WO2015060223A1 - Tôle d'acier laminée à chaud présentant une excellente dureté de surface après un traitement thermique de carburation et une excellente aptitude au façonnage à froid - Google Patents

Tôle d'acier laminée à chaud présentant une excellente dureté de surface après un traitement thermique de carburation et une excellente aptitude au façonnage à froid Download PDF

Info

Publication number
WO2015060223A1
WO2015060223A1 PCT/JP2014/077742 JP2014077742W WO2015060223A1 WO 2015060223 A1 WO2015060223 A1 WO 2015060223A1 JP 2014077742 W JP2014077742 W JP 2014077742W WO 2015060223 A1 WO2015060223 A1 WO 2015060223A1
Authority
WO
WIPO (PCT)
Prior art keywords
less
hot
crystal grains
steel
steel sheet
Prior art date
Application number
PCT/JP2014/077742
Other languages
English (en)
Japanese (ja)
Inventor
梶原　桂
土田　武広
Original Assignee
株式会社神戸製鋼所
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 株式会社神戸製鋼所 filed Critical 株式会社神戸製鋼所
Priority to DE112014004844.5T priority Critical patent/DE112014004844T5/de
Priority to US15/031,030 priority patent/US20160237515A1/en
Priority to CN201480057664.XA priority patent/CN105658829B/zh
Priority to MX2016005095A priority patent/MX2016005095A/es
Publication of WO2015060223A1 publication Critical patent/WO2015060223A1/fr

Links

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
    • 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
    • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • 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
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • 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
    • 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
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/10—Ferrous alloys, e.g. steel alloys containing cobalt
    • C22C38/105—Ferrous alloys, e.g. steel alloys containing cobalt containing Co and Ni
    • 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel 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
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • 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
    • 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
    • C21D2211/002—Bainite
    • 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
    • C21D2211/009—Pearlite

