Pearlite rail having superior abrasion resistance and excellent toughness

Abstract

This pearlite rail consists of a steel including: in terms of percent by mass, C: 0.65 to 1.20%; Si: 0.05 to 2.00%; Mn: 0.05 to 2.00%; P≦0.0150%; S≦0.0100%; Ca: 0.0005 to 0.0200%, and Fe and inevitable impurities as the balance, wherein a head surface portion which ranges from surfaces of head corner portions and a head top portion to a depth of 10 mm has a pearlite structure, a hardness Hv of the pearlite structure is in a range of 320 to 500, and Mn sulfide-based inclusions having major lengths in a range of 10 to 100 μm are present at an amount per unit area in a range of 10 to 200/mm 2 in a cross-section taken along a lengthwise direction in the pearlite structure.

1 . A pearlite rail consisting of a steel comprising: in terms of percent by mass,
 C, 0.65 to 1.20%;   Si: 0.05 to 2.00%;   Mn: 0.05 to 2.00%;   P≦0.0150%;   S≦0.0100%;   Ca: 0.0005 to 0.0200%; and   Fe and inevitable impurities as the balance,   wherein, in a head portion of the rail, a head surface portion which ranges from surfaces of head corner portions and a head top portion to a depth of 10 mm has a pearlite structure,   a hardness Hv of the pearlite structure is in a range of 320 to 500, and   Mn sulfide-based inclusions having major lengths in a range of 10 to 100 μm are present at an amount per unit area in a range of 10 to 200/mm 2  in a cross-section taken along a lengthwise direction in the pearlite structure.   
     
     
         2 . The pearlite rail according to  claim 1 ,
 wherein the steel further comprises, in terms of percent by mass, either one or both of Mg: 0.0005 to 0.0200% and Zr: 0.0005 to 0.0100%, and   Mg-based oxides, Zr oxides, and Mn sulfide-based inclusions having grain diameters in a range of 5 nm to 100 nm are present at an amount per unit area in a range of 500 to 50,000/mm 2  in a transverse cross-section in the pearlite structure.   
     
     
         3 . The pearlite rail according to  claim 1  or  2 ,
 wherein the steel further comprises, in terms of percent by mass, Co: 0.01% to 1.00%. 
 
     
     
         4 . The pearlite rail according to  claim 1 ,
 wherein the steel further comprises, in terms of percent by mass, either one or both of Cr: 0.01 to 2.00% and Mo: 0.01 to 0.50%.   
     
     
         5 . The pearlite rail according to  claim 1 ,
 wherein the steel further comprises, in terms of percent by mass, either one or both of V: 0.005 to 0.50% and Nb: 0.002 to 0.050%.   
     
     
         6 . The pearlite rail according to  claim 1 ,
 wherein the steel further comprises, in terms of percent by mass, B: 0.0001 to 0.0050%.   
     
     
         7 . The pearlite rail according to  claim 1 ,
 wherein the steel further comprises, in teems of percent by mass, Cu: 0.01 to 1.00%.   
     
     
         8 . The pearlite rail according to  claim 1 ,
 wherein the steel further comprises, in terms of percent by mass, Ni: 0.01 to 1.00%.   
     
     
         9 . The pearlite rail according to  claim 1 ,
 wherein the steel further comprises, in terms of percent by mass, Ti: 0.0050 to 0.0500%.   
     
     
         10 . The pearlite rail according to  claim 1 ,
 wherein the steel further comprises, in terms of percent by mass, Al: more than 0.0100 to 1.00%.   
     
     
         11 . The pearlite rail according to  claim 1 ,
 wherein the steel further comprises, in terms of percent by mass, N: 0.0060 to 0.0200%.