Abstract: There is provided a hot rolled steel according to one aspect of the invention including, as a predetermined chemical composition: Bi: 0.0001 mass % to 0.0050 mass %, in which 90 area % or more of a metallographic structure is configured with a ferrite and a pearlite, and an average number density of Mn sulfides measured on a cross section parallel to a rolling direction having an aspect ratio of more than 10 and 30 or less which is extended along the rolling direction, is 50 pieces/mm2 to 200 pieces/mm2.

Abstract: To provide a railway wheel which is excellent in corrosion fatigue resistance. The railway wheel according to the present embodiment has a chemical composition consisting of: in mass %, C: 0.65 to 0.80%, Si: 0.10 to 1.0%, Mn: 0.10 to 1.0%, P: not more than 0.030%, S: not more than 0.030%, Cr: 0.05 to 0.20%, Sn: 0.005 to 0.50%, Al: 0.010 to 0.050%, N: 0.0020 to 0.015%, Cu: 0 to 0.20%, Ni: 0 to 0.20%, Mo: 0 to 0.20%, V: 0 to 0.20%, Nb: 0 to 0.030%, and Ti: 0 to 0.030%, with the balance being Fe and impurities. A plate portion has a matrix structure composed of pearlite.

Abstract: A steel for cold forging has a predetermined chemical composition, satisfies d+3??10.0 and SA/SB<0.30, includes 1200/mm2 or more of sulfides having an equivalent circle diameter of 1.0 to 10.0 ?m in a microstructure, and has an average distance between the sulfides of less than 30.0 ?m. Here, d is an average value of equivalent circle diameters of sulfides having an equivalent circle diameter of 1.0 ?m or more, ? is a standard deviation of the equivalent circle diameters of the sulfides having an equivalent circle diameter of 1.0 ?m or more, SA is the number of sulfides having an equivalent circle diameter of 1.0 ?m or more and less than 3.0 ?m, and SB is the number of the sulfides having an equivalent circle diameter of 1.0 ?m or more.

Abstract: There is provided a brake lining for railway vehicle that can reduce brake squeal in braking. A brake lining for railway vehicle is used for a disc brake system of a railway vehicle. This brake lining includes a base plate, a sintered friction material, and a friction material supporting mechanism. The friction material supporting mechanism is disposed between the base plate and the sintered friction material and supports the sintered friction material in such a manner that the sintered friction material can move with respect to the base plate. The sintered friction material has a Young's modulus of 35.0 GPa or more.

Abstract: A crankshaft with improved seizure resistance is provided. A crankshaft includes a journal and a pin, each of the journal and pin having such a surface geometry that the arithmetical mean height of the primary profile, Pa, is 0.090 ?m or smaller and the reduced peak height Rpk is 0.070 ?m or smaller. As used herein, arithmetical mean height of a primary profile Pa is defined in JIS B 0601 (2001), and reduced peak height Rpk is defined in JIS B 0671 (2002).

Abstract: An induction-hardened crankshaft is provided that offers an excellent balance of fatigue strength, machinability and quench-cracking resistance. An induction-hardened crankshaft has a chemical composition of, in mass %: 0.30 to 0.60% C; 0.01 to 1.50% Si; 0.4 to 2.0% Mn; 0.01 to 0.50% Cr; 0.001 to 0.06% Al; 0.001 to 0.02% N; up to 0.03% P; 0.005 to 0.20% S; 0.005 to 0.060% Nb; and balance Fe and impurities, the non-induction-hardened portion having a microstructure mainly composed of ferrite-pearlite and having a fraction of ferrite F? satisfying the expression (1) provided below, the induction-hardened portion having a microstructure mainly composed of martensite or tempered martensite, and having a prior austenite grain diameter not larger than 30 ?m, F??150×[C %]+84 ??(1), where the C content in mass % in the induction-hardened crankshaft is substituted for [C %].

Abstract: A fiber module (1B) according to the present disclosure includes an input-side optical fiber (11), an output-side optical fiber (12), a ferrule (20) in which the input-side optical fiber and the output-side optical fiber are insertable in both ends and a groove (32) is formed in a direction orthogonal to a longitudinal direction (D1) in the middle of the longitudinal direction, a dielectric multilayer film filter (30) inserted in the groove, and an input-side GI fiber (15) and an output-side GI fiber (16) joined by fusion to respective terminal portions of the input-side optical fiber and the output-side optical fiber. The dielectric multilayer film filter is interposed between an end surface (15f) of the input-side GI fiber and an end surface (16f) of the output-side GI fiber in the longitudinal direction.

