[go: up one dir, main page]

WO2019150437A1 - ボルト及び締結構造 - Google Patents

ボルト及び締結構造 Download PDF

Info

Publication number
WO2019150437A1
WO2019150437A1 PCT/JP2018/002991 JP2018002991W WO2019150437A1 WO 2019150437 A1 WO2019150437 A1 WO 2019150437A1 JP 2018002991 W JP2018002991 W JP 2018002991W WO 2019150437 A1 WO2019150437 A1 WO 2019150437A1
Authority
WO
WIPO (PCT)
Prior art keywords
mass
bolt
iron
less
oxide film
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/JP2018/002991
Other languages
English (en)
French (fr)
Inventor
浜田 孝浩
小林 大介
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nissan Motor Co Ltd
Original Assignee
Nissan Motor Co Ltd
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
Application filed by Nissan Motor Co Ltd filed Critical Nissan Motor Co Ltd
Priority to US16/965,652 priority Critical patent/US11708622B2/en
Priority to MX2020007755A priority patent/MX2020007755A/es
Priority to PCT/JP2018/002991 priority patent/WO2019150437A1/ja
Priority to JP2019568433A priority patent/JP6988922B2/ja
Priority to CN201880088043.6A priority patent/CN111655895B/zh
Priority to EP18904436.5A priority patent/EP3748032B1/en
Publication of WO2019150437A1 publication Critical patent/WO2019150437A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0093Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for screws; for bolts
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/02Pretreatment of the material to be coated
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D1/00General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18Hardening; Quenching with or without subsequent tempering
    • C21D1/25Hardening, combined with annealing between 300 degrees Celsius and 600 degrees Celsius, i.e. heat refining ("Vergüten")
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D1/00General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/74Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • C21D1/76Adjusting the composition of the atmosphere
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D3/00Diffusion processes for extraction of non-metals; Furnaces therefor
    • C21D3/02Extraction of non-metals
    • C21D3/04Decarburising
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D6/00Heat treatment of ferrous alloys
    • C21D6/002Heat treatment of ferrous alloys containing Cr
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D6/00Heat treatment of ferrous alloys
    • C21D6/005Heat treatment of ferrous alloys containing Mn
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D6/00Heat treatment of ferrous alloys
    • C21D6/008Heat treatment of ferrous alloys containing Si
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/525Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/54Furnaces for treating strips or wire
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/002Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/02Ferrous alloys, e.g. steel alloys containing silicon
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/34Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/04Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/04Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material
    • C23C28/042Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material including a refractory ceramic layer, e.g. refractory metal oxides, ZrO2, rare earth oxides
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/10Oxidising
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/10Oxidising
    • C23C8/12Oxidising using elemental oxygen or ozone
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/10Oxidising
    • C23C8/12Oxidising using elemental oxygen or ozone
    • C23C8/14Oxidising of ferrous surfaces
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16BDEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B33/00Features common to bolt and nut
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16BDEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B33/00Features common to bolt and nut
    • F16B33/06Surface treatment of parts furnished with screw-thread, e.g. for preventing seizure or fretting

