High-strength and highly fatigue-resistant steel rail and production method thereof

Abstract

The present invention relates to a high-strength, highly wear-resistant, and highly contact-fatigue-resistant steel rail and a production method thereof, and belongs to the field of black steel manufacturing technology. The present invention provides a high-strength and highly fatigue-resistant steel rail, comprising the following chemical components by weight percentage: C: 0.76%˜0.86%; Si: 0.6%˜1%; Mn: 0.7%˜1.5%, Cr: 0.1%˜0.5%, and 0.8%≦Mn %+Cr %≦1.6%; V: 0.05%˜0.3%, Ni: 0.1%˜0.35%, and 0.15%≦V %+Ni %≦0.4%; Mo: ≦0.03%; P: ≦0.02%; S: ≦0.015%; Fe and inevitable impurities: the remaining content, wherein, the metallurgical structure of the steel rail is fine pearlite+A, where, A is proeutectoid ferrite or proeutectoid cementite, and A≦2%. The tensile strength of the obtained steel rail is 1,260 MPa˜1,420 MPa.

1 . A steel rail, comprising the following chemical components by weight percentage: C: 0.76%˜0.86%; Si: 0.60%˜1.00%; Mn: 0.70%˜1.50%, Cr: 0.10%˜0.50%, and 0.80%≦Mn %+Cr %≦1.60%; V: 0.05%˜0.30%, Ni: 0.10%˜0.35%, and 0.15%≦V %+Ni %≦0.40%; Mo: ≦0.03%; P: ≦0.020%; S: ≦0.015%; Fe and inevitable impurities: the remaining content, wherein, the metallurgical structure of the steel rail is fine pearlite+A, where, A is proeutectoid ferrite or proeutectoid cementite, and A≦2%. 
     
     
         2 . The steel rail according to  claim 1 , wherein, further comprising the following components by weight percentage: Ti: 0.05%˜0.30%, and Nb: 0.005%˜0.10%. 
     
     
         3 . The steel rail according to  claim 1 , wherein, A is ≦1%. 
     
     
         4 . The steel rail according to  claim 2 , wherein, A is ≦1%. 
     
     
         5 . The steel rail according to  claim 1 , wherein, tensile strength of the steel rail is 1,260 MPa˜1,420 MPa, hardness of the rail head tread is 390HB˜432HB, hardness of the part at 10 mm below the surface of rail head is 380HB˜420HB, and hardness of the part at 24 mm below the surface of rail head is 370HB˜401HB. 
     
     
         6 . The steel rail according to  claim 2 , wherein, tensile strength of the steel rail is 1,260 MPa˜1,420 MPa, hardness of the rail head tread is 390HB˜432HB, hardness of the part at 10 mm below the surface of rail head is 380HB˜420HB, and hardness of the part at 24 mm below the surface of rail head is 370HB˜401HB. 
     
     
         7 . The steel rail according to  claim 3 , wherein, tensile strength of the steel rail is 1,260 MPa˜1,420 MPa, hardness of the rail head tread is 390HB˜432HB, hardness of the part at 10 mm below the surface of rail head is 380HB˜420HB, and hardness of the part at 24 mm below the surface of rail head is 370HB˜401HB. 
     
     
         8 . The steel rail according to  claim 4 , wherein, tensile strength of the steel rail is 1,260 MPa˜1,420 MPa, hardness of the rail head tread is 390HB˜432HB, hardness of the part at 10 mm below the surface of rail head is 380HB˜420HB, and hardness of the part at 24 mm below the surface of rail head is 370HB˜401HB. 
     
     
         9 . A method for producing a steel rail, comprising the procedures in turn: converter smelting-LF refining-RH vacuum treatment-continuous casting-rolling-cooling-straightening, wherein, finish rolling temperature in the rolling procedure is controlled to be 930° C.˜1,000° C.; initial cooling temperature in the cooling procedure is controlled to be 780° C.˜880° C., final cooling temperature is controlled to be 300° C.˜400° C., and cooling rate is controlled to be 4.0° C.˜10.0° C./s;
 wherein, the steel rail comprises the following chemical components by weight percentage: C: 0.76%˜0.86%; Si: 0.60%˜1.00%; Mn: 0.70%˜1.50%, Cr: 0.10%˜0.50%, and 0.80%≦Mn %+Cr %≦1.60%; V: 0.05%˜0.30%, Ni: 0.10%˜0.35%, and 0.15%≦V %+Ni %≦0.40%; Mo: ≦0.03%; P: ≦0.020%; S: ≦0.015%; Fe and inevitable impurities: the remaining content, wherein, the metallurgical structure of the steel rail is fine pearlite+A, where, A is proeutectoid ferrite or proeutectoid cementite, and A≦2%. 
 
     
     
         10 . The method for producing the steel rail according to  claim 9 , wherein, the steel rail further comprising the following components by weight percentage: Ti: 0.05%˜0.30%, and Nb: 0.005%˜0.10%. 
     
     
         11 . The method for producing the steel rail according to  claim 9 , wherein, A is ≦1%. 
     
     
         12 . The method for producing the steel rail according to  claim 10 , wherein, A is ≦1%. 
     
     
         13 . The method for producing the steel rail according to  claim 9 , wherein, tensile strength of the steel rail is 1,260 MPa˜1,420 MPa, hardness of the rail head tread is 390HB˜432HB, hardness of the part at 10 mm below the surface of rail head is 380HB420HB, and hardness of the part at 24 mm below the surface of rail head is 370HB˜401HB. 
     
     
         14 . The method for producing the steel rail according to  claim 10 , wherein, tensile strength of the steel rail is 1,260 MPa˜1,420 MPa, hardness of the rail head tread is 390HB432HB, hardness of the part at 10 mm below the surface of rail head is 380HB˜420HB, and hardness of the part at 24 mm below the surface of rail head is 370HB˜401HB. 
     
     
         15 . The method for producing the steel rail according to  claim 11 , wherein, tensile strength of the steel rail is 1,260 MPa˜1,420 MPa, hardness of the rail head tread is 390HB432HB, hardness of the part at 10 mm below the surface of rail head is 380HB420HB, and hardness of the part at 24 mm below the surface of rail head is 370HB˜401HB. 
     
     
         16 . The method for producing the steel rail according to  claim 12 , wherein, tensile strength of the steel rail is 1,260 MPa˜1,420 MPa, hardness of the rail head tread is 390HB432HB, hardness of the part at 10 mm below the surface of rail head is 380HB420HB, and hardness of the part at 24 mm below the surface of rail head is 370HB˜401HB. 
     
     
         17 . The method for producing the steel rail according to  claim 9 , wherein, the cooling method is at least one selected from the group consisting of air blast cooling, water mist cooling, and water cooling.