Abstract: Provided is a rail that is effective in improving wear resistance and rolling contact fatigue (RCF) resistance. The rail has a metallic structure including a pearlitic structure and a structure other than the pearlitic structure in a surface layer from a surface of a rail head to a depth of at least 0.5 mm, where the pearlitic structure has Vickers hardness of 420 HV or more and 520 HV or less, and the structure other than the pearlitic structure has Vickers hardness of 350 HV or more and 420 HV or less.

Abstract: A dust collector includes a housing, a dust collecting bag that is installed in the housing and has an air permeability, a supply section that has a pipe coupled to the dust collecting bag, and supplies a powder into the housing via the pipe, a negative pressure generating section that generates a negative pressure in the housing, and a vibration applying section that applies a vibration to the dust collecting bag. The dust collecting bag includes a top surface, a bottom surface, and a side surface coupling the top surface and the bottom surface with each other, and a vibration transmitted to the top surface is larger than a vibration transmitted to the bottom surface.

Abstract: Provided is a method for producing a rail, with which the sweep in the height direction of a rail before straightening can be suppressed when producing standard rails specified in JIS E 1101. The method includes subjecting a bloom having a chemical composition containing, in mass %, C: 0.60% or more and 0.85% or less, Si: 0.10% or more and 1.00% or less, and Mn: 0.10% or more and 1.30% or less, with the balance being Fe and inevitable impurities, to hot rolling to obtain a rail, subjecting the rail to accelerated cooling under conditions where a cooling start temperature T1 of rail head is 750° C. or higher and 850° C. or lower, a cooling stop temperature T2 of rail head is higher than 700 ° C., and T1?T2 is 20 ° C. or more, and then allowing the rail to be naturally cooled.

Abstract: A method for selecting a rail steel and a wheel steel comprising: selecting a rail steel and a wheel steel to be used as a rail and a wheel on an actual track, respectively, the rail steel and the wheel steel having a specific chemical composition, such that the rail comprises a head portion having a yield strength YSR of 830 MPa or more, the wheel comprises a rim portion having a yield strength YSW of 580 MPa or more, and a ratio YSR/YSW of the yield strength YSR at the head portion of the rail to the yield strength YSW at the rim portion of the wheel falls within a range of: 0.85?YSR/YSW?1.95 (1).

Abstract: Proposed are the welding conditions under which welds are always stably formed such that the difference in hardness between flash-butt welds and rail base metal and the deflection in a bending test are in better ranges. A plurality of pieces of rail base metal are joined via welds formed by flash-butt welding, where the rail base metal has a chemical composition containing C: 0.60 to 1.20 mass %, Si: 0.10 to 1.50 mass %, Mn: 0.10 to 1.50 mass %, and Cr: 0.10 to 1.50 mass %, with the balance being Fe and inevitable impurities, and the flash-butt welding is performed with an amount of welding heat input of 1.50×105 kA2×sec or more and 4.50×105 kA2×sec or less.

Abstract: A rail achieves a high 0.2% proof stress after straightening treatment, the high 0.2% proof stress being effective at improving rolling contact fatigue resistance of the rail, by hot rolling a steel raw material to obtain a rail, the steel raw material having a chemical composition containing C: 0.70% to 0.85%, Si: 0.1% to 1.5%, Mn: 0.4% to 1.5%, P: 0.035% or less, S: 0.010% or less, and Cr: 0.05% to 1.50% with the balance being Fe and inevitable impurities; straightening the rail with a load of 50 tf or more; and subsequently subjecting the rail to heat treatment in which the rail is held in a temperature range of 150° C. or more and 400° C. or less for 0.5 hours or more and 10 hours or less.

Abstract: Provided is a rail that is effective in improving wear resistance and rolling contact fatigue (RCF) resistance. The rail has a metallic structure including a pearlitic structure and a structure other than the pearlitic structure in a surface layer from a surface of a rail head to a depth of at least 0.5 mm, where the pearlitic structure has Vickers hardness of 420 HV or more and 520 HV or less, and the structure other than the pearlitic structure has Vickers hardness of 350 HV or more and 420 HV or less.

