WO2018117157A1 - Fil machine - Google Patents

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Publication number
WO2018117157A1
WO2018117157A1 PCT/JP2017/045740 JP2017045740W WO2018117157A1 WO 2018117157 A1 WO2018117157 A1 WO 2018117157A1 JP 2017045740 W JP2017045740 W JP 2017045740W WO 2018117157 A1 WO2018117157 A1 WO 2018117157A1
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Prior art keywords
wire
content
less
region
steel
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PCT/JP2017/045740
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English (en)
Japanese (ja)
Inventor
大藤　善弘
Original Assignee
新日鐵住金株式会社
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.)
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Publication date
Application filed by 新日鐵住金株式会社 filed Critical 新日鐵住金株式会社
Priority to CN201780078216.1A priority Critical patent/CN110088318A/zh
Priority to US16/467,280 priority patent/US20200071791A1/en
Priority to JP2018558035A priority patent/JP6725007B2/ja
Priority to EP17884608.5A priority patent/EP3561100A4/fr
Publication of WO2018117157A1 publication Critical patent/WO2018117157A1/fr

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    • 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
    • C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
    • C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
    • 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
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/525—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
    • 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
    • C22C38/18—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
    • C22C38/28—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
    • 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
    • C21D2211/003—Cementite
    • 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 wire.
  • This application claims priority based on Japanese Patent Application No. 2016-246866 filed in Japan on December 20, 2016, the contents of which are incorporated herein by reference.
  • a steel wire for a steel cord used as a reinforcing material for a radial tire of an automobile, various belts and hoses, or a steel wire for a sawing wire is generally obtained by the procedure described below.
  • a steel wire with a diameter of 4 to 6 mm that has been adjusted and cooled after hot rolling (hereinafter, “steel wire” is simply referred to as “wire”) is subjected to primary wire drawing to a diameter of 3 to 4 mm.
  • an intermediate patenting process is performed, and further secondary wire drawing is performed to obtain a diameter of 1 to 2 mm. In many cases, the diameter is 1 to 2 mm by omitting the intermediate patenting process for cost reduction.
  • the steel wire drawn to a diameter of 1 to 2 mm is then subjected to a final patenting treatment, followed by brass plating and further a final wet drawing to a diameter of 0.06 to 0.40 mm. .
  • the thin high-strength steel wire (extra fine steel wire) manufactured in this way is twisted into a “twisted steel wire” by, for example, twisting to form a steel cord or the like.
  • Patent Document 1 in mass%, C: 0.6 to 1.1%, Si: 0.1 to 1.5%, Mn: 0.2 to 1%, P: 0.025% or less , S: not more than 0.025%, Al: not more than 0.003%, and if necessary, further containing Ni, Co, Cu, Cr, V, total oxygen amount, average composition of nonmetallic inclusions
  • “high carbon steel wire rods excellent in wire drawability and stranded wire properties” defined for Ti content is disclosed.
  • the technique proposed in Patent Document 1 limits the amount of Ti for the control of oxide-based nonmetallic inclusions, and does not consider TiN.
  • the technique proposed in Patent Document 1 does not consider element segregation.
  • Patent Document 2 in mass%, C: 0.70 to 0.90%, Si: 0.05 to 1.20%, Mn: 0.10 to 1.0%, Al: 0.05% or less “High carbon steel wire rods with excellent resistance to breakage of coupling” are disclosed which each contain (not including 0%), consist of the remainder Fe and inevitable impurities, and define the Si concentration in the cross section of the wire rod.
  • segregation of Mn and Cr is not considered, and TiN is not considered. Therefore, according to the technique proposed in Patent Document 2, if the amount of processing in the final wet wire drawing, that is, the amount of true strain is increased in order to increase the strength, the frequency of occurrence of disconnection tends to increase. It was difficult to produce a steel wire industrially stably.
  • the present invention has been made in view of the above situation, and its purpose is to produce a steel wire that is suitable for processing to steel cords, sawing wires, etc., has excellent wire drawing workability, and has high tensile strength. It is to provide a wire that is possible.
  • the present inventors have repeatedly investigated and studied the influence of the chemical composition, microstructure, and inclusions of the wire on the disconnection during wire drawing, and analyzed the results in detail. Upon examination, the following findings were obtained.
  • the wire has a pearlite structure and the remainder is any of ferrite, cementite, and bainite, and does not include a martensite structure. .
  • Mn and Cr are elements that are easily segregated in the wire.
  • Mn and Cr are likely to segregate positively (concentrate) at the center of the wire. Therefore, the strength of the central portion of the wire is likely to increase, and the deformability decreases accordingly. Further, a high tensile stress is applied to the central portion of the wire during the wire drawing process. For this reason, if the positive segregation of Mn and Cr at the center of the wire is large, disconnection is likely to occur during wire drawing. Further, when Mn and Cr are positively segregated at the center of the wire, martensitic transformation is likely to occur at the center. This also contributes to the occurrence of disconnection. Therefore, it is necessary to appropriately control the amount of Mn and the amount of Cr. In addition, the degree of the influence of Cr on the tensile strength of the wire and the formation of martensite is about twice that of Mn.
  • Mn and Cr are liable to segregate even in areas other than the center of the wire.
  • Mn and Cr are easily segregated in a band shape. This band-shaped segregation can be observed in a cross section parallel to the rolling direction. Since the segregated portion becomes hard and cracks easily develop along the segregated portion by wire drawing, the band-shaped segregation easily causes disconnection. Even in this case, the degree of influence of Cr on the disconnection is about twice that of Mn.
  • the present inventors conducted further detailed experiments and research based on these findings (a) to (e). As a result, it was found that the component composition of the wire, the condition of the metal structure mainly composed of pearlite, the size of TiN, and the segregation of Mn and Cr may be appropriately adjusted. And according to the wire rod in which these items are within an appropriate range, the present inventors can solve the above-mentioned problems, and stably produce a high-strength steel wire suitable as a steel cord material with a low frequency of disconnection. The present invention has been conceived after confirming that it is possible.
