WO2007086215A1 - Joint universel homocinetique presentant une excellente tenue a la fatigue de roulement, arbre de transmission de puissance presentant une excellente tenue a la fatigue en torsion, et processus pour leur production - Google Patents

Joint universel homocinetique presentant une excellente tenue a la fatigue de roulement, arbre de transmission de puissance presentant une excellente tenue a la fatigue en torsion, et processus pour leur production Download PDF

Info

Publication number
WO2007086215A1
WO2007086215A1 PCT/JP2006/325444 JP2006325444W WO2007086215A1 WO 2007086215 A1 WO2007086215 A1 WO 2007086215A1 JP 2006325444 W JP2006325444 W JP 2006325444W WO 2007086215 A1 WO2007086215 A1 WO 2007086215A1
Authority
WO
WIPO (PCT)
Prior art keywords
constant velocity
velocity universal
universal joint
steel
graphite
Prior art date
Application number
PCT/JP2006/325444
Other languages
English (en)
Japanese (ja)
Inventor
Takashi Iwamoto
Kunikazu Tomita
Hideto Kimura
Yasuhiro Omori
Takaaki Toyooka
Kazuhiko Yoshida
Original Assignee
Jfe Steel Corporation
Ntn Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2006017924A external-priority patent/JP5016825B2/ja
Priority claimed from JP2006017826A external-priority patent/JP5016824B2/ja
Application filed by Jfe Steel Corporation, Ntn Corporation filed Critical Jfe Steel Corporation
Publication of WO2007086215A1 publication Critical patent/WO2007086215A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
    • F16D3/16—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts
    • F16D3/20—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members
    • F16D3/202—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints
    • F16D3/205—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints the pins extending radially outwardly from the coupling part
    • F16D3/2055—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints the pins extending radially outwardly from the coupling part having three pins, i.e. true tripod joints
    • 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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/06—Surface hardening
    • C21D1/09—Surface hardening by direct application of electrical or wave energy; by particle radiation
    • C21D1/10—Surface hardening by direct application of electrical or wave energy; by particle radiation by electric induction
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • 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
    • C21D9/28—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for plain shafts
    • 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
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • 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
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
    • F16D3/16—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts
    • F16D3/20—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members
    • F16D3/22—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members the rolling members being balls, rollers, or the like, guided in grooves or sockets in both coupling parts
    • F16D3/223—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members the rolling members being balls, rollers, or the like, guided in grooves or sockets in both coupling parts the rolling members being guided in grooves in both coupling parts
    • F16D3/226—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members the rolling members being balls, rollers, or the like, guided in grooves or sockets in both coupling parts the rolling members being guided in grooves in both coupling parts the groove centre-lines in each coupling part lying on a cylinder co-axial with the respective coupling part
    • F16D3/227—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members the rolling members being balls, rollers, or the like, guided in grooves or sockets in both coupling parts the rolling members being guided in grooves in both coupling parts the groove centre-lines in each coupling part lying on a cylinder co-axial with the respective coupling part the joints being telescopic
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2250/00—Manufacturing; Assembly
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2300/00—Special features for couplings or clutches
    • F16D2300/10—Surface characteristics; Details related to material surfaces
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Definitions