Abstract: In this steel component, the concentration of C in a surface layer is 0.85 mass % or more to 1.2 mass % or less, which is higher than the concentration of C in a starting material steel, the surface layer has a volume ratio of a retained-austenite structure higher than 0% and lower than 10%, the remainder of the surface layer is a martensitic structure, the area fraction of grain boundary carbides in the surface layer is lower than 2%, a layer inside the surface layer is higher than the surface layer in a volume ratio of a retained-austenite structure, and in the layer inside the surface layer, the remainder is a martensitic structure.

Abstract: There is provided a hot forging steel including, by mass %, C: more than 0.30% and less than 0.60%, Si: 0.10% to 0.90%, Mn: 0.50% to 2.00%, S: 0.010% to 0.100%, Cr: 0.01% to 1.00%, Al: more than 0.005% and 0.100% or less, N: 0.0030% to 0.0200%, Bi: more than 0.0001% and 0.0050% or less, Ti: 0% or more and less than 0.040%, V: 0% to 0.30%, Ca: 0% to 0.0040%, Pb: 0% to 0.40%, and a remainder including Fe and impurities, in which P and O in the impurities are respectively P: 0.050% or less and O: 0.0050% or less, an expression d+3?<20 is satisfied, and a presence density of MnS having an equivalent circle diameter of smaller than 2.0 ?m is 300 pieces/mm2 or more in a cross section parallel to a rolling direction of a steel.

Abstract: To provide a railway wheel which is excellent in corrosion fatigue resistance. The railway wheel according to the present embodiment has a chemical composition consisting of: in mass %, C: 0.65 to 0.80%, Si: 0.10 to 1.0%, Mn: 0.10 to 1.0%, P: not more than 0.030%, S: not more than 0.030%, Cr: 0.05 to 0.20%, Sn: 0.005 to 0.50%, Al: 0.010 to 0.050%, N: 0.0020 to 0.015%, Cu: 0 to 0.20%, Ni: 0 to 0.20%, Mo: 0 to 0.20%, V: 0 to 0.20%, Nb: 0 to 0.030%, and Ti: 0 to 0.030%, with the balance being Fe and impurities. A plate portion has a matrix structure composed of pearlite.

Abstract: Steel for a suspension spring including, as a chemical composition, by % by mass: C: more than 0.40% and 0.65% or less; Si: 1.00% to 3.50%; Mn: more than 2.00% and 3.00% or less; Cr: 0.01% to 2.00%; V: 0.02% to 0.50%; P: 0.020% or less; S: 0.020% or less: N: 0.0100% or less; and a remainder of Fe and impurities, in which Kf is 280 or more, in which a structure contains a tempered martensite of which an area ratio is 90% or more, in which a Fe-based carbide precipitated in the tempered martensite is a cementite, and in which an average of an area ratios of prior austenite grains which stretch in a longitudinal direction of the steel and of which an aspect ratio exceeds 3.0, is 80% or more in a case of depths of 0.1 mm, 0.2 mm, and 0.3 mm in a sheet thickness direction from a surface of the steel.

Abstract: Spring steel includes: as a chemical composition, by mass %, C: 0.40% to 0.60%, Si: 0.90% to 2.50%, Mn: 0.20% to 1.20%, Cr: 0.15% to 2.00%, Ni: 0.10% to 1.00%, Ti: 0.030% to 0.100%, B: 0.0010% to 0.0060%, N: 0.0010% to 0.0070%, Cu: 0% to 0.50%, Mo: 0% to 1.00%, V: 0% to 0.50%, Nb: 0% to 0.10%, P: limited to less than 0.020%, S: limited to less than 0.020%, Al: limited to less than 0.050%, and a remainder including Fe and impurities, in a case where [Ti] represents a Ti content and [N] represents a N content by mass %, the chemical composition satisfies ([Ti]?3.43×[N])>0.03, and a total number density of a Ti carbide and a Ti carbonitride having a diameter of 5 nm to 100 nm is more than 50 piece/?m3.

Abstract: A railway wheel in which formation of pro-eutectoid cementite is suppressed is stably produced. After heating an intermediate product containing, in mass %, C: 0.80 to 1.15% to a temperature not less than Acm transformation point, the intermediate product is cooled such that the cooling rate (° C./sec) in a range from 800 to 500° C. satisfies the following conditions: Surface other than the tread and the flange surface: not more than Fn1 defined by Formula (1), Cooling rate in a region in which cooling rate is slowest: not less than Fn2 defined by Formula (1), and Tread and flange surface: not less than Fn2: Fn1=?5.0+exp(5.651?1.427×C?1.280×Si?0.7723×Mn?1.815×Cr?1.519×Al?7.798×V)??(1) Fn2=0.515+exp(?24.816+24.121×C+1.210×Si+0.529×Mn+2.458×Cr?15.116×Al?5.

