WO2005035814A1 - 転がり軸受 - Google Patents
転がり軸受 Download PDFInfo
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- WO2005035814A1 WO2005035814A1 PCT/JP2004/014787 JP2004014787W WO2005035814A1 WO 2005035814 A1 WO2005035814 A1 WO 2005035814A1 JP 2004014787 W JP2004014787 W JP 2004014787W WO 2005035814 A1 WO2005035814 A1 WO 2005035814A1
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- rolling
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- 238000005096 rolling process Methods 0.000 title claims abstract description 76
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 57
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 32
- 229910001566 austenite Inorganic materials 0.000 claims abstract description 28
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 26
- 239000010959 steel Substances 0.000 claims abstract description 26
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 6
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 4
- 238000005275 alloying Methods 0.000 claims abstract description 3
- 239000012535 impurity Substances 0.000 claims abstract description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 3
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 3
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 3
- 239000000463 material Substances 0.000 claims description 48
- 239000010410 layer Substances 0.000 claims description 10
- 239000013078 crystal Substances 0.000 claims description 8
- 239000002344 surface layer Substances 0.000 claims description 7
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 229910052720 vanadium Inorganic materials 0.000 claims description 2
- 239000002245 particle Substances 0.000 abstract description 7
- 229910052804 chromium Inorganic materials 0.000 abstract description 4
- 229910052759 nickel Inorganic materials 0.000 abstract description 3
- 239000000126 substance Substances 0.000 abstract description 3
- 229910052717 sulfur Inorganic materials 0.000 abstract description 3
- 239000000203 mixture Substances 0.000 abstract 1
- 238000012360 testing method Methods 0.000 description 40
- 238000005256 carbonitriding Methods 0.000 description 28
- 238000010791 quenching Methods 0.000 description 22
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 21
- 229910052739 hydrogen Inorganic materials 0.000 description 21
- 230000000171 quenching effect Effects 0.000 description 21
- 239000001257 hydrogen Substances 0.000 description 20
- 230000000052 comparative effect Effects 0.000 description 19
- 238000010438 heat treatment Methods 0.000 description 19
- 238000000034 method Methods 0.000 description 19
- 230000000694 effects Effects 0.000 description 14
- 238000005259 measurement Methods 0.000 description 13
- 230000035882 stress Effects 0.000 description 13
- 230000008859 change Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 10
- 239000007789 gas Substances 0.000 description 10
- 230000002829 reductive effect Effects 0.000 description 10
- 230000003068 static effect Effects 0.000 description 10
- 239000011651 chromium Substances 0.000 description 9
- 238000005336 cracking Methods 0.000 description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 8
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 7
- 238000009863 impact test Methods 0.000 description 7
- 239000011572 manganese Substances 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 238000011282 treatment Methods 0.000 description 6
- 230000032683 aging Effects 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 150000001247 metal acetylides Chemical class 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000012159 carrier gas Substances 0.000 description 3
- 239000000356 contaminant Substances 0.000 description 3
- 238000011109 contamination Methods 0.000 description 3
- 238000007656 fracture toughness test Methods 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 238000005121 nitriding Methods 0.000 description 3
- 238000005496 tempering Methods 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000009661 fatigue test Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 230000000670 limiting effect Effects 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- FFBHFFJDDLITSX-UHFFFAOYSA-N benzyl N-[2-hydroxy-4-(3-oxomorpholin-4-yl)phenyl]carbamate Chemical compound OC1=C(NC(=O)OCC2=CC=CC=C2)C=CC(=C1)N1CCOCC1=O FFBHFFJDDLITSX-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000005255 carburizing Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000004453 electron probe microanalysis Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 238000009940 knitting Methods 0.000 description 1
- 238000011089 mechanical engineering Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000013001 point bending Methods 0.000 description 1
- 229920002338 polyhydroxyethylmethacrylate Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2201/00—Treatment for obtaining particular effects
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/40—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rings; for bearing races
Definitions
- the present invention relates to a rolling bearing used for a reduction gear, a drive pinion, a transmission, and the like, and more specifically, has a long rolling contact fatigue characteristic and a high degree of crack resistance. Rollers having strength and aging-related dimensional changes relate to re-bearings.
- BACKGROUND ART As a heat treatment method that gives long life to rolling contact fatigue of bearing parts, the atmosphere during quenching and heating The ammonia gas is added to the RX gas, and the surface layer of the bearing parts is carbonitrided. (For example, Japanese Unexamined Patent Publication No. Hei 8-47074, Japanese Unexamined Patent Publication No. Hei 11-107247).