  • the present invention relates to a constant velocity universal joint that is manufactured by induction hardening and tempering and is used for an automobile having a rolling surface and a power transmission shaft having the constant velocity universal joint at one end of a stub shaft. It is intended to improve rolling fatigue characteristics after tempering, as well as machinability and forgeability during cold or warm working. Background art
  • Parts that make up constant velocity universal joints for automobiles and stub shafts that make up power transmission shafts use so-called steel for machine structural use, either cold forging or warm forging, or a combination of them, and further cut to a predetermined It is often manufactured according to a method that secures the required properties as machine parts by processing into a shape and then induction hardening and tempering.
  • steel for machine structural use it is common to add free-cutting elements such as Pb, S, Bi and P alone or in combination to the steel.
  • free-cutting elements such as Pb, S, Bi and P alone or in combination to the steel.
  • Pb is frequently used because it has an extremely strong effect of improving machinability.
  • Pb is also an element harmful to the human body, and it requires large exhaust facilities in the manufacturing process of steel materials and the process of adding machine parts, and it is problematic that it is included in steel materials from the viewpoint of steel recycling. .
  • the induction hardening and tempering treatment is often used in the field of machine parts and the like in order to form a hardened layer on the surface of the steel material in a short time and improve the wear resistance and fatigue strength.
  • the induction hardening and tempering treatment is applied to the steel using the above-described graphite precipitation, the solid solution of the graphite particles during the quenching heating is caused. Without progressing sufficiently, Graphite particles remain in the vicinity of the treated surface, or the graphite itself dissolves, but vacancies remain as traces of its existence, and these work as a stress concentration source due to rolling fatigue. This causes the problem of deterioration of rolling fatigue characteristics. Alternatively, these may act as a stress concentration source in a torsional fatigue environment, resulting in a problem that the torsional fatigue strength characteristics of the steel material deteriorate.
  • An object of the present invention is to advantageously solve the above-described problems of the prior art.
  • the object of the present invention is to cut at least as much as conventional Pb-added free-cutting steel without necessarily using a free-cutting component such as Pb and without inhibiting cold and warm forgeability.
  • the shaft is proposed together with its advantageous manufacturing method.
  • the inventors have industrially stabilized a steel material excellent in all of machinability, cold and warm forgeability, and rolling fatigue characteristics after induction hardening and tempering. As a result of intensive studies on the manufacturing method, the following knowledge was obtained.
  • the processing rate of cold or warm working before induction hardening is set to 50% or more in steel. It was also found effective to refine the dispersion of graphite particles and to promote solid solution of graphite in the parent phase by setting the heating temperature to 950 ° C or higher.
  • the present invention is derived from the above findings. That is, the gist of the present invention is as follows.
  • An outer member having a plurality of guide grooves on the inner peripheral portion, an inner member having a plurality of guide grooves on the outer peripheral portion, and a plurality of ball traps formed by the guide grooves of the outer member and the inner member.
  • a constant velocity universal joint provided with torque transmission balls respectively arranged on the bearings and a cage for holding these torque transmission balls,
  • the outer member and the heel member are made of steel having a graphite phase of 5 mass% or more of the C content at the time of molding of the member, and are present in the surface layer portion after induction quenching and tempering, and are caused by residual graphite particles and graphite A constant velocity universal joint with excellent rolling fatigue characteristics characterized by having an equivalent circle diameter of 7 ⁇ or less.
  • the outer member and tripod member are made of steel having a graphite phase of 5 mass% or more of the C content when forming the member, and are present in the surface layer portion after induction hardening and tempering.
  • a constant velocity universal joint with excellent rolling fatigue characteristics characterized by graphite particles and graphite-derived pores with an equivalent circle diameter of 7 ⁇ ra or less.
  • An outer member having a plurality of guide grooves on the inner peripheral portion, an inner member having a plurality of guide grooves on the outer peripheral portion, and a plurality of cross-bows formed by the guide grooves of the outer member and the inner member.
  • a constant velocity universal joint comprising a torque transmission ball arranged at each cross section of a lutrack and a cage for holding these torque transmission balls,
  • the outer member and the inner member are made of steel having a graphite phase of 5 mass% or more of the C content at the time of forming the member, and are present in the surface layer portion after induction quenching and tempering, and residual graphite particles and graphite-induced vacancy.
  • a constant velocity universal joint with excellent rolling fatigue characteristics characterized by a hole with an equivalent circle diameter of 7 ⁇ ra or less.
  • the component composition of the steel is C: 0.4 to 0.6 mass%
