RAIL WHOSE INTERNAL HAS HIGH HARDNESS

PROBLEM TO BE SOLVED: To provide a rail which has a hardness of ≥370 HB at a point to the inside of 20 mm from the surface of the head, and in which the formation of the metallic structure of micro martensite at the inside of the boundary region between the head and a columnar part is suppressed, and its hardness is increased to the inside. SOLUTION: The rail whose inside has high hardness is composed of a steel having a composition comprising 0.60 to 0.86% C, 0.10 to 1.20% Si, 0.40 to 1.50% Mn and 0.05 to 2.00% Cr, and in which Ceq defined by formula Ceq=C+Si/10+Mn/4.75+Cr/5.0 satisfies ≥1.00 and QP defined by formula QP=(0.06+0.4C)×(1+0.64×Si)×(1+4.1×Mn)×(1+2.33×Cr) satisfies ≤7.0, respectively. The whole face of the head has a metallic structure of pearlite, hardness to a point to the inside of 20 mm with the surface of the top of the head as the starting point is ≥370 HB, and a difference in the hardness between the surface of the top of the head and the point to the inside of 20 mm with the surface as the starting point is ≤30 HB. COPYRIGHT: (C)2010,JPO&INPIT