EP3323904A1 - Stahlblech für textilmaschinenteil und herstellungsverfahren dafür - Google Patents

Stahlblech für textilmaschinenteil und herstellungsverfahren dafür Download PDF

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EP3323904A1
EP3323904A1 EP15898320.5A EP15898320A EP3323904A1 EP 3323904 A1 EP3323904 A1 EP 3323904A1 EP 15898320 A EP15898320 A EP 15898320A EP 3323904 A1 EP3323904 A1 EP 3323904A1
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textile machinery
steel sheet
machinery parts
content
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EP15898320.5A
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English (en)
French (fr)
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EP3323904A4 (de
Inventor
Masaru Fujihara
Dai Miyawaki
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Nippon Steel Corp
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Nisshin Steel Co Ltd
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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
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/124—Accessories for subsequent treating or working cast stock in situ for cooling
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    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
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    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • C21D1/28—Normalising
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    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/84—Controlled slow cooling
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    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/002—Heat treatment of ferrous alloys containing Cr
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    • C21D6/00—Heat treatment of ferrous alloys
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    • C21D6/00—Heat treatment of ferrous alloys
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    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/02—Hardening by precipitation
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    • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/021—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving particular fabrication steps or treatments of ingots or slabs
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    • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
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    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
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    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
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    • 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
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    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
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    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
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    • 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
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with 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
    • C22C38/18—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
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    • 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
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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    • 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
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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    • 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
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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    • 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
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    • 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
    • C21D2211/004—Dispersions; Precipitations

Definitions

  • the present invention relates to a steel sheet for textile machinery parts excellent in wear resistance and toughness and a method for manufacturing the same.
  • Textile machinery parts to be used for knitting machines such as latch needles, needle plates, sinkers, selectors and jacks are required to have wear resistance, so that in general, quenched/tempered high carbon steel materials are used.
  • These textile machinery parts are subjected to abrasive wear due to contaminants contained in yarn, such as Al 2 O 3 and SiO 2 .
  • the selector collides with a needle plate to break the needle plate.
  • the needle plate is fixed to the main body of a knitting machine while being held by several wires, and thus the broken needle plate cannot be easily exchanged.
  • PTL 1 to PTL 4 describe textile machinery parts excellent in strength, toughness, and anti-corrosion characteristics, which are used for felt needles, sewing machine needles, latch needles and the like.
  • medium carbon steel is used as a base and Cr, Mo, V and the like are added, so as to improve wear resistance and the use life.
  • PTL 5 to PTL 13 describe stainless steel to be used for weaving machine members.
  • martensite-based stainless steel is used as a base and the total amount of precipitated carbides such as Ti and Nb is specified, so as to highly strengthen the steel and suppress the wear of the steel sheet that comes into contact with fibers.
  • Cr forms a passive film, so as to improve anti-corrosion characteristics.
  • Textile machinery parts wear because of contaminants with a diameter of about 3 ⁇ m contained in yarn, such as Al 2 O 3 and SiO 2 . Recently, yarn of poor quality containing high levels of contaminants may be used. Such yarn contains contaminants such as K 2 O and CaO having a diameter of about 5 ⁇ m, which are slightly coarser than conventional contaminants. These coarse contaminants have been revealed to significantly affect the wear of textile machinery parts.
  • warp yarn to be used herein is set by an air jet or water jet blowing. Hence, anti-corrosion characteristics should be taken into consideration and thus relatively expensive stainless steel is used.
  • textile machinery parts are mechanically activated to set warp yarn, and oil is added dropwise to parts that come into contact with the yarn, leading to less concern about anti-corrosion characteristics.
  • the toughness of weaving machine members is evaluated using bendability found by a bending test, as an indicator.
  • textile machinery parts have extremely complicated forms of wear. Accordingly, there is a tendency to improve wear resistance by simply using a high-strength material while leaving the cause of the wear of sites unknown. The wear resistance of textile machinery parts may not be appropriately improved.
  • the present invention has been achieved in view of these points, and an object of the present invention is to provide a steel sheet for textile machinery parts that can be manufactured at a low cost and is excellent in wear resistance and toughness, and a method for manufacturing the same.
