| 摘要 |
PROBLEM TO BE SOLVED: To attain the gamma transgranular transformed grain refinement of a rail steel by the use of oxide metallurgy and to improve toughness. SOLUTION: A bloom of a steel, which is prepared by adding one or >=2 deoxidizing elements among Zr, Mn, and Si to a molten steel to perform deoxidizing treatment and further successively adding, supplementarily, Ti-containing Zr, and has a composition consisting of, by mass, 0.55-0.85% C, 0.20-1.20% Si, 0.50-1.50% Mn, 0.002-0.035% S, 0.1-1.0% Cr, 0.001-0.020% Ti resultant from supplementarily added Zr, and the balance iron with inevitable impurities, is hot-rolled into rail. By this method, a high strength rail excellent in toughness and ductility, in which the number of MnS of a size of 0.1-10μm is regulated to (30 to 10000) pieces per mm<2> , is produced. This rail can clear the toughness specification specified by Russian GOST standard.
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