WO2018020660A1 - Tôle d'acier à haute résistance - Google Patents

Tôle d'acier à haute résistance Download PDF

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WO2018020660A1
WO2018020660A1 PCT/JP2016/072316 JP2016072316W WO2018020660A1 WO 2018020660 A1 WO2018020660 A1 WO 2018020660A1 JP 2016072316 W JP2016072316 W JP 2016072316W WO 2018020660 A1 WO2018020660 A1 WO 2018020660A1
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strength
steel sheet
strength steel
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PCT/JP2016/072316
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Japanese (ja)
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仁秀 吉村
皆川　昌紀
紀正 川端
岳史 都築
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新日鐵住金株式会社
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Priority to CN201680085629.8A priority Critical patent/CN109154041B/zh
Priority to EP16910563.2A priority patent/EP3492610B1/fr
Priority to KR1020187032277A priority patent/KR102142472B1/ko
Priority to JP2018530300A priority patent/JP6501042B2/ja
Priority to BR112018071948-0A priority patent/BR112018071948B1/pt
Priority to PCT/JP2016/072316 priority patent/WO2018020660A1/fr
Publication of WO2018020660A1 publication Critical patent/WO2018020660A1/fr

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    • 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
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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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/02—Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation
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    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
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    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
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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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    • 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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    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
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    • C22C38/00—Ferrous alloys, e.g. steel alloys
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    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
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    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
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    • 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
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    • 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
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    • 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
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    • 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
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    • C22C38/00—Ferrous alloys, e.g. steel alloys
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    • 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
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    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • 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
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    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
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    • 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
    • C21D2211/008—Martensite

Definitions

  • the steel plate When the elongation at break becomes small, the processing becomes difficult. Therefore, when the steel plate is used as a member of a construction machine or an industrial machine, the steel plate is required to have not only strength but also ductility such as elongation at break. Further, when used as a structural member, low temperature toughness is also necessary to prevent brittle fracture.
  • Patent Document 1 a high-strength steel sheet having a tensile strength of 780 MPa or more, and further 950 MPa, and a method for producing the same have been proposed.
  • Patent Document 1 a steel sheet having high strength and excellent toughness obtained by hot rolling and quenching a steel to which an alloy is added so as to obtain an appropriate hardenability while reducing the amount of C, and its manufacture. A method has been proposed.
  • Patent Document 1 does not consider the workability of the steel sheet.
  • Patent Documents 2 to 4 disclose a high-strength hot-rolled steel sheet manufactured by winding a steel strip into a coil shape after hot rolling as a steel sheet used for construction machinery and the like, and a method for manufacturing the same. Proposed. Specifically, in Patent Documents 2 to 4, after hot rolling, the martensite phase is rapidly cooled to the vicinity of the temperature (Ms) at which martensitic transformation starts, held for a predetermined time, and then wound into a coil shape. Alternatively, a method for producing a hot-rolled steel sheet having a tempered martensite phase as a main phase is disclosed.
  • Patent Document 5 discloses a high-strength steel sheet that suppresses the contents of Mn and Ni, while increasing the contents of Mo and V, suppresses the formation of martensite, and has a lower bainite-based structure, and a method for manufacturing the same. Has been proposed. However, since the technique of Patent Document 5 is based on a structure obtained by setting the cooling stop temperature to 300 to 450 ° C., sufficient elongation at break cannot be obtained. When the present inventors made a steel plate according to the disclosure of Patent Document 5 and conducted a test, the elongation at break of 12% or more was not obtained.
  • Japanese Unexamined Patent Publication No. 2009-287081 Japanese Unexamined Patent Publication No. 2011-52320 Japanese Unexamined Patent Publication No. 2011-52321 Japanese Unexamined Patent Publication No. 2012-77336 International Publication No. 2012/60405
  • This invention is made
  • the plate thickness is 4.5 to 20 mm
  • the yield strength is 885 MPa or more
  • the tensile strength is 950 MPa or more
  • the Charpy absorbed energy at ⁇ 20 ° C. is 59 J / cm 2 or more
  • the elongation at break is 12%.
  • the high-strength steel sheet according to one embodiment of the present invention has a chemical composition of mass%, C: 0.050 to 0.100%, Si: 0 to 0.50%, Mn: 1.20 to 1. 70%, P: 0.020% or less, S: 0.0050% or less, N: 0 to 0.0080%, B: 0.0003 to 0.0030%, Ti: 0.003 to 0.030% Nb: 0.003 to 0.050%, Cr: 0 to 2.00%, Mo: 0 to 0.90%, Al: 0 to 0.100%, Cu: 0 to 0.50%, Ni: 0 to 0.50%, V: 0 to 0.100%, W: 0 to 0.50%, Ca: 0 to 0.0030%, Mg: 0 to 0.0030%, REM: 0 to 0.0030 %, Balance: Fe and impurities, and one or both of Cr and Mo are contained in total of 0.20% or more, and the Mo content is more than 0.50%.