  • a steel sheet for textile machinery parts according to claim 1 contains in mass%, C: 0.60% or more and 1.25% or less, Si: 0.50% or less, Mn: 0.30% or more and 1.20% or less, P: 0.03% or less, S: 0.03% or less, Cr: 0.30% or more and 1.50% or less, and Nb: 0.10% or more and 0.50% or less, with the balance being Fe and unavoidable impurities, wherein Nb-containing carbides having a particle size of 0.5 ⁇ m or more are present in the matrix at a density of 3000/mm 2 or more and 9000/mm 2 or less.
  • a steel sheet for textile machinery parts according to claim 2 is the steel sheet for textile machinery parts according to claim 1 containing in mass%, Ti: 0% (no Ti added)or more and 0.50% or less, and B: 0% (no B added) or more and 0.005% or less.
  • a steel sheet for textile machinery parts according to claim 3 is the steel sheet for textile machinery parts according to claim 1 or 2 contains in mass%, any one or more types of Mo: 0% (no Mo added) or more and 0.50% or less, V: 0% (no V added) or more and 0.50% or less, and Ni: 0% (no Ni added) or more and 2.0% or less.
  • the steel sheet for textile machinery parts contains in mass%, 0.60% or more and 1.25% or less C, 0.50% or less Si, 0.30% or more and 1.20% or less Mn, 0.03% or less P, 0.03% or less S, 0.30% or more and 1.50% or less Cr, and 0.10% or more and 0.50% or less Nb, with the balance being Fe and unavoidable impurities, and thus the steel sheet can be manufactured at a low cost.
  • Nb-containing carbides having a particle size of 0.5 ⁇ m or more are present in the matrix at a density of 3000/mm 2 or more, so that the wear resistance is good, and Nb-containing carbides having a particle size of 0.5 ⁇ m or more are present in the matrix at a density of 9000/mm 2 or less, so that the toughness is good.
  • the steel sheet for textile machinery parts contains 0.60% or more and 1.25% or less C (carbon), 0.50% or less Si (silicon), 0.30% or more and 1.20% or less Mn (manganese), 0.03% or less P (phosphorus), 0.03% or less S (sulfur), 0.30% or more and 1.50% or less Cr (chromium), and 0.10% or more and 0.50% or less Nb (niobium), with the balance being Fe (iron) and unavoidable impurities.
  • C carbon
  • Si silicon
  • Mn manganesese
  • P phosphorus
  • S sulfur
  • Cr chromium
  • Nb niobium
  • the steel sheet for textile machinery parts preferably contains as necessary, 0% (no Ti added) or more and 0.50% or less Ti (titanium), and, 0% (no B added) or more and 0.005% or less B (boron).
  • the steel sheet for textile machinery parts preferably contains as necessary any one or more types of 0% (no Mo added) or more and 0.50% or less Mo (molybdenum), 0% (no V added) or more and 0.50% or less V (vanadium), and, 0% (no Ni added) or more and 2.0% or less Ni (nickel).
  • Carbon (C) is an element required for improving the strength of steel sheets, and the C content should be 0.60% or more in order to ensure the strength required for use in textile machinery parts.
  • the C content of higher than 1.25% increases the amount of coarse undissolved carbides and causes deterioration in impact characteristics and the like. Therefore, the C content is determined to be 0.60% or more and 1.25% or less.
  • Si Silicon
  • the Si content is determined to be 0.50% or less (no Si added), and preferably 0.30% or less.
  • Manganese (Mn) is an element effective for improving the hardenability of steel, and hardenability cannot be sufficiently improved when the Mn content is less than 0.30%.
  • Mn contained in a large amount specifically, the Mn content of higher than 1.20% causes hardening and damages manufacturability and toughness. Therefore, the Mn content is determined to be 0.30% or more and 1.20% or less.
  • P and S contents are preferably as low contents as possible. Therefore, both P and S contents are determined to be 0.03% or less.
  • Chromium (Cr) is an element having an effect of improving the hardenability of steel, an effect of improving the strength of steel sheets, an effect of improving the wear resistance of steel sheets, and an effect of suppressing the coarsening of cementite upon annealing.
  • the Cr content should be 0.30% or more for Cr to exert each of the above effects.
  • Cr may adversely affect such that Cr inhibits the solution treatment of cementite while heating is maintained in quenching treatment. Accordingly, the Cr content of higher than 1.50% can cause an increased amount of undissolved cementite upon quenching treatment. Therefore, the Cr content is determined to be 0.30% or more and 1.50% or less.