- An object of the present invention is to provide a rolling bearing having a high degree of cracking resistance and dimensional stability, and having excellent rolling fatigue life even in a high temperature environment.
- the rolling bearing of the present invention is a rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements, wherein at least one member of the inner ring, the outer ring, and the rolling elements includes an inner ring, an outer ring, and a rolling element.
- C is an essential element for ensuring strength as a rolling bearing, and it is necessary to contain 0.6% or more to maintain the hardness after a predetermined heat treatment. Limited to 0.6%. Also, in the present invention, carbides play an important role in rolling fatigue life as described later, but when the C content exceeds 1.3%, large carbides are generated, and It has been found that the fatigue life is reduced, The upper limit of the C content was limited to 1.3%.
- Si is desirably added because it has the effect of suppressing softening at high temperatures and improving the heat resistance of rolling bearings.
- the lower limit of the Si content is limited to 0.3%.
- the heat resistance improves with an increase in the Si content, but if the content exceeds 3.0%, the effect is saturated and the hot workability and machinability decrease. Therefore, the upper limit of the Si content was limited to 3.0%.
- Mn is an element used for deoxidation in the production of steel and is an element that improves hardenability.To achieve this effect, it is necessary to add 0.2% or more of Mn.
- the lower limit was limited to 0.2%. However, if it is contained in a large amount exceeding 1.5%, the machinability is greatly reduced. Therefore, the upper limit of the Mn content is limited to 1.5%.
- the upper limit of the content of P is set to 0.03%.
- the upper limit of the S content is set to 0.03%.
- S has a harmful surface as described above, but also has an effect of improving the machinability, so it is desirable to reduce S as much as possible. Is done.
- Cr is an element that plays an important role in the present invention, and is added to improve hardenability, secure hardness by carbide and improve life. Since the addition of 0.3% or more is necessary to obtain the specified carbide, the lower limit of the Cr content is limited to 0.3%. It was. However, if the content exceeds 5.0%, large carbides are formed and the rolling fatigue life is shortened. Therefore, the upper limit of the Cr content is limited to 5.0%.
- AI is used as a deoxidizing agent in the production of steel, but it is desirable to reduce it because hard oxide-based inclusions are formed and the rolling fatigue life is reduced. Also, when a large amount of AI exceeds 0.050%, a remarkable decrease in rolling fatigue life was observed, so the upper limit of the AI content was limited to 0.050%. In order to reduce the AI content to less than 0.005%, steel production costs increase. Therefore, it is desirable to limit the lower limit of the AI content to 0.005%.
- T i, O and N form oxides and nitrides in the steel and become the starting point of fatigue fracture as non-metallic inclusions, which reduce the rolling fatigue life.
- N: 0.01 5% was set as the upper limit of each element.
- Ni is an element that plays an important role in the present invention, and in particular, suppresses the structural change in the rolling fatigue process when used in a high-temperature environment and suppresses the decrease in hardness in the high-temperature region. It has the effect of improving the rolling fatigue life. In addition, Ni improves toughness, improves life under foreign material environments, and is effective in improving corrosion resistance. For this reason, since it is necessary to contain Ni at 0.1% or more, the lower limit of the Ni content is limited to 0.1%. However, if a large amount of N ⁇ exceeds 3.0%, a large amount of residual austenite is generated during the quenching process, and the predetermined hardness cannot be obtained, and the cost of the steel material increases. Was limited to 3.0%.
- the steel material may further contain at least one of Mo in an amount of 0.05% or more and less than 0.25% and V of 0.05% or more and 1.0% or less in mass%.
- Mo in an amount of 0.05% or more and less than 0.25%
- V of 0.05% or more and 1.0% or less in mass%.
- Mo has the effect of improving the hardenability of steel and preventing softening during tempering by forming a solid solution in carbides.
- Mo has been added because it has been found to improve rolling fatigue life at high temperatures.
- the Mo content was limited to less than 0.25%. If the Mo content is less than 0.05%, there is no effect on carbide formation, so the lower limit of the Mo content was limited to 0.05%.
- V combines with carbon to precipitate fine carbides, promotes the refinement of crystal grains, and has the effect of improving strength and toughness.