  • the gist of the present invention is as follows.
  • the chemical component is mass%, C: 0.90 to 1.20%, Si: 0.10 to 1.00%, Mn: 0.20 to 0 80%, Cr: 0.10 to 0.40%, Al: 0 to 0.002%, Ti: 0 to 0.002%, N: 0 to 0.0050%, P: 0 to 0.020% , S: 0 to 0.010%, O: 0 to 0.0040%, Mo: 0 to 0.20%, B: 0 to 0.0030%, with the balance being Fe and impurities,
  • the average value of% Mn + 2 ⁇ % Cr over the entire area is 0.50 to 1.00%, and the metal structure is pearlite with an area fraction of 90% or more, and the balance is either ferrite, cementite, or bainite.
  • the area fraction of the said cementite is less than 3%, and the largest particle size of TiN is 15 micrometers.
  • S content and O content in the central part which is less than m and measured in a section perpendicular to the length direction of the wire, from the central axis of the wire to 1/10 of the diameter of the wire.
  • the maximum value of% Mn + 2 ⁇ % Cr in the region where the amount is less than 1% is 2.0 times or less of the average value of% Mn + 2 ⁇ % Cr over the entire wire, and in the length direction of the wire % Mn + 2 of the region where the S content and the O content are less than 1% in the outer peripheral portion, which is the region from the outer edge of the central portion to the depth of 0.1 mm of the surface of the wire, measured at the perpendicular cutting plane
  • the ratio of the maximum value and the minimum value of x% Cr is 2.0 or less.
  • % Mn and% Cr represent the content in mass% of Mn and Cr.
  • the chemical component is any one of Mo: 0.02 to 0.20% and B: 0.0003 to 0.0030% in mass%. You may contain 2 types.
  • the wire rod of the present invention it is possible to stably produce a steel wire for steel cord, a steel wire for sawing wire or the like having a high strength of, for example, 4100 MPa or more with a low disconnection frequency.
  • the chemical component composition of the wire according to one embodiment of the present invention (hereinafter sometimes simply referred to as “wire”), the condition of the metal structure, and the like will be described in more detail.
  • the wire 1 according to the present embodiment includes a central portion 11 that is a region from the central axis of the wire to 1/10 of the diameter of the wire, and a region from the outer edge of the central portion 11 to a depth of 0.1 mm on the surface of the wire 1. A certain outer peripheral portion 12.
  • the chemical component of the wire which concerns on this embodiment is demonstrated.
  • the chemical component of the wire according to the present embodiment described below is the amount of the alloy element contained in the material of the wire, and thus is the average value of the chemical components over the entire wire.
  • the chemical composition of the wire is measured not by a local analysis that is affected by element segregation but by an analysis that measures the average value of a region of a certain size.
  • C 0.90 to 1.20%
  • C is an effective component for increasing the tensile strength of steel.
  • the C content is less than 0.90%, it is difficult to stably impart a high strength to the final product, for example, a tensile strength of 4100 MPa.
  • the lower limit of the C content is 1.00. % Or more is desirable.
  • the C content is too large, the steel material becomes hard and breaks during wire drawing.
  • the C content is determined to be in the range of 0.90 to 1.20%.
  • the lower limit value of the C content may be 0.92%, 0.95%, or 1.00%.
  • the upper limit of C content it is good also considering the upper limit of C content as 1.15%, 1.12%, or 1.10%.
  • Si 0.10 to 1.00% Si is also an effective component for increasing the strength of the steel material, and is also a necessary component as a deoxidizer. However, if the Si content is less than 0.10%, the effect of Si cannot be sufficiently obtained. On the other hand, if Si is contained exceeding 1.00%, the ductility of the wire rod or steel wire after wire drawing will fall. Therefore, the Si content is determined to be in the range of 0.10 to 1.00%. Since Si is an element that affects the hardenability of steel materials and the formation of proeutectoid cementite, the Si content is 0.30 to 0.80% from the viewpoint of ensuring a desired microstructure stably in the wire. It is more desirable to adjust within the range.
  • the lower limit value of the Si content may be 0.15%, 0.20%, 0.30%, or 0.40%. Further, the upper limit value of the Si content may be 0.95%, 0.90%, 0.85%, 0.80%, 0.70%, or 0.50%.
  • Mn 0.20 to 0.80% Mn affects the time required for the phase transformation from austenite to various low-temperature structures, and is an effective component for generating a stable pearlite structure in the wire, and at the same time, has the effect of increasing the strength of the final product. However, if the Mn content is less than 0.20%, the above effect cannot be obtained sufficiently. On the other hand, Mn is an element that easily segregates, and if it is contained in excess of 0.80%, Mn is segregated particularly in the central portion 11 of the wire, and martensite is generated in the segregated portion. Disconnection is likely to occur. Therefore, the Mn content is determined to be in the range of 0.20 to 0.80%. The lower limit value of the Mn content may be 0.25%, 0.30%, or 0.40%. Moreover, it is good also considering the upper limit of Mn content as 0.75%, 0.70%, or 0.60%.
  • Cr 0.10 to 0.40% Cr greatly affects the time required for the phase transformation from austenite to various low-temperature structures, and is effective for generating a stable pearlite structure in the wire, and at the same time increases the strength of the final product by reducing the pearlite lamella spacing. There is an effect. And, in order to stably obtain a tensile strength of 4100 MPa or more in the final product, a Cr content of 0.10% or more is required. However, if Cr is contained exceeding 0.40%, Cr is segregated particularly in the central portion 11 of the wire, martensite is generated in the segregated portion, and breakage is likely to occur during wire drawing. . Therefore, the Cr content is determined to be in the range of 0.10 to 0.40%. The lower limit value of the Cr content may be 0.12%, 0.15%, or 0.20%. Moreover, it is good also considering the upper limit of Cr content as 0.35%, 0.30%, or 0.25%.