  • Niobium (Nb) forms extremely hard Nb-containing carbides in steel during a cooling process after casting, and contributes to improvement in wear resistance, and particularly resistance to abrasive wear. Further, Nb contributes to improvement in toughness by refining crystal grains upon quenching. The Nb content should be 0.10% or more for Nb to exert each of these effects. However, Nb added in a large amount results in excessive formation of Nb-containing carbides. Moreover, the Nb-containing carbides serve as a starting point of destruction and a crack propagation path, causing deterioration in toughness.
  • the Nb content is determined to be 0.10% or more and 0.50% or less.
  • Titanium (Ti) forms extremely hard Ti-containing carbides in steel, similar to Nb, during a cooling process after casting, and contributes to wear resistance. Further, titanium carbide (TiC) precipitated during hot rolling or cooling after re-solution treatment upon hot rolling or the like contributes to improvement in toughness by refining crystal grains upon quenching. Furthermore, binding force between Ti and N is strong, so that the feature is effective to prevent the formation of boron nitride (BN) upon addition of boron (B), and to exploit an effect of improving the hardenability of B. Therefore, Ti is preferably added as necessary, and the Ti content determined to be 0.01% or more is effective for Ti to exert each of the above effects.
  • the Ti content of higher than 0.50% tends to cause deterioration in toughness, since Ti-based carbides are present in a large amount in the steel sheet.
  • the Ti content is preferably determined to be 0.50% or less.
  • B Boron
  • B is an element effective for improving hardenability, and is preferably added as necessary.
  • the B content should be 0.0003% or more.
  • B's effect of improving hardenability is saturated when the B content is 0.005%. Therefore, when B is contained, the B content is preferably determined to be 0.005% or less.
  • Molybdenum (Mo) and vanadium (V) are both elements effective for improving toughness, and are preferably added as necessary.
  • Mo to exert an effect of improving toughness, the Mo content determined to be 0.1% or more is effective.
  • Mo and V are relatively expensive elements, and thus the addition of Mo and V in excessive amounts increases the cost.
  • the Mo content and the V content are each preferably determined to be 0.50% or less.
  • Nickel (Ni) is an element effective for improving hardenability and low-temperature toughness, and is preferably added as necessary.
  • the Ni content determined to be 0.1% or more is effective.
  • adding Ni in an excessive amount damages cost efficiency.
  • the Ni content is preferably determined to be 2.0% or less.
  • Nb-containing carbides are used.
  • carbides of Ti are also effective for improving wear resistance.
  • the particle size of carbides should be controlled.
  • the steel sheet for textile machinery parts that are final parts after thermal refining heat treatment has a metallographic structure in which Nb-containing carbides or Nb- and Ti-containing carbides having a particle size of 0.5 ⁇ m or more are present in the matrix at a density of 3000/mm 2 or more and 9000/mm 2 or less, the wear resistance is improved and a harmful effect of deteriorating toughness can be avoided.
  • Nb-containing carbides refers to hard carbides containing NbC as a principal component.
  • Nb- and Ti-containing carbides refers to hard carbides (hereafter, these Nb-containing carbides and Nb- and Ti-containing carbides are referred to as hard carbides.) containing (Nb, Ti)C or the like as a principal component.
  • Whether or not precipitated particles contained in steel correspond to hard carbides can be confirmed by microscopic analysis such as EDX. Moreover, hard carbides confirmed in such a manner are each subjected to area measurement, the diameter of a perfect circle having the same area as that of each carbide is calculated and the diameter is designated as the particle size of the hard carbide.
  • the hard carbides in steel having a particle size of 0.5 ⁇ m or more are present at less than 3000/mm 2 , the hard carbides' effect of improving wear resistance is insufficient and wear resistance sufficient for use in textile machinery parts may not be ensured. Furthermore, when hard carbides having a particle size of 0.5 ⁇ m or more are present at a level higher than 9000/mm 2 , these hard carbides serve as a starting point of destruction and a crack propagation path, causing deterioration in toughness. Therefore, the steel sheet for textile machinery parts is specified such that hard carbides having a particle size of 0.5 ⁇ m or more are present in the matrix at a density of 3000/mm 2 or more and 9000/mm 2 or less.