  • the Cr content is 0.80% or less
  • the DI obtained by the following formula 1 is 2.0 to 7.8, and the Pcm obtained by the following formula 2 is 0.189% or more.
  • the metal structure includes one or two of martensite and bainite having a total area ratio of 99% or more
  • the aspect ratio of the prior austenite grains is 2.0 or more
  • the length in the major axis direction is 1
  • the number fraction of cementite having a length in the major axis direction of 0.1 ⁇ m or more with respect to cementite having a length of 0.1 ⁇ m or more is 5% or less
  • the plate thickness is 4.5 mm to 20 mm
  • the yield strength is 885 MPa.
  • the present invention provides a high-strength steel plate that is suitably used as a structural member for construction machinery and industrial machinery, and contributes to increasing the size and weight of construction machinery and industrial machinery, without significantly increasing manufacturing costs. The industrial contribution is extremely remarkable.
  • a high-strength steel sheet according to an embodiment of the present invention (hereinafter, may be referred to as a high-strength steel sheet according to the present embodiment) will be described in detail.
  • C (C: 0.050 to 0.100%) C is a useful element that increases the strength of the steel and is an extremely important element that determines the elongation at break of a steel having a martensite structure.
  • the C content needs to be 0.050% or more in order to obtain sufficient strength.
  • the C content is preferably 0.060% or more, 0.065% or more, or 0.070% or more.
  • the C content if the C content exceeds 0.100%, the ductility and toughness of the steel deteriorate due to the formation of excess carbides. Therefore, in order to obtain good elongation at break and toughness, the C content needs to be 0.100% or less.
  • the C content is preferably 0.095% or less, 0.090% or less, or 0.085% or less.
  • the Si amount is limited to 0.50% or less.
  • the lower limit of the Si amount is 0%.
  • the Si content is preferably 0.03% or more in order to obtain sufficient effects.
  • Si is also an element that suppresses the formation of carbides, and when obtaining this effect, the Si amount is preferably 0.10% or more, and more preferably 0.20% or more.
  • the upper limit of the Si amount may be 0.45%, 0.40%, or 0.35%.
  • P and S are elements inevitably contained in the steel as impurities, and are elements that deteriorate the toughness of the steel.
  • the element deteriorates the toughness of the weld heat affected zone. Therefore, the P amount is limited to 0.020% or less, and the S amount is limited to 0.0050% or less.
  • the P content may be 0.015% or less and the S content may be 0.0030% or less. The smaller the amount of P and S, the better. Therefore, it is not necessary to particularly define the lower limits of the P amount and the S amount, and the lower limits of the P amount and the S amount are 0%.
  • the P content may be 0.001% or more and S: 0.0001% or more.
  • B is an element that segregates at the grain boundary and enhances the hardenability of the steel, and is a useful element that exhibits its effect even when contained in a small amount.
  • the B content is set to 0.0003% or more in order to increase martensite in the metal structure.
  • the B amount is 0.0005% or more.
  • the B amount is set to 0.0030% or less.
  • the B amount is 0.0020% or less or 0.0015% or less.
  • Ti is an element that forms nitride, and is an element that fixes N in steel as TiN and suppresses the generation of BN.
  • B is an element that enhances hardenability, but if BN is formed, the effect cannot be obtained.
  • the Ti content needs to be 0.003% or more in order to suppress the formation of BN and ensure the hardenability.
  • the Ti content is 0.005% or more, more preferably 0.010% or more.
  • the Ti content is 0.030% or less.
  • the Ti amount is 0.020% or less.
  • Nb is an element that remarkably improves the hardenability of steel by being contained simultaneously with B.
  • the Nb content is set to 0.003% or more in order to increase the area ratio of martensite in the metal structure.
  • Nb is an element that forms fine nitrides, contributes to refinement of crystal grains, and increases toughness.
  • the Nb content is preferably 0.005% or more. More preferably, the Nb amount is 0.010% or more or 0.015% or more.
  • the Nb content is 0.050% or less.
  • the Nb content is 0.040% or less, 0.035% or less, or 0.030% or less.
  • Cr and Mo are important elements that improve the hardenability, and contain one or both.