Definitions

  • the present invention relates to a bolt, and more particularly, to a high-strength bolt that can easily manage a fastening axial force.
  • the delayed fracture is a kind of environmental embrittlement caused by the interaction of material-environment-stress, and is considered to be caused by the embrittlement of the material by hydrogen.
  • Surface treatment such as chrome plating is performed.
  • Patent Document 1 discloses a high-strength bolt that suppresses delayed fracture by using high-carbon steel having a predetermined composition containing silicon, and describes that it is preferable to coat with a chromium plating film or an iron phosphate film. Has been.
  • bolts using high carbon steel containing silicon are excellent in tensile strength and delayed fracture resistance, but have a large variation in fastening axial force with respect to tightening torque, making it difficult to manage the fastening axial force.
  • the present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a high-strength bolt that has excellent delayed fracture resistance and a stable fastening axial force. It is in.
  • the present inventors have found that bolts using high-carbon steel containing silicon have low affinity with the surface treatment material, and defects in the surface coating are caused by high tightening torque. As a result, it was found that the variation of the fastening axial force caused by the change in the friction coefficient of the bolt occurred.
  • the bolt of the present invention is 0.50 mass% or more and 0.65 mass% or less of carbon (C), 1.5 mass% or more and 2.5 mass% or less of silicon (Si), 1.0 mass% or more and 2.0 mass% or less of chromium (Cr), 0.2% by mass or more and 1.0% by mass or less of manganese (Mn); Containing 1.5% by mass or more and 5.0% by mass or less of molybdenum (Mo),
  • the total content of phosphorus (P) and sulfur (S) as impurities is 0.03% by mass or less,
  • the balance has a composition that is iron (Fe).
  • the surface is provided with an iron-based oxide film having a film thickness of 3 ⁇ m or more and 20 ⁇ m or less.
  • the fastening structure of the present invention is characterized in that a member to be fastened is fastened by the bolt.
  • an iron-based oxide film having a film thickness of 3 ⁇ m or more and 20 ⁇ m or less is provided on the surface, it is possible to provide a high-strength bolt that has excellent delayed fracture resistance and a stable fastening axial force. .
  • the bolt of the present invention will be described in detail.
  • the bolts are 0.50 mass% or more and 0.65 mass% or less of carbon (C), 1.5 mass% or more and 2.5 mass% or less of silicon (Si), and 1.0 mass% or more and 2.
  • the total content of phosphorus (P) and sulfur (S) as impurities is 0.03% by mass or less, and the balance is iron (Fe), and the film thickness is 3 ⁇ m to 20 ⁇ m on the surface.
  • the following iron-based oxide film is provided.
  • the iron-based oxide film is an oxide film formed by a reaction of the bolt itself by subjecting the rolled bolt to a predetermined heat treatment, for example, other materials such as a surface treatment material such as plating. Since it is not a film that covers the surface of the bolt, film defects such as peeling are unlikely to occur. Therefore, since the friction coefficient of the bolt does not change, variation in the fastening axial force with respect to the fastening torque can be suppressed.
  • the thickness of the iron-based oxide film is 3 ⁇ m or more and 20 ⁇ m or less.
  • the film thickness of the iron-based oxide film is less than 3 ⁇ m, the iron-based oxide film is thin and film defects are likely to occur due to tightening torque. Further, in order to form an iron-based oxide film exceeding 20 ⁇ m, tempering at a high temperature is necessary, and the tensile strength of the bolt is lowered. Further, when the thickness of the oxide film is increased, the strength of the oxide film itself is weakened and the oxide film is easily peeled off at the time of fastening.
  • the iron-based oxide film preferably contains a Si-based oxide.
  • the Si-based oxide is derived from silicon in the bolt that has entered the iron-based oxide film due to diffusion, and the iron-based oxide film contains the Si-based oxide, so that peeling of the iron-based oxide film during clamping is suppressed.
  • the iron-based oxide film preferably contains at least Fe 3 O 4 and Fe 2 SiO 4 .
  • the iron-based oxide film contains FeO 3 , the friction with the counterpart material is reduced and the fastening axial force with respect to the fastening torque is increased.
  • the iron-based acid oxide film contains Fe 2 SiO 4 , the affinity between the iron-based oxide film and the bolt base material is improved, and the iron-based oxide film is prevented from being peeled off. Variations can be suppressed.
  • the iron-based oxide film rich in Fe 3 O 4 on the surface side of the bolt base material side, it is preferable rich in Fe 2 SiO 4 to the bolt base material side from the surface side.
  • the iron-based oxide film has a layer mainly composed of Fe 2 SiO 4 on the bolt base material side and a layer mainly composed of FeO 3 on the surface side, thereby improving the affinity with the bolt base material.