  • the steel sheet for textile machinery parts is manufactured through casting, hot rolling and thermal refining heat treatment.
  • Nb-containing hard carbides or, Nb- and Ti-containing hard carbides are precipitated in steel during a cooling process.
  • the strict control of the C content, the Nb content, and the cooling rate upon casting is important.
  • casting conditions are adjusted so that the value of an average cooling rate (°C/min) for cooling a slab central part from the liquidus line temperature to the solidus line temperature upon casting is equal to or less than a Z value represented by formula (1)
  • Z value 3.24exp (4.61X).
  • an extremely slow cooling rate for example, 1°C/min or less
  • cooling is performed at a cooling rate of 5°C/min or more.
  • the Z value represented by the formula (1) is an indicator representing the allowable upper limit (°C/min) of an average cooling rate for cooling a slab central part from the liquidus line temperature to the solidus line temperature upon casting based on the C content, the Nb content and the slab heating temperature. Furthermore, if the heating temperatures are the same, there is a tendency such that the higher the Z value, the coarser the hard carbides.
  • the particle size and the density of Nb-containing carbides to be precipitated in steel are also influenced by slab heating temperatures and the cooling rates thereafter in steps following the casting step, but are influenced more significantly in the cooling process in the casting step.
  • the lower the average cooling rate for slabs in the casting step the more progressed coarsening of hard carbides.
  • the lower limit of the average cooling rate is preferably determined to be 5°C/min.
  • the heating temperature T can be set at 1100°C or higher and 1350°C or lower.
  • the time for maintaining heating is preferably 30 minutes or more and 240 minutes or less.
  • the heating temperature T of the slab heat treatment is determined depending on the C content and the Nb content in steel, so that the Z value is 6 or more and 20 or less, and then casting conditions are adjusted on the basis of the Z value calculated based on the thus determined heating temperature T of the slab heat treatment.
  • the temperature for finish rolling is determined to be 800°C or higher and 900°C or lower, for example, and the temperature for winding is determined to be 630°C or lower, for example.
  • steel sheets after hot rolling are subjected to annealing and cold rolling.
  • Conditions for annealing can be adjusted as necessary. Specifically, heating is preferably maintained for 10 to 50 hours, for example, within a temperature range below the Ac 1 point at which austenite formation begins.
  • cold rolling is performed as necessary after annealing, and then annealing is performed again. In this manner, annealing and cold rolling may be repeated for several times. In addition, conditions for cold rolling can also be adjusted as necessary.
  • the steel sheet has an annealed structure in which the matrix is ferrite phase, and is then subjected to thermal refining heat treatment such as quenching and tempering.
  • Thermal refining heat treatment is performed after processing of a steel sheet subjected to annealing and cold rolling into the shape of parts, the parts are thermally refined by quenching and tempering to have a hardness of 53 to 62 HRC, for example.
  • thermal refining heat treatment is performed under general conditions except that temperatures of 1000°C or lower are employed for solution treatment, so as not to disturb the previously adjusted distribution of hard carbides.
  • the metallographic structure of the steel sheet after thermal refining heat treatment is a hard carbide-containing martensitic structure.
  • the above steel sheet for textile machinery parts contains, in mass%, 0.60% or more and 1.25% or less C, 0.50% or less Si, 0.30% or more and 1.20% or less Mn, 0.03% or less P, 0.03% or less S, 0.30% or more and 1.50% or less Cr, and 0.10% or more and 0.50% or less Nb, with the balance being Fe and unavoidable impurities.
  • the steel sheet can be manufactured at a low cost and is suitable for application to nearly thousands of textile machinery parts, for example.
  • the steel sheet for textile machinery parts has the above chemical components, and specifically Nb-containing carbides having a particle size of 0.5 ⁇ m or more are present in the matrix at a density of 3000/mm 2 or more and 9000/mm 2 or less.
  • Nb-containing carbides having a particle size of 0.5 ⁇ m or more are present in the matrix at a density of 3000/mm 2 or more and 9000/mm 2 or less.
  • the steel sheet for textile machinery parts contains Ti as necessary, so that wear resistance and toughness can be improved by the effect of improving wear resistance and the effect of improving toughness, which are exerted by Ti-containing hard carbides.