  • the total amount of Cr and Mn is 0.20% or more in order to increase the martensite area ratio in the metal structure.
  • the total amount of Cr and Mn is 0.30% or more, and more preferably 0.40% or more.
  • the lower limit of the Cr content and the Mo content is 0%.
  • the lower limit of the Cr amount may be 0.20% or 0.30%.
  • the lower limit of the Mo amount may be 0.20% or 0.30%.
  • the Cr amount and the Mo amount are set to 2.00% or less and 0.90% or less, respectively.
  • the Cr content is preferably 1.50% or less or 1.00% or less, more preferably 0.90% or less or 0.80%.
  • the Mo amount is preferably 0.70% or less, more preferably 0.60% or less or 0.50%. Further, when both Cr and Mo are contained, if the content is excessive, the toughness is lowered.
  • the Cr amount when the Mo amount exceeds 0.50%, the Cr amount needs to be 0.80% or less. There is. In this case, the Cr amount may be 0.70% or less. On the other hand, when the Cr content is more than 0.80%, the Mo content should be 0.50% or less, and when the Cr content is more than 1.20%, the Mo content should be 0.40% or less. Good.
  • the total of the Cr content and the Mo content may be 2.50% or less, but may be 2.00% or less, 1.50% or less, 1.30% or less, or 1.10% or less.
  • N is an impurity and is inevitably contained. N forms BN and inhibits the hardenability improving effect of B. Therefore, the N content is limited to 0.0080% or less. Preferably, the N content is limited to 0.0060% or less, more preferably 0.0050% or less. The amount of N is preferably reduced as much as possible, and the lower limit is 0%. However, from the viewpoint of denitrification cost, the N amount may be 0.0001% or more. On the other hand, the N content may be 0.0020% or more in order to make the metal structure finer by the nitride.
  • the high-strength steel sheet according to the present embodiment includes the essential elements, the remaining Fe, and impurities (other than the above-mentioned impurity elements and in some cases In principle, it has a component composed of an impurity element).
  • the high-strength steel sheet according to the present embodiment in addition to the above components, is part of Fe for deoxidation, improvement of strength and / or ductility, refinement of the metal structure, and sulfide morphology control.
  • Mg 0.0030% or less
  • REM 0.0030% or less
  • Al is a deoxidizing element.
  • the Al content is preferably 0.010% or more in order to obtain a sufficient effect.
  • the Al content is limited to 0.100% or less.
  • it is limited to 0.080% or less, more preferably 0.050% or less, and still more preferably 0.030% or less.
  • V is an element that forms carbide or nitride.
  • the V content is preferably 0.005% or more.
  • the upper limit of the V amount in the case of inclusion is 0.100%.
  • the V amount is 0.050% or less.
  • W is an element that improves the hardenability of steel.
  • the W amount is preferably 0.05% or more.
  • W amount shall be 0.50% or less or 0.30% or less. If necessary, the W content may be 0.02% or less or 0.01% or less.
  • Ca is an element that controls the form of oxides and sulfides.
  • the Ca content is preferably 0.0001% or more. More preferably, the Ca content is 0.0005% or more, and further preferably 0.0010% or more.
  • the Ca content is 0.0030% or less.
  • Mg is an element having an action of increasing the toughness of steel by refining the structure.
  • the Mg content is preferably 0.0005% or more.
  • Mg amount shall be 0.0030% or less.
  • REM 0.0030% or less
  • REM rare earth element
  • MnS form of sulfide
  • the REM content is preferably 0.0001% or more.
  • REM amount shall be 0.0030% or less.
  • DI and Pcm which are determined by the chemical composition, satisfy the following ranges after the individual elements are in the above ranges.
  • DI is preferably 7.8 or less. More preferably, DI is 7.0 or less, and more preferably 6.5 or less.
  • a welded joint is usually required to have a tensile strength (joint strength) that is equal to or higher than the required tensile strength for the base material used for welding.
  • joint strength tensile strength
  • the present inventors have a case where the tensile strength of the welded joint (joint strength) is lower than the tensile strength of the base metal due to softening of the weld heat affected zone. Found that there is. Therefore, the present inventors manufactured and tested a welded joint using various high-strength steel plates with varying welding heat input.
  • Pcm a joint strength of 950 MPa or more can be secured even in the case of 10.0 kJ / cm, which is welding heat input that does not require special management during welding. That is, by making Pcm 0.196% or more, the strength of the welded joint can be made 950 MPa or more without performing special welding construction management.