Definitions

  • the present invention relates to a hot-rolled steel sheet that exhibits a good cold workability during processing before heat treatment, and exhibits a predetermined surface hardness and a desired hardness even deep from the surface after carburizing heat treatment.
  • steel materials used as various structural parts especially for parts subjected to surface hardening by carburizing or carbonitriding to improve wear resistance and fatigue resistance, such as automobiles
  • the present invention relates to a hot-rolled steel sheet that is useful as a material for manufacturing a clutch, a damper, a gear (gear), and the like.
  • a case where the present invention is applied to clutches will be taken up as a representative, and the description will proceed.
  • the present invention is not limited to the manufacture of the present invention, and its excellent carburizing hardenability and carbonitriding are also described. It is effectively utilized as a material for manufacturing parts that require high surface hardness and excellent impact properties by making the surface layer hard while maintaining the high toughness of the core by utilizing the permeability.
  • cold working (cold forging) has advantages of higher productivity than hot working and warm working and good dimensional accuracy and yield of steel materials.
  • the problem in manufacturing parts by such cold working is that in order to ensure the strength of the cold-worked parts to be higher than the expected value, the strength, ie deformation, is inevitably required. It is necessary to use a steel material with high resistance. However, the higher the deformation resistance of the steel material to be used, there is a difficulty in reducing the life of the cold working mold.
  • carburizing heat treatment is performed to produce a high-strength part with a predetermined strength and surface hardness.
  • the cold workability before heat treatment is reduced. Therefore, there has been a demand for a solution that ensures both cold workability and improved surface hardness after carburizing heat treatment.
  • Patent Documents 2 to 6 are listed as conventional techniques related to hot-rolled steel sheets.
  • the hot-rolled steel sheet disclosed in Patent Document 2 has an area ratio of 70% or more of the metal structure in the ferrite phase, an average crystal grain size of 50 ⁇ m or less, an aspect ratio of 3 or less, and 70% of the ferrite grain boundary.
  • the above is composed of large-angle grain boundaries, the maximum diameter of the ferrite phase formed at the large-angle grain boundaries is 30 ⁇ m or less, and the area ratio of precipitates having a minimum diameter of 5 nm or more is 2% or less of the metal structure.
  • the average crystal grain size of the second phase having the largest area ratio among the remaining phases excluding the precipitates is 50 ⁇ m or less, and there is a large-angle grain boundary of the ferrite phase between the closest second phases. It is said that the balance between strength and stretch flangeability is improved.
  • the hot rolled steel sheet disclosed in Patent Document 3 has an average ferrite grain size of 1 to 10 ⁇ m, a standard deviation of ferrite grain size of 3.0 ⁇ m or less, and an inclusion shape ratio of 2.0 or less. It is said that stretch flangeability is improved.
  • the hot-rolled steel sheet disclosed in Patent Document 4 has a ferrite bainite structure with a ferrite phase fraction of 50% or more and a residual bainite structure in the range of 1 / 8t to 3 / 8t of the sheet thickness t. It is said that stretch flangeability is improved when the Mn microsegregation is in a range satisfying 0.10 ⁇ ⁇ / Mn.
  • the hot-rolled steel sheet disclosed in Patent Document 5 has a structure in which the area ratio of the ferrite phase is 20% or more, the area ratio of the tempered martensite phase is 10 to 60%, the area ratio of the martensite phase is 0 to 10%, By setting the volume ratio of the retained austenite phase to 3 to 15%, elongation and stretch flangeability are improved.
  • Patent Documents 2 to 5 are excellent in cold workability, there is no mention of the surface hardness after carburizing heat treatment, and the improvement effect is unknown.
  • the hot-rolled steel sheet (carburized steel strip) disclosed in Patent Document 6 has an average hardness of 170 HV or more up to a depth of 50 ⁇ m in the thickness direction surface layer portion, and has a metal structure of ferrite + pearlite, surface carbon
  • Patent Document 6 Although the hot-rolled steel sheet (carburized steel strip) disclosed in Patent Document 6 is excellent in surface hardness after carburizing heat treatment, there is no mention of cold workability and its improvement effect is unknown.
  • an object of the present invention is to provide a hot rolled steel sheet having both cold workability and surface hardness after carburizing heat treatment.
  • the carburizing heat treatment includes not only normal carburizing but also heat treating for carbonitriding.
  • the invention described in claim 1 The plate thickness is 2-10mm, Ingredient composition % By mass (hereinafter the same for chemical components) C: 0.05 to 0.30%, Mn: 0.3 to 3.0%, Al: 0.015 to 0.1%, N: 0.003 to 0.30% included,
  • the balance consists of iron and inevitable impurities, Organization In area ratio, Ferrite: 10-50%, Perlite: 15-50%,
  • the rest bainite About crystal grains of all phases containing the ferrite and pearlite (hereinafter referred to as “all crystal grains”),
  • the number of crystal grains having an aspect ratio (major axis / minor axis) of 3 or less is 60% or more of the number of all crystal grains, and the average crystal grain size of all crystal grains is in the range of 3 to 50 ⁇ m.
  • the invention described in claim 2 The hot rolled steel sheet according to claim 1, wherein among the inevitable impurities, Si: 0.5% or less, P: 0.030% or less, and S: 0.035% or less.
  • V selected from the group consisting of 0.5% or less (not including 0%), Ti: 0.1% or less (not including 0%), and Nb: 0.1% or less (not including 0%)
  • a hot rolled steel sheet that has a predetermined surface hardness after carburizing heat treatment while ensuring cold workability by equiaxing and refining crystal grains.
  • the hot-rolled steel sheet according to the present invention (hereinafter also referred to as “the steel sheet of the present invention” or simply “the steel sheet”) will be described in more detail.
  • the steel sheet of the present invention overlaps with the hot forging material (high strength and high toughness case hardening steel) described in Patent Document 1 above, but the structure is ferrite + pearlite main structure and the crystal grains are the same. It differs in that it is made axial and finer.
  • the steel sheet of the present invention has a thickness of 2 to 10 mm. If the plate thickness is less than 2 mm, rigidity as a structure cannot be secured. On the other hand, if the plate thickness exceeds 10 mm, it is difficult to achieve the tissue form defined in the present invention, and the desired effect cannot be obtained.
  • the lower limit of the plate thickness is preferably 3 mm or more, and more preferably 4 mm or more. Further, the upper limit is preferably 9 mm or less, and more preferably 7 mm or less.
  • C is an element indispensable for securing the core strength of the carburized (or carbonitrided) quenching part finally obtained. If it is less than 0.05%, sufficient strength cannot be obtained. However, if it is contained excessively, the toughness is deteriorated, and the machinability and cold forgeability are deteriorated and the workability is impaired, so 0.30% is made the upper limit.
  • a preferable content of C is in the range of 0.08 to 0.25%.
