Railway vehicle wheel and method for manufacturing railway vehicle wheel

Abstract

Provided is a railway vehicle wheel that enables further reducing wear and fatigue damage of the wheel and rail in total. A railway vehicle wheel containing, in mass %: 0.65% to 0.84% of C; 0.1% to 1.5% of Si; 0.05% to 1.5% of Mn; 0.025% or less of P; 0.015% or less of S; 0.001% to 0.08% of Al; and 0.05% to 1.5% of Cr, the balance being Fe and incidental impurities, wherein a microstructure at least in a region extending from a tread to a depth of 15 mm is a pearlite structure, and a pearlite lamellar spacing at least in the region is 150 nm or less.

1 - 8 . (canceled) 
     
     
         9 . A railway vehicle wheel containing, in mass %: 0.65% to 0.84% of C; 0.1% to 1.5% of Si; 0.05% to 1.5% of Mn; 0.025% or less of P; 0.015% or less of S; 0.001% to 0.08% of Al; and 0.05% to 1.5% of Cr, the balance being Fe and incidental impurities, wherein a microstructure at least in a region extending from a tread to a depth of 15 mm is a pearlite structure, and a pearlite lamellar spacing at least in the region is 150 nm or less. 
     
     
         10 . The railway vehicle wheel according to  claim 9  further containing, in mass %, one or more of: 0.03% to 0.5% of Cu; 0.03% to 0.5% of Ni; 0.02% to 0.2% of Mo; 0.003% to 0.3% of V; 0.003% to 0.1% of Nb; and 0.002% to 0.02% of Ti. 
     
     
         11 . The railway vehicle wheel according to  claim 9 , wherein the region has a mean pearlite block size of 30 μm or less. 
     
     
         12 . The railway vehicle wheel according to  claim 10 , wherein the region has a mean pearlite block size of 30 μm or less. 
     
     
         13 . The railway vehicle wheel according to  claim 9 , wherein the railway vehicle wheel has a 0.2% yield strength (YS) of 700 MPa or more and a yield ratio of 60% or more, when measured at 15 mm inside the tread. 
     
     
         14 . The railway vehicle wheel according to  claim 10 , wherein the railway vehicle wheel has a 0.2% yield strength (YS) of 700 MPa or more and a yield ratio of 60% or more, when measured at 15 mm inside the tread. 
     
     
         15 . The railway vehicle wheel according to  claim 11 , wherein the railway vehicle wheel has a 0.2% yield strength (YS) of 700 MPa or more and a yield ratio of 60% or more, when measured at 15 mm inside the tread. 
     
     
         16 . The railway vehicle wheel according to  claim 12 , wherein the railway vehicle wheel has a 0.2% yield strength (YS) of 700 MPa or more and a yield ratio of 60% or more, when measured at 15 mm inside the tread. 
     
     
         17 . The railway vehicle wheel according to  claim 11 , wherein the railway vehicle wheel has a 0.2% yield strength (YS) of 700 MPa or more, a yield ratio of 60% or more, an elongation of 12% or more, and a Charpy impact value at 20° C. of 15 J or more, when measured at 15 mm inside the tread. 
     
     
         18 . The railway vehicle wheel according to  claim 12 , wherein the railway vehicle wheel has a 0.2% yield strength (YS) of 700 MPa or more, a yield ratio of 60% or more, an elongation of 12% or more, and a Charpy impact value at 20° C. of 15 J or more, when measured at 15 mm inside the tread. 
     
     
         19 . A method for manufacturing a railway vehicle wheel comprising:
 preparing steel by steelmaking in an electric heating furnace or converter, the steel containing, in mass %, 0.65% to 0.84% of C, 0.1% to 1.5% of Si, 0.05% to 1.5% of Mn, 0.025% or less of P, 0.015% or less of S, 0.001% to 0.08% of Al, and 0.05% to 1.5% of Cr, the balance being Fe and incidental impurities;   casting the steel to obtain a material;   subjecting the material to hot rolling and/or hot forging to form a wheel;   heating the formed wheel to a heating temperature of Ac 3  point+50° C. or higher;   subjecting the wheel to accelerated cooling at a cooling start temperature of 700° C. or higher, a cooling rate of 1° C./s to 10° C./s, a cooling stop temperature of 500° C. to 650° C.; and   then subjecting the wheel to air cooling.   
     
     
         20 . The method for manufacturing a railway vehicle wheel according to  claim 19 , wherein the steel further contains, in mass %, one or more of: 0.03% to 0.5% of Cu; 0.03% to 0.5% of Ni; 0.02% to 0.2% of Mo; 0.003% to 0.3% of V; 0.003% to 0.1% of Nb; and 0.002% to 0.02% of Ti. 
     
     
         21 . The method for manufacturing the railway vehicle wheel according to  claim 19 , wherein the heating temperature is Acs point+150° C. or lower. 
     
     
         22 . The method for manufacturing the railway vehicle wheel according to  claim 20 , wherein the heating temperature is Acs point+150° C. or lower.