  • the lubricity with the counterpart material is further improved.
  • a main component means containing 50 mass% or more.
  • the layer mainly composed of Fe 2 SiO 4 and the layer mainly composed of Fe 3 O 4 are formed by a difference in diffusion rate of iron, oxygen and silicon by a predetermined heat treatment.
  • the bolt preferably has a tensile strength of 1500 MPa to 1800 MPa. If the tensile strength is in the above range, fastening with a large fastening axial force is possible, and for example, it can be suitably used for the lower link of a reciprocating engine having a multi-link mechanism.
  • the said bolt has an iron-type oxide film on the surface
  • the said iron-type oxide film and the said to-be-fastened member contact directly the fastening structure which fastened the to-be-fastened member with the said bolt. Therefore, friction between the bolt and the mating member is reduced to prevent galling, and defects in the iron-based oxide film due to fastening can be prevented, and variation in fastening axial force can be suppressed.
  • Carbon (C) is 0.50 mass% or more and 0.65 mass% or less.
  • the carbon content is less than 0.50% by mass, sufficient tempering softening resistance cannot be obtained, and softening is performed by tempering, so that tempering at a high temperature cannot be performed and delayed fracture resistance is lowered.
  • the carbon content exceeds 0.65% by mass, the amount of cementite that accumulates hydrogen is remarkably increased, so that the delayed fracture resistance is not excellent.
  • Si silicon
  • Si Content of silicon (Si) is 1.5 mass% or more and 2.5 mass% or less. If the silicon content is less than 1.5% by mass, the tensile strength decreases, and sufficient temper softening resistance cannot be obtained, so that tempering at a high temperature cannot be performed, resulting in reduced delayed fracture resistance. . If the silicon content exceeds 2.5% by mass, the forgeability is remarkably deteriorated, so that it is difficult to form the bolt into a predetermined shape.
  • Content of chromium (Cr) is 1.0 mass% or more and 2.0 mass% or less.
  • the chromium content is less than 1.0% by mass, sufficient tempering softening resistance cannot be obtained, and tempering at a high temperature cannot be performed, so that delayed fracture resistance decreases.
  • content of chromium exceeds 2.0, the cold forgeability of steel materials will fall.
  • the content of manganese (Mn) is 0.2% by mass or more and 1.0% by mass or less.
  • Manganese is an element for improving hardenability, and the tensile strength is improved by including 0.2% by mass or more.
  • the manganese content exceeds 1.0% by mass, segregation to the crystal grain boundaries is promoted, whereby the grain boundary strength is lowered and the delayed fracture resistance is lowered.
  • Molybdenum is 1.5 mass% or more and 5.0 mass% or less. If the molybdenum content is less than 1.5% by mass, the amount of molybdenum-based carbides that serve as hydrogen trap sites is not sufficient, so that hydrogen embrittlement cannot be suppressed and delayed fracture resistance is reduced. Molybdenum is an effective element for increasing the hardenability to obtain a martensite structure, increasing softening resistance during tempering treatment, and obtaining high strength, but increases even if contained in excess of 5.0% by mass. The effect by cannot be obtained.
  • the total content of phosphorus and sulfur is 0.03% by mass or less, and more preferably 0.02% by mass or less. If the total content of phosphorus and sulfur exceeds 0.03% by mass, segregation at the grain boundary is promoted, the grain boundary bonding force is reduced, and the grain boundary strength is lowered, so that delayed fracture resistance is lowered.
  • the bolt of the present invention is heated to 900 ° C. to 950 ° C. and then quenched and quenched, and then the oxygen concentration is adjusted to an atmosphere containing oxygen lower than the atmosphere (20.95%) according to the screw diameter of the bolt. It can be produced by heating and tempering in a temperature range of 580 ° C. to 620 for 90 to 120 minutes.
  • the oxygen concentration is preferably tempered in an atmosphere containing oxygen of 10% or less, more preferably 5% or less.
  • Comparative Example 2 peeled off the oxide scale generated by the heat treatment.
  • Comparative Examples 4 and 5 a manganese phosphate coating and a zinc phosphate coating were formed on the iron-based oxide film, respectively.
  • Comparative Example 6 after the chromium plating was formed, the heat treatment shown in Table 2 was performed.
  • Fatigue strength of the bolts of Examples 1 to 3 and Comparative Examples 1 to 8 were attached to an axial fatigue tester at room temperature (25 ° C.) and in an air atmosphere using bolts and subjected to repeated tensile loads. A fatigue test was conducted, the tensile fatigue strength (MPa) was determined by the steer case method, and the safety factor for the required fatigue strength was calculated. (Implemented based on JISB1081) ⁇ : Safety factor 1.1 or more ⁇ : Safety factor less than 1.1

