Abstract: A bearing for alternators and a bearing for pulleys for reducing hydrogen embrittlement or cracking is used when the bearing is in an environment having a severe condition, such as, when hydrogen is generated from grease or the like. The bearing includes a rolling element, an inner ring and an outer ring, and at least one of the rolling element, where the inner and outer rings have a nitrogen enriched layer containing austenite crystal grains having a grain size number exceeding 10.

Abstract: A gas supply device includes a first flow channel connecting a heat-treating furnace and a power generation device, a pressure control valve arranged in the first flow channel for controlling a pressure of exhaust gas flowing through the first flow channel, and a furnace pressure gauge measuring a pressure within the heat-treating furnace. If the pressure within the heat-treating furnace measured by the furnace pressure gauge becomes lower than a predetermined value, the pressure control valve controls the pressure of the exhaust gas to increase the pressure of the exhaust gas within the first flow channel.

Abstract: Disclosed is a method for heat-treating a ring-shaped member, which makes it possible to form a quench-hardened region having a uniform annular shape in the circumferential direction, while the production costs in terms of the quenching apparatus are kept down. The method includes the following steps: a step in which a coil which is disposed in such a way as to face a rolling contact surface of a ring-shaped formed body made of steel and which performs induction heating of the formed body is rotated relative to the formed body in the circumferential direction thereof, whereby an annular heating region which is heated to a temperature at or above an A1 point is formed on the formed body; and a step in which the whole of the heating region is simultaneously cooled to a temperature at or below an MS point.

Abstract: A method of restrained-quenching of an annular member, that can readily ensure a sufficient effect of restraint, increase treatment efficiency of a quench hardening treatment, and suppress production cost of the annular member, includes a heating step, a first cooling step, a restraint step, and a second cooling step. In the heating step, a bearing ring formed as the annular member is heated to a temperature not lower than an A1 point. In the first cooling step, the bearing ring is cooled to a first cooling temperature not higher than an MS point. In the restraint step, the bearing ring is restrained with a restraint member. In the second cooling step, the bearing ring is cooled to a second cooling temperature lower than a restraint start temperature while it remains restrained.

Abstract: A carbonitriding method that can improve the nitrogen permeating rate to render the carbonitriding process effective is directed to carbonitriding a workpiece formed of steel that contains at least 0.8 mass % of carbon by heating in an atmosphere including ammonia, carbon monoxide, carbon dioxide and hydrogen. The method includes an atmosphere control step, and a heating pattern control step. The atmosphere control step includes an undecomposed NH3 partial pressure control step, a CO/CO2 partial pressure control step, and an H2 partial pressure control step. The undecomposed NH3 partial pressure control step, the CO/CO2 partial pressure control step and the H2 partial pressure control step are carried out such that the partial pressure of hydrogen in the heat treatment furnace is at least 0.1 atmospheric pressure and not more than 0.3 atmospheric pressure, and ? defined by the following equation (1) is at least 2.0 and not more than 6.0, in the atmosphere control step.

Abstract: A bearing part having long life against rolling contact fatigue, excellent in anti-crack strength and restricted in an increase of aged dimensional change, a heat treatment method thereof, and a rolling bearing including the bearing part are obtained. Steel for a bearing part is subjected to carbonitriding at a carbonitriding temperature exceeding the A1 transformation temperature, and cooled to a temperature lower than the A1 transformation temperature. The steel is reheated to a temperature for quenching that is not lower than the A1 transformation temperature but lower than the carbonitriding temperature, and then quenched.

Abstract: An outer ring, an inner ring and a ball serving as mechanical components configuring a deep groove ball bearing are formed of steel containing at least 0.77 mass % and not more than 0.85 mass % of carbon, at least 0.01 mass % and not more than 0.25 mass % of silicon, at least 0.01 mass % and not more than 0.35 mass % of manganese, at least 0.01 mass % and not more than 0.15 mass % of nickel, at least 3.75 mass % and not more than 4.25 mass % of chromium, at least 4 mass % and not more than 4.5 mass % of molybdenum and at least 0.9 mass % and not more than 1.1 mass % of vanadium with a remainder consisting of iron and impurity, and have raceway/rolling contact surfaces, the surface being included in a region having a nitrogen enriched layer having a nitrogen concentration of at least 0.05 mass %, the nitrogen enriched layer having a carbon concentration and the nitrogen concentration, in total, of at least 0.82 mass % and not more than 1.9 mass %.

Abstract: Obtain a bearing's component, a heat treatment method thereof, and a rolling bearing having a long life against rolling contact fatigue and high anti-crack strength, and suppressed long-term dimensional variation rate. The bearing's component is carbonitrided at a carbonitriding temperature higher than an A1 transformation point of steel for the bearing's component and then cooled to a temperature lower than the A1 transformation point, and subsequently, using a heat treatment apparatus that successively moves and heats each individual bearing's component, reheated to a range of quenching temperature of no less than the A1 transformation point and less than the carbonitriding temperature to be quenched.

Abstract: An outer ring, an inner ring and a ball serving as mechanical components configuring a deep groove ball bearing are formed of steel containing at least 0.77 mass % and not more than 0.85 mass % of carbon, at least 0.01 mass % and not more than 0.25 mass % of silicon, at least 0.01 mass % and not more than 0.35 mass % of manganese, at least 0.01 mass % and not more than 0.15 mass % of nickel, at least 3.75 mass % and not more than 4.25 mass % of chromium, at least 4 mass % and not more than 4.5 mass % of molybdenum and at least 0.9 mass % and not more than 1.1 mass % of vanadium with a remainder consisting of iron and impurity, and have raceway/rolling contact surfaces, the surface being included in a region having a nitrogen enriched layer having a nitrogen concentration of at least 0.05 mass %, the nitrogen enriched layer having a carbon concentration and the nitrogen concentration, in total, of at least 0.82 mass % and not more than 1.9 mass %.

