EP3533886A1 - Procédé de production d'élément en acier, et élément en acier - Google Patents

Procédé de production d'élément en acier, et élément en acier Download PDF

Info

Publication number
EP3533886A1
EP3533886A1 EP16919933.8A EP16919933A EP3533886A1 EP 3533886 A1 EP3533886 A1 EP 3533886A1 EP 16919933 A EP16919933 A EP 16919933A EP 3533886 A1 EP3533886 A1 EP 3533886A1
Authority
EP
European Patent Office
Prior art keywords
steel sheet
steel
less
carburized layer
content
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.)
Withdrawn
Application number
EP16919933.8A
Other languages
German (de)
English (en)
Other versions
EP3533886A4 (fr
Inventor
Riki Okamoto
Nobusato Kojima
Kazuo HIKIDA
Noriyuki Maekawa
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.)
Nippon Steel Corp
Original Assignee
Nippon Steel Corp
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 Nippon Steel Corp filed Critical Nippon Steel Corp
Publication of EP3533886A1 publication Critical patent/EP3533886A1/fr
Publication of EP3533886A4 publication Critical patent/EP3533886A4/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0257—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment with diffusion of elements, e.g. decarburising, nitriding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/20—Deep-drawing
    • 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
    • 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
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • 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
    • C21D1/62—Quenching devices
    • C21D1/673—Quenching devices for die quenching
    • 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
    • C21D1/78—Combined heat-treatments not provided for above
    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0447—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment
    • C21D8/0457—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment with diffusion of elements, e.g. decarburising, nitriding
    • 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
    • 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
    • C21D9/0081—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for slabs; for billets
    • 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
    • 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
    • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
    • 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
    • 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
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • 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
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • C23—COATING 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
    • C23C—COATING 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
    • C23C8/00—Solid 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
    • C23C8/06—Solid 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
    • C23C8/08—Solid 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
    • C23C8/20—Carburising
    • C—CHEMISTRY; METALLURGY
    • C23—COATING 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
    • C23C—COATING 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
    • C23C8/00—Solid 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
    • C23C8/06—Solid 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
    • C23C8/08—Solid 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
    • C23C8/20—Carburising
    • C23C8/22—Carburising of ferrous surfaces
    • C—CHEMISTRY; METALLURGY
    • C23—COATING 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
    • C23C—COATING 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
    • C23C8/00—Solid 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
    • C23C8/06—Solid 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
    • C23C8/28—Solid 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 more than one element being applied in one step
    • C23C8/30—Carbo-nitriding
    • C23C8/32—Carbo-nitriding of ferrous surfaces
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite

Definitions

  • the present invention relates to a manufacturing method of a steel component and a steel component.
  • a machine mounted on an automobile such as one typified by a torque converter or the like, and an industrial machine are generally configured by including a plurality of steel components having various shapes. Further, a lot of such steel components are formed by presswork.
  • Patent Literature 1 discloses a method in which when a pressed steel sheet is quenched, it is cooled while being held by metal dies, to thereby secure a good shape, but, since the steel sheet with high C amount is used, the toughness after the quenching has not been sufficient.
  • Patent Literature 1 Japanese Laid-open Patent Publication No. 10-96031
  • the present invention has an object to provide a manufacturing method of a steel component having high toughness, high abrasion resistance, high fatigue strength, and high shape fixability, and the steel component.
  • the steel component described in (5) or (6) is characterized in that an effective case depth is 0.05 to 0.5 mm.
  • the manufacturing method of the steel component of the present invention it is possible to manufacture the steel component having high toughness, high abrasion resistance, high fatigue strength, and high shape fixability. Further, the steel component of the present invention has high toughness, high abrasion resistance, high fatigue strength, and high shape fixability.
  • % being a unit of content of each element contained in a steel component and a steel sheet used for manufacturing the steel component means “mass%” unless otherwise mentioned.
  • a manufacturing method of a steel component according to a first embodiment has a step of heating a steel sheet in a carburizing atmosphere to form a carburized layer of austenite on a surface of the steel sheet (described as “carburizing step”, hereinafter), and a step of forming the steel sheet by using metal dies in a state where austenite exists and performing quenching on the steel sheet in a state of housing the steel sheet in the metal dies to transform austenite into martensite and make a part of the steel sheet on the further inside than the carburized layer to be a steel structure represented by ferrite with an area fraction of 50% or more (described as "hot stamping step", hereinafter).
  • the steel sheet has a chemical composition represented by, in mass%, C: 0.0005 to 0.1%, Si: 0.01 to 2.0%, Mn: 0.05 to 3.0%, Al: 0.9% or less, P: 0.05% or less, S: 0.01% or less, Ti: 0.0 to 0.2%, Nb: 0.0 to 0.1%, Cr: 0 to 2%, Mo: 0.0 to 0.2%, B: 0.000 to 0.005%, and the balance: Fe and impurities.
  • the impurities are those contained in a raw material such as an ore or scrap, and those contained during manufacturing processes.
  • the C content of the steel sheet is 0.0005 to 0.1% or less.
  • Si increases the strength through solid-solution strengthening. If an Si content exceeds 2.0%, an Ac3 transformation point is excessively increased, resulting in that it becomes difficult to austenitize a carburized layer and it is not possible to obtain martensite when performing quenching. Therefore, the Si content is 2.0% or less. On the other hand, an excessive reduction in the Si content leads to an increase in cost. Therefore, the Si content is 0.01 to 2.0%.
  • Mn is an element which increases the strength through the solid-solution strengthening. Further, Mn is an element which improves hardenability, so that if an Mn content exceeds 3.0%, even if the C content is 0.1% or less, the inside of the steel sheet is turned into martensite when performing the quenching, which makes the toughness deteriorate. Therefore, the Mn content is 3.0% or less. On the other hand, if the Mn content is reduced to less than 0.05%, a cost significantly increases. Therefore, the Mn content is 0.05% or more.
  • Al is not an essential element, and is contained as an impurity in the steel sheet, for example. Further, Al is an element which increases the strength through the solid-solution strengthening, and thus it may be optionally added. A formation of AlN makes an austenite grain diameter of the carburized layer finer and lower the hardenability, so that when the solid-solution strengthening is not required, the lower the Al content, the better. In particular, if the Al content exceeds 0.9%, the Ac3 transformation point is excessively increased, and it becomes difficult to austenitize the carburized layer. Therefore, the Al content is set to 0.9% or less. However, a cost is required to reduce the Al content, and if the Al content is tried to be reduced to less than 0.002%, the cost significantly increases. For this reason, the Al content may also be set to 0.002% or more.
  • P is not an essential element, and is contained as an impurity in the steel sheet, for example. From a viewpoint of the toughness of the carburized layer after the quenching, the lower the P content, the better. In particular, if the P content exceeds 0.05%, the toughness is lowered significantly. Therefore, the P content is set to 0.05% or less. However, a cost is required to reduce the P content, and if the P content is tried to be reduced to less than 0.001%, the cost significantly increases. For this reason, the P content may also be 0.001% or more.
  • S is not an essential element, and is contained as an impurity in the steel sheet, for example.
  • S forms MnS and lower the toughness of the carburized layer after the quenching, so that the lower the S content, the better.
  • the S content is set to 0.01% or less.
  • a cost is required to reduce the S content, and if the S content is tried to be reduced to less than 0.0005%, the cost significantly increases. For this reason, the S content may also be 0.0005% or more.
  • Ti, Nb, Cr, Mo, and B are not essential elements, but are optional elements which may be appropriately contained, up to a predetermined amount as a limit, in the steel sheet.
  • Ti contributes to make ferrite grains finer, and is used for obtaining a predetermined steel structure. Further, Ti increases the strength through precipitation strengthening. Therefore, Ti may be contained. However, if a Ti content exceeds 0.2%, ductility of the steel sheet before being subjected to carburizing treatment deteriorates. Therefore, the Ti content is 0.2% or less.