  • Average value of% Mn + 2 ⁇ % Cr throughout the wire 0.50 to 1.00%
  • Mn and Cr greatly affect the phase transformation time from austenite to various low-temperature structures, and in order to obtain a stable pearlite structure with a wire, each content of Mn and Cr must be within a predetermined range. Don't be.
  • the present inventors also set the average value of the Mn content throughout the wire and the total value of the average value of the Cr content throughout the wire multiplied by 2 within the predetermined range. I found it necessary to do.
  • the Mn content is indicated by the symbol “% Mn”
  • the Cr content is indicated by the symbol “% Cr”.
  • the effect of Cr on tensile strength is about twice that of Mn. If the average value of% Mn + 2 ⁇ % Cr (hereinafter sometimes referred to as Mn + 2Cr) throughout the wire is less than 0.50%, the final product cannot stably obtain a tensile strength of 4100 MPa or more. Therefore, the lower limit of the average value of Mn + 2Cr over the entire wire is 0.50% or more. In order to further improve the tensile strength, the average value of Mn + 2Cr over the entire wire is preferably 0.60% or more, 0.70% or more, or 0.80% or more.
  • both Mn and Cr are easily segregated at the central portion 11 of the wire, and when the average value of Mn + 2Cr over the wire exceeds 1.00%, the segregated portion of Mn and Cr is martensified. A site is generated, and disconnection is likely to occur during wire drawing. Therefore, the average value of Mn + 2Cr over the entire wire was determined to be in the range of 0.50 to 1.00%.
  • the upper limit of the average value of Mn + 2Cr over the entire wire may be 0.95%, 0.90%, or 0.80%.
  • the wire according to the present embodiment includes the above-described essential elements, and may further include an arbitrary element described below. However, since the wire according to the present embodiment can solve the problem without including an arbitrary element, the lower limit value of each arbitrary element is 0%.
  • Al is an element that forms oxide inclusions containing Al 2 O 3 as a main component and reduces the wire drawing workability of the wire.
  • the Al content is regulated to 0.002% or less.
  • the Al content is 0.001% or less.
  • the wire according to the present embodiment does not require any Al in order to solve the problem, and can obtain good characteristics even if the Al content is 0%. Therefore, the lower limit of the Al content is 0%.
  • the Al content may be defined as 0.0005% or more, or 0.001% or more.
  • Ti 0 to 0.002% Ti tends to form TiN when the wire contains N. Since TiN is very hard and does not deform by hot rolling or wire drawing, it is likely to become a disconnection starting point during wire drawing. Even if the manufacturing method is taken into consideration, if the Ti content exceeds 0.002%, it is difficult to make the maximum particle size of TiN of the wire measured by the method described below less than 15 ⁇ m, and disconnection may occur during wire drawing. It tends to occur. Therefore, the Ti content is regulated to 0.002% or less. Preferably, the Ti content is 0.001% or less. As described above, the wire according to the present embodiment does not require any Ti in order to solve the problem, and can obtain good characteristics even when the Ti content is 0%. Therefore, the lower limit of the Ti content is 0%. On the other hand, since the manufacturing cost may increase due to the reduction of the Ti content, the Ti content may be defined as 0.0005% or more, or 0.001% or more.
  • N 0 to 0.0050% N easily forms TiN when the wire contains Ti, and TiN is very hard and is not deformed by hot rolling or wire drawing. Therefore, N tends to be a starting point of wire breakage during wire drawing. Even if the manufacturing method is taken into consideration, if the N content exceeds 0.0050%, it is difficult to make the maximum particle size of TiN of the wire measured by the method described below less than 15 ⁇ m, and disconnection occurs during wire drawing. It tends to occur. Therefore, the N content is restricted to 0.0050% or less. Preferably, the N content is 0.0040% or less.
  • P 0 to 0.020%
  • P is an element that segregates at the grain boundary and lowers the wire drawing workability.
  • the P content is restricted to 0.020% or less.
  • the P content is 0.010% or less.
  • S 0 to 0.010%
  • S is also an element that reduces wire drawing workability. And when S content exceeds 0.010% especially, since the fall of wire drawing work will become remarkable, S content will be controlled to 0.010% or less. Preferably, the S content is 0.008% or less.
  • O 0 to 0.0040%
  • O is an element that easily forms an oxide, and when it is present in the wire together with Al, it is an element that forms oxide inclusions mainly composed of hard Al 2 O 3 and lowers the wire drawing workability.
  • the O content is regulated to 0.0040% or less.
  • the O content is 0.0030% or less, or 0.0025% or less.
  • Mo 0 to 0.20%
  • Mo has the effect of increasing the tensile strength of the steel wire after wire drawing.
  • the Mo content is preferably 0.02% or more.
  • the upper limit of the Mo content is 0.20%. More preferably, the upper limit of the Mo content is 0.10% or 0.07%.
  • the lower limit of the Mo content is more preferably 0.04%.
  • B 0 to 0.0030%
  • B has the effect of increasing the balance between tensile strength and ductility of the steel wire after wire drawing. In order to acquire this effect, it is preferable to make B content 0.0003% or more. However, if the B content exceeds 0.0030%, coarse BN is likely to be generated, and the wire drawing workability may be lowered. Therefore, the upper limit of the B content is set to 0.0030%. More preferably, the upper limit of the B content is 0.0020% or 0.0015%. On the other hand, from the viewpoint of optimizing the balance between the tensile strength and ductility of the wire or steel wire, the lower limit of the B content is more preferably 0.0005%.
  • the balance of the chemical component of the wire contains Fe and impurities.
  • Impurities are components that are mixed due to various factors in the production process, such as ore or scrap, when industrially producing steel materials, and do not adversely affect the wire according to the present embodiment. Means what is allowed.