  • Pcm may be 0.200% or more, 0.205% or more, 0.210% or more, or 0.215% or more in order to ensure the strength of the welded joint even with larger welding heat input. A larger welding heat input is preferable because the number of welding passes can be reduced and productivity is improved.
  • the upper limit of Pcm is not particularly required, but may be 0.250% or less or 0.240% or less for preventing weld cracking.
  • FIG. 2 is a graph showing the relationship between [Mo] / [Cr] and Charpy absorbed energy at ⁇ 40 ° C.
  • “ ⁇ ” indicates an actual measurement value
  • “ ⁇ ” indicates an average value of the actual measurement values.
  • the Charpy absorbed energy at ⁇ 40 ° C. tends to increase as [Mo] / [Cr] increases, and when [Mo] / [Cr] is 0.20 or more, It can be seen that the Charpy absorbed energy at ⁇ 40 ° C. is 59 J / cm 2 or more. Therefore, when low temperature toughness is required, [Mo] / [Cr] is preferably 0.20 or more.
  • Mo is an element that easily forms fine carbides and clusters as compared with Cr. Therefore, when Mo is contained in excess of Cr, toughness may be reduced, and [Mo] / [Cr] may be 2.00 or less or 1.50 or less.
  • the Charpy absorbed energy was measured by a Charpy test conducted according to JIS Z 2242.
  • the plate thickness of the steel plate from which the test piece was taken was 8 mm
  • the test piece taken from the central portion of the plate thickness with the longitudinal direction as the rolling direction was a subsize of 10 mm ⁇ 5 mm.
  • Total area ratio of one or two of martensite and bainite 99% or more and elongation at break: 12% or more
  • the present inventors examined the hardenability of the high-strength steel sheet and the relationship between the metal structure and the elongation at break. As a result, when the hardenability is insufficient, the inventors reduce the elongation at break. Further, the cause of the decrease in elongation at break, that is, the decrease in ductility is due to bainite as shown in FIGS. 4A and 4B. It was found that voids originated from the generated coarse carbides.
  • the total area ratio of martensite and bainite is 99% or more and the elongation at break is 12% or more, it is judged that bainite that causes the formation of coarse cementite is suppressed. it can. Therefore, in the high-strength steel sheet according to the present embodiment, the total area ratio of one or two of martensite and bainite is 99% or more, and the elongation at break is 12% or more as a structure index. In the case where martensite and bainite can be sufficiently distinguished by structural observation, the martensite area ratio is preferably 90% or more.
  • the martensite having a metal structure is as-quenched and is different from the tempered martensite obtained by tempering treatment.
  • Tempered martensite is not preferred because cementite grows by prolonged tempering.
  • the remainder other than the above may be one or more of ferrite, pearlite, and retained austenite.
  • the magnification is 5000 times, and a range of 50 ⁇ m ⁇ 40 ⁇ m is photographed.
  • the acicular structure is assumed to be martensite, and the area ratio of the region is obtained.
  • the product of the needle-like structure area ratio in the optical microscope and the martensite area ratio in the SEM is defined as the area ratio of the martensite structure of the steel type.
  • the area ratio of the structure in which the acicular lath structure is developed by the optical microscope is defined as the total area ratio of martensite and bainite.
  • the present inventors can reduce the number fraction of coarse carbides (particularly cementite) whose length in the major axis direction is 1.0 ⁇ m or more, and as a result, It has been found that the formation of voids can be suppressed and the elongation at break can be improved. Specifically, among the cementite having a length in the major axis direction of 0.1 ⁇ m or more, the number fraction of cementite having a length in the major axis direction of 1.0 ⁇ m or more is set to 5% or less. It has been found that the elongation at break can be improved.
  • the accelerated cooling is stopped at a temperature equal to or lower than Mf and lower than 300 ° C., whereby a martensite-based structure in which the formation of coarse carbides is suppressed can be obtained. That is, by controlling the acceleration cooling stop temperature, it is possible to suppress generation of voids starting from coarse cementite having a length in the major axis direction of 1.0 ⁇ m or more. The number density of cementite is measured by a scanning electron microscope (SEM).
  • the shape of the carbide is not particularly limited.
  • the “length in the major axis direction” indicates the major axis.
  • the aspect ratio of prior austenite grains is 2.0 or more
  • the aspect ratio of the prior austenite grains is set to 2.0 or more.
  • the aspect ratio of the prior austenite grains can be 2.0 or more.
  • the processed structure by rolling is not inherited, and the aspect ratio of the prior austenite grains is less than 2.0.
  • the aspect ratio of prior austenite grains is measured by the following method.