  • Nb contributes to make ferrite grains finer, and is used for obtaining the predetermined steel structure. Further, Nb increases the strength through the precipitation strengthening. Therefore, Nb may be contained. However, if an Nb content exceeds 0.1%, the ductility of the steel sheet before being subjected to the carburizing treatment deteriorates. Therefore, the Nb content is 0.1% or less.
  • Cr is a solid-solution strengthening element, so that it may be appropriately added for the purpose of increasing the strength.
  • Cr is an element which improves the hardenability, so that if a Cr content exceeds 2%, even if the C content is 0.1% or less, the inside of the steel sheet is turned into martensite when performing the quenching, which makes the toughness deteriorate. Therefore, the Cr content is 2% or less.
  • Mo is an element which improves the hardenability, so that if an Mo content exceeds 0.2%, even if the C content is 0.1% or less, the inside of the steel sheet is turned into martensite when performing the quenching, which makes the toughness deteriorate. Therefore, the Mo content is 0.2% or less.
  • B is an element which increases the hardenability of the steel sheet, and is used for controlling the steel structure. Therefore, B may be contained. However, if a B content exceeds 0.005%, the effect is saturated. Therefore, the B content is 0.005% or less.
  • the steel sheet preferably has a steel structure represented by ferrite with an area fraction of 70% or more. This is because, if a lot of hard structures of bainite, martensite, pearlite, and the like exist, the formability of the steel sheet deteriorates. Therefore, the area fraction of ferrite is preferably 70% or more.
  • a sheet thickness t of the steel sheet is not particularly limited. Further, a tensile strength of the steel sheet is preferably 630 MPa or less, more preferably 590 MPa or less, and still more preferably 440 MPa or less. In the present embodiment, an abrasion resistance and a fatigue strength of a steel component to be manufactured are secured by a carburized layer of a surface layer portion. Therefore, by suppressing the strength of the steel sheet itself to be used for manufacturing the steel component, it is possible to increase the toughness of the steel component to be manufactured. From a viewpoint of formability, the strength is preferably low.
  • a part of the steel sheet used for manufacturing the steel component is not subjected to plastic working at an equivalent strain in a range of 5% or more and less than 20%. This is because a part which is subjected to the working at the equivalent strain in the range of 5% or more and less than 20%, in the steel sheet, has crystal grains coarsened at a time of performing soaking in the carburizing step, resulting in that the toughness of the steel component to be manufactured is lowered. Note that a part which is not required to have high toughness may be subjected to the plastic working at the equivalent strain of 5% or more and less than 20%.
  • the carburizing is performed on the steel sheet having the above-described chemical composition and steel structure, and the steel structure of the surface layer portion of the steel sheet is turned into austenite.
  • the "carburizing" in the present invention includes carbonitriding as well. Therefore, a carburized layer to be formed includes a carbonitrided layer as well.
  • gas carburizing, vacuum carburizing can be applied, for example.
  • a soaking temperature (carburizing temperature) of the steel sheet in the carburizing step is 820 to 1100°C, for example.
  • the carburized steel sheet is directly pressed by metal dies and quenched.
  • the steel structure of the surface layer portion having carbon entered and diffused through the carburizing is austenitized.
  • the soaking temperature is more preferably 840°C or more.
  • the carburizing temperature exceeds 1100°C, there is a case where crystal grains become coarse and the toughness is lowered. Therefore, a preferable upper limit of the soaking temperature is 1100°C.
  • the C content of the surface layer portion is adjusted to be not less than 0.5% nor more than 0.9%, for example.
  • a soaking time at the above-described soaking temperature is, for example, not less than 1.0 hour nor more than 5.0 hours. If the soaking time is excessively short, an effective case depth of the carburized layer is difficult to reach a predetermined depth, which is, for example, 0.05 mm or more. Therefore, the soaking time is preferably 1.0 hour or more, and more preferably 1.5 hours or more. On the other hand, if the soaking time is excessively long, the effective case depth of the carburized layer becomes excessively large and becomes a depth exceeding a predetermined depth of 0.5 mm, for example. Therefore, the soaking time is preferably 5.0 hours or less, for example.
  • a temperature at which the austenitizing of the steel structure of the steel sheet starts becomes lower as the C content increases. For this reason, when the soaking temperature in this carburizing step is lower than the temperature at which the austenitizing of the steel structure of the steel sheet starts, the C content is increased from a surface of the steel sheet due to the inflitration of carbon, and in accordance with that, the temperature at which the austenitizing starts is lowered. In this case, the austenitizing starts at a portion where the temperature at which the austenitizing starts becomes lower than the soaking temperature.
  • a thickness of the carburized layer is increased in accordance with the lapse of time, and in accordance with the increase in the thickness of the carburized layer, a thickness of the austenitized portion is also increased from the surface.
  • the soaking temperature in this carburizing step is higher than the temperature at which the austenitizing of the steel structure of the steel sheet starts, the steel structure of the steel sheet is austenitized, and carbon enters the austenitized portion.
  • the steel sheet after being subjected to the carburizing step is subjected to hot stamping in a state where austenite exists in the steel sheet, for example, before the temperature of the steel sheet becomes 800°C or less.
  • the steel sheet is not subjected to quenching.
  • the carburizing step is terminated, the steel sheet is subjected to the soaking at a temperature of 820°C or more, and the steel structure of the surface layer portion of the steel sheet is in a state of austenite.
  • the C content of the surface layer portion of the steel sheet becomes not less than 0.5% nor more than 0.9%, for example.