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Ceramic Engineering (AREA)
  • Heat Treatment Of Articles (AREA)
  • Connection Of Plates (AREA)

Abstract

本発明のボルトは、 0.50質量%以上0.65質量%以下の炭素(C)と、 1.5質量%以上2.5質量%以下のケイ素(Si)と、 1.0質量%以上2.0質量%以下クロム(Cr)と、 0.2質量%以上1.0質量%以下マンガン(Mn)と、 1.5質量%以上5.0質量%以下モリブデン(Mo)を含有し、 不純物であるリン(P)と硫黄(S)との合計含有量が0.03質量%以下であり、残部が、鉄(Fe)である組成を有し、 表面に膜厚が3μm以上20μm以下の鉄系酸化膜を備えており、耐遅れ破壊性に優れ、安定した締結軸力が得られる。

Description

ボルト及び締結構造
 本発明は、ボルトに係り、更に詳細には、締結軸力の管理が容易な高強度ボルトに関する。
 自動車の軽量化、コンパクト化、高性能化への要求から、ボルトの高強度化が要求されており、引張強さが1200MPaを超える高炭素鋼のボルトが知られている。
 しかし、高炭素鋼の高強度ボルトは、静的応力下において、ある時間経過後、突然脆性的に破壊する、所謂「遅れ破壊」の発生が顕著であり、ボルト強度が高いほどその発生の危険性が高い。
 上記遅れ破壊は、材料-環境-応力の相互作用によって生じる一種の環境脆化であり、水素による材料の脆化が原因であると考えられており、一般に、耐遅れ破壊性を向上させるために、クロムめっきなどの表面処理がなされる。
 特許文献1には、ケイ素を含む所定の組成の高炭素鋼を用いることで、遅れ破壊を抑制した高強度ボルトが開示され、クロムめっき皮膜やリン酸鉄皮膜で被覆することが好ましい旨が記載されている。
国際公開第2016/031528号
 高強度ボルトは、締結軸力が大きいことから、ボルトの折れや座面の陥没がないように締結軸力を管理することが重要であり、一般的にトルクレンチにより締めつけトルクを管理することで締結軸力を担保している。
 しかしながら、締めつけトルクは、その全てが締結軸力として作用するのではなく、ねじ面や座面の摩擦によっても消費されるため、同じトルクで締めつけてもボルトの表面荒さや潤滑状態などによって締結軸力がばらついてしまう。
 つまり、締めつけトルクが同じであっても、ボルトと被締結物との摩擦が大きいと摩擦損失が多く発生して締結軸力が小さくなり、逆に摩擦が小さいと締結軸力が大きくなる。
 特に、ケイ素を含む高炭素鋼を用いたボルトは、引張強度や耐遅れ破壊性が優れる一方で、締めつけトルクに対する締結軸力のばらつきが大きく、締結軸力の管理が困難である。
 また、高炭素鋼を用いたボルトに対し、相手材とのかじり防止や締結性の安定させるためにリン酸被膜などの表面処理を行うと、水素侵入による遅れ破壊が生じ易くなり、加えて表面荒れによる疲労強度低下が発生する。
 本発明は、このような従来技術の有する課題に鑑みてなされたものであり、その目的とするところは、耐遅れ破壊性に優れ、安定した締結軸力が得られる高強度ボルトを提供することにある。
 本発明者は、上記目的を達成すべく鋭意検討を重ねた結果、ケイ素を含む高炭素鋼を用いたボルトは、表面処理材との親和性が低く、高い締めつけトルクにより表面被膜に欠陥が生じ、ボルトの摩擦係数が変化しての締結軸力のばらつきが生じていることを突き止めた。
 そして、めっきやリン酸系被膜処理などの表面処理に替えて、表面に膜厚が3μm以上20μm以下の鉄系酸化膜を形成することにより、上記目的が達成できることを見出し、本発明を完成するに至った。
 即ち、本発明のボルトは、
 0.50質量%以上0.65質量%以下の炭素(C)と、
 1.5質量%以上2.5質量%以下のケイ素(Si)と、
 1.0質量%以上2.0質量%以下のクロム(Cr)と、
 0.2質量%以上1.0質量%以下のマンガン(Mn)と、
 1.5質量%以上5.0質量%以下のモリブデン(Mo)を含有し、
 不純物であるリン(P)と硫黄(S)との合計含有量が0.03質量%以下であり、
 残部が、鉄(Fe)である組成を有する。
 そして、表面に膜厚が3μm以上20μm以下の鉄系酸化膜を備えることを特徴とする。
 また、本発明の締結構造は、被締結部材を上記ボルトで締結したことを特徴とする。