  • the cross section parallel to the rolling direction in the vicinity of the 1/4 t portion, which is 1/4 of the thickness t from the surface in the thickness direction, is corroded with nital, and the magnification is 500 times with an optical microscope, 120 ⁇ m ⁇ 100 ⁇ m Shoot two fields of view.
  • From the obtained image for at least 50 or more prior austenite grains, measure the length of the major axis and the length of the minor axis, and divide the major axis length by the minor axis length to determine the aspect ratio for each grain. Ask. And the average value of the aspect ratio of these prior austenite grains is obtained.
  • the plate thickness of high-strength steel plates used for cranes and the like is generally 4.5 to 20 mm. Therefore, the plate thickness of the high-strength steel plate according to this embodiment is 4.5 to 20 mm. However, it is preferably 4.5 to 15 mm in terms of contribution to weight reduction. (Yield strength: 885 MPa or more) (Tensile strength: 950 MPa or more) In order to contribute to the increase in size and weight of construction machinery and industrial machinery, high strength is required.
  • the yield strength is 885 MPa or more, and the tensile strength is It is necessary to be 950 MPa or more.
  • the upper limit of the yield strength is not particularly required, but may be 1100 MPa or less.
  • the upper limit of the tensile strength is not particularly required, but may be 1300 MPa or less or 1250 MPa or less.
  • the elongation at break is also an index of the structure as to whether bainite, which causes the formation of coarse cementite, is suppressed.
  • Yield strength, tensile strength, and elongation at break are measured by performing a tensile test in accordance with JIS Z 2241.
  • the value of the elongation at break in the tensile test depends on the shape of the test piece.
  • the above-mentioned limitation on elongation at break (12% or more) is that, as a tensile test piece, a JIS Z2241 No. 5 test piece (the distance between original marks is 50 mm, the width of the parallel part is 25 mm, and the thickness of the test piece is the thickness of the steel plate.
  • the elongation conversion formula based on the difference in the shape of the test piece is also defined in ISO2566-1.
  • the 12% elongation of the JIS Z2241 No. 5 test piece is the tensile test piece of the JIS Z2241 No. 13B test piece (original The distance between the gauge points is 50 mm, the width of the parallel part is 12.5 mm, and the thickness of the test piece is a flat type test piece with the thickness of the steel plate, which is 10.4%, and the tensile test piece is JIS Z2241 No.
  • the Charpy absorbed energy at -20 ° C: 59 J / cm 2 or more When construction machines and industrial machines are used in cold regions, low-temperature toughness may be required for high-strength steel sheets. Therefore, the Charpy absorbed energy at ⁇ 20 ° C. is preferably 59 J / cm 2 . More preferably, the Charpy absorbed energy at ⁇ 40 ° C. is 59 J / cm 2 or more.
  • the high-strength steel sheet according to the present embodiment melts molten steel having the chemical composition in the above-described range by a conventional method, heats a steel piece obtained by casting the molten steel, performs hot rolling, and accelerated cooling. And after accelerating cooling stop, it can cool to room temperature as it is and can manufacture.
  • tempering heat treatment such as tempering is not performed after the accelerated cooling is stopped or after cooling to room temperature. When tempering is performed, martensite becomes tempered martensite.
  • the high-strength steel sheet according to the present embodiment is manufactured in a so-called non-tempered manufacturing process in which the tempering heat treatment is omitted for the purpose of shortening the work period and reducing the manufacturing cost.
  • the high-strength steel plate according to this embodiment manufactured by the non-tempered manufacturing process may be referred to as a non-tempered high-strength steel plate. Below, the preferable conditions of each process are demonstrated.
  • Heating temperature of steel slab 1100 ⁇ 1250 °C
  • carbides and nitrides of alloy elements are generated in the steel slab subjected to hot rolling.
  • the heating temperature is set to 1100 ° C. or higher.
  • the heating temperature of the steel slab is too high, the crystal grain size becomes coarse and the toughness may decrease, so the heating temperature is set to 1250 ° C. or lower.
  • Hot rolling is performed on the heated steel slab. After hot rolling, in order to obtain a metal structure mainly composed of martensite by accelerated cooling, it is necessary to start accelerated cooling at a temperature at which the metal structure is austenite. Therefore, the hot rolling must be finished at a temperature at which the metal structure is austenite. Therefore, the finishing temperature of hot rolling is set to Ar3 (° C.) or higher.
  • Ar3 (° C.) is a temperature at which ferrite transformation starts from austenite during cooling, and can be obtained from thermal expansion behavior. Ar3 (° C.) can be easily obtained by, for example, the following (formula b).