  • austenite that exists in the surface layer portion of the steel sheet is turned into martensite. Further, a part of the steel sheet on the further inside than the carburized layer becomes a steel structure represented by ferrite with an area fraction of 50% or more.
  • metal dies in which a cooling medium circulates is used, for example. Further, the steel sheet in a state of having austenite is quenched by removing heat thereof while performing press forming on the steel sheet by using these metal dies.
  • the steel sheet with low C content for example, the steel sheet with the C content of 0.005 to 0.1% is subjected to the soaking at the temperature at which the surface layer portion is austenitized, and then subjected to the presswork in the state where austenite generated in this soaking exists.
  • a C content of a base material of the manufactured steel component to a low C content of, for example, 0.005 to 0.1%.
  • the steel structure of the base material to have ferrite with an area fraction of 50% or more. Accordingly, it is possible to manufacture the steel component having high toughness.
  • the carburized layer made of martensite is formed on the surface layer portion of the steel component by performing the carburizing step and the hot stamping step, the surface layer portion can be hardened more when compared to the inside (namely, the base material). Therefore, the abrasion resistance and the fatigue strength can be secured by the carburized layer made of martensite and existing in the surface layer portion of the steel component.
  • the metal dies is used to form the steel sheet, and the steel sheet is quenched in a state of being housed in these metal dies, so that it is possible to suppress a deformation of the steel component in the quenching. Therefore, it is possible to manufacture the steel component having excellent shape fixability. As described above, with the use of the manufacturing method of the steel component, it is possible to manufacture the steel component having high toughness, high abrasion resistance, high fatigue strength, and high shape fixability.
  • the steel sheet is one in which a part thereof required to have high toughness is not subjected to the plastic working at the equivalent strain in the range of 5% or more and less than 20%, it is possible to suppress that ferrite grains in that part grow abnormally and coarsen (for example, the grain diameter becomes 200 ⁇ m or more in terms of a circle-equivalent diameter). Therefore, when ferrite grains that exist in the steel sheet are not austenitized and remain in the steel component, it is possible to suppress a reduction in the toughness caused by the coarsened ferrite grains in the part required to have high toughness.
  • the steel component according to the embodiment of the present invention is manufactured by the above-described manufacturing method.
  • the steel component according to the present embodiment includes a base material, and a carburized layer made of martensite and existing on a surface of the base material.
  • a C content of the base material is 0.0005 to 0.1%, and a chemical composition of the base material is the same as the chemical composition of the steel sheet.
  • the C content of the base material can be analyzed by an EPMA at a center position of a sheet thickness of the steel component.
  • a steel structure of the base material contains ferrite.
  • the steel structure of the base material preferably has ferrite with an area fraction of 50% or more.
  • a part other than ferrite of the steel structure of the base material is, for example, pearlite and bainite.
  • a total area fraction of ferrite grains each having a grain diameter of 200 ⁇ m or more in terms of a circle-equivalent diameter (referred to as a coarse ferrite ratio, hereinafter) is preferably 5% or less.
  • the steel component manufactured by the manufacturing method of the present embodiment preferably has few number of ferrite grains coarsened by abnormal grain growth (ferrite grains each having a grain diameter of 200 ⁇ m or more in terms of a circle-equivalent diameter).
  • the coarse ferrite ratio of the base material is measured by the following method.
  • a sheet thickness of the steel component is defined as t (mm).
  • a sample is collected from an arbitrary position in a range of t/4 to 3t/4 from a surface of the steel component.
  • a surface (observation surface) of the sample is etched by nital.
  • ferrite grains are specified.
  • a circle-equivalent diameter of the specified each ferrite grain is determined.
  • a circle-equivalent diameter ( ⁇ m) is defined by a diameter of circle when each ferrite grain is converted to a circle having the same area. After the circle-equivalent diameter of each ferrite grain is determined, a coarse ferrite grain whose circle-equivalent diameter is 200 ⁇ m or more is specified. A total area of the coarse ferrite grains in the respective visual fields is determined, the total area is divided by a total area of the measured all visual fields, thereby determining a coarse ferrite ratio (area%).
  • the specification of ferrite, the calculation of the circle-equivalent diameter, and the coarse ferrite ratio can be carried out by using a general-purpose image processing application.
  • a Vickers hardness (HV) of the base material is preferably 250 or less. This is because if the hardness is excessively high, the toughness deteriorates. Further, a lower limit of the Vickers hardness (HV) of the base material is preferably 80, and more preferably 150. This is because the strength as a mechanical component is determined by not the hardness of the surface layer but the hardness of the base material.
  • the Vickers hardness (HV) of the base material is determined by the following method. Arbitrary three points at a center position of a sheet thickness of the steel component are selected. At the selected positions, a Vickers hardness test based on JISZ2244(2009) is performed. At this time, a test force is set to 2.942 N (0.3 kgf). An average value of the obtained hardness is defined as the Vickers hardness (HV) of the base material.
  • a C content of the carburized layer is, for example, not less than 0.5% nor more than 0.9%.
  • the C content of the carburized layer can be analyzed by the EPMA (electron probe micro analyzer).
  • a steel structure of the carburized layer is made of martensite.
