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.

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.

Provided is a sliding member including: a back-metal layer and a sliding layer including a copper alloy. The back-metal layer includes a hypoeutectoid steel including 0.07 to 0.35 mass % of carbon and has a structure including a ferrite phase and pearlite. The back-metal layer has a high ferrite phase portion at a bonding surface between the back-metal layer and the sliding layer. A volume ratio Pc and a volume ratio Ps satisfy Ps/Pc0.4, where the volume ratio Pc is a volume ratio of pearlite in the structure at a center portion in a thickness direction of the back-metal layer, and the volume ratio Ps is a volume ratio of pearlite in the high ferrite phase portion.

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.

Provided is a large crankshaft comprising a pin fillet portion, wherein: an average initial compression stress in a surface layer region from a surface of the pin fillet portion to a depth of 500 m is 500 Mpa or more; an average Vickers hardness of the surface of the pin fillet portion is 600 or more; an arithmetic average roughness Ra of the surface of the pin fillet portion is 1.0 m or less; and an average prior austenite grain size of a metallographic structure is 100 m or less. The large crankshaft has composition comprising C: 0.2% by mass to 0.4% by mass, Si: 0% by mass to 1.0% by mass, Mn: 0.2% by mass to 2.0% by mass, Al: 0.005% by mass to 0.1% by mass, N: 0.001% by mass to 0.02% by mass, and a balance being Fe and inevitable impurities.

A fine grain steel alloy and automotive components produced therefrom are provided. The fine grain steel alloy includes iron, about 0.20 to about 0.60 weight percent carbon, about 1.80 to about 2.50 weight percent manganese, about 0.20 to about 1.20 weight percent silicon, and about 0.10 to about 0.25 weight percent of a transition metal, where the transition metal is vanadium, niobium, or a combination of vanadium and niobium. The fine grain steel alloy may also include about 0.60 to about 1.50 weight percent chromium, about 0.01 to about 0.20 weight percent aluminum, and about 0.01 to about 0.20 weight percent titanium.

This steel material for bearings includes prescribed components in the steel, the oxide inclusions in the steel that have a minor axis of 1 m or greater satisfying the following conditions (1) and (2). (1) The average composition contains specific respective amounts of CaO, Al.sub.2O.sub.3, SiO.sub.2, and TiO.sub.2, and CaO+Al.sub.2O.sub.3+SiO.sub.2+TiO.sub.260%. (2) The proportion of oxide inclusions in which TiN occurs at the interface of the oxide inclusions and the steel is 30% or more of the total of the oxide inclusions.

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.