  • the hot rolling may be performed by a conventional method, but the recrystallization zone rolling in which the cumulative rolling reduction in the temperature range of 1050 ° C. or higher is 50 to 80%, and the cumulative rolling reduction in the temperature range of Ar 3 to 950 ° C. is 50 It is preferable to perform non-recrystallized zone rolling to ⁇ 90%.
  • the cooling rate of accelerated cooling needs to be 30 ° C./s or more in order to increase the area ratio of martensite. If it is less than 30 ° C./s, a sufficient martensite area ratio cannot be obtained. In order to promote martensitic transformation, it is preferable to increase the cooling rate, but the upper limit may be set to 200 ° C./s or less because of restrictions on the plate thickness and equipment.
  • the cooling rate is calculated by measuring the temperature change of the surface of the steel sheet after hot rolling, and dividing the difference between the surface temperature before the start of water cooling and the surface temperature immediately after the stop of water cooling by the time required for cooling.
  • the metal structure In order to change the metal structure to martensite, it is necessary to cool to a temperature of at least Ms (° C.) or less, and when cooled (quenched) to a temperature of Mf (° C.) or less, 90% or more of the metal structure is martensite. Become a site. However, when the cooling stop temperature is 300 ° C. or higher, cooling may become unstable and part of martensite may be bainite. Therefore, the cooling stop temperature is set to Mf (° C.) or less and lower than 300 ° C. As described above, the accelerated cooling stop temperature is extremely important, and it is a precondition that the accelerated cooling stop temperature is lower than the temperature Ms (° C.) at which the martensitic transformation starts. When accelerated cooling is performed to a temperature Mf (° C.) or lower at which the martensitic transformation is completed and below 300 ° C., the metal structure becomes a martensite-based structure in which the formation of carbides is suppressed.
  • the lower limit of the accelerated cooling stop temperature is not particularly limited, and accelerated cooling may be performed to room temperature.
  • the stop temperature of accelerated cooling is preferably 100 ° C. or higher. After stopping the accelerated cooling, it is allowed to cool to room temperature without any tempering heat treatment such as tempering.
  • the surface temperature of the steel plate was measured with a radiation thermometer, and the “cooling rate” was calculated by obtaining the temperature at the center of the plate thickness from the surface temperature by heat conduction calculation. None of the steel sheets was tempered. The obtained steel sheet was evaluated for the metal structure and mechanical properties (yield strength, tensile strength, elongation at break, toughness, joint strength).
  • the determination of the metal structure and the measurement of the area ratio of martensite and bainite were performed by the following methods. After mirror polishing the cross section of the steel plate, the cross section parallel to the rolling direction in the vicinity of the 1/4 t portion is corroded by nital, and two optical fields of 120 ⁇ m ⁇ 100 ⁇ m are photographed with an optical microscope at a magnification of 500 times, and are needle-shaped. The area ratio of the tissue in which the lath structure was developed was measured. Moreover, about the acicular structure, after carrying out the electrolytic polishing of the cross section of a steel plate, the 1/4 t part vicinity of the steel plate cross section was observed with the scanning electron microscope (SEM).
  • SEM scanning electron microscope
  • the magnification was 5000 times, and a range of 50 ⁇ m ⁇ 40 ⁇ m was photographed.
  • the acicular structure is assumed to be martensite, and the area ratio of the region was obtained.
  • the product of the needle-like structure area ratio in the optical microscope and the martensite area ratio in the SEM was defined as the martensite area ratio of the steel type.
  • the acicular structure other than martensite was used as bainite.
  • the vicinity of a 1/4 t portion of the cross section of the steel plate was observed with a scanning electron microscope (SEM), and the number density of cementite was measured.
  • SEM scanning electron microscope
  • the range of 50 ⁇ m ⁇ 40 ⁇ m was photographed with a scanning electron microscope (SEM) at a magnification of 5,000 in the vicinity of a 1 ⁇ 4 t portion of the cross section of the steel plate. From the contrast of the obtained image, using image analysis software, the number of precipitates having an aspect ratio of 2.0 or more and a length in the major axis direction of 0.1 ⁇ m or more was counted as being cementite.
  • the number of cementite having an aspect ratio of 2.0 or more and a length in the major axis direction of 1.0 ⁇ m or more was counted. Then, by dividing the number of the obtained precipitates of 1.0 ⁇ m or more by the number of mentites of 0.1 ⁇ m or more, a cementite number fraction (%) of 1.0 ⁇ m or more was obtained. In addition, it was judged that the cementite number fraction of 1.0 ⁇ m or more was 5% or less.