  • the steel material is used for the outer member, the inner member or the tripod member of the constant velocity universal joint. annealed After hot working, then forged and machined by molding the various members shape ⁇ then hit the making by performing induction hardening, 'said annealing 680 ° C to residence time in the 720 ° C 3 It is characterized by performing cold forging with a processing rate of 50% or more or warm forging with a processing rate of 50% or more in a temperature range of 3 points or less prior to induction hardening after that. A method for producing constant velocity self-joints with excellent dynamic fatigue characteristics.
  • the annealing is characterized in that the residence time at 680 ° C to 720 ° C is 3 hours or more, and at least the surface of the steel material is kept at a temperature of 950 ° C or more during the subsequent induction hardening.
  • the outer member, the inner member or the tripod member of the constant velocity universal joint is hot-worked and then annealed.
  • the annealing time is set to 3 hours or more at 680 ° C to 720 ° C, and thereafter
  • a method for producing a constant velocity universal joint excellent in rolling fatigue characteristics characterized in that at least the surface of a steel material is maintained at a temperature of 950 ° C or higher during induction hardening.
  • the stub shaft of the power transmission shaft is annealed after hot working the steel material, and then forged.
  • the annealing time is set to 3 hours or more at 680 ° C to 720 ° C, and prior to the subsequent induction hardening, the processing rate
  • a method for producing a power transmission shaft with excellent torsional fatigue characteristics characterized by performing cold forging with a temperature of 50% or more or A forging in a temperature range of 3 points or less.
  • the annealing is characterized in that the residence time at 680 ° C to 720 ° C is 3 hours or more, and at least the surface of the steel material is kept at a temperature of 950 ° C or more during the subsequent induction hardening.
  • the stub shaft of the power transmission shaft is subjected to annealing after hot working the steel material, and then In order to fabricate by forming into a predetermined shape by forging and cutting, and then performing induction hardening, the annealing time is set to 3 hours or more at 680 ° C to 720 ° C, and during the subsequent induction hardening heating
  • a method of manufacturing a power transmission shaft having excellent torsional fatigue characteristics characterized by maintaining at least the surface of a steel material at a temperature of 950 ° C or higher.
  • the steel material whose Miku mouth structure is controlled within an appropriate range is applied to parts requiring rolling fatigue in constant velocity universal joints and stub shafts in power transmission shafts, excellent workability is achieved.
  • Dynamic fatigue characteristics can be provided.
  • excellent fatigue characteristics can be imparted to the power transmission shaft incorporating the part.
  • the above effects can be realized without using elements that adversely affect the human body such as Pb, it is possible to provide products with extremely low environmental impact, including recycling.
  • FIG. 1 is a cross-sectional view showing a constant velocity universal joint of the present invention.
  • FIGS. 2A and 2B are sectional views showing another constant velocity universal joint of the present invention.
  • 3A, 3B, and 3C are cross-sectional views showing still another constant velocity universal joint of the present invention.
  • FIG. 4 is a cross-sectional view showing a power transmission shaft of the present invention.
  • the fixed type constant velocity universal joint shown in FIG. 1 is a joint between a cylindrical outer member 1 and an inner member 2 disposed inside the outer member 1.
  • the inner peripheral portion 1 a of the outer member 1 has a plurality of (for example, six) straight draft grooves 1 b extending in the axis L direction.
  • the spherical outer periphery of the member 2 has a plurality of (for example, six) linear guide grooves 2b that also extend in the axis L direction.
  • a plurality of (for example, six) torque transmission balls 3 are arranged on a ball track formed by the guide groove 1 b of the outer member 1 and the guide groove 2 b of the inner member 2. Is held by a cage 4.
  • the constant velocity universal joint having the above configuration has an operating angle (an axis that takes the axis center of the outer member 1 and an axis that takes the axis center of the shaft fitted to the inner member 2 and the operating angle is 0 °. Is a state in which these two axes coincide with each other, and the bending angle when the outer member 1 is fixed and the shaft is bent with reference to these axes; the angle formed by both axes) Rotation torque is transmitted under ⁇ At this time, the cage 4 rotates to the position of the torque transmission ball 3 moving on the ball track according to the inclination of the inner member 2, and the torque transmission ball 3 is rotated into the angle bisector ( ⁇ Z 2). This ensures the constant velocity of the joint.
  • Fig. 2A and Fig. 2B show a tri-board type constant velocity universal joint.
  • This constant velocity universal joint has, for example, three track grooves 5 in the periphery 1 a of the outer member 1, and has axial roller guide surfaces 5 a on both sides of each track groove 5.
  • the tripod member 6 incorporated in the inner side of the outer member 1 has three leg shafts 6a protruding in the radial direction.
  • a roller 8 is rotatably attached to each of the three leg shafts 6a of the tripod member 6 via a rolling element 7 such as a needle roller.
  • Each roller 8 is accommodated in a roller guide surface 5 a on both sides of the track groove 5.
  • FIGS 3A and 3B show cross group constant velocity universal joints.
  • This constant velocity universal joint has a plurality of (usually six) guide grooves 1 b on the spherical inner peripheral surface 1 a of the outer member 1, and similarly the spherical outer diameter surface 2 of the inner member 2.
