A steel alloy for a bearing, the alloy having a composition that provides: from 0.8 to 1.0 wt. % carbon, from 0.1 to 0.5 wt. % silicon, from 0.2 to 0.9 wt. % manganese, from 2.0 to 3.3 wt. % chromium, from 0 to 0.4 wt. % molybdenum, from 0 to 0.2 wt. % cobalt, from 0 to 0.2 wt. % iridium, from 0 to 0.2 wt. % rhenium, from 0 to 0.2 wt. % vanadium, from 0 to 0.1 wt. % niobium, from 0 to 0.5 wt. % tungsten, from 0 to 0.2 wt. % nickel, from 0 to 0.4 wt. % copper, from 0 to 0.05 wt. % aluminum, from 0 to 150 ppm nitrogen, and the balance iron, together with any unavoidable impurities.

A method for producing a case-hardened martensitic stainless steel article includes: providing an article comprised, at least in part, of a martensitic stainless steel, carburizing the article within a temperature range of 1625° F.-1680° F. (885° C.-916° C.), and then carbo-nitriding the article within a temperature range of 1575° F.-1625° F. (857° C.-885° C.). An article, such as a bearing ring, comprising such a case-hardened martensitic stainless steel is also disclosed.

A bearing component formed from a steel alloy having from 0.7 to 0.9 wt. % carbon, from 0.05 to 0.16 wt. % silicon, from 0.7 to 0.9 wt. % manganese, from 1.4 to 2.0 wt. % chromium, from 0.7 to 1.0 wt. % molybdenum, from 0.03 to 0.15 wt. % vanadium, from 0 to 0.25 wt. % nickel, from 0 to 0.3 wt. % copper, from 0 to 0.2 wt. % cobalt, from 0 to 0.1 wt. % aluminum, from 0 to 0.1 wt. % niobium, from 0 to 0.2 wt. % tantalum, from 0 to 0.025 wt. % phosphorous, from 0 to 0.015 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 0.002 wt. % lead, up to 350 ppm nitrogen, up to 20 ppm oxygen, up to 50 ppm calcium, up to 30 ppm boron, up to 50 ppm titanium, the balance iron, together with any unavoidable impurities.

A method of manufacturing a slide of a variable oil pump for a vehicle includes preparing a molded body for a slide of a variable oil pump using prealloy powder including, in percent (%) by weight of the entire composition, 0.45 to 0.55% of carbon (C), 2.8 to 3.2% of chromium (Cr), 0.45 to 0.55% of molybdenum (Mo), 0.35 to 0.5% of manganese (Mn), 0.1 to 0.25% of sulfur (S), and the remainder of iron (Fe) and inevitable impurities. A sintered body is prepared by sintering the molded body. The sintered body is slowly cooled such that a temperature of the sintered body reaches a first temperature range and rapidly cooled when the first temperature range is reached.

The invention relates to a crankshaft (1) for a reciprocating piston internal combustion engine having at least two main bearings (2) a crank pin (3). Crankshaft flanges (4) are arranged between each of the main bearings and the crank pin and connect the main bearings to the crank pin. The crankshaft has at least one ring gear (5) spaced apart axially from a main bearing for a drive of a chain drive. A crankshaft surface between the main bearing and the first ring gear has an averaged roughness depth R z of less than 3 micrometres. Due to the configuration of the crankshaft according to the invention for a reciprocating piston internal combustion engine, higher torsional moments can be transmitted or the crankshaft can be designed to be lighter in the area having the higher surface quality.

An annular ring having a contact portion, a raceway and a squirrel-type cage secured to the contact portion. The contact portion is formed from a first metal material, and the squirrel cage is formed from a second composite-type material including a matrix in which reinforcing fibres are embedded, the pierced portion of the squirrel cage being attached to an outer surface of the contact portion. Also, a bearing assembly with rolling elements having an outer ring, an inner ring coaxial with the outer ring, and a plurality of rolling elements housed between the raceway of the contact portion of the outer ring and a raceway of the inner ring.

The invention relates to the technical field of microstructure refinement and homogenization of bearing steel, and specifically relates to a high-carbon bearing steel and a method of preparing same. The high-carbon bearing steel of the invention has the following chemical composition: C: 0.80˜1.20 wt %, Cr: 0.40˜2.0 wt %, Mn: 0.15˜0.75 wt %, Si: 0.15˜0.75 wt %, Nb: 0˜0.20 wt %, Mo: 0˜0.20 wt %, V: 0˜0.20 wt %, P≤0.015 wt %, S≤0.01 wt %, the remaining is Fe and unavoidable impurities; the contents of Nb, Mo and V are not 0 at the same time. According to the invention, microalloying elements such as Nb, Mo and V, in combination with other elements, are added into the high-carbon bearing steel to effectively refine the bearing steel matrix and promote the precipitation of a large amount of nano-carbides, thereby enhancing the contact fatigue life of the high-carbon bearing steel.

A bearing component composed of a chromium-molybdenum-vanadium alloyed tool steel is produced by a process that includes: (i) performing a first preheating within a temperature range of 600-650° C., (ii) performing a second preheating within a temperature range of 850-900° C., (iii) austenitizing in vacuum at 1000-1180° C. for 20-40 min, (iv) gas quenching at a minimum of 4-5 bar overpressure, and (v) tempering by performing either a double temper at 520-560° C. for 1.5-2.5 hours in each temper, or a triple temper at 520-560° C. for 0.5-1.5 hours in each temper. The steel alloy may be composed (in mass percent) of 1.32-1.45 C, 0.32-0.50 Si, 0.26-0.48 Mn, 4.0-4.85 Cr, 3.35-3.55 Mo, 3.55-3.85 V, 0-0.13 W, 0-0.20 Ni, 0-0.15 Cu, 0-0.8 Co, 0-0.03 P, and 0-0.03 S, the balance being iron and unavoidable impurities. Mo may be replaced with W or vice versa in a replacement ratio Mo:W of 1:2.

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 layer≤equivalent diameter of rolling sliding member×1.4×10.sup.−3.

A blood flow assist system can include an impeller assembly including an impeller shaft and an impeller on the impeller shaft, a primary flow pathway disposed along an exterior surface of the impeller. The system can include a rotor assembly at a proximal portion of the impeller shaft. A secondary flow pathway can be disposed along a lumen of the impeller shaft. During operation of the blood flow assist system, blood can be pumped proximally along the primary flow pathway and the secondary flow pathway. The system can include a sleeve bearing distal the impeller. The system can include a drive unit having a distal end disposed distal a proximal end of the second impeller. The drive unit comprising a drive magnet and a drive bearing between the drive magnet and the impeller assembly.