  • Mn is an element effective for deoxidation of molten steel, and in order to exert its effect effectively, it must be contained in an amount of 0.3% or more. However, if it is excessively contained, cold workability and machinability are reduced. In addition to having an adverse effect and increasing the amount of segregation to the crystal grain boundary, it lowers the grain boundary strength and thus adversely affects the impact characteristics, so it must be suppressed to 3.0% or less.
  • a preferable content of Mn is in the range of 0.5 to 2.0%.
  • Al is an element contained in steel as a deoxidizing material for steel, and has an action of binding to N in steel to produce AlN and preventing coarsening of crystal grains. In order to exert such an effect effectively, it must be contained at 0.015% or more, but the effect is saturated at about 0.1%, and beyond that, it combines with oxygen to form a non-metallic inclusion, Since it adversely affects the characteristics, etc., the upper limit was set to 0.1%. Preferably it is 0.08% or less, More preferably, it is 0.06% or less, Most preferably, it is 0.04% or less.
  • N combines with Al, V, Ti, Nb, etc. in steel to produce nitrides, and has the effect of suppressing the coarsening of crystal grains.
  • the effect is by containing 0.003% or more. Effectively demonstrated. Preferably, it is 0.005% or more. However, these effects are saturated at about 0.30%, and if it is contained more than that, nitrides become inclusions and adversely affect the physical properties, so 0.30% was set as the upper limit.
  • it is 0.10% or less, More preferably, it is 0.05% or less, Most preferably, it is 0.03% or less.
  • the steel sheet of the present invention basically contains the above components, and the balance is iron and inevitable impurities, but it is desirable to suppress Si, P and S which are inevitably mixed in as little as possible for the following reasons.
  • Si effectively acts as a strengthening element or a deacidifying element, but promotes grain boundary oxidation to deteriorate bending fatigue properties and adversely affects cold forgeability. Therefore, in order to eliminate such obstacles, the content must be suppressed to 0.5% or less, and particularly when a high level of bending fatigue characteristics is required, it is desirable to suppress the content to 0.1% or less. It is. From such a viewpoint, the more preferable content of Si is in the range of 0.02 to 0.1%.
  • ⁇ P 0.030% or less> P segregates at the grain boundaries and lowers the toughness, so the upper limit was set to 0.030%.
  • the more preferable content of P is 0.020% or less, and further preferably 0.010% or less.
  • S generates MnS and contributes to the improvement of machinability.
  • the S content must be suppressed to 0.035% or less.
  • the more preferable content of S is 0.025% or less, and further preferably 0.020% or less.
  • the steel sheet of the present invention can contain the following permissible components within the range not impairing the action of the present invention.
  • Cr has an excellent effect of improving hardenability
  • Mo is an incompletely hardened structure. This effectively acts to improve the hardenability and the grain boundary strength, and Ni contributes to the improvement of impact resistance by refining the structure after quenching.
  • Such an effect is preferably exhibited by containing at least one of Cr: 0.2% or more, Mo: 0.08% or more, and Ni: 0.2% or more.
  • Cu is an element that effectively acts to improve corrosion resistance, and the effect is preferably exerted by inclusion of 0.3% or more, but the effect is saturated at 2.0%, so it is contained more than that. Is useless. If Cu is contained alone, the hot workability of the steel material tends to deteriorate. Therefore, in order to avoid such adverse effects, Ni having the effect of improving the hot workability should be used in the above content range. Is desirable.
  • Cu and Co are elements that have an effect of strain aging and hardening the steel material, and are effective in improving the strength after processing.
  • these elements are preferably contained in an amount of 0.1% or more, and more preferably 0.3% or more.
  • the Co content is excessive, the effects of strain aging and hardening of the steel material, and the effect of improving the strength after processing are saturated, and there is a possibility of promoting cracking, so the Co content is It is recommended to set it to 5% or less, further 4% or less, especially 3% or less.
  • V 0.5% or less (excluding 0%)
  • Ti 0.1% or less (excluding 0%)
  • Nb at least one selected from the group consisting of 0.1% or less (not including 0%)>
  • V 0.03%
  • Ti 0.005%
  • Nb 0.005%
  • action which improves the impact characteristic of a horizontal eye, since those effects are saturated at 0.08%, respectively, it is 0.08% or less, Furthermore, 0.05% or less, Especially 0.01% or less It is recommended to do.
  • the preferable lower limit for making the said effect of these elements exhibit effectively is Ca: 0.0005% (further 0.001%), Zr: 0.002%.
  • Sb 0.02% or less (excluding 0%)> Sb is an element effective for suppressing the grain boundary oxidation and increasing the bending fatigue strength, but since the effect is saturated at 0.02%, the addition of more is economically useless.
  • a preferable lower limit value for effectively exhibiting the effect of addition of Sb is 0.001%.
  • ⁇ REM 0.05% or less (excluding 0%), Mg: 0.02% or less (excluding 0%), Li: 0.02% or less (excluding 0%), Pb: 0.5% or less (excluding 0%), Bi: at least one selected from the group consisting of 0.5% or less (excluding 0%)> REM, like Zr and Ca, is an element that spheroidizes sulfide compound inclusions such as MnS to increase the deformability of steel and contribute to the improvement of machinability.
  • REM is preferably contained in an amount of 0.0005% or more, more preferably 0.001% or more. However, even if contained excessively, the effect is saturated and an effect commensurate with the content cannot be expected.
  • REM means a lanthanoid element (15 elements from La to Ln), Sc (scandium) and Y (yttrium). Among these elements, it is preferable to contain at least one element selected from the group consisting of La, Ce and Y, more preferably La and / or Ce.
  • Mg is an element that spheroidizes sulfide compound inclusions such as MnS to increase the deformability of steel and contribute to the improvement of machinability.
  • Mg is preferably contained in an amount of 0.0002% or more, more preferably 0.0005% or more.
  • 0.02% or less is saturated and an effect commensurate with the content cannot be expected, so 0.02% or less, further 0.015% or less, and particularly 0.01% or less is recommended.
  • Li like Zr and Ca, can spheroidize sulfide compound inclusions such as MnS to improve the deformability of steel, and lower the melting point of Al-based oxides to make them harmless. It is an element that contributes to improvement.
  • Li is preferably contained in an amount of 0.0002% or more, and more preferably 0.0005% or more. However, even if contained excessively, the effect is saturated and an effect commensurate with the content cannot be expected, so 0.02% or less, further 0.015% or less, and particularly 0.01% or less is recommended.
  • Pb is an effective element for improving machinability.
  • Pb is preferably contained in an amount of 0.005% or more, and more preferably 0.01% or more. However, if it is contained excessively, production problems such as generation of rolling defects occur, so 0.5% or less, further 0.4% or less, particularly 0.3% or less is recommended.
  • Bi is an element effective for improving the machinability like Pb.
  • Bi is preferably contained in an amount of 0.005% or more, and more preferably 0.01% or more.
  • the effect of improving the machinability is saturated even if contained excessively, 0.5% or less, further 0.4% or less, and particularly 0.3% or less are recommended.
