Steel for wheel

Abstract

There is provided steel for wheel having a chemical composition consisting of, by mass percent, C: 0.65 to 0.84%, Si: 0.02 to 1.00%, Mn: 0.50 to 1.90%, Cr: 0.02 to 0.50%, V: 0.02 to 0.20%, and S: 0.04% or less, in which 34≦2.7+29.5×C+2.9×Si+6.9×Mn+10.8×Cr+30.3×Mo+44.3×V≦43, and 0.76×exp(0.05×C)×exp(1.35×Si)×exp(0.38×Mn)×exp(0.77×Cr)×exp(3.0×Mo)×exp(4.6×V)25, the balance being Fe and impurities, and the impurities containing P: 0.05% or less, Cu: 0.20% or less, and Ni: 0.20% or less. This steel for wheel is excellent in balance between the wear resistance, rolling contact fatigue resistance and the spalling resistance, and can give a long life to the wheel.

1 . Steel for wheel having a chemical composition consisting of, by mass percent, C: 0.65 to 0.84%, Si: 0.02 to 1.00%, Mn: 0.50 to 1.90%, Cr: 0.02 to 0.50%, V: 0.02 to 0.20%, and S: 0.04% or less, in which Fn1 expressed by Formula (1) is 34 to 43, and Fn2 expressed by Formula (2) is 25 or less, the balance being Fe and impurities, and the impurities containing P: 0.05% or less, Cu: 0.20% or less, and Ni: 0.20% or less.
     Fn 1=2.7+29.5×C+2.9×Si+6.9×Mn+10.8×Cr+30.3×Mo+44.3×V   (1)
       Fn 2=exp(0.76)×exp(0.05×C)×exp (1.35×Si)×exp(0.38×Mn)×exp (0.77×Cr)×exp(3.0×Mo)×exp(4.6×V)   (2)
   
       in Formulas (1) and (2), C, Si, Mn, Cr, Mo and V each mean the content in percent by mass of the element. 
     
     
         2 . The steel for wheel according to  claim 1 , wherein 0.20% or less of Mo is contained by mass percent in lieu of a part of Fe. 
     
     
         3 . The steel for wheel according to  claim 1  wherein 0.20% or less of Al is contained by mass percent in lieu of a part of Fe. 
     
     
         4 . The steel for wheel according to  claim 2  wherein 0.20% or less of Al is contained by mass percent in lieu of a part of Fe.