  • the area fraction of the pearlite structure of the wire must be 90% or more.
  • the area fraction of pearlite may be 92% or more, 95% or more, 97% or more, or 100%.
  • the remainder (non-pearlite region) of the structure of the wire contains one or more of ferrite, cementite, bainite, and the like, and the area fraction of cementite needs to be less than 3%.
  • the remainder of the wire structure preferably does not contain martensite, but the martensite content is allowed up to a maximum area fraction of about 0.2%.
  • the ferrite structure in the wire according to the present embodiment does not include the ferrite structure in the pearlite structure and the ferrite structure in the bainite structure.
  • the cementite structure in the wire according to the present embodiment is a pro-eutectoid cementite that transforms into a prior austenite grain boundary, and does not include cementite in the pearlite structure and cementite structure in the bainite structure.
  • ⁇ Maximum particle size of TiN> When Al was 0.002% or less and O was 0.0040% or less in the chemical composition of the wire, inclusions other than TiN, that is, sulfides and oxides, were not observed at the starting point of the disconnection.
  • the maximum particle size of TiN measured by the method described later is 15 ⁇ m or more, disconnection occurred during wire drawing even if other requirements were satisfied. Therefore, in the wire according to the present embodiment, the maximum particle size of TiN is restricted to less than 15 ⁇ m.
  • the maximum particle size of TiN is preferably 12 ⁇ m or less, more preferably 10 ⁇ m or less. Although it is not necessary to define the lower limit of the maximum particle size of TiN, it may be 5 ⁇ m or 6 ⁇ m. In order to reduce the maximum particle size of TiN of the wire material, it is necessary to at least increase the solidification rate as much as possible when producing a slab to be a material of the wire material.
  • the area fraction of the pearlite structure is measured by the following method.
  • the cross section of the wire that is, the cut surface perpendicular to the length direction of the wire
  • FE-SEM field emission type scanning electron microscope
  • 10 points on the observation surface of the sample are photographed at a magnification of 3000 times.
  • the observation locations are 5 locations where the depth from the surface of the wire includes a position that is 1/4 of the radius of the wire, and 4 locations where the depth from the surface of the wire includes a location that is 1/2 of the radius of the wire. It is one location which is a location and a region in the center of the wire.
  • the observation may be performed on a plurality of cross sections.
  • the area per field of view is 5.0 ⁇ 10 ⁇ 4 mm 2 (vertical 20 ⁇ m, horizontal 25 ⁇ m).
  • the area fraction of the tissue other than the pearlite structure is obtained by an image analysis apparatus capable of analyzing the shape and area of the crystal grains.
  • the value obtained by removing the area fraction (%) other than the pearlite structure from 100% is defined as the area fraction of the pearlite structure.
  • the area fractions of the ferrite structure, cementite structure, bainite structure, etc. are also determined by the same method.
  • the maximum particle size of TiN is measured by the following method. First, a cross section perpendicular to the rolling direction (the length direction of the wire) is cut out from the wire, and the cross section is mirror-polished to obtain an observation sample, and TiN in the sample is observed with an optical microscope. Observation is performed for each 2.5 mm ⁇ 2.5 mm range, a photograph is taken of the maximum TiN within this observation range, the area of the maximum TiN is obtained by image analysis of the photograph, and the maximum TiN area is calculated. The 1/2 power is regarded as the maximum grain size of TiN. That is, the length of one side when the maximum TiN shape within the observation range is regarded as a square is regarded as the maximum TiN particle size within the observation range.
  • the above-mentioned cross section is prepared for 20 samples per sample, and this measurement is carried out for each sample by 20 fields of view, thereby obtaining the maximum particle size of TiN in the observation range of 125 mm 2 in total.
  • the maximum particle size of TiN confirmed in the observation range of 125 mm 2 in total has a strong correlation with the maximum particle size of TiN contained in the entire wire. It is impossible to make the entire TiN particle size measurement object, and in the case of a wire with the maximum particle size of TiN confirmed in the observation range of 125 mm 2 in total within the above range, the wire is TiN at the time of wire drawing. The possibility of causing disconnection is extremely low.
  • the maximum particle diameter of TiN confirmed in the observation range of 125 mm 2 in total is referred to as the maximum particle diameter of TiN of the wire.
  • TiN exhibits a gold color when observed with an optical microscope, it can be easily distinguished from other inclusions.
  • whether or not it is TiN may be specified by an energy dispersive electron beam microanalyzer (EPMA) described later.
  • EPMA energy dispersive electron beam microanalyzer
  • the observation range of 2.5 mm ⁇ 2.5 mm described above is arranged at the center of the cross section of the wire. That is, the center of the observation range substantially coincides with the center of the cross section of the wire. This is because coarse TiN tends to segregate in the vicinity of the central axis of the wire.
  • the diameter of a wire is small and the observation range of 2.5 mm x 2.5 mm mentioned above does not fit in the cross section of a wire, you may reduce the observation range of TiN suitably.
  • the total area of the observation range may be set to 125 mm 2 or more by increasing the number of measurement cross sections. Further, it is desirable that the length of the diagonal line in the observation range of TiN be 90% or less of the diameter of the wire.
  • the chemical component of the wire according to the present embodiment (the average value of the chemical components over the entire wire) is as described above.
  • the chemical component obtained by local analysis of the cross section of the wire using EPMA or the like may be slightly different from the average value of the chemical component of the wire due to the segregation of the alloy component and the effect of precipitation of inclusions. is there.
  • segregation of the alloy elements is suppressed within a predetermined range, thereby having the characteristics described below.
  • the region from the central axis to 1/10 of the diameter of the wire rod of the wire rod 1 according to the present embodiment is defined as the central portion 11.