Abstract: A dust collector includes a housing, a dust collecting bag that is installed in the housing and has an air permeability, a supply section that has a pipe coupled to the dust collecting bag, and supplies a powder into the housing via the pipe, a negative pressure generating section that generates a negative pressure in the housing, and a vibration applying section that applies a vibration to the dust collecting bag. The dust collecting bag includes a top surface, a bottom surface, and a side surface coupling the top surface and the bottom surface with each other, and a vibration transmitted to the top surface is larger than a vibration transmitted to the bottom surface.

Abstract: A rail achieves a high 0.2% proof stress after straightening treatment, the high 0.2% proof stress being effective at improving rolling contact fatigue resistance of the rail, by hot rolling a steel raw material to obtain a rail, the steel raw material having a chemical composition containing C: 0.70% to 0.85%, Si: 0.1% to 1.5%, Mn: 0.4% to 1.5%, P: 0.035% or less, S: 0.010% or less, and Cr: 0.05% to 1.50% with the balance being Fe and inevitable impurities; straightening the rail with a load of 50 tf or more; and subsequently subjecting the rail to heat treatment in which the rail is held in a temperature range of 150° C. or more and 400° C. or less for 0.5 hours or more and 10 hours or less.

Abstract: A rail exhibits a high 0.2% proof stress after shipping, which is effective for improving rolling contact fatigue resistance of the rail, the rail having a chemical composition containing C: 0.70% to 0.85%, Si: 0.1% to 1.5%, Mn: 0.4% to 1.5%, P: 0.035% or less, S: 0.010% or less, and Cr: 0.05% to 1.50%, with the balance being Fe and inevitable impurities, and exhibiting, at least 90 days after a preparation date of a steel material inspection certificate of the rail which describes at least a measurement result of a 0.2% proof stress of a head of the rail, an improvement margin of a 0.2% proof stress of 40 MPa or more, relative to the 0.2% proof stress described in the steel material inspection certificate.

Abstract: A method for manufacturing a railway vehicle wheel is provided. The method comprises: in an electric heating furnace or converter, preparing steel containing, in mass %. 0.65% to 0.84% of C, 0.1% to 1.5% of Si, 0.05% to 1.5% of Mn, 0.025% or less of P, 0.015% or less of S, 0.001% to 0.08% of Al, and 0.05% to 1.5% of Cr, the balance being Fe and incidental impurities; casting the steel to obtain a material; hot rolling and/or hot forging the material to form a wheel; heating the wheel to Ac3 point +50° C. or higher; cooling the wheel from a start temperature of 700° C. or higher to a stop temperature of 500° C. to 650° C. at a rate of 1° C./s to 10° C./s; and then air cooling the wheel.

Abstract: A method for selecting a rail steel and a wheel steel comprising: selecting a rail steel and a wheel steel to be used as a rail and a wheel on an actual track, respectively, the rail steel and the wheel steel having a specific chemical composition, such that the rail comprises a head portion having a yield strength YSR of 830 MPa or more, the wheel comprises a rim portion having a yield strength YSW of 580 MPa or more, and a ratio YSR/YSW of the yield strength YSR at the head portion of the rail to the yield strength YSW at the rim portion of the wheel falls within a range of: 0.85?YSR/YSW?1.95 (1).

Abstract: Provided is high strength steel for springs that, compared to conventional high strength steel for springs, has excellent decarburization resistance and scale exfoliation property, by optimization of the added amounts of C, Si, Mn, and Cr as well as of Sb and Sn. The steel for springs contains C: more than 0.45 mass % and less than 0.65 mass %, Si: 0.15 mass % or more and 0.70 mass % or less, Mn: 0.10 mass % or more and 1.00 mass % or less, Cr: 0.20 mass % or more and 1.50 mass % or less, P: 0.025 mass % or less, S: 0.025 mass % or less, O: 0.0015 mass % or less, Sb: 0.010 mass % or more and less than 0.030 mass %, and Sn: 0.010 mass % or more and 0.030 mass % or less, under predetermined conditions.

Abstract: A method is provided with which a bearing steel, even when obtained from an ingot, is made to have a segregation part reduced in the degree of segregation and maximum inclusion diameter. The ingot contains 0.56-0.70 mass % C, 0.15-0.50 mass %, excluding 0.50 mass %, Si, 0.60-1.50 mass % Mn, 0.50-1.10 mass % Cr, 0.05-0.5 mass % Mo, up to 0.025 mass % P, up to 0.025 mass % S, 0.005-0.500 mass % Al, up to 0.0015 mass % O, and 0.0030-0.015 mass % N, with the remainder comprising Fe and incidental impurities. The ingot has a degree of segregation of 2.8 or less and a predicted value of the maximum diameter of inclusions present in 30,000 mm2 of the ingot, as calculated by extreme value statistics, of 60 ?m or less.

