Abstract: A rolled steel bar has a composition consisting, by mass percent, of C: 0.27 to 0.37%, Si: 0.30 to 0.75%, Mn: 1.00 to 1.45%, S: 0.008% or more and less than 0.030%, Cr: 0.05 to 0.30%, Al: 0.005 to 0.050%, V: 0.200 to 0.320%, and N: 0.0080 to 0.0200%, the balance being Fe and impurities. The contents of P, Ti and O in the impurities are, by mass percent, P: 0.030% or less, Ti: 0.0040% or less, and O: 0.0020% or less. Y1 expressed by the formula <1> is 1.05 to 1.18. Y1=C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V?(5/7)S ??<1>. C, Si, Mn, Cr, V, and S in the formula represent mass percent of the elements. A hot-forged part having a tensile strength of 900 MPa or higher and a transverse endurance ratio of 0.47 can be obtained by the rolled steel bar.

Abstract: Disclosed is a steel alloy that includes as alloying ingredients carbon, silicon, manganese, aluminum, and oxygen. In accordance with this embodiment of the disclosed invention, carbon is present in an amount ranging from 0.40 to 0.77 wt. %; silicon is present in an amount ranging from 0.40 to 1.20 wt. %; manganese is present in an amount ranging from 0.40 to 1.20 wt. %, aluminum is present in an amount ranging from 0.003 to 0.060 wt. %; and oxygen is present in an amount ranging up to 0.0030 wt. %. Also disclosed is a railway wheel that comprises a hub, a rim, and a connecting plate. In accordance with this embodiment of the disclosed invention, at least the rim, and preferably the entire railway wheel, is composed of the disclosed steel composition.

Abstract: Disclosed is a steel alloy that includes as alloying ingredients carbon, silicon, manganese, aluminum, and oxygen. In accordance with this embodiment of the disclosed invention, carbon is present in an amount ranging from 0.40 to 0.77 wt. %; silicon is present in an amount ranging from 0.40 to 1.20 wt. %; manganese is present in an amount ranging from 0.40 to 1.20 wt. %, aluminum is present in an amount ranging from 0.003 to 0.060 wt. %; and oxygen is present in an amount ranging up to 0.0030 wt. %. Also disclosed is a railway wheel that comprises a hub, a rim, and a connecting plate. In accordance with this embodiment of the disclosed invention, at least the rim, and preferably the entire railway wheel, is composed of the disclosed steel composition.

Abstract: Disclosed is a steel alloy that includes as alloying ingredients carbon, silicon, manganese, aluminum, and oxygen. In accordance with this embodiment of the disclosed invention, carbon is present in an amount ranging from 0.40 to 0.77 wt. %; silicon is present in an amount ranging from 0.40 to 1.20 wt. %; manganese is present in an amount ranging from 0.40 to 1.20 wt. %, aluminum is present in an amount ranging from 0.003 to 0.060 wt. %; and oxygen is present in an amount ranging up to 0.0030 wt. %. Also disclosed is a railway wheel that comprises a hub, a rim, and a connecting plate. In accordance with this embodiment of the disclosed invention, at least the rim, and preferably the entire railway wheel, is composed of the disclosed steel composition.

Abstract: A method for easily and effectively preventing shattered-rim fracture in a railway wheel. Generally, the method comprises the steps of providing a railway wheel, measuring the maximum defect size within the rim of the railway wheel, and determining whether the maximum defect size is less than a predetermined maximum permissible defect size, the maximum permissible defect size being determined based on an analysis of the likelihood of Mode II crack propagation from the defect when the railway wheel has been subjected to the load. The disclosed invention also encompasses a method for grading railway wheels for maximum load suitability.

Abstract: A wheel has both wear resistance and heat-crack resistance sufficient for use in a high-speed railway vehicle. The chemical composition of a base steel comprises 0.4 to 0.75 % C, 0.4 to 0.95% Si, 0.6 to 1.2% Mn and less than 0.2% Cr. The wheel has a pearlitic microstructure in a region of at least 50 mm in depth from the tread surface of the wheel. When the tread of the wheel is quenched, a particular cooling process is applied in order to obtain the pearlitic structure.