| 摘要 |
PROBLEM TO BE SOLVED: To provide a pearlitic rail which has high toughness and high ductility in a cold district. SOLUTION: The pearlitic rail having excellent toughness and ductility has a composition containing, by mass, 0.55 to 1.20% C, 0.10 to 1.20% Si, 0.1 to 1.5% Mn, 0.002 to 0.05% S, 0.005 to 1% V, 0.0004 to 0.02% Mg, 0.0005 to 0.03% N, <=0.05% Al and <=0.05% T, or further containing one or more metals selected from 0.1 to 1.0% Cr, 0.01 to 0.5% Mo, 0.001 to 0.05% Nb, 0.1 to 4% Ni and 0.0001 to 0.005% B. At least the rail head has a substantially pearlitic structure, and also, in the optional cross section of the pearlitic structure, (1) Mg oxide, Mg-Al oxides and Mg sulfides, (2) inclusions in which MnS is singly precipitated, or those in which MnS is precipitated with the (1) as neuclei, (3) inclusions in which V carbonitrides alone are precipitated, or those in which MnS is precipitated over the (1) and (2), and (4) inclusions containing TiN in addition to the (1) to (4), respectively having a diameter of 0.01 to 10μm are present by 50 to 2 millions in total in 1 mm<2> , and the size of pearlitic blocks is <50μm. |