  • the steel sheet for textile machinery parts contains B as necessary, so that the hardenability can be improved.
  • Ti is further contained so that the formation of BN (boron nitride) due to binding of B and N can be prevented, and thus B can easily exert its effect of improving hardenability.
  • the steel sheet for textile machinery parts contains at least one type of Mo, V and Ni, as necessary, so that toughness, hardenability, and low-temperature toughness can be improved.
  • a heating temperature T of slab heat treatment is determined depending on the C content and the Nb content so that the Z value represented by formula (1) is 6 or more. This can prevent excessive progression of the solution treatment of Nb-containing hard carbides upon slab heat treatment. Accordingly, the particle size or the density of hard carbides can be easily controlled, and a steel sheet for textile machinery parts having good wear resistance and good toughness resulting from the use of the effects of the hard carbides can be manufactured.
  • casting conditions are adjusted, so that the value of the average cooling rate when a slab central part is cooled from the liquidus line temperature to the solidus line temperature upon casting is equal to or less than the Z value calculated with the formula (1) using the above-determined heating temperature T.
  • This enables precipitation of the appropriate number of hard carbides having an appropriate size in steel. Accordingly, the particle size and the density of hard carbides can be easily controlled, and a steel sheet for textile machinery parts excellent in wear resistance and toughness can be manufactured.
  • Table 1 shows chemical components of steel sheets serving as base materials for textile machinery parts.
  • Table 1 Copper Chemical composition (mass%) C Si Mn P S Cr Nb Ti Mo V Ni B Category A 0.92 0.32 0.77 0.012 0.008 1.01 0.33 - - - - - Example of the invention B 0.83 0.31 0.42 0.015 0.006 0.53 0.19 0.02 - - - 0.0010
  • Example of the invention C 0.66 0.19 1.03 0.022 0.010 0.89 0.17 - - 0.18 - -
  • Example of the invention D 1.02 0.05 0.91 0.019 0.003 1.44 0.36 0.14 0.29 - - -
  • Example of the invention E 1.18 0.24 0.58 0.025 0.016 0.37 0.27 0.21 - - 0.89 -
  • Example of the invention F 0.79 0.42 1.06 0.016 0.013 0.96 0.46 - - - 0.51 -
  • Example of the invention G 0.53 0.63 0.82 0.014 0.005 0.
  • Each steel slab shown in Table 1 was melt-formed, and then 30kg of a steel ingot for melting and solidification experiments was cut. Next, the steel ingot was melted in a crucible furnace to produce molten steel, and then the cooling rate upon solidification was controlled, thereby obtaining a solidified ingot simulating a slab obtained by varying the cooling rate upon casting.
  • a steel block was melted by the heat of a heater 4 within a cylindrical crucible 3 covered with a heat insulating material 2, thereby obtaining a molten steel 5.
  • the cylindrical crucible 3 is placed on a stage 7 capable of moving up and down through firebricks 6. Then, from the state of the molten steel temperature of 1700°C, the stage 7 was moved down to transfer the cylindrical crucible 3 accommodating the molten steel 5 into a cooling zone where a water-cooled coil 8 was placed, to solidify the molten steel 5.
  • the temperatures of the molten steel 5 and the solidified ingot resulting from solidification of the molten steel 5 were monitored by a thermocouple 9 placed at the center of the cylindrical crucible 3, and the descending speed of the stage 7, the heat amount of the heater 4, and the heat reduction amount of the water cooling coil 8 were adjusted, so that the average cooling rate while cooling from the liquidus line temperature to the solidus line temperature was a predetermined value ranging from 5°C/min or more to 20°C/min.
  • the thus obtained solidified ingot was a product simulating the slab resulting from the control of the rate of cooling the slab central part upon casting.
  • the solidified ingots are designated as simulated slabs, and the average cooling rate of the above cooling is considered to be the average cooling rate while cooling of the slab central parts from the liquidus line temperature to the solidus line temperature upon casting.
  • Simulated slabs were each treated in order of hot rolling, annealing, cold stretching, annealing and thermal refining heat treatment, thereby manufacturing impact test pieces having a sheet thickness of 1.8 mm.
  • these steel sheets were further repeatedly subjected to cold stretching and annealing, thereby manufacturing wear test pieces having a sheet thickness of 0.2 mm.
