Patent ID: 9534278
Date: 2017-01-03
CPC Classifications: C21D,C22C,E01B

Claim:
1. A rail having a chemical composition comprising, by mass %: C: 0.75% to 1.20%; Si: 0.10% to 2.00%; Mn: 0.10% to 2.00%; P: 0.0250% or less; S: 0.0250% or less; Cr: 0% to 2.00%; Mo: 0% to 0.50%; Co: 0% to 1.00%; B: 0% to 0.0050%; Cu: 0% to 1.00%; Ni: 0% to 1.00%; V: 0% to 0.50%; Nb: 0% to 0.050%; Ti: 0% to 0.0500%; Mg: 0% to 0.0200%; Ca: 0% to 0.0200%; REM: 0% to 0.0500%; Zr: 0% to 0.0200%; N: 0% to 0.0200%; and Al: 0% to 1.00%, the remainder being Fe and impurities, wherein the rail includes, a top head which is a flat region extending along a longitudinal direction of the rail and is located at a top of a head of the rail, a side head which is a flat region extending along the longitudinal direction of the rail and is located at a side of the head of the rail, a corner head which is a region including a rounded corner extending between the top head and the side head along the longitudinal direction of the rail, and an upper half of the side head, and a surface of the top head of the rail which is a region including a surface of the top head and a surface of the corner head, wherein in a range from the surface of the head of the rail to a depth of 30 mm, 95% or more of a structure is composed of a pearlite structure by area %, and in a range with a depth of 20 mm to 30 mm from the surface, an average grain size of a pearlite block in a transverse section is 120 μm to 200 μm.