• 专利附录
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    • 专利摘要:
    23 ABSTRACT There is provided a method for producing a machinecomponent which has a surface hardness of 58 HRC or moreand can stably exhibit a superior roiling contact fatigue life, ascompared to a steel material in which the amount and size ofthe non-metallic inclusions are reduced at the time of producingsteel, even without reducing the amount and size of thenon-metailic inclusions at the time of producing steel. Thismethod comprises the steps of suhjecting the machinestructural steel to a step for providing a shape as a steelmaterial or a step for providing a shape as a subsequentmachine component, wherein the steel is subjected to a plasticworking; heating the steel to which the plastic working isconducted to 780 °C or higher to apply a hydrostatic pressure of80 MPa or more, whereby bringing the non-metaillc inclusioncontained in the steel and the steel as a matrix into closecontact with each other in the interface; and then subjecting apart or the whole of the steel to quenching and temperingtreatment
    公开号:SE1051359A1
    申请号:SE1051359
    申请日:2009-05-26
    公开日:2011-01-19
    发明作者:Kazuya Hashimoto；Takeshi Fujimatsu；Norimasa Tsunekage；Kazuhiko Hiraoka
    申请人:Sanyo Special Steel Co Ltd；
    IPC主号:
    专利说明:

    [5] Even the use of a steel materia! with such highcleanliness cannot sufficiently prevent a failure in a short life.
    [6] [0006] The inventors have currently found that, even withoutreciucing the amount and size of the non-metailic inclusions atthe time of producing steel, it is possible to provide a machinecomponent which has a surface hardness of 58 HRC or more,prevents flaking, and has a superior roliing contact fatigue life,by providing a steel material with a condition where the cavitybetween the non-metallic inclusions and the matrix phase in thesteei is closed.
    [7] That is, in order to improve roliing contact fatigue iifein bearlngs and other machine components, it is important toreduce the amount of the non ~ metallic inclusions in the steeimaterials for these machine components. It is also known that,since the existence of a large inciusion under the roiling tracksurface of the hearing or other machine component may causeflaking in the machine component to lead to failure, it isparticularly important to reduce the size of the non-metalliicinclusions which may be an origin of flaking under the roliingtrack surface of the bearing or other machine component forimproving the service life of the hearing and other machinecomponent. Aithough a iarge number of inventions were madefor reducing the size of the inclusions in the mass productionprocess, it was difficult to stabiy reduce the size of thenon-metallic inclusions.
    [8] [0008] The inventors extensively investigated the process1015202530353which leads to failure in roliing contact fatigue, i.e., flaking, byobserving the cracks with use of materiais containing artificiaipore defects. It has been found that, in the process that cracksoriginated from the non-metallic inclusion lead to the generationof flaking through their growth, the process undergoes the crackinitiation stage with a crack being displaced (hereinafter, "ModeI-type initial crack ") by stress concentration effect around thenon-metallic inclusions. The process then undergoes thepropagation of the cracks depending on shearing stress to leadto failure, as conventionaliy known. This means that, withoutgeneration of a Mode I-type initial crack that the inventors havefound, the subsequent crack propagation and failure will notoccur. In addition, the Mode I-type initial cracks occur on thepremise that a physical cavity forms at the interface betweenthe non-metallic inclusions and the matrix. It is confirmed bystress anaiysis that an Model I-type initial crack does not occur,without formation of a physical cavity (see, Iron and Steel(Tetsu-to-i-iagane), 94 (2008), p.13; and a doctoral dissertationof University of Hyogo in 2008 written by Kazuhiko Hiraoka(January 2008), which are incorporated herein by reference.)