  • the steel sheet of the present invention is mainly composed of ferrite and pearlite, and in particular, the degree of equiaxing and the size of crystal grains of all phases including ferrite and pearlite are controlled within a specific range. It is characterized by doing.
  • ⁇ Structure consists of ferrite: 10-50%, pearlite: 15-50%, balance: bainite>
  • the proportion of phases is an important factor that determines the strength level of the steel sheet.
  • the tensile strength needs to be about 350 to 700 MPa from the viewpoint of ensuring the cold workability and the strength of the base material at the center portion of the plate thickness after the heat treatment.
  • the tensile strength is less than 350 MPa, the surface hardness is ensured even after the carburizing heat treatment, but the hardness of the portion deep from the surface is insufficient, and the strength and hardness of the center portion of the plate thickness are insufficient.
  • the tensile strength exceeds 700 MPa, cold workability before heat treatment cannot be ensured.
  • the strength level if there is too little ferrite and / or too much pearlite, the tensile strength becomes too high and molding is impossible.
  • the base strength is insufficient, the strength at the center of the plate thickness is insufficient, and the fatigue strength is reduced. For this reason, it is assumed that the structure is composed of ferrite: 10 to 50% and pearlite: 15 to 50% in area ratio. The balance is bainite.
  • the number of crystal grains with an aspect ratio (major axis / minor axis) of 3 or less is 60% or more of the total number of crystal grains> It is necessary for the shape of the crystal grains to be equiaxed grains in order to improve both stretch flangeability (hole expandability) and secure the hardness of the center of the plate thickness, which is a deep portion from the surface after heat treatment. Therefore, the number of crystal grains that are equiaxed grains and have an aspect ratio (major axis / minor axis) of 3 or less is 60% or more, preferably 70% or more, more preferably 80% or more of the total number of crystal grains. And
  • “all crystal grains” mean crystal grains of all phases including the ferrite and pearlite.
  • the average crystal grain size of all crystal grains is in the range of 3-50 ⁇ m> If the crystal grains become too large, the surface properties deteriorate, causing surface cracks, and the hole expandability deteriorates. For this reason, the average crystal grain size of all crystal grains is 50 ⁇ m or less, preferably 40 ⁇ m or less, and more preferably 30 ⁇ m or less. On the other hand, as the lower limit value, the finer the crystal grains, the better the characteristics, but it is necessary to increase the rolling capacity and cooling capacity, and the productivity is lowered. For this reason, the average crystal grain size of all crystal grains is 3 ⁇ m or more, preferably 5 ⁇ m or more, and more preferably 7 ⁇ m or more.
  • the steel sheet of the present invention is obtained, for example, by melting and casting raw material steel having the above-mentioned composition to form a slab, and by subjecting the slab as it is or surface chamfered to each step of heating, hot rough rolling, and finish rolling. It can be manufactured as a hot rolled coil rising material. Thereafter, pickling and skin pass may be further performed according to necessary conditions such as surface condition and plate thickness accuracy.
  • a desired oxide can be generated by adding a predetermined alloy element in a predetermined order to molten steel in which the dissolved oxygen amount and the total oxygen amount are adjusted. Particularly in the present invention, it is extremely important to adjust the total oxygen amount after adjusting the dissolved oxygen amount so that coarse oxides are not formed.
  • Dissolved oxygen means oxygen in a free state that does not form oxides and exists in molten steel. Total oxygen means the sum of all oxygen contained in molten steel, that is, free oxygen and oxygen forming oxides.
  • the dissolved oxygen content of the molten steel is adjusted to a range of 0.0010 to 0.0060%.
  • the amount of dissolved oxygen in the molten steel is less than 0.0010%, the amount of dissolved oxygen in the molten steel is insufficient, so that a predetermined amount of Al—O-based oxide cannot be secured, and a desired size distribution cannot be obtained.
  • the amount of dissolved oxygen is set to 0.0010% or more.
  • the dissolved oxygen is preferably 0.0013% or more, more preferably 0.0020% or more.
  • the amount of dissolved oxygen should be suppressed to 0.0060% or less.
  • the amount of dissolved oxygen is preferably 0.0055% or less, more preferably 0.0053% or less.
  • the amount of dissolved oxygen in molten steel primarily refined in a converter or electric furnace usually exceeds 0.010%. Therefore, in the production method of the present invention, it is necessary to adjust the amount of dissolved oxygen in the molten steel to the above range by some method.
  • Examples of the method for adjusting the amount of dissolved oxygen in the molten steel include a method of vacuum C deoxidation using an RH type degassing refining device, a method of adding a deacidifying element such as Si, Mn, and Al.
  • the amount of dissolved oxygen may be adjusted by appropriately combining these methods.
  • a method of adding a deacidifying element such as Si may be adopted to adjust the amount of dissolved oxygen.
  • the deoxidizing element may be added when steel is removed from the converter to the ladle.
  • the molten steel is stirred, and the oxides in the molten steel are floated and separated so that the total oxygen content in the molten steel is 0.0010 to 0.00. Adjust to 0070%.
  • the molten steel in which the amount of dissolved oxygen is appropriately controlled is stirred to remove unnecessary oxides, and then generation of coarse oxides, that is, coarse inclusions can be prevented.
  • the total oxygen amount is set to 0.0010% or more.
  • the total oxygen amount is preferably 0.0015% or more, more preferably 0.0018% or more.
  • the total oxygen amount should be suppressed to 0.0070% or less.
  • the total oxygen amount is preferably 0.0060% or less, more preferably 0.0050% or less.
  • the total amount of oxygen in the molten steel changes generally in correlation with the stirring time of the molten steel, it can be controlled by adjusting the stirring time. Specifically, the total amount of oxygen in the molten steel is appropriately controlled while appropriately measuring the total amount of oxygen in the molten steel after stirring the molten steel and removing the floating oxide.
  • the total oxygen content in the molten steel is adjusted to the above range, and then REM is added before casting.
  • the desired oxide can be obtained by adding the above elements to the molten steel with the total oxygen content adjusted.
  • the form of REM and Ca added to the molten steel is not particularly limited.
  • REM pure La, pure Ce, pure Y, or pure Ca
  • Fe—Si—La alloy, Fe—Si—Ce alloy, An Fe—Si—Ca alloy, Fe—Si—La—Ce alloy, Fe—Ca alloy, Ni—Ca alloy, or the like may be added.
  • Misch metal is a mixture of cerium group rare earth elements, and specifically contains about 40 to 50% Ce and about 20 to 40% La.
  • misch metal often contains Ca as an impurity, when the misch metal contains Ca, it is necessary to satisfy the preferred range defined in the present invention.
  • the stirring time is preferably within 40 minutes.
  • the stirring time is more preferably within 35 minutes, and further preferably within 30 minutes.
  • the lower limit of the stirring time of the molten steel is not particularly limited, but if the stirring time is too short, the concentration of the additive element becomes non-uniform, and the desired effect cannot be obtained as a whole steel material. Accordingly, a desired stirring time corresponding to the container size is required.