  • Maximum of% Mn + 2 ⁇ % Cr (hereinafter sometimes referred to as Mn + 2Cr) in a region where the S content and O content in the central portion 11 are less than 1%, as measured at a cut surface perpendicular to the length direction
  • Mn + 2Cr Maximum of% Mn + 2 ⁇ % Cr in a region where the S content and O content in the central portion 11 are less than 1%, as measured at a cut surface perpendicular to the length direction
  • the value is not more than 2.0 times the average value of% Mn + 2 ⁇ % Cr throughout the wire.
  • the influence of sulfides and oxides needs to be excluded. In the region of sulfides and oxides, the S content or the O content greatly exceeds 1%.
  • the region where the S content and the O content are less than 1% can be regarded as a region in which no sulfide and oxide are present in the wire according to the present embodiment having the above-described chemical components.
  • % Mn + 2 ⁇ % Cr of the region where the S content and O content of the central portion 11 are less than 1%, measured by a cutting plane perpendicular to the length direction of the wire is simply referred to as “Mn + 2Cr of the central portion 11”. May be written.
  • the maximum value of Mn + 2Cr in the central portion 11 exceeds 2.0 times the Mn + 2Cr of the entire wire 1, the deformability of the central portion 11 is significantly reduced. As a result, disconnection is likely to occur during wire drawing. Therefore, the maximum value of Mn + 2Cr in the central portion 11 is set to 2.0 times or less of the entire Mn + 2Cr.
  • the maximum value of Mn + 2Cr in the central portion 11 is preferably 1.7 times or less, more preferably 1.5 times or less of the entire Mn + 2Cr.
  • % Mn and% Cr represent the contents in terms of mass% of Mn and Cr, respectively.
  • the lower limit of the ratio between the maximum value of Mn + 2Cr in the central portion 11 and the overall Mn + 2Cr it may be 1.2, 1.4, or 1.5.
  • the ratio of the maximum value of Mn + 2Cr in the central part 11 and the average value of Mn + 2C of the whole wire 1 is referred to as “central Mn + 2Cr segregation amount”.
  • ⁇ Ratio between the maximum value and the minimum value of% Mn + 2 ⁇ % Cr in the outer peripheral portion 12 of the wire (maximum value / minimum value)>
  • region from the outer edge of the center part to the 0.1-mm depth of the surface of the wire which concerns on this embodiment is defined as the outer peripheral part 12.
  • the outer peripheral part 12 like the central part 11, in evaluating the segregation of Mn and Cr, the influence of sulfide and oxide needs to be excluded. Therefore, the region where the S content or O content exceeds 1% is excluded, and the value of% Mn + 2 ⁇ % Cr in the region where the S content and O content is less than 1% is measured.
  • % Mn + 2 ⁇ % Cr of the region where the S content and O content of the outer peripheral portion 12 are less than 1%, measured by a cut surface perpendicular to the length direction of the wire is simply referred to as “Mn + 2Cr of the outer peripheral portion 12”. May be written.
  • the ratio between the maximum value and the minimum value of Mn + 2Cr in the outer peripheral portion 12 exceeds 2.0, Mn and Cr are segregated in a band shape and become hard in the wire, so that cracking occurs along that region by wire drawing. Progresses and breaks easily. Therefore, the ratio between the maximum value and the minimum value of Mn + 2Cr in the outer peripheral portion 12 is set to 2.0 or less.
  • the ratio between the maximum value and the minimum value of Mn + 2Cr in the outer peripheral portion 12 is preferably 1.6 or less, and more preferably 1.4 or less.
  • peripheral part Mn + 2Cr segregation amount the ratio (maximum value of Mn + 2Cr / minimum value of Mn + 2Cr) between the maximum value and the minimum value of Mn + 2Cr in the outer peripheral part 12 may be referred to as “peripheral part Mn + 2Cr segregation amount”.
  • Mn concentration and the Cr concentration in the region where the S content and the O content are less than 1% in the central portion 11 of the wire, as measured at the cutting plane perpendicular to the length direction of the wire are as follows. taking measurement. First, five cross sections (cut surfaces perpendicular to the length direction) are cut out from the wire at intervals of 200 mm in length. Next, as shown in FIG. 1, in the line analysis region 13 extending from the center of each cut surface to 1/10 of the diameter D, energy dispersive electrons are obtained for each element of Mn, Cr, S, and O.
  • Line analysis is performed using a line microanalyzer (EPMA), and the concentration distribution of each element in the line analysis region 13 of each cut surface is measured.
  • the line analysis by EPMA is preferably performed at an acceleration voltage of 15 kV, a beam diameter of 1 ⁇ m, a scanning speed of 200 ⁇ m / min, and a measurement point interval of 2 ⁇ m.
  • the measurement results of the region where 1% or more S exists and / or the region where 1% or more of O exists are excluded from the measurement results of the Mn and Cr concentration line analysis obtained.
  • the influence of oxides and sulfides that are inclusions can be removed from the segregation evaluation result.
  • the maximum value of% Mn + 2 ⁇ % Cr is obtained for the line analysis region 13 of each cut surface excluding the region where 1% or more S exists and / or the region where 1% or more O exists.
  • the maximum value of% Mn + 2 ⁇ % Cr in the line analysis region 13 of the five cut surfaces is measured at a cut surface perpendicular to the length direction of the wire, and the S content and O content in the central portion 11 are 1
  • the average value of% Mn + 2 ⁇ % Cr over the entire wire may be calculated based on the chemical composition of the wire (the average value of the chemical composition over the entire wire). That is, when the material of the wire is known, the average value of% Mn + 2 ⁇ % Cr over the entire wire may be calculated based on the amount of Mn and the amount of Cr contained in the wire material. When the material of the wire is unknown, the average value of the Mn content and the average value of the Cr content are obtained by the usual chemical composition analysis method, and based on these, the% Mn + 2 ⁇ % Cr throughout the wire What is necessary is just to calculate the average value.
  • The% Mn + 2 ⁇ % Cr of the region where the S content and the O content are less than 1% of the outer peripheral portion 12 of the wire, which is measured at a cutting plane perpendicular to the length direction of the wire, is measured by the following method. .