    [9] [0009] Moreover, it has also been found that the physicalcavity is formed by some plastic working which is necessarilyconducted in the process of producing a steel materiai or theprocess of shaping the steel material into a component, i.e., hotrolling, cold rolling, hot forging, warm forging, cold forging,rolling forging, cold rolling, coid header, and drawing. Fig. 1shows a conceptual view of an image in whichexistence / absence of a cavity around the inclusions is observedby means of scanned electronic microscopy (FE-SEN) aftercutting out of a hot-rolled steel material and conducting ionmilling. In Fig. 1, reference number 2 indicates AlzOg, whilereference number 3 indicates a cavity. In particular, in themachine structural steel, Ai is normally used as oxide formationelement for deoxidization. It has been confirmed that the Al203inciusion tends to form a cavity particularly at the interface withthe matrix due to the difference in deforrnability with steel and1015202530354the shape. 'The presentinvenüon has beenrnade on the basßof the above new findings.
    [10] Accordingly, it is an object of the invention to provide amethod for producing a machine component which can stablyexhibât a superior rolling contact fatigue life as compared to thesteel material in which the amount and size of the non-metallichu fl uaons are reduced at the thne of produdng steeh byimproving the condition of the interface between thenon-metallic inclusions and the matrix in the steel material,even without reducing the amount and size of the non-metallicinclusions at the time of producing steel.{0O11] Accon fi ng hathe presentinvenhon, thereis pnnnded arnethod for prodtnïng a rnachine conwponent having a surfacehardness of 58 l4RC or n fi ona and a supenor roHing contactfatigue life by subjecting a part or the whole of a machinestructurai steei to a quenching and tempering treatment, thennethod conwpnsing the steps of:subjecüng the rnachine structural steel to a step forproviding a shape as a steel material or a subsequent step forproviding a shape as a machine component, where the steel issubjected to a plastic working;heating the steel, to which the plastic working hasbeen conduded, to 780 ° C or mgherto apmy a hydro fi atmpressure of 80 MPa or rnore, whereby bringing the non ~ metallicinclusion contained in the steel and the steel as a matrix intoclose contact with each other in an interface; and thereaftersubjecting a part or the whole of the steel to aquenchirig and tempering treatment.
    [12] According to a first preferred embodiment of thepresent invenüon, there is prowded the above produ fi ngmethod, where the heating is conducted at 800 ° C or higher,and where the hydrostatic pressure is 100 MPa or higher.
    [13] According to a second preferred embodiment of thepresent invention, there is provided the above producingnnethod, nnwerein the nwachine structuralsteelto be subjected tothe wormng has deoxkhzed by adding aplastic been1015202530355cleoxiclization agent containing Si in addition to generally-usedAi or by not adding a deoxidization agent containing Al.
    [14] [0014] According to a third preferred embociiment of thepresent invention, there is provided the above producingmethod, wherein the machine structural steel to be subjected tothe piastic working has been deoxiciized by adding adeoxidization agent containing Ca in addition to generaily ~ usedAl.
    [15] According to the method for producing a machinecomponent, even without reducing the amount and size of thenon ~ metaliic inclusions at the time of producing steel, whenclosing the physical cavity formed at the interface between thematrix and the non-metallic inclusions, which have beencontained in the steel through some piastic working, it ispossible to avoid fiaking which occurs due to rolling contactfatigue originated from a non-metallic inclusion, resulting in asignificant improvement in service life.
    [16] Fig. 1 is a conceptual figure depicting an image in thesurrounding of the non-metailic inclusion, which was observedwith a scanning electron microscope (FE ~ SEM) after cutting outof the hot-rolled steei and conducting ion miiiing.
    [17] The machine structural steel of the present inventionbroadly includes steels that are required for machinecomponents, such as bearings, gears, hub units, constantlyvariable transmissions, constant-velocity joints, piston pins andthe like. Specifically, as such machine structural steel, thereare generally used high carbon chromiurn bearing steeis definedin JIS G 4805, carbon steels for machine structural use defied in315 G 4051, structure steels with specified hardenability bandsdefined in JIS G 4052 (H steel), low-alloyed steel for machinestructural use defined in JIS G 4053, alloy steel tubes formachine purposes defined in JIS G 3441, carbon steel tubes for1015202530356machine structural purposes defined in JIS G 3445, carbonsteels for cold heading - the first part: wire rods defined in JISG 3507-1, carbon steels for cold heading ~ the second part:wires defined ln JIS G 3507-2, low-alloyed steels for coldheading - the first part: wire rods defined in JIS G 3509-31.,low-alloyed steels for cold heading - the second part: wlresdefined in JIS G 3509-2, their relatlve foreign standard steels,steels having similar components, and steels having improvedcomponents. The disclosures of these JIS standards areincorporated herein by reference. The machine structural steelin the present invention includes steels satisfying the chemicalcomponents described in the above JIS standards.