  • a lower limit of the Vickers hardness (HV) of the carburized layer is preferably 500, and more preferably 600. This is for securing the abrasion resistance and the fatigue strength.
  • the Vickers hardness (HV) of the carburized layer is determined by the following method. In a carburized layer portion at a position in a depth direction of 0.05 mm from a surface of the steel component, arbitrary three points are selected. At the selected positions, the Vickers hardness test based on JISZ 2244(2009) is performed. At this time, a test force is set to 2.942 N (0.3 kgf). An average value of the obtained hardness is defined as the Vickers hardness (HV) of the carburized layer.
  • the C content of the base material of the steel component according to the present embodiment is 0.0005 to 0.1%, for example.
  • the area fraction of ferrite is 50% or more, and the coarse ferrite ratio is 5% or less, for example.
  • the steel component having such a base material has high toughness.
  • the carburized layer exists on the surface of the base material of the steel component. This carburized layer is made of martensite, and has excellent hardness. Therefore, the steel component has excellent abrasion resistance and fatigue strength.
  • the steel component according to the present embodiment is manufactured in a manner that the steel sheet is formed by using the metal dies, and the quenching is performed in a state of housing the steel sheet in these metal dies. For this reason, the steel component according to the present embodiment has excellent shape fixability. As described above, the steel component according to the present embodiment has high toughness, high abrasion resistance, high fatigue strength, and high shape fixability.
  • the manufacturing method of the steel component according to the second embodiment further includes a step of introducing a working strain into a steel sheet (referred to as "strain introducing step”, hereinafter), in a stage previous to the carburizing step.
  • strain introducing step a step of introducing a working strain into a steel sheet
  • the other steps are the same as those of the first embodiment.
  • a part required to have high toughness in a state of being formed into a steel component, in the steel sheet having the above-described chemical composition and steel structure, is subjected to working at an equivalent strain of less than 5% or 20% or more.
  • the method of plastic working is not limited, and presswork or rolling may be employed, for example.
  • a condition in the examples is a condition adopted to confirm feasibility and an effect of the present invention, and the present invention is not limited to this case of the condition.
  • the present invention it is possible to adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.
  • steel types having chemical compositions indicated in Table 1 were used.
  • Each of steel types A to D has a C content which falls within the range of the present invention, and a steel type E has a C content which is out of the range of the present invention.
  • a tensile strength was measured by a tensile test at room temperature in the atmosphere.
  • a ferrite fraction was 70% or more.
  • a steel sheet with a sheet thickness of 3.2 mm of each of the steel types was subjected to punching, to thereby manufacture a disk-shaped steel sheet 10 illustrated in FIG. 1 .
  • the steel sheet 10 is a disk having a through hole 20 at a center thereof.
  • An outside diameter of the steel sheet 10 is 200 mm, and an inside diameter of the steel sheet 10 is 50 mm.
  • FIG. 2 illustrates the manufactured steel component 30.
  • the steel component 30 has a bottom portion 50 at a peripheral edge portion thereof, and has a convex portion 40 at a center portion thereof.
  • An outside diameter of the convex portion 40 is 120 mm, and a height of the convex portion 40 from the bottom portion 50 is 3 mm.
  • step in Table 2, the manufacturing step of each test number is described.
  • A in the column of “step” indicates a manufacturing method in which the steel sheet 10 is subjected to soaking in a carburizing atmosphere to be carburized, and after that, it is subjected to press forming by using metal dies in a state where austenite exists in the steel sheet 10, and quenched, to thereby manufacture the steel component 30.
  • B in the column of “step” indicates a step of manufacturing the steel component 30 in a manner that the steel sheet 10 is pressed to be formed in a shape illustrated in FIG. 2 , the formed steel sheet 10 is subjected to soaking in a carburizing atmosphere to be carburized, and then subjected to oil quenching.
  • the convex portion 40 of the steel component 30 is formed together with the quenching, after the soaking in the carburizing atmosphere (carburizing step).
  • the convex portion 40 of the steel component 30 is formed through the presswork in the stage previous to the soaking in the carburizing atmosphere (carburizing step) and the quenching performed after that.
  • the column of "equivalent strain ratio in prior working step” indicates a maximum value of the equivalent strain introduced into the steel sheet in the prior working step.
  • the prior working step is working of introducing a strain into the steel sheet 10 in a stage previous to the soaking under the carburizing atmosphere. In this prior working step, a strain was introduced through cold rolling into the steel sheet 10 before being punched in the disk shape, and press forming work was simulated.
  • the column of "soaking temperature” indicates a soaking temperature under the carburizing atmosphere (a carburizing temperature with a unit of °C).
  • the column of "soaking time” indicates a soaking time (hr) of the steel sheet 10 under the carburizing atmosphere.
  • a steel structure of a carburized layer and a base material of the manufactured steel component 30 of each test number was observed by the following method.
  • the steel component 30 was cut in a radial direction, a sample including a cut surface of the bottom portion 50 was embedded in a resin, and the cut surface was polished.
  • the polished cut surface was etched by nital.
  • a carburized layer at a position in a depth direction of 0.05 mm from a surface of the surface layer portion and a base material at a center portion of a sheet thickness were observed by an optical microscope with a magnification of 100 to 500 diameters, to thereby specify a steel structure.