  • the wire rod is separated from the center of the cross section of the wire rod by 1/10 of the diameter D (that is, the outer edge of the center portion 11).
  • the concentration of Mn, Cr, S, and O in the central portion 11 for each element of Mn, Cr, S, and O Similar to the measurement, line analysis is performed using EPMA, and the concentration distribution of each element in the line analysis region 14 of each cut surface is measured.
  • the measurement results of the region where 1% or more of S exists and / or the region where 1% or more of O exists are excluded from the obtained Mn and Cr concentration line analysis results.
  • the influence of sulfides and oxides that are inclusions can be excluded from the segregation evaluation results.
  • the maximum value of% Mn + 2 ⁇ % Cr is obtained for the line analysis region 14 of each cut surface excluding the region where 1% or more S exists and / or the region where 1% or more O exists.
  • the maximum value of% Mn + 2 ⁇ % Cr in the line analysis region 14 at the five cut surfaces is measured at a cut surface perpendicular to the length direction of the wire, and the S content and O content in the outer peripheral portion 12 are 1
  • the minimum value of% Mn + 2 ⁇ % Cr concentration is determined for the line analysis region 14 of each cut surface excluding the region where 1% or more S exists and / or the region where 1% or more O exists.
  • the minimum content of% Mn + 2 ⁇ % Cr concentration in the line analysis region 14 of the five cut surfaces is determined and measured at the cut surface perpendicular to the length direction of the wire, S content and O content in the outer peripheral portion 12 Is the minimum value of% Mn + 2 ⁇ % Cr in the region where the ratio is less than 1%.
  • the diameter of the wire according to this embodiment is not particularly limited.
  • the diameter of the wire distributed in the market is often in the range of 3.6 to 8.0 mm, so the diameter of the wire according to the present embodiment may be 3.6 to 8.0 mm.
  • the composition of steel, the target performance, the wire, so that the area fraction of pearlite, the structure other than pearlite, and the maximum particle size of TiN can reliably satisfy the above-mentioned conditions. What is necessary is just to set a process and each process condition according to a diameter.
  • the raw material When casting a small amount of steel for the experiment, if the weight of the steel is 150 kg or less, the raw material is first melted and then evacuated for 20 minutes or more, and then cast using a mold having an internal average cross-sectional area of 120 cm 2 or less. And get an ingot.
  • the material of the mold used when obtaining the ingot include cast iron.
  • An example of an undesirable material is silica.
  • a portion with a volume fraction of 15% is not used, and the portion of the ingot is cut before hot forging.
  • the ingot from which both ends have been removed is heated at 1260 to 1300 ° C. for 8 to 12 hours and cooled to 500 ° C. or less in the furnace.
  • the ingot is heated to 1200 to 1250 ° C. and then hot forged to obtain a steel slab.
  • the wire according to the present embodiment When manufacturing the wire according to the present embodiment by a manufacturing method including continuous casting, after melting the molten steel by a converter, the molten steel is sufficiently stirred, and the average cooling rate from the start of solidification to the end of solidification is 5 ° C. / Min. And slab is obtained by further rolling down during solidification.
  • the cast slab is heated at 1260 to 1300 ° C. for 8 to 12 hours and cooled to 500 ° C. or less in the furnace.
  • the slab is heated at 1200 to 1250 ° C. for 4 to 6 hours, and then rolled into pieces to obtain a steel slab.
  • the steel slab produced by any of the above methods is heated to 1050 to 1150 ° C., held in this temperature range for 40 to 60 minutes, and then hot rolled at a rolling finish temperature of 900 to 1000 ° C.
  • the diameter of the wire after hot rolling is not particularly limited, but is often set to 3.6 to 8.0 mm as described above.
  • the wire rod after finish rolling is cooled immediately after finishing finish rolling by cooling (primary cooling) combined with water cooling and air cooling until it reaches the temperature range of 680 to 730 ° C. at an average cooling rate of 30 ° C./s or more.
  • the wire according to the present embodiment is manufactured by the above method.
  • the wire thus obtained is a so-called hot-rolled wire, but the wire obtained by further performing cold working such as cold rolling and wire drawing also satisfies the above requirements. It is a wire concerning this embodiment.
  • the heating temperature of the steel slab refers to the surface temperature of the steel slab
  • the rolling finish temperature refers to the surface temperature of the wire immediately after finish rolling
  • the cooling rate after finish rolling is the surface of the wire.
  • the average cooling rate in the primary cooling combined with water cooling and air cooling is the surface temperature of the wire at the time when the injection of water or air into the wire starts and the injection of water or air into the wire ends This is a value obtained by dividing the difference from the surface temperature of the wire at the point of time by the injection time.
  • the average cooling rate in air cooling (secondary cooling) by the air is the surface temperature of the wire at the time when injection into the air wire is started, and the surface temperature of the wire at the time when injection into the air is finished Is a value obtained by dividing the difference by the injection time.
  • coolant injected to a wire in primary cooling and secondary cooling is not limited to water or air
  • the wire according to the present embodiment has a predetermined component composition, has a metal structure in which the area fraction of the pearlite structure is 90% or more, and the balance is any of ferrite, cementite, bainite, and the like. Or an area fraction of cementite of less than 3% or less, a maximum particle size of TiN of less than 15 ⁇ m, and measured at a cutting plane perpendicular to the length direction of the wire.
  • the maximum value of% Mn + 2 ⁇ % Cr in the region where the S content and the O content are less than 1% in the central portion 11 which is a region from the central axis of the wire to 1/10 of the diameter of the wire extends over the entire wire.
  • the wire rod of this embodiment is excellent in a wire drawing workability, and when a wire drawing process is performed to make a steel wire, a high-strength steel wire can be produced with a low disconnection frequency.
  • the conditions of the examples are one example of conditions adopted for confirming the feasibility and effects of the present invention, and the present invention is limited to this one example of conditions. It is not something.
