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 method for producing a bearing ring of a double row tapered roller bearing includes the steps of: preparing a formed body; forming a heated region; cooing; and removing. In the step of forming a heated region, an induction heating coil arranged to face part of the groove and induction-heating the fixated body is relatively rotated along the circumferential direction of the groove to form a heated region including the bottom surface of the groove and heated to a temperature of at least an A.sub.l point. In the cooling step, the whole of the heated region is simultaneously cooled to a temperature of not more than an M.sub.s point. After the step of forming a heated region before the step of cooling, the method further includes the step of retaining the formed body in a state where heating is stopped.

A bearing component composed of steel which contains carbon not less than 0.95 mass % and not more than 1.1 mass %, silicon less than 0.3 mass %, manganese less than 0.5 mass %, sulfur less than 0.008 mass %, and chromium not less than 1.4 mass % and less than 1.6 mass % and is composed of remainder iron and an impurity and having a carbonitrided layer formed at a surface portion is provided. An average concentration of nitrogen in the surface portion is not lower than 0.3 mass % and not higher than 0.6 mass % and variation in nitrogen concentration is not higher than 0.1 mass %. An amount of retained austenite is not greater than 8 volume %. An area ratio of a precipitate in the inside where no carbonitrided layer is formed is not lower than 11%.

A bearing constituent member includes a base material including steel and a carbonitrided layer that is a surface layer on the steel, the steel including 0.3 to 0.45 mass % of carbon, 0.5 mass % or lower of silicon, 0.4 to 1.5 mass % of manganese, 0.3 to 2 mass % of chromium, 0.1 to 0.35 mass % of molybdenum, 0.2 to 0.4 mass % of vanadium, and a remainder of iron and unavoidable impurities. Surface Vickers hardness at a position at a depth of 50 m from a surface of a rolling sliding surface is 700 to 800, internal hardness is 550 to 690 in terms of Vickers hardness, and an amount of residual austenite in a range from the surface to a depth of 10 m is at least 30 vol %.

A steel alloy for bearings contains: 0.6 to 0.9 wt. % carbon, 0.1 to 0.5 wt. % silicon, 0.1 to 1.5 wt. % manganese, 1.5 to 2.0 wt. % chromium, 0.2 to 0.6 wt. % molybdenum, 0 to 0.25 wt. % nickel, 0 to 0.3 wt. % copper, 0 to 0.2 wt. % vanadium, 0 to 0.2 wt. % cobalt, 0 to 0.2 wt. % aluminium, 0 to 0.1 wt. % niobium, 0 to 0.2 wt. % tantalum, 0 to 0.05 wt. % phosphorous, 0 to 0.03 wt. % sulphur, 0 to 0.075 wt. % tin, 0 to 0.075 wt. % antimony, 0 to 0.075 wt. % arsenic, 0 to 0.01 wt. % lead, up to 350 ppm nitrogen, up to 100 ppm oxygen, up to 50 ppm calcium, up to 50 ppm boron, up to 50 ppm titanium, the balance being iron, together with any other unavoidable impurities. Furthermore, the steel alloy contains (i) molybdenum and silicon in a weight ratio of 0.4<Mo/Si<6.0 and (ii) molybdenum and chromium in a weight ratio of 0.1<Mo/Cr<0.4.

A near-eutectoid bearing steel having from 0.7 to 0.9 wt. % carbon, from 0.1 to 0.35 wt. % silicon, from 0.7 to 1.2 wt. % manganese, from 1.0 to 2.0 wt. % chromium, from 0.1 to 0.35 wt. % molybdenum, from 0.2 to 0.6 wt. % nickel, from 0.4 to 1.2 wt. % copper, from 0 to 0.15 wt. % vanadium, from 0 to 0.15 wt. % niobium, from 0 to 0.15 wt. % tantalum, from 0 to 0.2 wt. % cobalt, from 0 to 0.1 wt. % aluminum, from 0 to 0.05 wt. % phosphorous, from 0 to 0.03 wt. % sulphur, from 0 to 0.075 wt. % tin, from 0 to 0.075 wt. % antimony, from 0 to 0.04 wt. % arsenic, from 0 to 0.01 wt. % lead, up to 350 ppm nitrogen, up to 100 ppm oxygen, up to 50 ppm calcium, up to 50 ppm boron, up to 50 ppm titanium, the balance iron, together with any other unavoidable impurities.

There is provided a rolling bearing capable of suppressing the occurrence of white structure spalling. A rolling bearing contains a structure having a solid solution carbon amount in a martensitic structure after heat treatment of 0.35 mass % or more and 0.65 mass % or less and a volume ratio of spheroidized carbides having a diameter of 200 nm or more of 4.5% or less.

A steel alloy comprising from: (a) 0.6 to 0.9 wt. % carbon, (b) 0.1 to 0.5 wt. % silicon, (c) 0.1 to 1.5 wt. % manganese, (d) 1.5 to 2.0 wt. % chromium, (e) 0.2 to 0.6 wt. % molybdenum, and up to: (f) 0.25 wt. % nickel, (g) 0.3 wt. % copper, (h) 0.2 wt. % vanadium, (i) 0.2 wt. % cobalt, (j) 0.2 wt. % aluminum, (k) 0.1 wt. % niobium, (l) 0.2 wt. % tantalum, (m) 0.05 wt. % phosphorous, (n) 0.03 wt. % sulphur, (o) 0.075 wt. % tin, (p) 0.075 wt. % antimony, (q) 0.075 wt. % arsenic, (r) 0.01 wt. % lead, (s) 350 ppm nitrogen, (t) 100 ppm oxygen, (u) 50 ppm calcium, (v) 50 ppm boron, (w) 50 ppm titanium, the balance iron, including any other unavoidable impurities, wherein the alloy comprises molybdenum and silicon in a weight ratio of 0.4Mo/Si6.0 and comprises molybdenum and chromium in a weight ratio of 0.1Mo/Cr0.4.

A retainer (30) for maintaining a relative angular spacing of a plurality of rolling elements includes a body (34) having an annular portion (38) and a plurality of engaging portions (42). Each of the engaging portions is configured to engage at least one of the plurality of rolling elements. The body is made of a sintered powdered metal infiltrated with bronze.

A bearing component including a first metallic material and a second metallic material. The first metallic material provides a first carbon content and the second metallic material presents a second carbon content. The first metallic material and the second metallic material have been joined by a diffusion welding process. The diffusion welding process results in a transition zone with a varying carbon content between the first metallic material and the second metallic material. Varying carbon content in the transition zone is within an interval and the interval end points are defined by the carbon contents of the first metallic material and the second metallic material.