- the addition of V improves the heat resistance of steel materials, It has the effect of suppressing softening, improving rolling fatigue life and reducing life variability. Since the V content at which this effect can be obtained is 0.05% or more, the lower limit of the V content is limited to 0.05%. However, if V is contained in a large amount exceeding 1.0%, machinability and hot workability deteriorate, so the upper limit of the V content was limited to 1.0%.
- the nitrogen-enriched layer is a layer with an increased nitrogen content formed on the raceway ring (outer or inner ring) or the surface layer of the rolling element, and is formed by, for example, carbonitriding, nitriding, or nitriding. Can be done.
- the nitrogen content in the nitrogen-enriched layer is preferably in the range from 0.1% to 0.7%. If the nitrogen content is less than 0.1%, there is no effect, and the rolling life is shortened especially under the condition of foreign matter contamination. If the nitrogen content is more than 0.7%, voids called voids are formed, and the residual austenite becomes too large, resulting in short life due to insufficient hardness.
- the nitrogen content is the value at the surface 50 m of the raceway surface after grinding.
- it can be measured by EPMA (wavelength dispersive X-ray micro analyzer). can do.
- the austenitic grain size number is 10 or less, the rolling fatigue life is not significantly improved. Normally, it should be 11 or more. The finer the austenite particle size is, the better, but it is usually difficult to obtain a particle size number exceeding 13.
- the austenitic grains of the bearing parts described above do not change in the surface layer, which is greatly affected by the carburizing and nitriding treatment, or in the inside thereof. Therefore, the target positions in the above range of the grain size number are the surface layer and the inside.
- FIG. 1 is a schematic sectional view showing a rolling bearing according to an embodiment of the present invention.
- FIG. 2 is a diagram illustrating a method for heat-treating a rolling bearing according to an embodiment of the present invention.
- FIG. 3 is a diagram illustrating a modification of the heat treatment method for a rolling bearing according to the embodiment of the present invention.
- FIG. 4A is a diagram showing the microstructure of the bearing component of the present invention, particularly austenite grains.
- FIG. 4B is a diagram showing the microstructure of a conventional bearing component, particularly austenite grains.
- FIG. 5A shows an austenite grain boundary that illustrates FIG. 4A.
- FIG. 5B shows an austenite grain boundary illustrating FIG. 4B.
- FIG. 6 is a diagram showing a test piece for a static crush strength test (measurement of fracture stress value).
- FIG. 7A is a schematic front view of a rolling fatigue life tester.
- FIG. 7B is a schematic side view of the rolling fatigue life tester.
- FIG. 8 is a view showing a test piece for a static fracture toughness test.
- FIG. 1 is a schematic sectional view showing a rolling bearing according to an embodiment of the present invention.
- the rolling bearing 10 includes an outer ring 1, an inner ring 2, and a rolling element 3.
- the drawings show radial ball bearings, ball bearings, tapered roller bearings, cylindrical roller bearings, and needle roller bearings are also objects of the embodiments of the present invention.
- the moving body 3 is rotatably supported by a cage arranged between the outer ring 1 and the inner ring 2.
- At least one of the bearings of the outer ring 1, the inner ring 2 and the rolling element 3 of the re-bearing is Explaining a heat treatment including a carbonitriding process as a specific example of a process for forming a nitrogen-enriched layer
- Fig. 2 shows a heat treatment method for a rolling bearing in an embodiment of the present invention.
- Fig. 3 is a diagram for explaining the method, and
- Fig. 3 is a diagram for explaining a modified example thereof.
- Figure 3 is a heat treatment pattern showing the method of performing primary quenching and secondary quenching.Figure 3 shows that during quenching, the material is cooled to below A, the transformation point temperature, then reheated and finally quenched.
- process 1 ⁇ after carbon and nitrogen are sufficiently diffused into the steel base while diffusing carbon and nitrogen, the steel is cooled to below the transformation point.
- process T 2 of the in reheated to a temperature lower than or transformation temperature and process, wherein the performing the oil quenching.
- the above heat treatment as it is once hardened following the conventional carbonitriding hardening i.e. carbonitriding
- FIG. 4 is a diagram showing the microstructure of a bearing component, particularly austenite grains.
- FIG. 4A shows a bearing part of the example of the present invention
- FIG. 4B shows a conventional bearing part. That is, FIG. 4A shows the austenite grain size of the bearing steel to which the heat treatment pattern shown in FIG. 2 is applied.