  • impact test pieces and wear test pieces were thermally refined by thermal refining heat treatment to have a thermal refining hardness of 62 HRC.
  • hot rolling was performed by keeping heating temperatures of 1250°C to 1350°C for 60 minutes, followed by finishing at a finishing temperature of 850°C and winding at a winding temperature of 590°C, thereby obtaining a hot-rolled sheet having a hot-rolled sheet thickness of 3.5 mm (adjusted to be 3.0 mm by grinding processing). Annealing was performed by heating the sheet to 690°C and then keeping it at the temperature for 18 hours.
  • thermal refining heat treatment was performed by carrying out heat treatment at 830°C for 15 minutes, and oil quenching at 60°C.
  • thermal refining materials having a thermal refining hardness of 740 HV was obtained according to the compositions. All thermally refined materials were each found to have a hardness within the range of 740 HV ⁇ 15 HV as measured with a Vickers hardness tester.
  • the cross sections (L section) of a steel sheet which were parallel to the rolling direction and the direction of sheet thickness, were subjected to mirror polishing, subjected to etching with Murakami reagent (alkaline solution of red prussiate of potash), and then observed under a confocal scanning microscope.
  • the images were processed, and then the quantity of Nb-containing carbides (hard carbides) existing in the area of a visual field was measured, thereby calculating the density of the carbides existing in the area.
  • Nb-containing hard carbides particles existing in an observance area of 90 * 60 ⁇ m * 20 visual fields and having a particle size of 0.5 ⁇ m or more were counted, and then each value was converted to the number per 1 mm 2 based on the results.
  • the particle size refers to a diameter of the area of a circle corresponding to the particle area. Particles having a particle size of 0.5 ⁇ m or more were picked up through image processing.
  • Figure 2 schematically shows a method for testing yarn guide wear. After thermal refining heat treatment, a strip-shaped test piece 11 having a sheet thickness of 0.2 mm, the length in a lengthwise direction of 60 mm, the length in a width direction of 20 mm was fixed with a jig, and then a load of 2N was applied using a weight, preparing a condition where friction exists between the surface of the test piece 11 and a yarn 12.
  • the yarn guide wear test was conducted using a 110-decitex domestic polyester spun yarn, a feed rate of 30 m/min, and a friction distance of 10000 m while adding dropwise silicone oil for a sewing machine to the contact surface between the test piece 11 and the yarn 12.
  • each test piece 11 was measured by a laser microscope, pieces having a comparative wear amount of less than 0.6 * 10 -7 mm 3 /Nm were determined to have acceptable wear resistance as a steel sheet for textile machinery parts. In addition, on the friction surfaces of the test pieces 11, streaked wear traces similar to those observed on textile machinery parts recovered from the market were observed.
  • Figure 3 shows the shape of an impact test piece.
  • a test piece 21 in the impact test was produced to have a sheet thickness of 1.8 mm, the length in the lengthwise direction of 55 mm, and the length in a width direction of 10 mm, and a U notch 22 with R1 mm at the central part in the lengthwise direction.
  • Table 2 shows slab heat treatment conditions, the results of measuring the density of hard carbides, the results of the yarn guide wear test, and the results of the impact test.
  • the examples of the present invention were manufactured by using the predetermined chemical components, determining the heating temperature T of slab heat treatment so that the Z value represented by formula (1) was 6 or more and 20 or less, and, controlling the cooling rate of a simulated slab, so that the value of average cooling rate was equal to or less than the Z value while the central part of the simulated slab was cooled from the liquidus line temperature to the solidus line temperature.
  • the examples were found to have the adjusted number of hard carbides with a particle size of 0.5 ⁇ m or more, ranging from 3000 to 9000/mm 2 . As a result, the examples of the present invention were excellent in both wear resistance and toughness and had high impact characteristics.
  • comparative examples No. 6, No. 28 and No. 29 had the average cooling rates of slabs higher than the Z value, and thus the number of hard carbides was less than 3000/mm 2 , and the wear resistance was insufficient.
  • Comparative example No . 11 had the Z value of less than 6, and the value of the cooling rate of higher than the Z value, so that the number of hard carbides was less than 3000/mm 2 , and the wear resistance was insufficient.