  • the aspect ratio of the prior austenite grains was measured. Specifically, the cross section parallel to the rolling direction in the vicinity of the 1/4 t part is corroded with nital, the magnification is 500 times with an optical microscope, and two fields of view in the range of 120 ⁇ m ⁇ 100 ⁇ m are photographed, and from the obtained image
  • the major axis length and minor axis length of at least 50 prior austenite grains were measured, and the major axis length was divided by the minor axis length to determine the aspect ratio for each grain.
  • the average value of the aspect-ratio of these prior austenite grains was calculated
  • Welded joints were produced using steel plates (steel numbers 1 to 16) with good mechanical properties and steel plate numbers 32 with Pcm less than 0.189%.
  • the welding method was MAG welding, and the welding heat input was 7.0 kJ / cm or 10.0 kJ / cm.
  • the welding conditions are current 280 A, voltage 27 V, welding speed 65 cm / min, and when 10.0 kJ / cm, current 305 A, voltage 29 V, welding speed 53 cm / min. did.
  • the tensile strength (joint strength) of the welded joint was evaluated by a tensile test specified in JIS Z 3121, and 950 MPa or more was evaluated as good.
  • Table 3 shows the above evaluation results.
  • an underlined numerical value indicates that the value is outside the scope of the present invention, or the target characteristics are not obtained.
  • Steel plate numbers 1 to 16 are examples of the present invention, and excellent strength, ductility and toughness are obtained. Also, the joint strength is 950 MPa or more. Further, in the case where Mo / Cr is 0.20 or more, excellent toughness is obtained even at a test temperature of ⁇ 40 ° C.
  • steel plates Nos. 17 to 35 are comparative examples, and one or more of yield strength, tensile strength, elongation at break, and vE- 20 do not satisfy the target. Steel plates Nos. 17, 26, and 29 have low strength because they each have a small amount of C or Mn. For steel plate numbers 26 and 29, the martensite fraction was not sufficient.
  • Steel plate numbers 18, 19, 21, 22, 23, 27, 28, and 30 had excessive amounts of C, Si, Mn, Cr, or Mo, respectively, and had low ductility and toughness.
  • Steel plate number 32 had a low Pcm, so the joint strength was below 950 MPa.
  • Steel plate number 35 had a low rolling reduction in the non-recrystallized region, and the aspect ratio of the prior austenite grains was less than 2.0, so the toughness was low.

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Abstract

L'invention porte sur une tôle d'acier à haute résistance qui présente une composition chimique prescrite et qui comprend un ou les deux types parmi la martensite et la bainite, dans laquelle DI (diamètre critique idéal) est de 2,0 à 7,8, le Pcm (paramètre métallique critique pour la fissuration d'une soudure) est de 0,189 % ou plus, et la structure métallique représente 99 % ou plus dans le rapport surfacique total. Le rapport d'aspect des anciens grains d'austénite est de 2,0 ou plus ; la fraction en nombre de cémentite dans laquelle la longueur dans la direction du grand axe est de 1,0 µm ou plus par rapport à la cémentite dans laquelle la longueur dans la direction du grand axe est de 0,1 µm ou plus est de 5 % ou moins ; l'épaisseur de la tôle est de 4,5 à 20 mm ; la limite d'élasticité est de 885 MPa ou plus ; la résistance à la traction est de 950 MPa ou plus ; l'allongement à la rupture est de 12 % ou plus ; et l'énergie absorbée de Charpy à -20°C est de 59 J/cm2 ou plus.