Abstract: Provided is a railway vehicle wheel that enables further reducing wear and fatigue damage of the wheel and rail in total. A railway vehicle wheel containing, in mass %: 0.65% to 0.84% of C; 0.1% to 1.5% of Si; 0.05% to 1.5% of Mn; 0.025% or less of P; 0.015% or less of S; 0.001% to 0.08% of Al; and 0.05% to 1.5% of Cr, the balance being Fe and incidental impurities, wherein a microstructure at least in a region extending from a tread to a depth of 15 mm is a pearlite structure, and a pearlite lamellar spacing at least in the region is 150 nm or less.

Abstract: Disclosed is high strength spring steel that can limit the depth of pitting occurring when corroded and therefore possesses high strength as well as excellent pitting corrosion resistance and corrosion fatigue property, with a composition containing: C: greater than 0.35 mass % and less than 0.50 mass %; Si: greater than 1.75 mass % and less than or equal to 3.00 mass %; Mn: 0.2 mass % to 1.0 mass %; Cr: 0.01 mass % to 0.04 mass %; P: 0.025 mass % or less; S: 0.025 mass % or less; Mo: 0.1 mass % to 1.0 mass %; and O: 0.0015 mass % or less, under a condition that a PC value calculated by PC=4.2×([C]+[Mn])+0.1×(1/[Si]+1/[Mo])+20.3×[Cr]+0.001×(1/[N]) is greater than 3.3 and equal to or less than 8.0. Also disclosed is a preferred method for manufacturing the same.

Abstract: Provided is high strength steel for springs that, compared to conventional high strength steel for springs, has excellent decarburization resistance and scale exfoliation property, by optimization of the added amounts of C, Si, Mn, and Cr as well as of Sb and Sn. The steel for springs contains C: more than 0.45 mass % and less than 0.65 mass %, Si: 0.15 mass % or more and 0.70 mass % or less, Mn: 0.10 mass % or more and 1.00 mass % or less, Cr: 0.20 mass % or more and 1.50 mass % or less, P: 0.025 mass % or less, S: 0.025 mass % or less, O: 0.0015 mass % or less, Sb: 0.010 mass % or more and less than 0.030 mass %, and Sn: 0.010 mass % or more and 0.030 mass % or less, under predetermined conditions.

Abstract: The present invention provides bearing steel, comprising a chemical composition including by mass %, C: 0.56%?[% C]?0.70%, Si: 0.15%?[% Si]<0.50%, Mn: 0.60%?[% Mn]?1.50%, Cr: 0.50%?[% Cr]?1.10%, Mo: 0.05%?[% Mo]?0.5%, P: [% P]?0.025%, S: [% S]?0.025%, Al: 0.005%?[% Al]?0.500%, O: [% O]?0.0015%, N: 0.0030%?[% N]?0.015%, and remainder as Fe and incidental impurities.

Abstract: A pearlite rail contains, by % by mass, 0.70 to 1.0% C, 0.1 to 1.5% Si, 0.01 to 1.5% Mn, 0.001 to 0.035% P, 0.0005 to 0.030% S, and 0.1 to 2.0% Cr by mass with the balance being Fe and inevitable impurities, wherein a ?+? temperature range is 100° C. or lower.

Abstract: A method is provided with which a bearing steel, even when obtained from an ingot, is made to have a segregation part reduced in the degree of segregation and maximum inclusion diameter. The ingot contains 0.56-0.70 mass % C, 0.15-0.50 mass %, excluding 0.50 mass %, Si, 0.60-1.50 mass % Mn, 0.50-1.10 mass % Cr, 0.05-0.5 mass % Mo, up to 0.025 mass % P, up to 0.025 mass % S, 0.005-0.500 mass % Al, up to 0.0015 mass % O, and 0.0030-0.015 mass % N, with the remainder comprising Fe and incidental impurities. The ingot has a degree of segregation of 2.8 or less and a predicted value of the maximum diameter of inclusions present in 30,000 mm2 of the ingot, as calculated by extreme value statistics, of 60 ?m or less.