  • the present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.
  • the ingot from which both ends were removed was heat-treated under the heat treatment conditions (ingot heat treatment conditions) shown in Table 1, and cooled to 400 ° C. in a furnace.
  • the ingot was heated to 1230 ° C., formed into a steel piece having a diameter of 80 mm by hot forging, and allowed to cool to room temperature.
  • steels B2 to F2 having the component compositions (chemical compositions) shown in Table 2 were melted by a converter and then continuously cast. During casting, the molten steel was sufficiently agitated, the average cooling rate from the start of solidification to the end of solidification was 6 ° C./min, and further reduced during the solidification. Next, the cast slab was heat-treated under the heat treatment conditions (slab slab heat treatment conditions) shown in Table 2 and allowed to cool to 500 ° C. or lower in the furnace. Next, after heating under the conditions shown in Table 2, a 122 mm square steel piece was obtained by split rolling.
  • the steel slab manufactured by the above method is heated to the steel slab heating temperature shown in Table 3, and the temperature is maintained at the same heating temperature only during the steel slab heating and holding time shown in Table 3, and the rolling shown in Table 3 is performed.
  • the hot rolling process was performed so that the finish rolling diameter (diameter) was 5.5 mm at the finishing temperature.
  • the wire was cooled to 700 ° C. at an average cooling rate shown in Table 3 by cooling (primary cooling) combining water cooling and air cooling by the atmosphere. Thereafter, the wire was cooled from 700 ° C. to 610 ° C. at an average cooling rate shown in Table 3 by air cooling (secondary cooling) with the air.
  • the average cooling rate to 700 ° C. (primary cooling rate) and the average cooling rate from 700 ° C. to 610 ° C. (secondary cooling rate) for each sample were as shown in the table.
  • the wire rod having a temperature of less than 610 ° C. was allowed to cool (tertiary cooling) to obtain a wire rod.
  • the area fraction of the pearlite structure, ferrite structure, cementite structure, bainite structure, center Mn + 2Cr segregation amount (that is, measured at the cut surface perpendicular to the length direction of the wire)
  • outer periphery Mn + 2Cr segregation amount that is, the maximum value and the minimum value of% Mn + 2 ⁇ % Cr in the region where the S content and the O content are less than 1% in the outer peripheral portion, as measured by a cut surface perpendicular to the length direction of the wire
  • Value the maximum particle size of TiN.
  • the dry drawing process was performed by the pass schedule from which the area reduction rate in each die
  • An 18 kg wire was drawn from a diameter of 5.5 mm to a diameter of 1.50 mm, and a 10 kg wire was drawn from a diameter of 5.5 mm to a diameter of 1.10 mm.
  • Table 4 and Table 5 show the number of disconnections when wire drawing is performed from a diameter of 5.5 mm to a diameter of 1.10 mm.
  • the primary wire drawing workability was not evaluated, and the secondary wire drawing workability described later was evaluated.
  • the true strain when the wire is drawn from a diameter of 5.5 mm to a diameter of 1.10 mm is 3.22.
  • the true strain ( ⁇ ) is expressed by the following equation (i) using the diameter (d 0 ) before wire drawing and the diameter (d) of the steel wire after wire drawing.
  • the above-described wire drawing material (steel wire) having a diameter of 1.50 mm was subjected to a patenting treatment using a heating furnace and a lead bath furnace.
  • the heating furnace was set so that the temperature of the steel wire was maintained at 975 to 990 ° C. for 5 to 15 seconds.
  • the temperature of the lead bath was 585 to 595 ° C., and the immersion time in the lead bath was 7 to 10 seconds.
  • the steel wire after patenting was subsequently subjected to brass plating by a usual method.
  • the steel wire subjected to brass plating was subjected to wet wire drawing (final wire drawing) to a diameter of 0.19 mm with a pass schedule in which the area reduction rate of each die was 15% on average.
  • the true strain when the wire is drawn from a diameter of 1.50 mm to a diameter of 0.19 mm is 4.13.
  • wire drawing workability was evaluated, and the results are shown in Table 4 and Table 5.
  • the case where the wire drawing of 18 kg from a diameter of 1.50 mm to a diameter of 0.19 mm was wet drawn was evaluated as having good secondary drawing workability when the number of breaks was zero.
  • the number of disconnections was 1 or more, it was evaluated that the wire drawing workability was poor. Note that when the number of wire breaks was two, wire drawing up to a diameter of 0.19 mm and evaluation thereafter were stopped.
  • the strength of the steel wire after wet drawing was examined as follows. About the steel wire which could be drawn to a diameter of 0.19 mm, the tension test was done for 3 each, the tensile strength was measured, and the average value of 3 tensile strength was shown in Table 4 and Table 5.
  • the target performance of the wire rod of the present invention is that the number of wire breaks when a 10 kg wire rod is dry-drawn to a true strain of 3.22 is 0, and 18 kg with a patenting and brass plating.
  • test numbers satisfying all the conditions defined in the present invention satisfy all the above-mentioned performances. Moreover, about some test numbers, the preferable result from which the tensile strength of a steel wire with a diameter of 0.19 mm became 4300 Mpa or more was shown. A test number outside the conditions defined in the present invention did not satisfy at least one of the above-described performances. Hereinafter, test numbers that deviate from the conditions defined in the present invention will be described.
  • Test No. 1 has a C content outside the scope of the present invention
  • Test No. 3 has Mn + 2Cr outside the scope of the present invention
  • Test No. 5 has a Cr content outside the scope of the present invention. Therefore, the tensile strength of the steel wire was insufficient for any of the test numbers.
  • Mn + 2Cr was outside the scope of the present invention.
  • the steel wire was disconnected during dry wire drawing and wet wire drawing.
  • the Cr content and Mn + 2Cr were out of the scope of the present invention.