  • a has a plurality of (usually 6) guide grooves 2b, and a plurality of ball tracks formed by the guide grooves 1b of the outer member 1 and the guide grooves 2b of the inner member 2 are arranged in an intersecting manner.
  • torque transmission balls 3 are arranged, and the torque transmission balls 3 are held by a cage 4.
  • the power transmission shaft 1 1 shown in Fig. 4 has a stub shaft 1 3 with a constant velocity universal joint 1 2 attached to one end and a stub shaft 1 5 with a constant velocity universal joint 1 4 attached to one end. It is welded and joined to the end of the.
  • a power transmission shaft 11 is, for example, a propeller shaft, and transmits a driving force from one to the other.
  • steel with a graphite phase of 5 raass% or more of the C content during the forming process of each material is reduced by reducing the amount of hard cementite due to the precipitation of graphite in the steel and cold forging.
  • the purpose is to improve deformability during warm forging and reduce deformation resistance.
  • graphite precipitation makes it possible to combine excellent machinability with steel materials, and according to each C amount, it is possible to obtain workability that could not be achieved with the same C amount.
  • the reason why the residual graphite particles and the pores caused by graphite in the surface layer after induction hardening and tempering are 7 m or less in terms of equivalent circle diameter is as follows.
  • the graphite exists even after induction hardening, the graphite becomes a stress concentration source in the environment of use, and the fatigue characteristics are remarkably deteriorated.
  • the fatigue characteristics are remarkably deteriorated.
  • graphite itself disappears, defects such as vacancies resulting from it remain in the steel, causing the same deterioration of fatigue properties.
  • the inventors have confirmed that if the size is equivalent to a circle equivalent diameter of 7 ⁇ or less, the fatigue properties are not directly affected.
  • the residual graphite particles and graphite-derived pores present in the surface layer portion after high-frequency quenching and tempering have an equivalent circle diameter of 7 / m or less.
  • Si is an element that does not dissolve in cementite and promotes graphitization by destabilizing cementite ⁇ and improves rolling life, so 0.5 mass% or more is added. To do. On the other hand, addition exceeding 1.0 raass% increases the deformation resistance during cold or warm processing, so the addition range is 0.5 to 1.0 raass%.
  • Mn 0-0.5 mass%
  • Mn is not only effective for deoxidizing steel, but is also an element that is useful for hardenability, so it is actively added. On the other hand, it dissolves in cementite and inhibits graphitization. . That is, addition of less than 0. lraass% has no effect on deoxidation, so at least
  • B combines with N in the steel to form BN, which acts as a nucleus for crystallization of graphite, promotes graphitization and refines the graphite grains. It is also an element useful for improving the hardenability of steel and ensuring the strength after quenching. That is, if the addition is less than 0.0003 raass%, the effect on graphitization and hardenability improvement is small, and addition of 0.0003 mass% or more is required, but if added over 0.0150 mass%, B Since stabilizing the cementite by dissolving it in the cementite will inhibit the graphitization, the addition should be 0.0150 mass% or less.
  • A1: 0.005-0.0lms% Al reacts with N in the steel to form A1N, which acts as a nucleation site for graphite and promotes graphitization, so it is actively added. That is, when the addition is less than 0.005 raass%, the effect is small, and the addition of at least 0.005 raass% is required. On the other hand, when it is added exceeding 0.1 lmass%, many A1 oxides are formed in the forging process. This oxide alone is not only a starting point for fatigue fracture, but extremely coarse graphite grains are formed with this oxide as a nucleus. In addition, since A1-based oxides are hard, the machinability is reduced by wearing the tool during cutting. For the above reasons, the amount of A1 added is limited to less than 0.1 lraass%.
  • O forms oxide-based non-metallic inclusions and reduces both cold and warm forgeability, machinability and fatigue strength, so it should be reduced as much as possible. Is acceptable.
  • P is an element that inhibits graphitization and deteriorates cold and warm forgeability by embrittlement of the ferrite layer.
  • segregation at the grain boundaries during quenching and tempering reduces the grain boundary strength, thereby reducing the resistance to fatigue crack propagation and lowering the fatigue strength. Therefore, it should be reduced as much as possible, but is allowed up to 0.020 ma S s%.
  • MnS in the steel, which becomes the starting point of cracking during cold and warm forging and degrades cold and warm forgeability.
  • MnS itself becomes a starting point for fatigue fracture, and it acts as a nucleus for crystallization of graphite to form coarse black lead. This has the effect of reducing fatigue strength, so it should be reduced as much as possible. However, it is allowed up to 0.035 mass%.
  • N combines with B to form BN, and this BN serves as a nucleus for crystallization of graphite, thereby remarkably refining graphite grains and promoting graphitization. Therefore, it is essential in the present invention.
  • BN is not sufficiently formed when added below 0.0015 mass%.
  • adding more than 0.0150 mass% promotes cracking of the flakes during continuous forging. Add less than 0150 mass%.
  • the balance other than the above elements is Fe and inevitable impurities.