- Fig. 4B shows the austenite grain size of the bearing steel by the conventional heat treatment method.
- FIGS. 5A and 5B show the austenite grain size illustrated in FIGS.
- the conventional austenite grain size is 10 incense in the particle size number of JIS standard, and according to the heat treatment method of the present invention, 12 incense fine particles can be obtained.
- the average particle diameter in FIG. 4A was 5.6 m as a result of measurement by the intercept method.
- Samples A to D (Examples of the present invention): Carbonitriding treatment 850 ° C, holding time 150 minutes. The atmosphere was a mixed gas of RX gas and ammonia gas. In the heat treatment pattern shown in Fig. 2, primary quenching is performed from a carbonitriding temperature of 850 ° C, and then a temperature range 780 lower than the carbonitriding temperature. The secondary quenching was performed by heating to G to 830 ° G. However, the secondary quenching temperature is 780. Sample A of G was excluded from the test because of insufficient quench hardness.
- Samples E and F Carbonitriding is performed with the same history as in Examples A to D of the present invention, and the secondary quenching temperature is 850 ° C to 870 ° C, which is 850 ° C or higher.
- Conventional carbonitrided product (comparative example): Carbonitriding 850 ° G, holding time 150 minutes.
- the atmosphere was a mixed gas of RX gas and ammonia gas. Quenching was performed as it was at the carbonitriding temperature, and secondary quenching was not performed.
- Normally quenched product (Comparative Example): Quenched by heating to 85CTG without carbonitriding. Secondary quenching was not performed. All of these were tempered at 180 ° G and a holding time of 120 minutes. Next, the test method will be described.
- the non-diffusible hydrogen content in the steel was analyzed using a DH-103 type hydrogen analyzer manufactured by LECO.
- the diffusible hydrogen content was not measured.
- the specifications of this LECO DH-103 hydrogen analyzer are shown below. Analysis range: 0.01 to 50. OO p pm
- Sample weight size 1 Omg ⁇ 35mg (Max: 12mm diameter x 10 Omm length
- Furnace temperature range 50 ° G ⁇ 1100 ° C
- Carrier gas Nitrogen gas
- Gas dosing gas Hydrogen gas Both gases have a purity of at least 99.99% and a pressure of 40 psi (2.8 kgf / cm 2 ).
- the outline of the measurement procedure is as follows. Insert the sample collected by the dedicated sampler into the above hydrogen analyzer together with the sampler. The diffusible hydrogen inside is guided to the thermal conductivity detector by the nitrogen carrier gas. This diffusible hydrogen is not measured in this example. Next, the sample is removed from the sampler, heated in a resistance heating furnace, and the non-diffusible hydrogen is guided to the thermal conductivity detector by the nitrogen carrier gas. The amount of non-diffusible hydrogen can be determined by measuring the thermal conductivity with a thermal conductivity detector. (2) Measurement of crystal grain size
- the Charpy impact test was performed based on the Charpy impact test method for metallic materials of JIS Z 2242.
- As the test piece a U-notch test piece (JIS No. 3 test piece) shown in JIS Z2202 was used. (4) Measurement of fracture stress value
- FIG. 6 is a diagram showing a test piece for a static crush strength test (measurement of fracture stress value). Apply a load in the P direction in the figure and measure the load until it is broken. After that, the obtained breaking load is converted into a stress value by the following stress calculation formula for a curved beam.
- the test piece is not limited to the test piece shown in FIG. 6, and a test piece having another shape may be used. Assuming that the fiber stress on the convex surface and the fiber stress on the concave surface of the test piece in Fig. 6 are ⁇ 2 , and ⁇ 2 can be obtained by the following formulas (Mechanical Engineering Handbook ⁇ 4 Knitting Material Dynamics ⁇ 4-40).
- ⁇ represents the axial force of the cross section including the axis of the annular test piece
- ⁇ represents the cross-sectional area
- e represents the outer radius
- e 2 represents the inner radius
- D is the section modulus of the curved beam.
- ⁇ 2 ( ⁇ / ⁇ ) + ⁇ / ( ⁇ 0 ) ⁇ [1-e 2 / [ ⁇ . I e 2 ) ⁇ ]
- Table 2 shows the test conditions for the rolling fatigue life test.
- FIG. 7 is a schematic diagram of a rolling fatigue life tester.
- FIG. 7A is a front view
- FIG. 7B is a side view.
