| 摘要 |
PURPOSE:To provide superior damage resistance by refining a molten steel by predeoxidation and secondary deoxidation with Ti or a Ti alloy and by subjecting the resulting molten steel having a specified composition to ingot making-cogging or continuous casting and hot rolling to manufacture a rail contg. a product of a specified grain size produced by the secondary deoxidation. CONSTITUTION:A molten steel is refined by predeoxidation to >=50ppm concn. of dissolved oxygen and secondary deoxidation with Ti or a Ti alloy to obtain a molten steel having a composition consisting of, by weight, 0.55-0.85% C, 0.2-1.2% Si, 0.5-1.5% Mn, <=0.025% P, <=0.01% S, <=0.004% N and the balance Fe with inevitable impurities. The molten steel is subjected to ingot making- cogging or continuous casting and hot rolling to manufacture a rail contg. a product of 0.6-6Xm grain size produced by the secondary deoxidation by 5X10<3>-1X10<6> grains per 1mm<3>. The rail does not contain coarse inclusions of >=70mum grain size. |