  • the steel material whose components are adjusted to the above preferred composition is hot-worked, for example, hot-rolled steel bar is rolled into a steel bar, this steel bar is cut to a predetermined length and then annealed, and then cold or warm forging process Then, it is formed into various member shapes by cutting, and then induction hardening is performed to produce the outer member, inner member, triboard member, and stub shaft in the power transmission shaft of the constant velocity universal joint.
  • the above-mentioned annealing is performed with a residence time at 680 ° C to 720 ° C of 3 hours or more.
  • the above temperature range is a temperature range in which graphite formation proceeds during annealing, and it is difficult to secure the required amount of graphite precipitation without obtaining sufficient residence time in the temperature range.
  • the processing rate is 50% or more prior to induction hardening.
  • the graphite particles cannot be sufficiently divided by the target processing in the present invention, and the graphite particles dissolve in the matrix during induction hardening at low temperature. Cannot progress sufficiently. As a result, graphite particles or defects resulting from the induction tend to remain after induction hardening, and it is difficult to control the size to 7 or less. If the temperature exceeds the three points A in the case of warm forging, it occurs dissolution of the graphite particles into the steel matrix phase, warm and cold workability improving effect of due to the presence of graphite particles, reduced accordingly Will be.
  • the surface temperature of the steel material is less than 950 ° C during induction hardening, the solid solution of black lead particles does not progress sufficiently in the steel matrix, and prior graphite grains such as by cold working In the case where the micronization is not performed, defects such as graphite and vacancies due to the graphite are remarkably easily left and it is difficult to control the size to 7 ra or less.
  • the as-rolled 25 ⁇ ⁇ round bar was subjected to soft annealing accompanied by graphite precipitation, and then the microstructure and cold forgeability were investigated. Furthermore, the material was forged into the shape of each member of the constant velocity universal joint, either cold or warm. After that, the final shape of each member of the constant velocity universal joint shown in Fig. 1 to Fig. 3A and Fig. 3B was prepared by cutting, and induction hardening was performed. Each heat treatment condition is shown in Table 2. In addition, when heating during induction hardening, the time until the water cooling starts after reaching the maximum temperature during heating is maintained. It was time. After quenching, each part was tempered at 150 ° C for 2 hours.
  • a cylindrical test piece with a length of 15 ⁇ ⁇ X 22.5mm was prepared from the material after annealing, a compression test was performed using a 300t press, and the deformation resistance was calculated from the load during the test.
  • the deformation resistance when the compression rate (height reduction rate) is 60% is shown.
  • the number of repetitions was 10, and the presence or absence of cracks on the side of the specimen was confirmed.
  • the compression ratio at which half of the specimens after the test were cracked was defined as the deformability index as the critical compression ratio.
  • a drilling test was performed on each member after cold or warm working.
  • the tool was a straight drill with a coating diameter of 4 mm, and dry cutting was performed at a feed rate of 0.15 ram / rev.
  • the machinability was evaluated based on the drilling depth until cutting became impossible. [Surface hardness and effective curing depth]
  • the hardness and induction hardness distribution after induction hardening and tempering were measured. From the cross-sectional hardness distribution, the distance from the surface that had the following hardness according to the C content was measured as the effective hardened layer depth.
  • a rolling fatigue test was conducted on each member after induction hardening and tempering. That is, in the rolling fatigue test, a torque with a surface pressure of 2 ⁇ 8 GPa is applied to the track part of the outer ring, and the driving is performed at an operating angle of 5 ° and a rotational speed of 650 rpm. The operation time (life time) until chipping occurred and operability deteriorated was investigated. The test results are shown in Table 3 with the ratio of JIS-S53C as 1.
  • the properties of the steel are No. 15 steel corresponding to JIS-S53C, and No. 16 is obtained by adding Ca and Pb.
  • the steel materials within the scope of the present invention have excellent machinability and cold forgeability equivalent to or better than steels G and H (No. 15, 16) corresponding to S53C with and without Pb added. is doing. Even in the examples of the present invention, it was recognized that the higher the graphite area ratio, the better the machinability and cold forgeability.
  • a torsional fatigue test was performed on each member after induction hardening and tempering.
  • the torsional fatigue test was carried out under full swing conditions with constant velocity joints attached to both ends of the shaft (see Fig. 4), with a torque that gives a maximum shear stress of 0.5 GPa at an operating angle of 0 °. did.
  • the test results are shown in Table 4 with the number of repetitions until the rupture (number of ruptures) of steel I as the standard, and the ratio of the number of rupture repetitions to the fatigue life ratio.
  • No. 15 is a steel equivalent to JIS-S53C, and No. 16 is obtained by adding Ca and Pb to it.
  • Steel materials within the scope of the present invention have excellent machinability and cold forgeability equivalent to or better than steels G and H (No. 15, 16) corresponding to S53C with and without Pb added. is doing. Even in the examples of the present invention, it was recognized that the higher the graphite area ratio, the better the machinability and cold forgeability.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • Heat Treatment Of Articles (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