  • the EPMA was employed to specify C contents in the surface layer portion and the center portion of the sheet thickness.
  • the column of "shape fixability” indicates an evaluation result of the shape fixability of the steel component 30.
  • “ ⁇ ” indicates high shape fixability
  • " ⁇ " indicates low shape fixability.
  • the shape fixability was evaluated based on a flatness of the convex portion 40 and the bottom portion 50 of the steel component 30. The flatness was determined from a shape of the convex portion 40 and the bottom portion 50 of each test number measured by using a three-dimensional shape measuring machine. Further, when each of the flatness of the convex portion 40 and the flatness of the bottom portion 50 was 0.2 mm or less, the shape fixability was evaluated as high (indicated by " ⁇ ” mark in Table 2). On the other hand, when either the flatness of the convex portion 40 or the flatness of the bottom portion 50 exceeded 0.2 mm, the shape fixability was evaluated as low (indicated by " ⁇ ” mark in Table 2).
  • the column of "toughness” indicates an evaluation result of the toughness of the steel component 30.
  • “ ⁇ ” indicates high toughness
  • “ ⁇ ” indicates somewhat low toughness
  • “ ⁇ ” indicates low toughness. Note that the evaluation of " ⁇ ” is also included in the examples.
  • the toughness was evaluated based on a result of a Charpy impact test.
  • a Charpy impact test piece was collected from the bottom portion 50 of the manufactured steel component 30, and the collected test piece was used to perform the Charpy impact test at -20°C and at room temperature based on JIS Z2242(2005). After the test, it was judged whether or not penetration of crack in the test piece was confirmed. When the penetration of crack did not occur at both of -20°C and the room temperature, the toughness was judged as high (indicated by " ⁇ " mark in Table 2). On the other hand, when the penetration of crack occurred in the test piece and the test piece was divided into two after the test at both of -20°C and the room temperature, the toughness was judged as low (indicated by "X” mark in Table 2). Further, when the penetration occurred at -20°C, but it did not occur at the room temperature, the toughness was judged as somewhat low (indicated by " ⁇ ” mark in Table 2).
  • test numbers 1 to 5, and 9 to 11 are examples in which each of the C content and the manufacturing step of the steel sheet 10 is within the range of the present invention.
  • the test numbers 1, 2, 4, 5 are examples in which the equivalent strain ratio in the prior working step, the soaking temperature, and the soaking time are within more preferable ranges.
  • Each of the steel components 30 of these test numbers 1, 2, 4, 5 was formed of the carburized layer made of martensite and the base material containing ferrite, the C content of the carburized layer was within a range of 0.5 to 0.9%, and the C content of the base material was 0.1% or less. Further, the coarse ferrite ratio of the base material of each of the steel components 30 of these test numbers 1, 2, 4, 5 was 5% or less.
  • the Vickers hardness (HV) of the base material was lower than that of the carburized layer that exists in the surface layer portion and was 250 or less. Further, in the Charpy impact test, the penetration of crack was not observed in the test piece, and thus excellent toughness was exhibited. Besides, the carburized layer had high hardness of 500 or more. Further, since the hot stamping step was performed after the carburizing step, the steel components 30 of these test numbers 1, 2, 4, 5 had the excellent shape fixability.
  • the carbon concentration of the surface layer portion was high, the effective case depth was large, and the hardness of the surface layer portion was high, when compared to the test number 9 being an example in which the soaking time was less than one hour, the test number 10 being an example in which the soaking temperature was less than 820°C, and the test number 11 being an example in which the soaking time was less than one hour and the soaking temperature was less than 820°C.
  • the carbon concentration of the surface was low and the austenitizing was sufficiently performed, and thus the area ratio of martensite was low, but, in each of the test numbers 1, 2, 4, 5, the structure having martensite with an area ratio of 100% was obtained in the surface layer portion.
  • the coarse ferrite ratio of each of the steel components 30 of these test numbers 1, 2, 4, 5 was lower than that of the steel component of the test number 3 being an example in which the equivalent strain ratio in the prior working step did not satisfy less than 5% or 20% or more.
  • test numbers 6 to 8 are examples in each of which the step of the manufacturing method does not satisfy the requirement of the present invention. Since the hot stamping is not performed, the shape fixability is not good. Further, the test number 7 is an example in which the equivalent strain ratio in the prior working step does not satisfy the condition of less than 5% or 20% or more. In the test number 7, coarse ferrite is generated in the center portion of the sheet thickness, and the toughness deteriorates.
  • the test numbers 12 to 15 are examples in each of which the C content of the steel sheet 10 exceeds 0.1%, and thus the requirement of the present invention is not satisfied.
  • the C content of the center portion of the sheet thickness is high, and the ferrite fraction is 50% or less, resulting in that the toughness deteriorates.
  • the test number 13 is an example in which the C content of the steel sheet 10 exceeds 0.1% and the soaking time is less than one hour, and thus the C content of the steel sheet 10 and the soaking time do not satisfy the requirement of the present invention.
  • the test number 14 is an example in which the C content of the steel sheet 10 exceeds 0.1% and the soaking temperature is less than 820°C, and thus the C content of the steel sheet 10 and the soaking temperature do not satisfy the requirement of the present invention.
  • the test number 15 is an example in which the C content of the steel sheet 10 exceeds 0.1%, the soaking temperature is less than 820°C, and the soaking time is less than one hour, and thus the C content of the steel sheet 10, the soaking temperature, and the soaking time do not satisfy the requirement of the present invention.
  • the present invention can be utilized for an industry related to press forming of a steel component, for example.