    [18] The numerical range (wtß / a) of preferred compositionsof the machine structural steel in the present invention are asfollows:Preferred More Preferred Further PreferredRange Rande RanoeC 0.10 ~ 1.10 0.95-1.10 0.95-1.10Si 2.0 or less 0.15-0.70 0.15 ~ 0.35Mn 3.0 or less 1.15 or less 0.50 or lessP 0.025 or less 0.025 or less 0.025 or lessS 0.100 or less 0.025 or less 0.025 or lessCr 15.0 or less 0.90-1.60 1.30 ~ 1.60Mo 2.0 or less 0.25 or less 0.08 or lessNi 5.0 or less 0.25 or less 0.25 or lessCu 0.25 or less 0.25 or less 0.25 or lessBalance Fe and unavoidable impurltlesRemarks JIS G 4805 JIS G 4805SUJ1-5 S032Note that unavoidable impurities may include Al and / or Ca as adeoxidant.
    [19] [0019] These machine structural steels are generally producedthrough 1) oxidation refining of molten steel in an arc meltingfurnace or a converter furnace, 2) reduction reflning in a ladlerefining furnace (LF), 3) rotary-flow vacuum degassingtreatment by a rotary-flow vacuum degaseer (RH treatment), 4)1015202530357casting of steel ingot by continuous casting or ingot casting and5) plastic Working step including hot rolling or hot press forgingand cold rolling or cold press forging of the steel ingot. Thestep for providing a shape as a steel material indicates theabove steps, While the shape of the steel material indicatesShaped steel, steel bar, steel tube, wire rod, steel plate, andsteel strip.
    [20] The steel material can be shaped to a desired materialby subjecting it to plastic working, such as hot forging, semi-hotforging, Warm forging, cold forging, rolling forging, cold roliing,cold heading and drawing, in some cases, drawing and coldheading, and the cornbinations thereof, if necessary, heattreatment for softening or structure control, or turning. Thestep for providing a shape as a machine component in thepresent invention indicates the above steps.
    [21] The term "hot" in hot plastic working refers torecrystaliization temperature of the steel or higher. The term"Warm" in Warm plastic working refers to a temperature in therange of from room temperature to recrystallizationtemperature, while the term "cold" in cold plastic working refersto around room temperature.
    [22] Generaily, steel to which plastic working was conductedis then subjected to quenching and tempering for attaining asurface hardness of 58 HRC or more, such as entire hardening(through hardening), carburizing and quenching, carbonitridingand quenching, nitriding and quenching, and inductionharclening, depending on the steel material and the intendeduse. The quenched and tempered steel is subjected to finishingtreatment such as polishing and grinding, to produce a machinecomponent that the present invention is to provide. The term"quenching and tempering treatment" used herein indicates theabove treatments.
    [23] [0023] However, in order to attain the effects of the presentinvention, it is necessary to mandatorily conduct the step ofclosing the cavity existing at the interface between oxideinclusion and the matrix, at a stage before quenching and1015202530358tempering the machine component to attain a surface hardnessof 58 HRC or more. The means for achieving this is preferredto be a method which is capable of applying a hydrostaticpressure of 80 MPa or more after heating to 780 ° C. Forexample, such method may be hot isostatic press (HIP) method,hot press method, or hot forging method almostcompletely-sealed by the.