  • molten steel with an adjusted composition can be obtained. It casts using the obtained molten steel, and obtains a steel piece.
  • manufacturing is performed by heating, hot rolling including finish rolling, rapid cooling after hot rolling, slow cooling after quenching stop, rapid cooling after slow cooling, and winding.
  • Heating before hot rolling is performed at 1150 to 1300 ° C.
  • An austenite single phase is obtained by this heating.
  • a solid solution element including additive elements such as V and Nb
  • the heating temperature is less than 1150 ° C., it cannot be dissolved in austenite, and coarse carbides are formed, so that the effect of improving fatigue characteristics cannot be obtained.
  • heating temperatures exceeding 1300 ° C. are difficult to operate.
  • Ti is contained as an additive element, the TiC solution solution temperature or higher and 1300 ° C. or lower are necessary also in terms of solid solution of Ti having the highest solution temperature among carbides.
  • a more preferable lower limit of the heating temperature is 1200 ° C.
  • the rough rolling temperature is set to 900 to 1200 ° C. in consideration of securing the temperature of the subsequent finish rolling, and the austenite grains in the rough rolling are refined and repeatedly recrystallized, so that the proportion of equiaxed grains having a predetermined shape is increased. Can be controlled.
  • the rough rolling temperature is more preferably 900 to 1100 ° C.
  • Hot rolling is performed so that the finish rolling temperature is 800 ° C. or higher. If the finish rolling temperature is too low, ferrite transformation occurs at a high temperature and the precipitated carbides in the ferrite are coarsened, so that a certain finish rolling temperature is required.
  • the finish rolling temperature is more preferably 850 ° C. or higher in order to coarsen austenite grains and increase the grain size of bainite.
  • the difference between the entry side temperature and the exit side temperature of hot finish rolling is set to 150 ° C. or less.
  • this temperature difference exceeds 150 ° C., the temperature before the finish rolling is high, the crystal grains (austenite grains) become coarse and the recrystallized grains generated during the finish rolling tend to be large.
  • the temperature difference between the entry side and the exit side is large, the recrystallized structure generated during finish rolling tends to be non-uniform, and crystal grains having a large aspect ratio tend to remain.
  • the number of crystal grains having an aspect ratio of 3 or less is less than 60% of the total number of crystal grains. This temperature difference is more preferably 100 ° C. or less.
  • the quenching stop temperature is 680 ° C. or more, the precipitated carbide in the ferrite is coarsened, and the fatigue resistance characteristics cannot be ensured.
  • the quenching stop temperature is preferably 600 to 650 ° C, more preferably 610 to 640 ° C.
  • the slow cooling rate is less than 5 ° C./s
  • the amount of pro-eutectoid ferrite is increased and coarse grains are produced, and coarse grains are produced in the final steel plate, resulting in a non-uniform state of carbides, resulting in cold workability. Deteriorate.
  • the cooling rate is 20 ° C./s or more, martensite is generated and cold workability is lowered.
  • a test steel containing chemical components shown in Table 1 was melted, cast into a 150 kg ingot, and cooled.
  • the components are adjusted for elements other than Al, REM, and Ca, and deoxidized using at least one element selected from C, Si, and Mn.
  • the amount of dissolved oxygen in the molten steel was adjusted.
  • the total amount of oxygen in the molten steel was adjusted by stirring the molten steel in which the amount of dissolved oxygen was adjusted for about 1 to 10 minutes to float and separate oxides in the molten steel.
  • the molten steel which adjusted the component was obtained by adding to the molten steel which adjusted the total oxygen amount.
  • REM was added in the form of a misch metal containing about 25% La and about 50% Ce
  • Ca was added in the form of a Ni—Ca alloy, a Ca—Si alloy, or a Fe—Ca compact. .
  • the obtained ingot was hot-rolled under the conditions shown in Table 2 to produce a hot rolled plate having a predetermined thickness.
  • Table 2 the rapid cooling rate after hot rolling and the cooling rate after stopping the quenching are not shown, but in each production example, the rapid cooling after hot rolling is 40 ° C / s, and the cooling after the rapid cooling stop is 10 ° C / s. The condition of s is adopted.
  • the area ratio of each phase in the steel sheet, the aspect ratio of the crystal grains, and the crystal grain ratio were measured by the measurement method described in the above-mentioned section [Mode for carrying out the invention]. The number etc. were investigated.
  • the tensile strength and the hole expansion rate are measured, and the tensile strength is in the range of 350 to 700 MPa and the hole expansion rate is 20% or more. Passed.
  • the carburizing and quenching test was performed under the following conditions.
  • steel no. 1, 2, and 6 to 20 are steels that satisfy the requirements of the compositional composition of the present invention and are manufactured under the recommended hot rolling conditions. Yes, the tensile strength, the hole expansion ratio, and the surface hardness after carburizing heat treatment all meet the acceptance criteria, and show a predetermined surface hardness (strength) after carburizing heat treatment while ensuring good cold workability It was confirmed that a hot-rolled steel sheet was obtained.
  • Steel No. Nos. 3 to 5 and 21 to 27 are comparative steels that do not satisfy at least one of the component composition and the structure requirement defined in the present invention, and are at least one of tensile strength, hole expansion ratio, and surface hardness after carburizing heat treatment. Does not meet the acceptance criteria.
  • steel No. 3 although the requirements of the component composition are satisfied, the heating temperature before hot rolling is too low outside the recommended range, pearlite is excessively formed, the crystal grains are flattened, and the tensile strength is too high. The hole-expanding property is inferior.
  • steel No. 22 (steel grade r) has a hot rolling condition in the recommended range, but because the C content is too high, pearlite is excessively formed, the crystal grains are flattened, the tensile strength is too high, and the hole expansion test is performed. Cracking occurred at the time of drilling (the hole spreading property was bad).
  • steel No. No. 24 steel type t
  • the hot rolling conditions are in the recommended range
  • the Mn content is too high
  • the formation of ferrite is insufficient while the pearlite is excessively formed
  • the number ratio of crystal grains having an aspect ratio of 3 or less The hole expandability is inferior.
  • steel No. 26 (steel type v) has a hot rolling condition in the recommended range, the Al content is too high, the number ratio of crystal grains having an aspect ratio of 3 or less is also low, and the hole expandability is also inferior.
  • Steel No. No. 27 (steel type w) has a hot rolling condition in the recommended range, but the N content is too high, the number ratio of crystal grains having an aspect ratio of 3 or less is low, and the hole expanding property is inferior.
  • the hot-rolled steel sheet of the present invention exhibits good cold workability during processing, is excellent in hardness at the surface and a predetermined depth after carburizing heat treatment, and is excellent in wear resistance, fatigue resistance, etc. It is useful as a material for manufacturing clutches, dampers, gears (gears) and the like.