  • No. 23, No. 24 and Nos. 30 to 36 contained no Nb, so that no hard carbides (Nb-containing carbide) were present, and the wear resistance was significantly low.
  • Comparative example No. 25 had a low Nb content and a low C content, so that the number of hard carbides was less than 3000/m 2 , and the wear resistance was insufficient.
  • Comparative examples No.26 and No.27 had excessive Nb contents, so that hard carbides remained in excessive amounts and the impact characteristics were significantly decreased.
  • the present invention can be used for textile machinery parts such as latch needles, needle plates, sinkers, selectors, and jacks to be used for knitting machines.

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  • Mechanical Engineering (AREA)
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  • Heat Treatment Of Steel (AREA)
EP15898320.5A 2015-07-16 2015-07-16 Stahlblech für textilmaschinenteil und herstellungsverfahren dafür Withdrawn EP3323904A4 (de)

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Cited By (3)

* Cited by examiner, † Cited by third party
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EP3674432A4 (de) * 2017-08-25 2020-12-16 Nippon Steel Corporation Verschleissfestes stahlblech mit ausgezeichneter zähigkeit
EP4324953A4 (de) * 2021-06-18 2025-10-15 Jfe Steel Corp Stahlteil und herstellungsverfahren für ein stahlteil
EP4324952A4 (de) * 2021-06-18 2025-10-15 Jfe Steel Corp Kaltgewalztes stahlblech, stahlbauteile, verfahren zur herstellung eines kaltgewalzten stahlblechs und verfahren zur herstellung von stahlbauteilen

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* Cited by examiner, † Cited by third party
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CN109141611B (zh) * 2018-08-16 2020-11-10 马鞍山钢铁股份有限公司 一种钢卷重量自动核查的方法
KR102329386B1 (ko) * 2019-11-08 2021-11-19 가부시키가이샤 도쿠슈 긴조쿠 엑셀 고탄소 냉연 강판 및 그 제조 방법 그리고 고탄소강제 기계 부품
CN112301274B (zh) * 2020-09-30 2022-01-18 首钢集团有限公司 一种非焊接耐磨构件用钢及其制备方法
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Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS512617A (ja) * 1974-06-27 1976-01-10 Kobe Steel Ltd Kakyosekikosenzai
JPH0730483B2 (ja) * 1987-08-27 1995-04-05 金井 宏之 紡機用トラベラ
JP4303644B2 (ja) * 2004-06-07 2009-07-29 新日本製鐵株式会社 耐粒界割れ性と靭性の優れた高炭素鋼板の製造法
JP5484103B2 (ja) * 2009-02-17 2014-05-07 日新製鋼株式会社 高強度機械部品用素材鋼板およびその製造方法並びに高強度機械部品製造方法
US20140013915A1 (en) * 2011-03-25 2014-01-16 Nisshin Steel Co., Ltd. Steel plate with excellent durability for band-shaped die-cutting blade, and band-shaped die-cutting blade
JP5660220B2 (ja) * 2011-09-09 2015-01-28 新日鐵住金株式会社 中炭素鋼板、焼き入れ部材およびそれらの製造方法
JP5854831B2 (ja) * 2011-12-28 2016-02-09 日新製鋼株式会社 疲労特性に優れる耐摩耗性鋼材およびその製造方法
KR101781792B1 (ko) * 2013-06-27 2017-09-26 닛신 세이코 가부시키가이샤 피로 특성이 우수한 내마모성 강재 및 그 제조 방법
CN104032221B (zh) * 2014-03-18 2016-07-06 北京科技大学 一种铌微合金化高碳铬轴承钢及其热轧生产方法

Cited By (3)

* Cited by examiner, † Cited by third party
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EP3674432A4 (de) * 2017-08-25 2020-12-16 Nippon Steel Corporation Verschleissfestes stahlblech mit ausgezeichneter zähigkeit
EP4324953A4 (de) * 2021-06-18 2025-10-15 Jfe Steel Corp Stahlteil und herstellungsverfahren für ein stahlteil
EP4324952A4 (de) * 2021-06-18 2025-10-15 Jfe Steel Corp Kaltgewalztes stahlblech, stahlbauteile, verfahren zur herstellung eines kaltgewalzten stahlblechs und verfahren zur herstellung von stahlbauteilen

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