- 7A and 7B the rolling fatigue life test piece 21 is driven by the driving roll 11 and is in contact with the ball 13 and rotates.
- the pole 13 is a 3-4 inch pole, and is guided by the guide rolls 12 and rolls while applying a high surface pressure to the rolling fatigue life test piece 21.
- the test results of Example I shown in Table 1 are described below.
- the value of the conventional carbonitrided product, which is still carbonitrided, is as high as 0.83 ppm. This is considered to be because ammonia (NH 3 ) contained in the carbonitriding atmosphere decomposed and hydrogen entered the steel.
- NH 3 ammonia
- Samples B to D the amount of hydrogen was reduced to almost half, from 0.42 to 0.45 ppm. This amount of hydrogen is the same level as that of ordinary hardened products.
- embrittlement of steel caused by solid solution of hydrogen can be reduced. That is, the Charpy impact values of Samples B to D of the present invention were significantly improved by reducing the amount of hydrogen.
- the austenite grains are markedly refined to grain size numbers 11 to 12 Have been.
- the austenite grains of Samples E and F and the conventional carbonitrided and normally quenched products have a crystal grain size number of 9, and are coarser than the samples B to D of the present invention.
- the Charpy impact value of the conventional carbonitrided product is 5.10 JZcm 2
- the Charpy impact value of Samples B to D of the present invention is 6.35 to 6.8.
- a high value of 0 J / cm 2 is obtained.
- the normally hardened product has a high Charpy impact value of 6.40 JZcm 2 .
- the above fracture stress value corresponds to the crack resistance.
- the conventional carbonitrided product has a fracture stress value of 208 OMPa.
- samples B to D An improved value of the breaking stress value of 2630 to 2800 MPa has been obtained.
- the fracture stress value of the normally quenched product is 2750 MPa, and it is estimated that the improved cracking resistance of Samples B to D is largely due to the reduction of the hydrogen content along with the refinement of the austenite crystal grains. You.
- the normal quenched product has a rolling fatigue life, reflecting that it does not have a carbonitrided layer on its surface. Is the lowest.
- the rolling fatigue life of conventional carbonitrided products is 1.4 times longer.
- the rolling fatigue life of Samples B to D is significantly improved compared to conventional carbonitrided products.
- Samples E and F are almost the same as conventional carbonitrided products.
- Samples B to D of the present invention have reduced hydrogen content, reduced austenite grain size to 11 or more, and improved Charpy impact value, cracking resistance and rolling fatigue life. Is done. (Example II)
- Example II A series of tests were performed on the following X, Y and Z materials. 1.2% by weight for heat treatment materials. One 1.0% by weight Si—0.
- Example of the present invention Bearing steel subjected to the heat treatment pattern shown in FIG. Carbonitriding temperature 8 45. C, retention time 150 minutes. The atmosphere for carbonitriding was RX gas + ammonia gas. The final quenching temperature was 800 ° G.
- Table 2 The rolling fatigue life test conditions and test equipment are as shown in Table 2 and FIG. 7 as described above.
- Table 3 shows the results of the rolling fatigue life test. 2004/014787
- the Y material of the comparative example was the X material of the comparative example, which was subjected to only ordinary quenching. It is 1.5 times longer than the life (life of one out of ten test pieces is broken), and the effect of extending the life by carbonitriding is recognized.
- Z material of the present invention example shows 1. 5-fold, and X material 2.2 times longer life of Y material. The main reason for this improvement is thought to be the micronization of the microstructure.
- FIG. 8 is a view showing a test piece for a static fracture toughness test. After introducing a pre-crack of about 1 mm into the notch portion of this test piece, a static load was applied by three-point bending, and the fracture load P was determined. The following equation (I) was used to calculate the fracture toughness (K 1 C value). Table 5 shows the test results.
- K 1 c ( ⁇ ⁇ _ ⁇ a / BW 2 ) (5.8.9.2 (a / W) +43.6 (a / W) 2 -75.3 (a ZW) 3 +77.5 (a / W) ⁇ ' ⁇ ⁇ (I)
- the Z material of the present invention was able to obtain about 1.1 times the value of the comparative example.
- Y material subjected to carbonitriding is lower than that of X material that is normally hardened.
- Z material of the present invention has a higher static crushing strength than the Y material, and has a level comparable to that of the X material.