Abstract: A steel according to an aspect of the present invention has a chemical composition within a predetermined range, in which a hardenability index Ceq ranges from greater than 7.5 to smaller than 44.0, a metallographic structure includes ferrite ranging from 85 to 100 area %, an average distance between sulfides, which are observed in a cross section parallel to a rolling direction of the steel and have an equivalent circle diameter ranging from 1 ?m or greater to smaller than 2 ?m, is shorter than 30.0 ?m, and a presence density of the sulfides, which are observed in the cross section parallel to the rolling direction of the steel and have an equivalent circle diameter ranging from 1 ?m or greater to smaller than 2 ?m, is 300 pieces/mm2 or more.

Abstract: Provided is a railway wheel capable of suppressing formation of pro-eutectoid cementite even if the C content is high. A railway wheel according to an embodiment of the present invention has a chemical composition consisting of: in mass %, C: 0.80 to 1.15%; Si: 0.45% or less; Mn: 0.10 to 0.85%; P: 0.050% or less; S: 0.030% or less; Al: 0.120 to 0.650%; N: 0.0030 to 0.0200%; Cr: 0 to 0.25%; and V: 0 to 0.12%, with the balance being Fe and impurities, wherein an amount of pro-eutectoid cementite, which is defined by Formula (1), in a microstructure of the railway wheel is not more than 1.50 pieces/100 ?m: Amount of pro-eutectoid cementite (pieces/ 100 ?m)=a total sum of the number of pieces of pro-eutectoid cementite which intersect with two diagonal lines in a square visual field of 200 ?m×200 ?m/(5.

Abstract: A sintered friction material is formed by pressure sintering mixed powder at 800° C. or above, the mixed powder consisting of, in mass %, Cu and/or Cu alloy: 40.0 to 80.0%, Ni: 0% or more and less than 5.0%, Sn: 0 to 10.0%, Zn: 0 to 10.0%, VC: 0.5 to 5.0%, Fe and/or Fe alloy: 2.0 to 40.0%, lubricant: 5.0 to 30.0%, metal oxide and/or metal nitride: 1.5 to 30.0%, and the balance being impurity.

Abstract: There is provided a sintered friction material for railway vehicles that has excellent frictional properties and wear resistance even in a high speed range of 280 km/hour or more. The sintered friction material for railway vehicles is a green compact sintered material containing, in mass %, Cu: 50.0 to 75.0%, graphite: 5.0 to 15.0%, one or more selected from the group consisting of magnesia, zircon sand, silica, zirconia, mullite, and silicon nitride: 1.5 to 15.0%, one or more selected from the group consisting of W and Mo: 3.0 to 30.0%, and one or more selected from the group consisting of ferrochromium, ferrotungsten, ferromolybdenum, and stainless steel: 2.0 to 20.0%, with the balance being impurities.

Abstract: A steel for cold forging has a predetermined chemical composition, satisfies d+3??10.0 and SA/SB<0.30, includes 1200/mm2 or more of sulfides having an equivalent circle diameter of 1.0 to 10.0 ?m in a microstructure, and has an average distance between the sulfides of less than 30.0 ?m. Here, d is an average value of equivalent circle diameters of sulfides having an equivalent circle diameter of 1.0 ?m or more, ? is a standard deviation of the equivalent circle diameters of the sulfides having an equivalent circle diameter of 1.0 ?m or more, SA is the number of sulfides having an equivalent circle diameter of 1.0 ?m or more and less than 3.0 ?m, and SB is the number of the sulfides having an equivalent circle diameter of 1.0 ?m or more.

Abstract: A steel for a carburizing and a carburized steel component having a steel portion and a carburized layer with a thickness of more than 0.4 mm to less than 2 mm which is formed on an outside of the steel portion. A chemical composition of the steel for the carburizing and the steel portion of the carburized steel component satisfies simultaneously equations of a hardness parameter, a hardenability parameter, and a TiC precipitation parameter.

Abstract: A steel for a carburizing and a carburized steel component having a steel portion and a carburized layer with a thickness of more than 0.4 mm to less than 2 mm which is formed on an outside of the steel portion. A chemical composition of the steel for the carburizing and the steel portion of the carburized steel component satisfies simultaneously equations of a hardness parameter, a hardenability parameter, and an AlN precipitation parameter.