 本発明によれば、表面に膜厚が3μm以上20μm以下の鉄系酸化膜を備えることとしたため、耐遅れ破壊性に優れ、安定した締結軸力が得られる高強度ボルトを提供することができる。
実施例のボルトの断面画像である。
 本発明のボルトについて詳細に説明する。
 上記ボルトは、0.50質量%以上0.65質量%以下の炭素(C)と、1.5質量%以上2.5質量%以下のケイ素(Si)と、1.0質量%以上2.0質量%以下のクロム(Cr)と、0.2質量%以上1.0質量%以下のマンガン(Mn)と、1.5質量%以上5.0質量%以下のモリブデン(Mo)を含有し、不純物であるリン(P)と硫黄(S)との合計含有量が0.03質量%以下であり、残部が、鉄(Fe)である組成を有し、表面に膜厚が3μm以上20μm以下の鉄系酸化膜を備える。
 上記鉄系酸化膜は、転造したボルトに対して所定の熱処理を行うことで、ボルト自体の反応によって形成される酸化膜であって、例えば、めっきのように、表面処理材など他の材料でボルトの表面を被覆する膜ではないため、剥離などの被膜欠陥が生じ難い。
 したがって、ボルトの摩擦係数が変化しないため、締め付けトルクに対する締結軸力のばらつきを抑制できる。
 上記鉄系酸化膜の膜厚は、3μm以上20μm以下である。鉄系酸化膜の膜厚が、3μm未満では、鉄系酸化膜が薄く締め付けトルクによって被膜欠陥が生じ易い。
 また、20μmを超える鉄系酸化膜を形成するには、高温での焼き戻しが必要であり、ボルトの引張強度が低下する。また、酸化膜の膜厚が厚くなると、酸化膜自体の強度が弱くなり、締結時の酸化膜の剥離を生じやすい。
 上記鉄系酸化膜は、Si系酸化物を含むことが好ましい。
 上記Si系酸化物は、拡散によって鉄系酸化膜に入り込んだボルト中のケイ素に由来し、鉄系酸化膜がSi系酸化物を含むことで、締め付け時における鉄系酸化膜の剥がれが抑制される。
 上記鉄系酸化膜は、少なくともFe及びFeSiOを含むことが好ましい。
 鉄系酸化膜がFeOを含むことで、相手材との摩擦が低減して締め付けトルクに対する締結軸力が大きくなる。また、鉄系酸酸化膜がFeSiOを含むことで、鉄系酸化膜とボルト基材との親和性が向上し、鉄系酸化膜の剥がれが防止されて締め付けトルクに対する締結軸力のばらつきを抑制できる。
 上記鉄系酸化膜が、Feをボルト基材側よりも表面側に多く含み、FeSiOを表面側よりもボルト基材側に多く含むことが好ましい。
 鉄系酸化膜が、ボルト基材側にFeSiOを主成分とする層と、表面側にFeOを主成分とする層を有することで、ボルト基材との親和性が向上すると共に、相手材との潤滑性がさらに向上する。
 なお、本発明において主成分とは、50質量%以上含むことをいう。
 上記FeSiOを主成分とする層と、Feを主成分とする層とは、所定の熱処理による鉄、酸素およびケイ素の拡散速度差によって層が形成される。
 上記ボルトは、引張強度が1500MPa以上1800MPa以下であることが好ましい。
 引張強度が上記範囲であれば、大きな締結軸力での締結が可能であり、例えば、複リンク機構を有するレシプロエンジンのロアリンクに好適に使用できる。
 そして、上記ボルトは、その表面に鉄系酸化膜を有するため、被締結部材を上記ボルトで締結した締結構造は、上記鉄系酸化膜と上記被締結部材とが直接接する。
 したがって、上記ボルトと相手材との摩擦が低減されてかじりが防止されると共に、締結による鉄系酸化膜の欠陥が防止されて締結軸力のばらつきを抑制できる。
 炭素(C)の含有量は、0.50質量%以上0.65質量%以下である。
 炭素の含有量が0.50質量%未満であると、十分な焼き戻し軟化抵抗が得られず、焼き戻しによって軟化するため、高温での焼き戻しができず、耐遅れ破壊性が低下する。
 また、炭素の含有量が0.65質量%を超えると、水素を集積するセメンタイトの量が著しく増加するため、耐遅れ破壊性が優れたものとならない。
 ケイ素(Si)の含有量は、1.5質量%以上2.5質量%以下である。
 ケイ素の含有量が1.5質量%未満であると引張強度が低下し、また、十分な焼き戻し軟化抵抗が得られず、高温での焼き戻しを実施できないため、耐遅れ破壊性が低下する。 ケイ素の含有量が2.5質量%を超えると、鍛造性が著しく悪化するため、ボルトを所定の形状に成形することが困難になる。
 クロム(Cr)の含有量は、1.0質量%以上2.0質量%以下である。
 クロムの含有量が1.0質量%未満であると、十分な焼き戻し軟化抵抗が得られず、高温での焼き戻しが実施できないため、耐遅れ破壊性が低下する。