    [24] In hot forging, semi ~ hot forging, warm forging, coldforging, rolling forging, coid rolling, cold heading or drawing, inwhich the steel is not completely sealed in the die, it isimpossible to attain the effects of the present invention becausethe hydrostatic pressure cannot be applied to the entire part ofthe steel or because the steel is continuousiy elongated in acertain direction.
    [25] [0025] The reasons for applying a hydrostatic pressure of 80MPa or more after heating to 780 ° C are as follows. That is,the steel is more deformable as the heating temperature of thesteel materiai is higher. Therefore, the hydrostatic pressurenecessary to close the cavity existing at the interface betweenoxicie-based non-metallic inciusions and the matrix can be loweras the heating temperature of the steel material is higher. As aresult of the inventors' earnest investigation, the effects of thepresent invention can be attained when the steel is heated to atemperature of 780 ° C or higher and a hydrostatic pressure of80 MPa or more is applied to the steel. According to the firstpreferred embodiment, the above heating is conducted at800 ° C while the hydrostatic pressure is 100 MPa or more.
    [26] According to the second preferred embodiment, themachine structural steel to be subjected to the plastic workinghas been deoxidized by adding a deoxidization agent containingSi in addition to generally-used Al or by not adding adeoxidation agent containing Ai. Generally, machinestructural steel is deoxidized with Al. Therefore, the oxideinclusions formed are mainly composed of Al203 base. SinceAl203 is hard inclusions, which tend to aggiomerate afterrefinement to form the configuration of type B defined in ASTM1015202530359E 45, the conditional range for applying an Optimum hydrostaticpressure is iimited in order to completely close the cavityexisting at the interface between the oxide inclusion and thematrix when appiying a hydrostatic pressure. Consequently,controlling the configuration of the oxide inclusions ieads to anincrease in the effect of completely closing the cavity existing atthe interface between the oxide inclusion and the matrix whenapplying a hydrostatic pressure. As means for achieving this, itis preferred that the oxide inclusion to be formed is softened toreduce the difference in deformability between the inciusion andthe matrix, through deoxidization by adding a deoxidizationagent containing Si in addition to generaliy-used Ai or by notadding a deoxidization agent containing Al.
    [27] According to the third preferred embodiment, themachine structural steel to be subjected to the plastic workinghas been deoxidized by adding a deoxidization agent containingCa in addition to generally-used Al. Generally, machinestructural steei is deoxidized with using AI. Therefore, theoxide inclusions formed are mainly composed of AlzOg. SinceAl203 constitutes a hard inclusion, which tends to agglornerateafter refinement to form the configuration of type B defined inASTM E 45, the conditional range for applying an Optimumhydrostatic pressure is limited in order to compieteiy close thecavity existing at the interface between the oxide inciusion andthe matrix when applying a hydrostatic pressure. Consequently,controlling the configuration of the oxide inclusion leads to anincrease in the effect of completely ciosing the cavity existing atthe interface between the oxide inclusion and the matrix whenapplying a hydrostatic pressure. As means for achieving this, itis preferred that the oxide inciusion to be formed is controlledto have the configuration of type D (granular) defined in ASTM E45, through deoxidization by adding a deoxidization agentcontaining Si in addition to generaily-used Al, so that ahydrostatic pressure can be evenly applied to the matrix at thesurrounding of the non ~ meta | ic inclusion.
    [28] [0028] It is a matter of course that the first, second and / or101520253010third preferred embodiments are arbitrarily combined to practicethe present invention.
    [29] [0029] The conditions for practicing the first embodiment andresults obtained thereby will be specifically explained. First ofail, the chemical composition of specimens is shown in Table 1.
    [30] [Table 1]Specimen Components (wt. ° / o except that O refers to ppm)Steel C Si Mn S Cr Mo Al OSUJ2 1.04 0.22 0.32 0.007 1.44 0.03 0.011 6
    [31] Furthermore, the above spheroidized annealed steelmaterial was processed in accordance with any one of conditions1 to 3 as shown below.