Joint universel homocinétique présentant une excellente tenue à la fatigue de roulement, dans lequel un acier au carbone pour structures de machines présentant une usinabilité favorablement comparable à celle des aciers de décolletage conventionnels au Pb, et présentant en même temps d'excellentes propriétés après nitruration, est utilisé dans au moins une pièce du joint universel homocinétique, et un arbre de transmission de puissance présentant une excellente tenue à la fatigue en torsion. Dans le joint universel homocinétique de l'invention, un élément extérieur et un élément intérieur sont constitués d'un acier doté d'une phase de graphite dont la teneur en carbone lors du moulage des éléments est supérieure ou égale à 5% en masse. Dans la partie superficielle après une trempe par induction et un revenu, des particules de graphite résiduelles et des pores issus du graphite présentent un diamètre circulaire équivalent ne dépassant pas 7 μm. L'arbre de transmission de puissance comporte un joint universel homocinétique installé à une extrémité d'un faux arbre. Le faux arbre est constitué d'un acier doté d'une phase de graphite dont la teneur en carbone lors du moulage est supérieure ou égale à 5% en masse. Dans la partie superficielle après une trempe par induction et un revenu, des particules de graphite résiduelles et des pores issus du graphite présentent un diamètre circulaire équivalent ne dépassant pas 7 μm.
PCT/JP2006/325444 2006-01-26 2006-12-14 Joint universel homocinetique presentant une excellente tenue a la fatigue de roulement, arbre de transmission de puissance presentant une excellente tenue a la fatigue en torsion, et processus pour leur production WO2007086215A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2006-017826 2006-01-26
JP2006017924A JP5016825B2 (ja) 2006-01-26 2006-01-26 捩り疲労特性に優れた動力伝達軸及びその製造方法
JP2006017826A JP5016824B2 (ja) 2006-01-26 2006-01-26 転動疲労特性に優れた等速自在継手及びその製造方法
JP2006-017924 2006-01-26