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)
  • Chemical Kinetics & Catalysis (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
  • Heat Treatment Of Articles (AREA)
EP16919933.8A 2016-10-31 2016-10-31 Procédé de production d'élément en acier, et élément en acier Withdrawn EP3533886A4 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2016/082222 WO2018078844A1 (fr) 2016-10-31 2016-10-31 Procédé de production d'élément en acier, et élément en acier

Publications (2)

Publication Number Publication Date
EP3533886A1 true EP3533886A1 (fr) 2019-09-04
EP3533886A4 EP3533886A4 (fr) 2020-04-01

Family

ID=62024607

Family Applications (1)

Application Number Title Priority Date Filing Date
EP16919933.8A Withdrawn EP3533886A4 (fr) 2016-10-31 2016-10-31 Procédé de production d'élément en acier, et élément en acier

Country Status (10)

Country Link
US (1) US20190218637A1 (fr)
EP (1) EP3533886A4 (fr)
JP (1) JP6835095B2 (fr)
KR (1) KR20190042067A (fr)
CN (2) CN109906278B (fr)
BR (1) BR112019005488A2 (fr)
CA (1) CA3040634A1 (fr)
MX (1) MX2019004389A (fr)
RU (1) RU2711060C1 (fr)
WO (1) WO2018078844A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7235621B2 (ja) * 2019-08-27 2023-03-08 株式会社神戸製鋼所 低強度ホットスタンプ用鋼板、ホットスタンプ部品およびホットスタンプ部品の製造方法

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE59503930D1 (de) * 1995-06-30 1998-11-19 Picard Fa Carl Aug Stammblatt einer Säge, wie einer Kreis- oder Gattersäge, einer Trennscheibe, einer Schneide- oder einer Schabvorrichtung
CN1146499A (zh) * 1996-04-18 1997-04-02 上海交通大学 中碳高合金渗碳冷成型模具钢
JP3407562B2 (ja) 1996-09-20 2003-05-19 住友金属工業株式会社 高炭素薄鋼板の製造方法および部品の製造方法
JP3543557B2 (ja) * 1997-08-28 2004-07-14 住友金属工業株式会社 浸炭歯車
JP2000204464A (ja) * 1999-01-12 2000-07-25 Komatsu Ltd 表面処理歯車とその製造方法、製造装置
JP2001011541A (ja) * 1999-06-29 2001-01-16 Nippon Steel Corp プレス成形用テーラード鋼帯及びその製造方法
JP2005200670A (ja) * 2004-01-13 2005-07-28 Nippon Steel Corp 高強度部品の製造方法
EP1889929B1 (fr) * 2005-09-26 2013-01-02 Aisin Aw Co., Ltd. Procédé de carburation d'éléments d'acier
US9797045B2 (en) * 2011-02-10 2017-10-24 Nippon Steel & Sumitomo Metal Corporation Steel for carburizing, carburized steel component, and method of producing the same
JP5458048B2 (ja) * 2011-03-29 2014-04-02 株式会社神戸製鋼所 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
DE102012001862B4 (de) * 2012-02-01 2015-10-29 Benteler Defense Gmbh & Co. Kg Verfahren zur Herstellung eines Panzerungsbauteils und Panzerungsbauteil
JP6114616B2 (ja) * 2013-04-08 2017-04-12 本田技研工業株式会社 浸炭部品、その製造方法及び浸炭部品用鋼
JP6127694B2 (ja) * 2013-04-30 2017-05-17 大同特殊鋼株式会社 歯面強度及び歯元強度に優れた高強度歯車及びその製造方法
JP6260117B2 (ja) * 2013-06-05 2018-01-17 大同特殊鋼株式会社 浸炭部品とその製造方法
DE102013107100A1 (de) * 2013-07-05 2015-01-08 Thyssenkrupp Steel Europe Ag Verschleißfestes, zumindest teilweise unbeschichtetes Stahlteil
JP6143355B2 (ja) * 2013-10-22 2017-06-07 株式会社神戸製鋼所 絞り加工性と浸炭熱処理後の表面硬さに優れる熱延鋼板
CN104152916A (zh) * 2014-05-06 2014-11-19 上海大学 热冲压专用超高热导率耐磨模具钢热处理和等离子氮碳共渗表面处理工艺方法
CN104388950A (zh) * 2014-10-27 2015-03-04 无锡乐华自动化科技有限公司 大直径高碳钢齿轮、齿套加工工艺