 また、クロムの含有量が2.0を超えると鋼材の冷間鍛造性が低下する。
 マンガン(Mn)の含有量は、0.2質量%以上1.0質量%以下である。
 マンガンは焼入れ性向上元素であり、0.2質量%以上含むことで引張強度が向上する。
 また、マンガンの含有量が1.0質量%を超えると、結晶粒界への偏析が促進されることによって、粒界強度が低下し耐遅れ破壊性が低下する。
 モリブデン(Mo)の含有量は、1.5質量%以上5.0質量%以下である。
 モリブデンの含有量が1.5質量%未満であると、水素のトラップサイトとなるモリブデン系炭化物の生成量が十分なものとならないため、水素脆化を抑制できず耐遅れ破壊性が低下する。
 また、モリブデンは、マルテンサイト組織を得る焼入れ性を高め、焼戻し処理の際に軟化抵抗増加させ、高強度を得るために有効な元素であるが、5.0質量%超えて含有しても増加による効果が得られない。
 リンと硫黄との合計含有量は、0.03質量%以下であり、0.02質量%以下であることがより好ましい。
 リンと硫黄との合計含有量が、0.03質量%を超えると、粒界偏析が促進され、粒界結合力が小さくなって粒界強度が低下するため、耐遅れ破壊性が低下する。
 次にボルトの製造方法について説明する。
 本発明のボルトは、900℃~950℃に加熱したのち急冷して焼入れした後、ボルトのネジ径などに応じて酸素濃度が大気(20.95%)よりも低く酸素を含有する雰囲気に調節された雰囲気中で、580℃~620の温度範囲で90~120分間加熱し焼き戻すことで作製できる。酸素濃度については、より好ましくは10%以下、さらに好ましくは5%以下の酸素を含有する雰囲気で焼き戻しをすることが好ましい。
 大気中での焼き戻しでは、上記温度範囲内で充分な焼き戻しを行うと鉄系酸化膜の膜厚が厚くなりすぎて均質な鉄系酸化膜を形成できない。そして、高温で焼き戻しを行うと引張強度が低下し、低温で焼き戻しを行うと靱性が低下し疲労強度が低下する。
 以下、本発明を実施例により詳細に説明するが、本発明は下記実施例に限定されるものではない。
 下記表1に示す組成の高強度ボルト用炭素鋼に対して、冷間鍛造、ねじ転造を行った後、900℃以上で焼入れし、酸素濃度が3%となるようにNを導入した雰囲気中で下記表2に示す条件で焼き戻しを行い、高強度ボルトを得た。
 なお、比較例2、3、比較例6及び8は、Nを導入せず、大気中で焼き戻しを行った。
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
 上記表2中、比較例2は、熱処理によって生じた酸化スケールを剥離した。
 比較例4、5は、鉄系酸化膜上にそれぞれ、リン酸マンガン被膜、リン酸亜鉛被膜を形成した。
 比較例6は、クロムメッキを形成した後に、表2に示す熱処理を行った。
 実施例1~3及び比較例1~6の高強度ボルトの断面を撮影して鉄系酸化膜の膜厚を測定した。比較例4,5は鉄系酸化膜とリン酸系被膜との合計膜厚、比較例6はクロムメッキの膜厚を測定した。実施例2のボルトの断面を図1に示す。
 また、電子プローブマイクロアナライザー (Electron Probe Micro Analyzer; EPMA)で鉄系酸化膜の構成元素を分析した。
 さらに、実施例1~3及び比較例1~6の高強度ボルトを以下の条件で評価した。評価結果を表3に示す。
<疲労試験>
 実施例1~3及び比較例1~8のボルトの疲労強度を、ボルト実体品を用いて、室温(25℃)、大気雰囲気にて、軸方向疲労試験機に取り付け、繰返し引張荷重を作用させ疲労試験を行い、ステアケース法にて引張疲労強度(MPa)を求め、必要疲労強度に対する安全率を算出した。(JISB1081に基づいて実施)
 ○:安全率1.1以上
 ×:安全率1.1未満
<締結性試験>
 実施例1~3及び比較例1~8のボルトを規定の締結トルクで被締結物を締結した際のかじり異音の発生の有無により締結の安定性を評価した。
 ○:かじり異音なし
 ×:かじり異音発生
Figure JPOXMLDOC01-appb-T000003
 上記結果より、鉄系酸化膜の膜厚が3μm以上20μm以下を満たす実施例1~3は、締結による鉄系酸化膜の欠陥が防止されて締結安定性が優れ、かつ十分な焼き戻しが行われて疲労強度が優れることがわかる。
 また、鉄系酸化膜上にリン酸系被膜を形成した比較例4,5は、被膜が剥がれやすく被膜欠陥が生じ、比較例7,8は鉄系酸化膜が不均一で締結安定性が低下した。