Publications (1)

Publication Number Publication Date
WO2007086215A1 true WO2007086215A1 (fr) 2007-08-02

Family

ID=38309016

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2006/325444 WO2007086215A1 (fr) 2006-01-26 2006-12-14 Joint universel homocinetique presentant une excellente tenue a la fatigue de roulement, arbre de transmission de puissance presentant une excellente tenue a la fatigue en torsion, et processus pour leur production

Country Status (1)

Country Link
WO (1) WO2007086215A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2388351A4 (fr) * 2009-01-16 2015-11-18 Nippon Steel & Sumitomo Metal Corp Acier pour durcissement en surface pour utilisation de structures de machines, et composant pour utilisation de structures de machines

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08283847A (ja) * 1995-04-12 1996-10-29 Nippon Steel Corp 靱性に優れた冷間鍛造用黒鉛鋼の製造方法
JP2000074082A (ja) * 1998-08-26 2000-03-07 Ntn Corp 等速ジョイント
JP2000204432A (ja) * 1999-01-12 2000-07-25 Ntn Corp 動力伝達軸
JP2000213553A (ja) * 1999-01-27 2000-08-02 Ntn Corp 等速自在継手
JP2005113157A (ja) * 2003-10-02 2005-04-28 Jfe Steel Kk 被削性並びに疲労特性に優れた鋼材およびその製造方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08283847A (ja) * 1995-04-12 1996-10-29 Nippon Steel Corp 靱性に優れた冷間鍛造用黒鉛鋼の製造方法
JP2000074082A (ja) * 1998-08-26 2000-03-07 Ntn Corp 等速ジョイント
JP2000204432A (ja) * 1999-01-12 2000-07-25 Ntn Corp 動力伝達軸
JP2000213553A (ja) * 1999-01-27 2000-08-02 Ntn Corp 等速自在継手
JP2005113157A (ja) * 2003-10-02 2005-04-28 Jfe Steel Kk 被削性並びに疲労特性に優れた鋼材およびその製造方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2388351A4 (fr) * 2009-01-16 2015-11-18 Nippon Steel & Sumitomo Metal Corp Acier pour durcissement en surface pour utilisation de structures de machines, et composant pour utilisation de structures de machines
US9777343B2 (en) 2009-01-16 2017-10-03 Nippon Steel & Sumitomo Metal Corporation Steel for surface hardening for machine structural use and part for machine structural use

Similar Documents

Publication Publication Date Title
EP1770181B1 (fr) Composant de structure mecanique, son procede de production et matiere de durcissement haute frequence
KR100845633B1 (ko) 기계구조용 부품 및 그 제조방법
JP5987992B2 (ja) ステアリングラックバー用圧延丸鋼材およびステアリングラックバー
WO2005116284A1 (fr) Tuyau d'acier inoxydable et sa méthode de production
JP5458048B2 (ja) 肌焼鋼およびその製造方法、並びに肌焼鋼を用いた機械構造部品
JP2008133530A (ja) 軸受鋼部品およびその製造方法並びに軸受
EP1731776A1 (fr) Dispositif de support de roue
JP2009127095A (ja) 動力伝達部品用肌焼鋼
JP2005232581A (ja) 疲労強度に優れた熱間鍛造品およびその製造方法
JP3815499B2 (ja) 機械構造用部品およびその製造方法
JP2005256897A (ja) 機械要素およびその製造方法
KR100883716B1 (ko) 기계구조용 부품 및 그 제조방법과 고주파 담금질용 소재
JP4320589B2 (ja) 機械構造軸部品とその製造方法
JP4940849B2 (ja) 減圧浸炭部品およびその製造方法
JP2005314756A (ja) 機械構造用部品
JP2008144226A (ja) 転動疲労特性に優れた等速自在継手及びその製造方法
WO2007086215A1 (fr) Joint universel homocinetique presentant une excellente tenue a la fatigue de roulement, arbre de transmission de puissance presentant une excellente tenue a la fatigue en torsion, et processus pour leur production
JP2841468B2 (ja) 冷間加工用軸受鋼
JP5016824B2 (ja) 転動疲労特性に優れた等速自在継手及びその製造方法
WO2017069064A1 (fr) Acier pour structures mécaniques et pièces d'acier durcies par induction
JP5016825B2 (ja) 捩り疲労特性に優れた動力伝達軸及びその製造方法
JP4127145B2 (ja) 疲労特性に優れた等速ジョイント内輪およびその製造方法
WO2023248556A1 (fr) Acier pour durcissement à haute fréquence
CN115335544B (zh) 钢材及渗碳钢部件
JP4127143B2 (ja) 疲労特性に優れた等速ジョイント外輪およびその製造方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 06835056

Country of ref document: EP

Kind code of ref document: A1