A crankshaft with improved fatigue strength is provided. A crankshaft 10 includes journals 11, pins 12, and fillets 14, each fillet 14 having a residual stress distribution where the residual stresses are compressive residual stresses from the surface down to a depth of at least 300 m, the maximum value of the compressive residual stress being not lower than 1000 MPa, the surface roughness Rz being lower than 3.00 m.

A drive shaft includes a first annular wall and a second annular wall joined together via a friction-welded portion. The first annular wall and the second annular wall have outer diameters of 30 to 50 mm and wall thicknesses of 3 to 5 mm. A burr created at the friction-welded portion has a connection radius of greater than or equal to 0.5 mm, a base radius of greater than or equal to 0.5 mm, a burr base angle of less than or equal to 40?, and a burr slope length of 0.2 to 5 mm.

An inner-flanged bushing for a hydraulic breaker is a tubular shape having an inner flange and is made of a steel containing at least 0.55% and less than 0.70% by mass of carbon, at least 0.15% and less than 0.35% by mass of silicon, at least 0.4% and less than 0.9% by mass of manganese, at least 0.4% and less than 1.3% by mass of chromium, and at least 0.10% and less than 0.55% by mass of molybdenum, with the balance being iron and unavoidable impurities. The bushing includes a base region having a hardness of at least 30 HRC and less than 45 HRC, and a quench hardened layer formed on an inner periphery side of the base region to include an inner peripheral surface of a region including the inner flange, the quench hardened layer having a hardness of at least 55 HRC and less than 63 HRC.

An improved railway car axle has a generally hollow cylindrical elongated body. The axle includes a journal near either end adapted to receive a bearing, and a dust guard adjacent the journals. A wheel seat is adjacent the dust guard and is adapted to receive a railway wheel thereon. The axial center interior portion of the railway axle is generally hollow. The railway axle is comprised of a steel with specified alloy range, mechanical properties and is of specified internal and external dimensions to allow the axle to be formed in a forging operation and to be utilized in heavy haul railway freight car service.

A bearing bushing for a track has an annular shape including an inner peripheral surface, an outer peripheral surface, a first end face, and a second end face located axially opposite the first end face. The bearing bushing for a track includes an inner peripheral surface-side hardened layer formed to include the inner peripheral surface, an outer peripheral surface-side hardened layer formed to include the outer peripheral surface, a first end face-side hardened layer formed to include the first end face and having a region with a hardness of 63 HRC or more that has a thickness of 3 mm or more from the first end face, and an unhardened region lower in hardness than the inner peripheral surface-side hardened layer, the outer peripheral surface-side hardened layer, and the first end face-side hardened layer, and including at least the second end face. The bearing bushing is made of steel.

A bearing steel according to an embodiment of the present disclosure includes, as a chemical composition: 0.51 to 0.56 wt % of carbon (C); 0.30 to 0.55 wt % of silicon (Si); 0.60 to 0.90 wt % of manganese (Mn); 0.025 wt % or less (excluding 0 wt %) of phosphorus (P); 0.008 wt % or less (excluding 0 wt %) of sulfur (S); 0.01 to 0.20 wt % of chromium (Cr); 0.08 wt % or less (excluding 0 wt %) of molybdenum (Mo); 0.25 wt % or less (excluding 0 wt %) of nickel (Ni); 0.01 to 0.20 wt % of vanadium (V); 0.20 wt % or less (excluding 0 wt %) of copper (Cu); 0.003 wt % or less (excluding 0 wt %) of titanium (Ti); 0.01 to 0.05 wt % of aluminum (Al); 0.0015 wt % or less (excluding 0 wt %) of oxygen (O); 0.001 wt % or less (excluding 0 wt %) of calcium (Ca); and iron (Fe) and unavoidable impurities as a remainder.

A rolling-sliding member that is high in hardness and continues to have a passivation film reliably even after being subjected to a process that does not require any processing for removal of scale etc., as well as a rolling bearing using the same and a method for manufacturing the rolling-sliding member.

A non-heat treated steel for a crankshaft of the present invention comprises iron (Fe) as a main component and also comprises 0.37 to 0.43 mass % of carbon (C), 0.15 to 0.35 mass % of silicon (Si), 0.90 to 1.30 mass % of manganese (Mn), 0.08 to 0.15 mass % of vanadium (V); and the content of phosphorous (P) is 0.030 mass % or less, the content of copper (Cu) is 0.300 mass % or less, the content of nickel (Ni) is 0.30 mass % or less, and the content of chromium (Cr) is 0.35 mass % or less.

The non-heat treated steel also comprises 0.010 to 0.035 mass % of sulfur (S) and 0.02 to 0.05 mass % of bismuth (Bi), which are machinability-improving elements. Thus, the non-heat treated steel has a high fatigue strength and a high yield strength and also has an excellent machinability.

A method for manufacturing a rolling or plain bearing ring includes providing a metallic ring member and applying a load carrying surface onto the metallic ring member by use of a steel wire Directed Energy Deposition (DED) operation and/or a steel metal powder DED operation. Preferably, the steel wire and/or the steel metal powder includes 0.10-0.50 wt % of carbon and 0.50-1.20 wt % of boron.

A rolling sliding member includes a base part and a surface layer. The base part has a composition that includes 0.30 mass % to 0.45 mass % of carbon, 0.15 mass % to 0.45 mass % of silicon, 0.40 to 1.50 mass % of manganese, 0.60 mass % to 2.00 mass % of chromium, 0.10 mass % to 0.35 mass % of molybdenum, 0.20 mass % to 0.40 mass % of vanadium, and 0.005 mass % to 0.100 mass % of aluminum, and a remainder of iron and inevitable impurities. The surface layer is positioned around the base part. The surface layer has a Vickers hardness of 700 to 800 and a retained austenite content of 25 volume % to 50 volume %. The thickness of a grain boundary oxide layer satisfies Formula: thickness of grain boundary oxide layerequivalent diameter of rolling sliding member1.410.sup.3.