Claims (6)

  1.  0.50質量%以上0.65質量%以下の炭素(C)と、
     1.5質量%以上2.5質量%以下のケイ素(Si)と、
     1.0質量%以上2.0質量%以下クロム(Cr)と、
     0.2質量%以上1.0質量%以下マンガン(Mn)と、
     1.5質量%以上5.0質量%以下モリブデン(Mo)を含有し、
     不純物であるリン(P)と硫黄(S)との合計含有量が0.03質量%以下であり、
     残部が、鉄(Fe)である組成を有し、
     表面に膜厚が3μm以上20μm以下の鉄系酸化膜を備えることを特徴とするボルト。
  2.  上記鉄系酸化膜が、Si系酸化物を含むことを特徴とする請求項1に記載のボルト。
  3.  上記鉄系酸化膜が、少なくともFe及びFeSiOを含むことを特徴とする請求項1又は2に記載のボルト。
  4.  上記鉄系酸化膜が、Feをボルト基材側よりも表面側に多く含み、FeSiOを表面側よりもボルト基材側に多く含むことを特徴とする請求項1~3のいずれか1つの項に記載のボルト。
  5.  引張強度が1500MPa以上1800MPa以下であることを特徴とする請求項1~4のいずれか1つの項に記載のボルト。
  6.  被締結部材をボルトで締結した締結構造であって、
     上記ボルトが上記請求項1~5のいずれか1つの項に記載のボルトであることを特徴とする締結構造。
PCT/JP2018/002991 2018-01-30 2018-01-30 ボルト及び締結構造 Ceased WO2019150437A1 (ja)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US16/965,652 US11708622B2 (en) 2018-01-30 2018-01-30 Bolt and fastened structure
MX2020007755A MX2020007755A (es) 2018-01-30 2018-01-30 Perno y estructura fijada.
PCT/JP2018/002991 WO2019150437A1 (ja) 2018-01-30 2018-01-30 ボルト及び締結構造
JP2019568433A JP6988922B2 (ja) 2018-01-30 2018-01-30 ボルト及び締結構造
CN201880088043.6A CN111655895B (zh) 2018-01-30 2018-01-30 螺栓和紧固结构
EP18904436.5A EP3748032B1 (en) 2018-01-30 2018-01-30 Bolt and fastened structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2018/002991 WO2019150437A1 (ja) 2018-01-30 2018-01-30 ボルト及び締結構造

Publications (1)

Publication Number Publication Date
WO2019150437A1 true WO2019150437A1 (ja) 2019-08-08

Family

ID=67477961

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/002991 Ceased WO2019150437A1 (ja) 2018-01-30 2018-01-30 ボルト及び締結構造

Country Status (6)

Country Link
US (1) US11708622B2 (ja)
EP (1) EP3748032B1 (ja)
JP (1) JP6988922B2 (ja)
CN (1) CN111655895B (ja)
MX (1) MX2020007755A (ja)
WO (1) WO2019150437A1 (ja)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120500549A (zh) 2023-01-13 2025-08-15 日产自动车株式会社 高强度螺栓