Abstract: A bearing for alternators and a bearing for pulleys for reducing hydrogen embrittlement or cracking is used when the bearing is in an environment having a severe condition, such as, when hydrogen is generated from grease or the like. The bearing includes a rolling element, an inner ring and an outer ring, and at least one of the rolling element, where the inner and outer rings have a nitrogen enriched layer containing austenite crystal grains having a grain size number exceeding 10.

Abstract: A heat treatment furnace that allows the atmosphere in the heat treatment furnace to be controlled with favorable accuracy includes a second heating zone identified as a reaction chamber, having a floor belt to hold a workpiece, and an atmosphere collect pipe having an opening in the second heating zone to collect an atmosphere in the second heating zone through the opening. The atmosphere collect pipe is installed to allow the distance between the opening and the floor belt to be modified.

Abstract: A bearing for alternators and a bearing for pulleys for reducing hydrogen embrittlement or cracking is used when the bearing is in an environment having a severe condition, such as, when hydrogen is generated from grease or the like. The bearing includes a rolling element, an inner ring and an outer ring, and at least one of the rolling element, where the inner and outer rings have a nitrogen enriched layer containing austenite crystal grains having a grain size number exceeding 10.

Abstract: A carbonitriding method that can improve the nitrogen permeating rate to render the carbonitriding process effective includes an atmosphere control step (50), and a heating pattern control step (60). The atmosphere control step (50) includes an undecomposed NH3 partial pressure control step (51), and a CO/CO2 partial pressure control step (53). The undecomposed NH3 partial pressure control step (51) and the CO/CO2 partial pressure control step (53) are carried out in the atmosphere control step (50) such that ac* defined by the following equation (1) is at least 0.88 and not more than 1.27, and ? defined by equation (2) is at least 0.012 and not more than 0.

Abstract: A rolling bearing (10) having an outer ring (1), an inner ring (2), and a plurality of rolling elements, wherein at least one of the members, the outer ring (1), inner ring (2) and rolling elements (3), has a nitrogen rich layer and the grain size number of austenite crystal grains is in the range exceeding the number 10.

Abstract: A transmission component is incorporated into a transmission in which an input shaft, an output shaft, or a gear is rotatably supported by a rolling bearing. The component has a nitriding layer at a surface layer and an austenite grain with a grain size number falling within a range exceeding 10. This provides a transmission component having an increased anti-crack strength, enhanced dimensional stability, and a long fatigue life. A method of manufacturing such a transmission component and a tapered roller bearing are also provided.

Abstract: There is provided a rolling bearing which has long life against rolling fatigue and exhibits no decrease in fracture strength and no increase in rate of dimensional change over time, even if the part size thereof is large, and which can obtain higher strength by crystal grains being further refined, if it has a size equal to or smaller than a prescribed size. The rolling bearing according to the present invention includes a race and a rolling element. At least one member of the race and the rolling element has a nitrogen-enriched layer in its surface layer, and a surface layer portion contains austenite crystal grains having a grain size number of at least 11. The member has hardenability allowing a position exhibiting HRC50 in a hardenability test method for steel to be apart from a quenched end by a distance of at least 12.7 mm ( 8/16 inch).

Abstract: A method of restrained-quenching of an annular member, that can readily ensure a sufficient effect of restraint, increase treatment efficiency of a quench hardening treatment, and suppress production cost of the annular member, includes a heating step, a first cooling step, a restraint step, and a second cooling step. In the heating step, a bearing ring formed as the annular member is heated to a temperature not lower than an A1 point. In the first cooling step, the bearing ring is cooled to a first cooling temperature not higher than an MS point. In the restraint step, the bearing ring is restrained with a restraint member. In the second cooling step, the bearing ring is cooled to a second cooling temperature lower than a restraint start temperature while it remains restrained.

Abstract: An outer ring and an inner ring of a rolling bearing are constituted of steel containing 0.77 to 0.85% of carbon, 0.01 to 0.25% of silicon, 0.01 to 0.35% of manganese, 0.01 to 0.15% of nickel, 3.75 to 4.25% of chromium, 4 to 4.5% of molybdenum and 0.9 to 1.1% of vanadium with the rest consisting of iron and impurities, a nitrogen-enriched layer having a nitrogen concentration of at least 0.05 mass % is formed on a region including a rolling surface, and the total of a carbon concentration and the nitrogen concentration in the nitrogen-enriched layer is at least 0.82 mass % and not more than 1.9 mass %. A DLC coating layer is arranged on a region including an outer ring contact surface.

Abstract: A compressor component incorporated into a compressor having a compressor body and a compressor pulley mechanism transmitting a driving force to the compressor body has an austenite grain with a grain size number falling within a range exceeding 10, a fracture stress value of at least 2650 MPa, or a hydrogen content of at most 0.5 ppm. This provides a compressor component and a compressor bearing with a long fatigue life, a high anti-crack strength, and a reduced secular dimensional variation.

Abstract: A carbonitriding method that allows the permeating rate of nitrogen to be increased to improve the efficiency of the carbonitriding process is directed to carbonitriding a workpiece formed of steel containing at least 0.8 mass % of carbon, including an atmosphere control step of controlling the atmosphere in a heat treatment furnace, and a heating pattern control step of controlling the temperature history applied to a workpiece. The atmosphere control step includes an undecomposed ammonia concentration control step of controlling the undecomposed ammonia concentration in the heat treatment furnace, and a partial pressure control step of controlling the partial pressure of at least one of carbon monoxide and carbon dioxide in the heat treatment furnace.