    [32] The washer-shaped products were respectivelysubjected to a hot isostatic press (HIP) treatment. Thetreatment conditions are shown in Table 2. Press conditions Aand B satisfy the heating temperature condition and the10152025'lihydrostatic pressure condition of the present invention. Pressconditions C to E fail to satisfy the heating temperaturecondition and the hydrostatic pressure condition of the presentinvention in that press conditions C and D does not satisfy thepress condition of the present invention and press condition Edoes not involve the HIP treatment. The washer-shapedproducts according to these press conditions A and B wereretained at 835 ° C for 20 minutes, quenched by oil quenching,and then tempered at 170 ° C for 90 minutes to attain a desiredhardness of 58 HRC or higher. Furthermore, the products werepolished to finish thrust-type roliing bearings, which wereevaluated for roliing contact fatigue life. A commerciallyavailable ball for a thrust-type roliing hearing was used as theroliing element.
    [33] [Table 2]Press ConditionsCondition Heating Press RemarksTemperature Pressure(° C) (MPH)A 800 100 WorkingB 1100 200 ExamplesC 700 100 ComparativeD 800 50 ExamplesE No press was conducted.
    [34] Thrust ~ type roliing fatigue test was conducted 10 timeson each press condition as shown above, with the maximumHertz stress Pmax being 5292MPa. From the results, thenumber of the cycle was measured until 10% of the specimenscause flaking by counting from the short life side on the basis ofWeibull distribution function, and named this number Lm life.
    [35] [Table 3]Process Press Surface Lm lifeCondition Condition Hardness (xlOs cycles.)(HRC)1 Å 60.9 83B 58.0 100 *C 59.1 10.9D 59.4 15.4E 61.9 8.92 Å 58.4 81B 61.3 100 *C 58.1 11.7D 60.3 10.1E 61.4 9.53 Å 58.2 100 *B 59.9 100 *C 59.1 13.3D 60.3 12.9E 59.3 10.6*: This symbol means that no flaking occurred in 1x108 cycles.
    [36] The symbol "*" for Llo life in Table 3 means that noflaking occurred in 1x108 cycles. In Table 3, press conditions Aand B satisfying the heating temperature condition and thehydrostatic pressure condition of the present invention result ina surface hardness of 58 HRC or more. Press conditions C to Enot satisfying the heating temperature condition and thehydrostatic pressure condition of the present invention alsoresult in a surface hardness of 58 HRC or more. l-iowever,working examples under conditions A and B result in asignificantly improved roiling contact fatigue life, compared withcomparative examples under press conditions C to E, regardlessor whether the finishing process is hot plastic working, Warmplastic working, or cold plastic working.
    [37] The conditions for practicing the second ernbodimentand results obtained thereby will be specifically explained.
    [38] [Table 4]Speclmen Components (wt.% Except that O refers to ppm)Steel C Si Mn S Cr Mo Al OA 1.00 0.26 0.30 0.009 1.41 0.03 0.003 10B 1.04 0.22 0.32 0.007 1.44 0.03 0.011 6
    [39] Furthermore, the above spheroidized annealed steelmaterial was processed in accordance with any one of conditions1 to 3 as shown below.
    [40] The washer-shaped productssubjected to a hot isostatic press (HIP) treatment or a hot presstreatment. The treatment conditions are shown in Table 5.
    [41] [Table 5]Press ConditionsCondition Heating Press RemarksTemperature Pressure(° C) (MP8)(1) 780 80 Working(2) 800 100 Examples(3) 1100 150(4) 700 80 Comparative(5) No press was conducted. Examples
    [42] Thrust-type roiling fatigue test was conducted 10 timeson each press condition as shown above, with the maximumHertz stress Prnax being 5292MPa. From the results, thenumber of cycie was measured until 10% of the specimenscause flaking by counting from the short life side on the basis ofWeibull distribution function, and named this number L1o iife.
