摘要:
A rolling bearing includes a rolling element made of a steel containing 0.9 to 1.1 wt. % C, 0.1 to 0.5 wt. % Si, 0.2 to 0.8 wt. % Mn, 1.0 to 1.8 wt. % Cr, with the balance being Fe and inevitable impurities. In the rolling bearing at least the surface of the rolling element includes carbides having an area fraction of 5% to 15%; of these carbides, carbides having an averaged particle diameter of 0.5 .mu.m or more share 50% or more of the area fraction of all the carbides; and of the carbides, carbides having an averaged particle diameter of 1 .mu.m or more share 2% or less of the area fraction of all the carbides; and wherein the rolling element has at least a Vickers surface hardness HV of 750 to 900.
摘要:
At least one of the components of a rolling member used in a manner in which it is rolled or slid with a mated member is made of carbon steel containing 0.8%-0.9% by weight of C, 0.1%-0.7% by weight of Si, 0.5%-1.1% by weight of Mn, and 0.1%-0.6% by weight of Cr and Fe substantially in the remaining part, wherein an ideal critical diameter DI value calculated from the compositions is 1.5-4.0, and the retained austenite amount after hardened heat treatment is 8%-22% by volume. The value DI is determined by the following equation:DI=(0.311.times.C %.sup.0.498).times.(0.7.times.Si %+1).times.(3.33.times.Mn %+1).times.(2.16.times.Cr %+1)
摘要:
A rolling bearing has components of an inner race, an outer race and rolling elements, one of the components being formed of an alloy steel containing 0.1-1.0 wt % of C, 0.1-1.5 wt % of Si, 0.1-1.5 wt % of Mn and 0.1-3.0 wt % of Cr, the alloy steel being carbonitrided and then ground to form a surface layer having a carbon and a nitrogen concentration of 0.6-1.5 wt % and 0.05-0.9 wt %, respectively. The surface layer has an appropriate amount of retained austenite .gamma..sub.R and is sufficiently hard to insure long life even under lubrication in the presence of foreign matter. By optimizing the choice of constituent materials, processing methods and heat treatments for each of the rolling elements and the inner and outer races, rolling bearings that have high performance can be produced at low cost.
摘要:
In manufacturing a rolling bearing, at least one component of an inner ring, an outer ring, and a rolling element is manufactured from an alloy steel comprising 0.05 weight %-0.5 weight % carbon, 0.5 weight %-18 weight % chromium, 1.5 weight % or less silicon, 5 weight % or less molybdenum, 4.0 weight % or less vanadium, 4 weight % or less nickel, and 8 weight % or less tungsten, by subjecting the alloy steel to carburizing, hardening and tempering. The carburizing is carried out by vacuum carburization. In the vacuum carburization, carburizing and diffusion are carried out by introducing an acetylene-based carburizing gas in a hot atmosphere under reduced pressure, followed by hardening and tempering. The use of the vacuum carburization enables carburization with the chromium (Cr) content being 3.0 weight % or more, and even up to 18 weight %, which was difficult to achieve with the conventional gas carburization (pre-oxidation+gas carburizing).
摘要:
A rolling bearing contains no more than 0.3 wt % of nitrogen in a grinding allowance portion after carbonitriding and hardening heat treatments, contains from 0.9 wt % (inclusive) up to 1.6 wt % (inclusive) of carbon and from 0.05 wt % (inclusive) up to 0.3 wt % (inclusive) of nitrogen in the surface layer of the finished part and has a nitrogen gradient of no more than 0.5 wt %/mm in the surface layer of the finished part. The rolling bearings are improved in grinding efficiency and which have their rolling life extended significantly.
摘要翻译:在碳氮共渗和硬化热处理之后,滚动轴承在研磨余量部分中含有不超过0.3重量%的氮,含有0.9重量%(含)至1.6重量%(含)的碳和0.05重量%(含) 在最终部件的表层中最多含有0.3重量%(含氮)氮,并且在成品部件的表面层中具有不超过0.5重量%/ mm 3的氮梯度。 滚动轴承的研磨效率提高,滚动寿命显着延长。
摘要:
The continuous annealing furnace has two or more treatment chambers sequentially connected with each other and respectively filled with a gas atmosphere differing in carburizing property, which includes a carburizing chamber wherein roller members to be treated are carburized at 750° C. to 820° C., a slow cooling chamber wherein the roller members are cooled at said temperature or less of the carburizing chamber, an intermediate chamber including atmosphere gas blocking doors that can open/close an exit of the carburizing chamber and an entrance of the slow cooling chamber independently, and transferring means, and each chambers is filled to satisfy a relationship of K1−K2≧2 where K1 represents a partial pressure ratio between CO and CO2 in an atmosphere within the carburizing chamber and K2 represents a partial pressure ratio between CO and CO2 in an atmosphere within the slow cooling chamber.
摘要:
The present invention provides a rolling bearing having high wear resistance at high temperature and with reduced manufacturing cost. At least one of an inner ring, an outer ring and rolling elements is formed of the following steel material into a predetermined shape, then applied with hardening and tempering at a temperature of 240° C. or higher or 350° C. or lower to make the Vickers hardness (Hv) on the raceway surface and/or rolling surface to 720 or more. The steel material contains, as the alloy ingredient, 0.8% by weight or more and 1.2% by weight or less of C, 0.5% by weight or more and 2.5% by weight or less of Si, 0.7% by weight or more and 1.5% by weight or less of Cr, 0.8% by weight or more and 2.0% by weight or less of Mo and 0.3% by weight or more and 1.2% by weight or less of Mn, with a ratio of Mo to Cr (Mo/Cr: weight ratio) of 1.1 or more.
摘要:
In a method and an apparatus for correcting a hardening deformation of an annular element made out of steel, during the cooling stage of hardening, the annular element which still has an austenitic structure is subjected to working on either the outside or inside diameter, with the degree of working being 0.05-1.0% if it is on the outside diameter with the annular element being pressed into a mold, and 0.5-3.0% if the working is on the inside diameter. Thus the deformation that develops in annular steel elements due to heat treatments is effectively corrected to yield completely round, strain-free or deformation-free annular elements.
摘要:
There is provided an aluminum die cast part strength evaluating method is provided for correctly evaluating strength of an actual aluminum die cast part. Strength of the actual aluminum die cast part will be correctly evaluated by conducting ultrasonic inspection of a predetermined range of a high stress region of an aluminum die cast part, which is found out through stress analysis beforehand, for an internal defect, and evaluating that the aluminum die cast part has a predetermined strength if the maximum internal defect area within the predetermined range is equal to or less than a predetermined value. Moreover, an actual aluminum die cast part with a predetermined strength will be evaluated correctly by: evaluating strength using the aluminum die cast part strength evaluating method and setting the maximum-possible internal defect area within the predetermined range of the high stress region to 0.8 mm2 or less.
摘要:
A full complement angular ball bearing with no cage and having a contact angle from 10 to 45° and an increased number of balls for use under severe conditions. The life is extended by defining the surface roughness of the inner ring and the outer ring, defining the roughness ratio of them relative to the rolling element, defining the Cr content in the alloy steel for the rolling element, forming the rolling element with oxide ceramics, or providing a dense nitride layer on the surface of the rolling element, avoiding the presence of particles with a mean diameter in excess of 3 μm on the raceway surfaces of the outer ring and the inner ring, or coating a film of a hardness higher than that of the raceway surface of the outer ring and the inner ring on the surface of the rolling element.