PCT/JP2016/072316 2016-07-29 2016-07-29 Tôle d'acier à haute résistance WO2018020660A1 (fr)

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JP2018530300A JP6501042B2 (ja) 2016-07-29 2016-07-29 高強度鋼板
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019173053A (ja) * 2018-03-27 2019-10-10 株式会社神戸製鋼所 高強度高延性鋼板
JP2019173054A (ja) * 2018-03-27 2019-10-10 株式会社神戸製鋼所 高強度高延性鋼板
WO2021125283A1 (fr) 2019-12-19 2021-06-24 日本製鉄株式会社 Tôle d'acier et son procédé de fabrication
WO2022045349A1 (fr) * 2020-08-31 2022-03-03 日本製鉄株式会社 Feuille d'acier et son procédé de production

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110846564A (zh) * 2019-09-30 2020-02-28 邯郸钢铁集团有限责任公司 低成本高强大梁钢750l及其生产方法
CN115074634B (zh) * 2022-07-08 2023-01-06 北京高创智信冶金科技有限公司 重型汽车用高强度非调质钢前轴及其生产工艺

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008184638A (ja) * 2007-01-29 2008-08-14 Sumitomo Metal Ind Ltd 厚肉高張力鋼板およびその製造方法
JP2010070845A (ja) * 2008-09-18 2010-04-02 Korea Inst Of Machinery & Materials 低温靭性に優れた溶接性の超高強度鋼及びその製造方法
JP2011052321A (ja) * 2009-08-06 2011-03-17 Jfe Steel Corp 低温靭性に優れた高強度熱延鋼板およびその製造方法
WO2011142285A1 (fr) * 2010-05-14 2011-11-17 新日本製鐵株式会社 Tôle d'acier à haute résistance et son procédé de production
WO2012060405A1 (fr) * 2010-11-05 2012-05-10 新日本製鐵株式会社 Feuille d'acier à haute résistance et son procédé de fabrication
JP2014047414A (ja) * 2012-09-03 2014-03-17 Nippon Steel & Sumitomo Metal 外観に優れ、靭性と降伏強度の等方性に優れた高強度熱延鋼板及びその製造方法
WO2014154104A1 (fr) * 2013-03-28 2014-10-02 宝山钢铁股份有限公司 Plaque d'acier faiblement allié de ténacité élevée et résistante à l'usure et son procédé de fabrication
JP2014529686A (ja) * 2012-07-31 2014-11-13 宝山鋼鉄股▲分▼有限公司 高強度・高靭性・耐磨耗鋼板およびその製造方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5151693B2 (ja) 2008-05-29 2013-02-27 新日鐵住金株式会社 高張力鋼の製造方法
JP5630125B2 (ja) 2009-08-06 2014-11-26 Ｊｆｅスチール株式会社 低温靭性に優れた高強度熱延鋼板およびその製造方法
JP5598225B2 (ja) 2010-09-30 2014-10-01 Ｊｆｅスチール株式会社 曲げ特性と低温靭性に優れた高強度熱延鋼板およびその製造方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008184638A (ja) * 2007-01-29 2008-08-14 Sumitomo Metal Ind Ltd 厚肉高張力鋼板およびその製造方法
JP2010070845A (ja) * 2008-09-18 2010-04-02 Korea Inst Of Machinery & Materials 低温靭性に優れた溶接性の超高強度鋼及びその製造方法
JP2011052321A (ja) * 2009-08-06 2011-03-17 Jfe Steel Corp 低温靭性に優れた高強度熱延鋼板およびその製造方法
WO2011142285A1 (fr) * 2010-05-14 2011-11-17 新日本製鐵株式会社 Tôle d'acier à haute résistance et son procédé de production
WO2012060405A1 (fr) * 2010-11-05 2012-05-10 新日本製鐵株式会社 Feuille d'acier à haute résistance et son procédé de fabrication
JP2014529686A (ja) * 2012-07-31 2014-11-13 宝山鋼鉄股▲分▼有限公司 高強度・高靭性・耐磨耗鋼板およびその製造方法
JP2014047414A (ja) * 2012-09-03 2014-03-17 Nippon Steel & Sumitomo Metal 外観に優れ、靭性と降伏強度の等方性に優れた高強度熱延鋼板及びその製造方法
WO2014154104A1 (fr) * 2013-03-28 2014-10-02 宝山钢铁股份有限公司 Plaque d'acier faiblement allié de ténacité élevée et résistante à l'usure et son procédé de fabrication

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019173053A (ja) * 2018-03-27 2019-10-10 株式会社神戸製鋼所 高強度高延性鋼板
JP2019173054A (ja) * 2018-03-27 2019-10-10 株式会社神戸製鋼所 高強度高延性鋼板
JP7048379B2 (ja) 2018-03-27 2022-04-05 株式会社神戸製鋼所 高強度高延性鋼板
JP7048378B2 (ja) 2018-03-27 2022-04-05 株式会社神戸製鋼所 高強度高延性鋼板
WO2021125283A1 (fr) 2019-12-19 2021-06-24 日本製鉄株式会社 Tôle d'acier et son procédé de fabrication
KR20220095232A (ko) 2019-12-19 2022-07-06 닛폰세이테츠 가부시키가이샤 강판 및 그 제조 방법
WO2022045349A1 (fr) * 2020-08-31 2022-03-03 日本製鉄株式会社 Feuille d'acier et son procédé de production
JP7099656B1 (ja) * 2020-08-31 2022-07-12 日本製鉄株式会社 鋼板およびその製造方法

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