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)
  • Heat Treatment Of Sheet Steel (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

L'invention concerne une tôle d'acier laminée à chaud qui : présente une épaisseur de tôle comprise entre 2 et 10 mm ; contient des quantités spécifiques de carbone (C), de manganèse (Mn), d'aluminium (Al) et d'azote (N), le reste comprenant du fer et des impuretés inévitables ; et présente une surface spécifique occupée par de la ferrite et de la perlite, le reste comprenant de la bainite. Du nombre total de grains cristallins présents dans la tôle d'acier laminée à chaud, 60 % sont des grains cristallins qui présentent un rapport de forme (axe majeur/axe mineur) égal ou inférieur à 3, et le diamètre moyen de grain cristallin de tous les grains cristallins varie entre 3 et 50 μm.
PCT/JP2014/077742 2013-10-22 2014-10-17 Tôle d'acier laminée à chaud présentant une excellente dureté de surface après un traitement thermique de carburation et une excellente aptitude au façonnage à froid WO2015060223A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
DE112014004844.5T DE112014004844T5 (de) 2013-10-22 2014-10-17 Warm-gewalztes Stahlblech mit ausgezeichneter Oberflächenhärte nach Aufkohlungs-Wärme-Behandlung und ausgezeichneter Kaltumformbarkeit
US15/031,030 US20160237515A1 (en) 2013-10-22 2014-10-17 Hot-rolled steel sheet having excellent surface hardness after carburizing heat treatment and excellent cold workability
CN201480057664.XA CN105658829B (zh) 2013-10-22 2014-10-17 冷加工性和渗碳热处理后的表面硬度优异的热轧钢板
MX2016005095A MX2016005095A (es) 2013-10-22 2014-10-17 Lamina de acero laminada en caliente que tiene excelente dureza de superficie despues de tratamiento termico carburizante y excelente aptitud para ser trabajo en frio.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2013219467A JP6068314B2 (ja) 2013-10-22 2013-10-22 冷間加工性と浸炭熱処理後の表面硬さに優れる熱延鋼板
JP2013-219467 2013-10-22