- Table 7 shows the surface hardness and the amount of residual austenite (50 depth), [Table 7]
- the Z material of the present invention is suppressed to 70% or less in comparison with the dimensional change rate of the Y material having a large amount of retained austenite.
- the Y material subjected to the conventional carbonitriding treatment was about 1.7 times as long, and the Z material of the present invention example had about 1.6 times longer life.
- the Z material of the present invention has less residual austenite than the Y material of the comparative example, it has almost the same long life due to the infiltration of nitrogen and the effect of the micronized microstructure. From the above results, the Z material, that is, the example of the present invention, simultaneously increased the rolling fatigue life, improved the cracking strength, and reduced the dimensional change rate over time, which were difficult with conventional carbonitriding. I understand that I can be satisfied.
- Comparative Example 1 is a standard hardened product
- Comparative Example 2 is a standard carbonitrided product
- Comparative Example 3 is a case where the same treatment as that of the example of the present invention was performed, but only the amount of nitrogen was excessive.
- the test conditions are as follows.
- Test bearing tapered roller bearing 30206 (Inner and outer rings, rollers are 1.2% by weight C—1.0% by weight Si—0.5%. /. Mn—1.0% by weight NM—1.5 Weight% Cr steel)
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Rolling Contact Bearings (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/574,567 US20070269336A1 (en) | 2003-10-10 | 2004-09-30 | Ball-and-Roller Bearing |
DE112004001914T DE112004001914T5 (de) | 2003-10-10 | 2004-09-30 | Kugel- und Rollenlager |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003-352998 | 2003-10-10 | ||
JP2003352998A JP4319001B2 (ja) | 2003-10-10 | 2003-10-10 | 転がり軸受 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2005035814A1 true WO2005035814A1 (ja) | 2005-04-21 |
Family
ID=34431143
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2004/014787 WO2005035814A1 (ja) | 2003-10-10 | 2004-09-30 | 転がり軸受 |
Country Status (5)
Country | Link |
---|---|
US (1) | US20070269336A1 (ja) |
JP (1) | JP4319001B2 (ja) |
CN (1) | CN100425723C (ja) |
DE (1) | DE112004001914T5 (ja) |
WO (1) | WO2005035814A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1788264A1 (en) * | 2004-08-02 | 2007-05-23 | Ntn Corporation | Rolling bearing for rocker arm |
EP2484926A1 (en) * | 2006-10-26 | 2012-08-08 | NTN Corporation | Thermal treatment of the outer ring of a rolling bearing |
Families Citing this family (18)
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WO2009069547A1 (ja) | 2007-11-27 | 2009-06-04 | Ntn Corporation | 機械部品および転がり軸受 |
JP5292897B2 (ja) * | 2008-03-31 | 2013-09-18 | Jfeスチール株式会社 | 異物環境下での疲労特性に優れた軸受部品およびその製造方法 |
JP5489111B2 (ja) * | 2009-03-25 | 2014-05-14 | Ntn株式会社 | 軸受部品、転がり軸受および軸受部品の製造方法 |
DK2458023T3 (en) * | 2009-07-22 | 2016-04-18 | Ntn Toyo Bearing Co Ltd | A method of heat-treating a ring shaped article, method of producing a ring-shaped article, the ring shaped article, bearing ring, roller bearing and the method of manufacturing a bearing ring |
KR101482364B1 (ko) * | 2009-11-30 | 2015-01-13 | 제이에프이 스틸 가부시키가이샤 | 베어링용 조괴재 및 베어링용 강의 제조 방법 |
JP5425736B2 (ja) | 2010-09-15 | 2014-02-26 | 株式会社神戸製鋼所 | 冷間加工性、耐摩耗性、及び転動疲労特性に優れた軸受用鋼 |