    [43] [Tabie 6]Process Press Surface Lw lifeCondition Condition l-iardness (x106 cycles)(HRC)1 (1) 58.2 100 *(2) 59.1 100 *(3) 60.3 100 *(4) 59.9 37.9(5) 61.3 23.12 (1) 59.6 100 *(2) 60.4 100 *(3) 58.0 100 *(4) 59.8 28.4(5) 60.4 11.33 (1) 59.7 100 *(2) 62.4 100 *(3) 60.9 100 *(4) 58.2 30.1(5) 60.6 10.9* z This symbol means that no flaking occurred in 1x108 cycles.
    [44] [Table 7]Process Press Surface Lm lifeCondition Condition Hardness (x106 cycles)(HRC)1 (1) 59.7 16.4(2) 60.1 80.4(3) 58.3 100 *(4) 61.4 10.9(5) 60.3 7.32 (1) 58.0 19.3(2) 59.1 65.3(3) 59.9 100 *(4) 58.3 10.4(5) 61.2 6.23 (1) 61.4 10.9(2) 59.8 77.9(3) 58.1 100 *(4) 60.9 9.9(5) 62.1 5.4* z This symbol means that no flaking occurred in 1x1O8 cycles.
    [45] Steel A in Table 6 and steel B in Table 7 satisfying theconfiguration of the present invention results in a surface101520253016hardness of 58 HRC or more. Press conditions (1) to (3)satisfying the heating temperature condition and the hycirostaticpressure condition of the present invention are superior inroiiing contact fatigue iife, compared with press conditions (4)and (5), which are comparative examples not satisfying theconditions of the present invention. Furthermore, steels A andB are superior to steel C in that it is possible to expand theranges of the conditions when applying an optimum hydrostaticpressure under press conditions (1) to (3), which satisfy theconditions of the present invention.
    [46] [0046] The conditions for practicing the third embodiment andresults obtained thereby will be specificallyaily explained. First ofall, compositions of specimens are shown in Tabie 8. Steels Aand B of this specimen are both based on SUJZ steel, whichsatisfies the composition of JIS G 4805. Moiten steel wassubjected to an oxidation refining in an ark melting furnace, areduction refining in a iadie refining furnace (LF), a rotary-flowdegassing treatment in a rotary ~ flow vacuum degasser (RHtreatment), and a continuous casting to cast a steel. The steelingot was hot-roiled to produce a steel material. Steel A of thespecimen has been basically deoxidized with Al, and added withCa after the LF compieted. Steei B has been deoxidized with Alas conventionaliy conducted. The steel material obtainedthrough the hot roiling was subjected to a spheroidizedannealing at 800 ° C.
    [47] [Table 8]Specimen Components (wtP / n except that Ca and O refer to ppm)Steel C Si Mn S Cr Mo Ai Ca 0A 1.01 0.22 0.35 0.008 1.42 0.03 0.015 9 8B 1.04 0.22 0.32 0.007 1.44 0.03 0.011 - 6
    [48] Furthermore, the above spheroidized annealed steelmaterial was processed in accordance with any one of conditions1 to 3 as shown below.
    [49] [0049] The washer ~ shaped products respectivelysubjected to a hot isostatic press (HIP) treatment or a hot presstreatment. The treatment conditions are shown in Table 9.
    [50] [Table 9]Press ConditionsCondition Heating Press RernarksTemperature Pressure(° C) (MPa)(1) 780 80 Working(2) 800 100 Examples(3) 1100 150(4) 700 80 Comparative(5) No press was conducted. Examples
    [51] Thrust ~ type roiling fatigue test was conducted 10 timeson each press condition as shown above, with the maximumHertz stress Pmax being 5292MPa. From the results, thenumber of cycle was measured until 10% of the specimenscause fiaking by counting from the short life side on the basis ofWeibull distribution function, and nameci this number Lm life.
    [52] [Table 10]19Process Press Surface Lw iifeCondition Condition Hardness (x106 cycles)(HRC)1 (1) 58.9 100 *(2) 58.1 100 *(3) 60.9 100 *(4) 58.0 29.1(5) 62.1 18.62 (1) 58.0 100 *(2) 61.3 100 *(3) 58.9 100 *(4) 61.8 22.3(5) 60.1 9.63 (1) 60.4 100 *(2) 61.3 100 *(3) 58.1 100 *(4) 59.9 34.3(5) 62.4 14.3*: This symbol means that no fiaking occurred in[oo53] [Tabæ 11]1x108 cycles.
