| 摘要 |
PROBLEM TO BE SOLVED: To attain the stable improvement of wear resistance and inside fatigue damage resistance required for the rail of a heavy load heavy railway, as to a rail having a compsn. composed of C, Si, Mn, B, Al and Fe, by allowing the rail head part to have a pearlitic structure having specified hardness. SOLUTION: A steel rail containg by weight, >0.85 to 1.20% C, 0.10 to 1.00% Si, 0.10 to 1.50% Mn. 0.0001 to 0.0040% B and 0.0050 to 0.0250% Al, furthermore contg., at need, one or more kinds among 0.05 to 1.00% Cr, 0.01 to 0.20% Mo, 0.05 to 0.50% Cu, 0.05 to 1.00% Ni, 0.01 to 0.50% V, 0.002 to 0.050% Nb, 0.0050 to 0.0300% Ti, 0.0010 to 0.0100% Mg, 0.0010 to 0.0150% Ca and 0.10 to 2.00% Co, and the balance Fe with inevitable impurities is subjected to heat treatment, and, the range to a depth of >=20 mm from the surfaces of the top part and head corner part surface of the rail is allowed to have a pearlitic structure having >=370 Hv, hardness and in which the difference in hardnesses between the head surface part and the head inside is <=30 Hv. |