Publications (1)

Publication Number Publication Date
WO2015060223A1 true WO2015060223A1 (fr) 2015-04-30

Family

ID=52992820

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2014/077742 WO2015060223A1 (fr) 2013-10-22 2014-10-17 Tôle d'acier laminée à chaud présentant une excellente dureté de surface après un traitement thermique de carburation et une excellente aptitude au façonnage à froid

Country Status (6)

Country Link
US (1) US20160237515A1 (fr)
JP (1) JP6068314B2 (fr)
CN (1) CN105658829B (fr)
DE (1) DE112014004844T5 (fr)
MX (1) MX2016005095A (fr)
WO (1) WO2015060223A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108291285A (zh) * 2015-11-27 2018-07-17 新日铁住金株式会社 钢、渗碳钢部件及渗碳钢部件的制造方法
CN108368574A (zh) * 2015-11-27 2018-08-03 新日铁住金株式会社 钢、渗碳钢部件及渗碳钢部件的制造方法
TWI634219B (zh) * 2016-04-07 2018-09-01 新日鐵住金股份有限公司 沃斯田（ａｕｓｔｅｎｉｔｉｃ）系不銹鋼材
US11111568B2 (en) 2016-09-30 2021-09-07 Nippon Steel Corporation Steel for cold forging and manufacturing method thereof

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107075644B (zh) * 2014-10-30 2019-03-29 杰富意钢铁株式会社 高强度钢板及其制造方法
KR102242067B1 (ko) 2016-11-16 2021-04-19 제이에프이 스틸 가부시키가이샤 고강도 강판 및 그 제조 방법
CN107245667A (zh) * 2017-06-09 2017-10-13 太仓东旭精密机械有限公司 一种摩托车用钢材料
CN109321837A (zh) * 2017-08-01 2019-02-12 宝钢特钢长材有限公司 用于喷油嘴阀体的渗碳钢及其制备方法
CN107604253A (zh) * 2017-08-30 2018-01-19 东风商用车有限公司 一种高淬透性Mn‑Cr系列渗碳钢
KR102057765B1 (ko) * 2017-12-29 2019-12-19 현대제철 주식회사 철근 및 이의 제조 방법
CN112601831B (zh) * 2018-08-23 2022-05-31 杰富意钢铁株式会社 方形钢管及其制造方法以及建筑构造物
NL2022286B1 (en) 2018-09-19 2020-05-07 Illumina Inc Structured illumination of a sample
JP7156500B2 (ja) * 2019-12-12 2022-10-19 Ｊｆｅスチール株式会社 鋼板およびその製造方法
US11802327B1 (en) * 2020-10-02 2023-10-31 Big River Steel, LLC Ultra-high strength hot-rolled steel with toughness and method of making same
CN112662942B (zh) * 2020-11-19 2022-04-19 南京钢铁股份有限公司 阻尼钢及其制备方法
CN114965525A (zh) * 2021-02-24 2022-08-30 宝武特种冶金有限公司 一种钛合金晶粒等轴度表征方法
CN113403568A (zh) * 2021-06-01 2021-09-17 温岭市云福热处理厂 一种低碳钢及其热处理工艺
KR102458518B1 (ko) * 2022-04-05 2022-10-25 신승호 내마모성 유압 브레이커용 프론트 커버

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09227949A (ja) * 1996-02-23 1997-09-02 Nippon Steel Corp 熱延連続化プロセスを用いた成形性に優れ靱性の良好な加工用熱延鋼板の製造方法
US5858130A (en) * 1997-06-25 1999-01-12 Bethlehem Steel Corporation Composition and method for producing an alloy steel and a product therefrom for structural applications
JPH11152544A (ja) * 1997-09-11 1999-06-08 Kawasaki Steel Corp 超微細粒を有する加工用熱延鋼板及びその製造方法並びに冷延鋼板の製造方法
JP2009263715A (ja) * 2008-04-24 2009-11-12 Nippon Steel Corp 穴広げ性に優れた熱延鋼板及びその製造方法
WO2010131303A1 (fr) * 2009-05-11 2010-11-18 新日本製鐵株式会社 Tôle d'acier laminée à chaud présentant une excellente aptitude au poinçonnage et d'excellentes propriétés de résistance à la fatigue, tôle d'acier galvanisée à chaud et procédé de fabrication associé
JP2011195882A (ja) * 2010-03-19 2011-10-06 Jfe Steel Corp 冷間加工性と焼入れ性に優れた熱延鋼板およびその製造方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4324225B1 (ja) * 2008-03-07 2009-09-02 株式会社神戸製鋼所 伸びフランジ性に優れた高強度冷延鋼板
JP4998755B2 (ja) * 2009-05-12 2012-08-15 Ｊｆｅスチール株式会社 高強度熱延鋼板およびその製造方法
JP5447278B2 (ja) * 2009-08-17 2014-03-19 新日鐵住金株式会社 内面突起つきスパイラル鋼管およびその製造法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09227949A (ja) * 1996-02-23 1997-09-02 Nippon Steel Corp 熱延連続化プロセスを用いた成形性に優れ靱性の良好な加工用熱延鋼板の製造方法
US5858130A (en) * 1997-06-25 1999-01-12 Bethlehem Steel Corporation Composition and method for producing an alloy steel and a product therefrom for structural applications
JPH11152544A (ja) * 1997-09-11 1999-06-08 Kawasaki Steel Corp 超微細粒を有する加工用熱延鋼板及びその製造方法並びに冷延鋼板の製造方法
JP2009263715A (ja) * 2008-04-24 2009-11-12 Nippon Steel Corp 穴広げ性に優れた熱延鋼板及びその製造方法
WO2010131303A1 (fr) * 2009-05-11 2010-11-18 新日本製鐵株式会社 Tôle d'acier laminée à chaud présentant une excellente aptitude au poinçonnage et d'excellentes propriétés de résistance à la fatigue, tôle d'acier galvanisée à chaud et procédé de fabrication associé
JP2011195882A (ja) * 2010-03-19 2011-10-06 Jfe Steel Corp 冷間加工性と焼入れ性に優れた熱延鋼板およびその製造方法

