of boron (B), based on a total weight of the carburizing alloy steel and iron (Fe) as a main component.   
     
     
         13 . A transmission for a vehicle manufactured by a carburizing alloy steel,
 wherein the carburizing alloy steel comprising: 0.1 to 0.35 wt % of carbon (C), 0.1 to 2.0 wt % of silicon (Si), 0.1 to 1.5 wt % of manganese (Mn), 0.5 to 1.5 wt % of chromium (Cr), 0.2 to 0.5 wt % of molybdenum (Mo), more than 0 wt % and less than or equal to 0.07 wt % of niobium (Nb), 0.1 to 0.6 wt % of nickel (Ni), more than 0 wt % and less than or equal to 0.5 wt % of vanadium (V), more than 0 wt % and less than or equal to 0.5 wt % of titanium (Ti), more than 0 wt % and less than or equal to 0.015 wt % of nitrogen (N), and 0.00002 to 0.00005 wt % of boron (B), based on a total weight of the carburizing alloy steel and iron (Fe) as a main component.