  • the area fraction of pearlite did not satisfy the scope of the present invention and martensite was generated in the steel structure, the steel wire was disconnected during the dry wire drawing and wet wire drawing.
  • Test No. 10 had a C content outside the scope of the present invention. Moreover, since the area fraction of cementite did not satisfy the scope of the present invention, the steel wire was disconnected during dry wire drawing and wet wire drawing. Test No. 11 had an Al content outside the scope of the present invention. Therefore, the steel wire was disconnected during wet wire drawing.
  • Test No. 12 has a Ti content outside the scope of the present invention
  • Test No. 13 has an N content outside the scope of the present invention.
  • the steel wire was disconnected during wet wire drawing.
  • the O content was outside the range of the present invention, and the evacuation time was 10 minutes. Therefore, the steel wire was disconnected at the time of dry drawing and wet drawing.
  • test number 17 is not preferable for the average cross-sectional area of the ingot, test number 18 has a cut volume fraction of 5% at both ends of the ingot, and therefore, the maximum particle size of TiN is within the scope of the present invention. It was outside. Therefore, the steel wire was disconnected during wet wire drawing. In Test No. 22, Mn + 2Cr was out of the scope of the present invention, and martensite was generated in the steel structure. Therefore, the steel wire was disconnected during dry wire drawing and wet wire drawing.
  • Test No. 24, Test No. 25, Test No. 27, and Test No. 43 are not preferable for the heat treatment conditions of the ingot. Therefore, the ratio between the maximum value and the average value of Mn + 2Cr in the central portion 11 and the maximum value of Mn + 2Cr in the outer peripheral portion 12 The ratio with the minimum value was out of the scope of the present invention. Therefore, in all the test numbers, the steel wire was disconnected at the time of dry drawing and wet drawing.
  • Test No. 28 since the rolling finishing temperature was not preferable, the area fraction of cementite was out of the scope of the present invention. Therefore, the steel wire was disconnected during dry wire drawing and wet wire drawing. In Test No. 29, the average cooling rate up to 700 ° C. is not preferable, and in Test No. 30, Test No. 39 and Test No. 40, the average cooling rate from 700 ° C. to 610 ° C. is not preferable. It was out of the scope of the present invention. Therefore, the steel wire was disconnected during the dry drawing process.
  • Test number 33 is not preferable for the average cooling rate from 700 ° C. to 610 ° C., and test number 34 is not preferable for the heating temperature of the steel slab, and the rolling finishing temperature is not preferable.
  • the area fraction was out of the scope of the present invention. Therefore, the steel wire was disconnected during the dry drawing process.
  • test number 45 since the heat treatment condition of the steel slab before hot rolling is not preferable, the ratio between the maximum value and the minimum value of Mn + 2Cr in the outer peripheral portion 12 is out of the scope of the present invention. Therefore, the steel wire was disconnected during wet wire drawing.

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Abstract

La présente invention a pour objet de réaliser un fil machine ayant une excellente aptitude à l'étirage de fil et permettant de produire un fil d'acier ayant une résistance à la traction élevée. Selon un mode de réalisation de la présente invention, un fil machine est configuré de telle sorte que : des composants chimiques sont compris dans des plages prédéterminées ; la valeur moyenne de %Mn+2×%Cr sur la totalité de la tige de fil est comprise entre 0,50 et 1,00 % ; la structure métallographique est de 90 % ou plus de perlite par fraction de surface ; la fraction de surface de la cémentite est inférieure à 3 % ; la taille de grain maximale de TiN est inférieure à 15 µm ; la valeur maximale de %Mn+2×%Cr dans une région où la teneur en S et la teneur en O sont inférieures à 1 % dans une section centrale, est au plus 2,0 fois la valeur moyenne de %Mn+2×%Cr sur la totalité de la route filaire ; et le rapport de la valeur maximale et de la valeur minimale de %Mn+2×%Cr dans une région où la teneur en S et la teneur en O sont inférieures à 1 % dans une section périphérique externe, est inférieur ou égal à 2,0.
PCT/JP2017/045740 2016-12-20 2017-12-20 Fil machine WO2018117157A1 (fr)

Priority Applications (4)

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CN201780078216.1A CN110088318A (zh) 2016-12-20 2017-12-20 线材
US16/467,280 US20200071791A1 (en) 2016-12-20 2017-12-20 Wire rod
JP2018558035A JP6725007B2 (ja) 2016-12-20 2017-12-20 線材
EP17884608.5A EP3561100A4 (fr) 2016-12-20 2017-12-20 Fil machine

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WO2020080415A1 (fr) * 2018-10-16 2020-04-23 日本製鉄株式会社 Fil machine laminé à chaud
JP2021161445A (ja) * 2020-03-30 2021-10-11 日本製鉄株式会社 鋼線材
JP2021161444A (ja) * 2020-03-30 2021-10-11 日本製鉄株式会社 伸線加工用鋼線材
JP2021161451A (ja) * 2020-03-30 2021-10-11 日本製鉄株式会社 伸線加工用鋼線材

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WO2020080415A1 (fr) * 2018-10-16 2020-04-23 日本製鉄株式会社 Fil machine laminé à chaud
JPWO2020080415A1 (ja) * 2018-10-16 2021-09-09 日本製鉄株式会社 熱間圧延線材
JP7063394B2 (ja) 2018-10-16 2022-05-09 日本製鉄株式会社 熱間圧延線材
JP2021161445A (ja) * 2020-03-30 2021-10-11 日本製鉄株式会社 鋼線材
JP2021161444A (ja) * 2020-03-30 2021-10-11 日本製鉄株式会社 伸線加工用鋼線材
JP2021161451A (ja) * 2020-03-30 2021-10-11 日本製鉄株式会社 伸線加工用鋼線材

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CN110088318A (zh) 2019-08-02
JPWO2018117157A1 (ja) 2019-10-31
EP3561100A4 (fr) 2020-07-29

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