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108291285A (zh) * 2015-11-27 2018-07-17 新日铁住金株式会社 钢、渗碳钢部件及渗碳钢部件的制造方法
CN108368574A (zh) * 2015-11-27 2018-08-03 新日铁住金株式会社 钢、渗碳钢部件及渗碳钢部件的制造方法
US10597765B2 (en) 2015-11-27 2020-03-24 Nippon Steel Corporation Steel, carburized steel component, and method for manufacturing carburized steel component
CN108291285B (zh) * 2015-11-27 2020-03-27 日本制铁株式会社 钢、渗碳钢部件及渗碳钢部件的制造方法
TWI634219B (zh) * 2016-04-07 2018-09-01 新日鐵住金股份有限公司 沃斯田（ａｕｓｔｅｎｉｔｉｃ）系不銹鋼材
US11111568B2 (en) 2016-09-30 2021-09-07 Nippon Steel Corporation Steel for cold forging and manufacturing method thereof

Also Published As

Publication number Publication date
US20160237515A1 (en) 2016-08-18
CN105658829A (zh) 2016-06-08
MX2016005095A (es) 2016-08-03
DE112014004844T5 (de) 2016-06-30
JP2015081366A (ja) 2015-04-27
CN105658829B (zh) 2017-08-25
JP6068314B2 (ja) 2017-01-25

Similar Documents

Publication Publication Date Title
JP6068314B2 (ja) 冷間加工性と浸炭熱処理後の表面硬さに優れる熱延鋼板
JP6143355B2 (ja) 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
JP5093422B2 (ja) 高強度鋼板及びその製造方法
WO2016148037A1 (fr) Tôle d'acier destinée à la cémentation possédant d'excellentes aptitudes au façonnage à froid et ténacité après traitement thermique de cémentation
JP5858174B2 (ja) 低降伏比高強度冷延鋼板およびその製造方法
WO2009110607A1 (fr) Tôles d'acier laminées à froid
JP5363922B2 (ja) 伸びと伸びフランジ性のバランスに優れた高強度冷延鋼板
JP5158272B2 (ja) 伸びフランジ性と曲げ加工性に優れた高強度鋼板およびその溶鋼の溶製方法
JP2005290547A (ja) 延性および伸びフランジ性に優れた高炭素熱延鋼板およびその製造方法
CN108315637B (zh) 高碳热轧钢板及其制造方法
KR101892526B1 (ko) 고탄소 열연 강판 및 그 제조 방법
JP5158271B2 (ja) 伸びフランジ性と曲げ加工性に優れた高強度鋼板およびその溶鋼の溶製方法
JP5302840B2 (ja) 伸びと伸びフランジ性のバランスに優れた高強度冷延鋼板
JP6284813B2 (ja) 強冷間加工性と加工後の硬さに優れる熱延鋼板
JP2019011510A (ja) 冷間加工性と浸炭熱処理後の靱性に優れる浸炭用鋼板
WO2015033933A1 (fr) Tôle d'acier laminée à chaud ayant une excellente aptitude à l'écrouissage et d'excellentes propriétés de surface et dureté après travail
JP5549450B2 (ja) ファインブランキング性に優れた高炭素熱延鋼板およびその製造方法
JP2007231337A (ja) 熱延鋼板および鋼部品
JP2007204794A (ja) 鋼部品
JP6068291B2 (ja) 軟質高炭素鋼板
JP2008274336A (ja) 伸びフランジ性と疲労特性に優れた高強度鋼板およびその溶鋼の溶製方法
JP6390685B2 (ja) 非調質鋼およびその製造方法
KR20190119085A (ko) 고강도 냉연 강판과 그의 제조 방법
JP6068172B2 (ja) 軟質高炭素鋼板
JP3945373B2 (ja) 微細粒組織を有する疲労特性に優れた冷延鋼板の製造方法

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: MX/A/2016/005095

Country of ref document: MX

WWE Wipo information: entry into national phase

Ref document number: 15031030

Country of ref document: US

WWE Wipo information: entry into national phase

Ref document number: 1120140048445

Country of ref document: DE

Ref document number: 112014004844

Country of ref document: DE

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

Ref document number: 14856186

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 14856186

Country of ref document: EP

Kind code of ref document: A1