CN101962734B (zh) * | 2010-09-28 | 2012-08-01 | 山东钢铁股份有限公司 | 一种球磨机钢球用钢及其制备方法 |
WO2012098988A1 (ja) | 2011-01-21 | 2012-07-26 | Ntn株式会社 | 軌道輪の製造方法、軌道輪および転がり軸受 |
EP2716781B1 (en) | 2011-05-25 | 2018-06-20 | Kabushiki Kaisha Kobe Seiko Sho | Bearing steel with excellent rolling fatigue characteristics |
DE102012204618A1 (de) * | 2012-03-22 | 2013-09-26 | Schaeffler Technologies AG & Co. KG | Wälzlager mit einem Lagerring mit gehärteter Randzone |
US10087989B2 (en) | 2013-06-06 | 2018-10-02 | Ntn Corporation | Bearing component and rolling bearing |
CN105264246B (zh) | 2013-06-06 | 2018-10-12 | Ntn株式会社 | 轴承部件及滚动轴承 |
JP6211811B2 (ja) * | 2013-06-06 | 2017-10-11 | Ntn株式会社 | 軸受部品および転がり軸受 |
CN105264247B (zh) | 2013-06-06 | 2018-04-17 | Ntn株式会社 | 轴承部件及滚动轴承 |
US10094422B2 (en) | 2013-06-06 | 2018-10-09 | Ntn Corporation | Bearing component and rolling bearing |
CN104451452B (zh) * | 2013-09-13 | 2016-09-28 | 宝钢特钢有限公司 | 一种用于风电设备的轴承钢及其制备方法 |
CN106893947B (zh) * | 2017-03-28 | 2018-07-27 | 北京科技大学 | 一种可耐400度高温的轴承钢的制备方法 |
US11778779B2 (en) | 2018-11-22 | 2023-10-03 | Denso Corporation | Electronic component cooling device |
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JP2001152252A (ja) * | 1999-11-22 | 2001-06-05 | Nsk Ltd | 転がり軸受 |
JP2002115031A (ja) * | 2000-10-11 | 2002-04-19 | Ntn Corp | 転がり軸受部品、駆動装置およびロール支持装置 |
JP2003113448A (ja) * | 2001-10-05 | 2003-04-18 | Nippon Koshuha Steel Co Ltd | 静粛性が優れた軸受用鋼 |
JP2003226919A (ja) * | 2001-11-29 | 2003-08-15 | Ntn Corp | 軸受部品および転がり軸受 |
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JP3538995B2 (ja) * | 1994-09-29 | 2004-06-14 | 日本精工株式会社 | 転がり軸受 |
US7438477B2 (en) * | 2001-11-29 | 2008-10-21 | Ntn Corporation | Bearing part, heat treatment method thereof, and rolling bearing |
-
2003
- 2003-10-10 JP JP2003352998A patent/JP4319001B2/ja not_active Expired - Lifetime
-
2004
- 2004-09-30 WO PCT/JP2004/014787 patent/WO2005035814A1/ja active Application Filing
- 2004-09-30 US US10/574,567 patent/US20070269336A1/en not_active Abandoned
- 2004-09-30 DE DE112004001914T patent/DE112004001914T5/de not_active Withdrawn
- 2004-09-30 CN CNB2004800295055A patent/CN100425723C/zh active Active
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JP2001152252A (ja) * | 1999-11-22 | 2001-06-05 | Nsk Ltd | 転がり軸受 |
JP2002115031A (ja) * | 2000-10-11 | 2002-04-19 | Ntn Corp | 転がり軸受部品、駆動装置およびロール支持装置 |
JP2003113448A (ja) * | 2001-10-05 | 2003-04-18 | Nippon Koshuha Steel Co Ltd | 静粛性が優れた軸受用鋼 |
JP2003226919A (ja) * | 2001-11-29 | 2003-08-15 | Ntn Corp | 軸受部品および転がり軸受 |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1788264A1 (en) * | 2004-08-02 | 2007-05-23 | Ntn Corporation | Rolling bearing for rocker arm |
EP1788264A4 (en) * | 2004-08-02 | 2009-05-06 | Ntn Toyo Bearing Co Ltd | BEARING BEARING FOR OSCILLATING ARMS |
US7614374B2 (en) | 2004-08-02 | 2009-11-10 | Ntn Corporation | Rolling bearing for rocker arm |
EP2484926A1 (en) * | 2006-10-26 | 2012-08-08 | NTN Corporation | Thermal treatment of the outer ring of a rolling bearing |
US8313246B2 (en) | 2006-10-26 | 2012-11-20 | Ntn Corporation | Rocker bearing with outer ring and air disk brake system |
Also Published As
Publication number | Publication date |
---|---|
CN1863935A (zh) | 2006-11-15 |
CN100425723C (zh) | 2008-10-15 |
JP2005113256A (ja) | 2005-04-28 |
DE112004001914T5 (de) | 2006-10-19 |
JP4319001B2 (ja) | 2009-08-26 |
US20070269336A1 (en) | 2007-11-22 |
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