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011048971A1 (ja) * 2009-10-22 2011-04-28 日産自動車株式会社 高強度ボルト用鋼及び高強度ボルトの製造方法
JP2013163865A (ja) * 2012-01-11 2013-08-22 Kobe Steel Ltd ボルトおよびボルトの製造方法
WO2016031528A1 (ja) 2014-08-29 2016-03-03 日産自動車株式会社 高強度ボルト用鋼及び高強度ボルト

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5166912B2 (ja) * 2008-02-27 2013-03-21 日本パーカライジング株式会社 金属材料およびその製造方法
JP5417086B2 (ja) 2009-08-25 2014-02-12 東洋ゴム工業株式会社 タイヤ成形方法及びタイヤ成形型
JP5449925B2 (ja) * 2009-08-27 2014-03-19 株式会社神戸製鋼所 耐遅れ破壊性の改善された高強度ボルト及びその製造方法
US20120247618A1 (en) * 2010-03-11 2012-10-04 Daisuke Hirakami High strength steel material and high strength bolt excellent in delayed fracture resistance and methods of production of same
CN108026626B (zh) * 2015-09-07 2020-10-02 松下知识产权经营株式会社 形成于铁系基材的氧化覆膜、形成有该氧化覆膜的滑动部件、以及具备该滑动部件的设备

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011048971A1 (ja) * 2009-10-22 2011-04-28 日産自動車株式会社 高強度ボルト用鋼及び高強度ボルトの製造方法
JP2013163865A (ja) * 2012-01-11 2013-08-22 Kobe Steel Ltd ボルトおよびボルトの製造方法
WO2016031528A1 (ja) 2014-08-29 2016-03-03 日産自動車株式会社 高強度ボルト用鋼及び高強度ボルト

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3748032A4

Also Published As

Publication number Publication date
EP3748032A1 (en) 2020-12-09
MX2020007755A (es) 2020-09-24
CN111655895A (zh) 2020-09-11
US11708622B2 (en) 2023-07-25
US20210017618A1 (en) 2021-01-21
EP3748032A4 (en) 2020-12-09
CN111655895B (zh) 2023-03-14
EP3748032B1 (en) 2021-08-11
JPWO2019150437A1 (ja) 2021-01-28
JP6988922B2 (ja) 2022-01-05

Similar Documents

Publication Publication Date Title
EP2530178B1 (en) Case-hardened steel and carburized material
WO2012043074A1 (ja) 肌焼鋼およびその製造方法
CN104040004A (zh) 螺栓用钢,螺栓以及螺栓的制造方法
JP6114616B2 (ja) 浸炭部品、その製造方法及び浸炭部品用鋼
TW201525158A (zh) 螺栓用鋼及螺栓、以及該等之製造方法
JP2021006660A (ja) 鋼部品およびその製造方法
CN103374682A (zh) 带式无级变速机滑轮用钢和带式无级变速机滑轮
JP7422854B2 (ja) 鋼部品の製造方法及び鋼部品
CN101688281A (zh) 用于冷成形高性能机器零件的具有良好耐氢性的微合金化钢
JPH05255809A (ja) 軸受用鋼
JP6988922B2 (ja) ボルト及び締結構造
JP5707938B2 (ja) 冷間加工性に優れる肌焼鋼および高疲労強度浸炭材
JP2001026836A (ja) 冷間加工性、転動疲労強度およびねじり疲労強度に優れた高周波焼入用鋼ならびに機械構造用部品
JP4206112B2 (ja) 無段変速機用プーリ
JP6263874B2 (ja) 高Si浸炭用鋼の浸炭方法
KR20220004758A (ko) 중공 스태빌라이저용 전봉 강관
JP5103987B2 (ja) 転がり軸受構成部材の製造方法および転がり軸受
US6391124B1 (en) Non-heat treated, soft-nitrided steel parts
JP4569961B2 (ja) ボールネジまたはワンウェイクラッチ用部品の製造方法
JP3262994B2 (ja) 焼入性に優れた高硬度ステンレス鋼
JP7069519B2 (ja) ボルト
JP2596051B2 (ja) 浸炭部品の製造方法
JP3408324B2 (ja) 軸受用鋼および軸受部材
JP7684828B2 (ja) 浸炭部品
JPH05279796A (ja) 軸受用肌焼鋼

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18904436

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2019568433

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2018904436

Country of ref document: EP

Effective date: 20200831