Also Published As

Publication number Publication date
KR20190042067A (ko) 2019-04-23
EP3533886A4 (fr) 2020-04-01
RU2711060C1 (ru) 2020-01-15
CN109906278A (zh) 2019-06-18
CA3040634A1 (fr) 2018-05-03
CN109906278B (zh) 2022-03-15
CN113881900B (zh) 2022-08-30
BR112019005488A2 (pt) 2019-06-04
JPWO2018078844A1 (ja) 2019-06-24
MX2019004389A (es) 2019-07-15
US20190218637A1 (en) 2019-07-18
JP6835095B2 (ja) 2021-02-24
WO2018078844A1 (fr) 2018-05-03
CN113881900A (zh) 2022-01-04

Similar Documents

Publication Publication Date Title
US8491732B2 (en) Hot-rolled steel bar or wire rod
US8876988B2 (en) Steel for nitriding and nitrided part
JP5397247B2 (ja) 熱間圧延棒鋼または線材
JP5742801B2 (ja) 熱間圧延棒鋼または線材
EP3072987B1 (fr) Tôle en acier à teneur élevée en carbone et son procédé de production
EP2530178A1 (fr) Acier cémenté et matériau carburisé
US10808304B2 (en) Steel for induction hardening
CN108138292B (zh) 制造渗碳锻造钢材的方法
KR101626227B1 (ko) 피로 강도가 우수한 질화용 열연 강판, 질화용 냉연 강판 및 그들의 제조 방법 및 그들을 사용한 피로 강도가 우수한 자동차 부품
US20190300993A1 (en) Steel for Induction Hardening
US10801091B2 (en) Steel for induction hardening
US20190300994A1 (en) Steel for Induction Hardening
US20190241997A1 (en) Steel for Induction Hardening
WO2017115842A1 (fr) Acier cémenté, élément cémenté et procédé destiné à la production d'acier cémenté
JP6819504B2 (ja) 鋼部材
EP3533886A1 (fr) Procédé de production d'élément en acier, et élément en acier
US10344371B2 (en) Steel sheet for soft-nitriding treatment, method of manufacturing same, and soft-nitrided steel
TWI674323B (zh) 鋼構件的製造方法及鋼構件
WO2022176984A1 (fr) Tôle d'acier pour nitruration douce en phase gazeuse
KR102145259B1 (ko) 탄소공구강 열처리 방법과 이를 이용한 탄소공구강
CN110651053B (zh) 刀具用钢带的制造方法及刀具用钢带
JP5145774B2 (ja) 転がり軸受構成部材の製造方法および転がり軸受

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20190418

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
A4 Supplementary search report drawn up and despatched

Effective date: 20200304

RIC1 Information provided on ipc code assigned before grant

Ipc: C23C 8/32 20060101ALI20200227BHEP

Ipc: C22C 38/00 20060101ALI20200227BHEP

Ipc: C23C 8/22 20060101ALI20200227BHEP

Ipc: B21D 22/20 20060101ALI20200227BHEP

Ipc: C22C 38/02 20060101ALI20200227BHEP

Ipc: C21D 1/18 20060101ALI20200227BHEP

Ipc: C21D 8/02 20060101ALI20200227BHEP

Ipc: C21D 1/06 20060101ALI20200227BHEP

Ipc: C22C 38/38 20060101ALI20200227BHEP

Ipc: C21D 1/673 20060101ALI20200227BHEP

Ipc: C22C 38/04 20060101ALI20200227BHEP

Ipc: C21D 9/00 20060101AFI20200227BHEP

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20210310

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20210525