    [54] In Table 10, steel A satisfying the configuration of thepresent invention resuitsin a surface harciness of 58 HRC ormore. Press conditions (1) to (3) satisfying the heating20temperature condition and the hydrostatic pressure condition ofthe present invention are superior in rolling contact fatigue life,compared with press conditions (4) and (5), which arecomparative examples not satisfying the conditions of thepresent invention. Furthermore, steel A is superior to steel Bshown in Table 11 in that it is possible to expand the ranges ofthe conditions when applying an Optimum hydrostatic pressureunder press conditions (1) to (3), which satisfy the conditions ofthe present invention.
    权利要求:
    Claims (7)
    [1]
    1. A method for producing a machine component having a surface hardness of 58 HRC or more and a superior rolling contact fatigue life by subjecting a part or the whole of a machine structural steel to a quenching and tempering treatment, the method comprisâng the steps of : subjecting the machine structural steei to a step for providing a shape as a steel material or a subsequent step for providing a shape as a machine component, wherein the steel is subjected to a plastic working; heating the steel, to which the plastic working has been conducted, to 780 ° C or higher to apply a hydrostatic pressure of 80 MPa or more, whereby bringing the non-metallic inclusion contained in the steel and the steel as a matrix into close contact with each other in an interface; and thereafter subjecting a part or the whole of the steel to a quenching and tempering treatment.
    [2]
    The method according to claim 1, wherein the heating is conducted at 800 ° C or higher, and wherein the hydrostatic pressure is 100 MPa or more.
    [3]
    The method according to claim 1 or 2, wherein the machine structural steei to be subjected to the plastic working has been deoxidized by adding a deoxidization agent comtaining Si in addition to generally-used Al or by not adding a deoxidization agent containing Al.
    [4]
    The method according to claim 1 or 2, wherein the machine structural steel to be subjected to the plastic working has been deoxidized by adding a deoxidizing agent containing Ca in addition to generally-used Al.
    [5]
    5. The method according to any one of clairns 1 to 4, wherein the plastic working was conducted a piurality of times, 22 where the last piastic working in the piuraiity of times is a hot piastic working.
    [6]
    6. The method according to any one of ciaims 1 to 4, wherein the piastic working was conducted a pluraiity of times, wherein the iast piastic working in the piurality of times is a Warm piastic working.
    [7]
    7. The method according to any one of claims 1 to 4, wherein the piastic working was conducted a plurality of times, wherein the last piastic working in the piurality of times is a coid piastic working.
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JPS6130002B2|1979-02-18|1986-07-10|Kobe Steel Ltd|
    JPH1046286A|1996-07-26|1998-02-17|Nippon Seiko Kk|Rolling bearing|
    JP2000190064A|1998-12-22|2000-07-11|Daido Steel Co Ltd|Ingot reforming method|
    JP4630075B2|2005-01-24|2011-02-09|新日本製鐵株式会社|High carbon chromium bearing steel and manufacturing method thereof|
    JP2007130642A|2005-11-08|2007-05-31|Jtekt Corp|Method for manufacturing annular member|
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    申请号 | 申请日 | 专利标题
    JP2008138775A|JP5473249B2|2008-05-27|2008-05-27|Manufacturing method of machine parts with excellent rolling fatigue life|
    JP2008138776A|JP5403946B2|2008-05-27|2008-05-27|Manufacturing method of machine parts with excellent rolling fatigue life|
    JP2008138774A|JP5403945B2|2008-05-27|2008-05-27|Manufacturing method of machine parts with excellent rolling fatigue life|
    PCT/JP2009/059573|WO2009145168A1|2008-05-27|2009-05-26|Manufacturing method for machine parts having superior rolling-contact fatigue life|
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