| 摘要 |
PROBLEM TO BE SOLVED: To improve the electric conductivity and rolling fatigue damage resistance of a rail by specifying the compsn. composed of C, Si, Mn, Cr, Mo, B, Al, P, S and Fe, controlling its electric resistance value to the specified one and forming the structure of the rail head of the bainitic one having specified hardness. SOLUTION: This rail contains by weight, 0.15 to 0.45% C, 0.10 to 0.50% Si, 0.20 to 1.80% Mn, 0.20 to 1.80% Cr, 0.01 to 0.60% Mo, 0.0001 to 0.0050% B, 0.0050 to 0.0250% Al, <=0.025% P and <=0.025% S and furthermore contg. one or more kinds among 0.005 to 0.05% Nb, 0.01 to 0.30% V, 0.05 to 0.50% Cu, 0.05 to 1.00% Ni and 0.005 to 0.050% Ti, in which electric resistance value by the formula is controlled to <=26.5μΩ.cm, and also, the structure of the range to a depth of at least 15 mm from the rail head corner part and top part surface is formed of the bainitic one having >=240 Hv hardness. In this way, the dark spot damage or the like of the rail is prevented, and, moreover, the reduction of its electric resistance is made possible.
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