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WO2019059660A1 - Tôle d'acier faiblement allié possédant une résistance et une ductilité excellentes et procédé de fabrication s'y rapportant - Google Patents

Tôle d'acier faiblement allié possédant une résistance et une ductilité excellentes et procédé de fabrication s'y rapportant Download PDF

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Publication number
WO2019059660A1
WO2019059660A1 PCT/KR2018/011097 KR2018011097W WO2019059660A1 WO 2019059660 A1 WO2019059660 A1 WO 2019059660A1 KR 2018011097 W KR2018011097 W KR 2018011097W WO 2019059660 A1 WO2019059660 A1 WO 2019059660A1
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Prior art keywords
steel sheet
strength
ductility
cold
rolling
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Ceased
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English (en)
Korean (ko)
Inventor
최점용
박미남
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Posco Holdings Inc
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Posco Co Ltd
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Priority to CN201880062303.2A priority Critical patent/CN111133122B/zh
Priority to EP18857908.0A priority patent/EP3674435A1/fr
Publication of WO2019059660A1 publication Critical patent/WO2019059660A1/fr
Anticipated expiration legal-status Critical
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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
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0236—Cold rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
    • 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
    • C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel 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
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • C—CHEMISTRY; METALLURGY
    • 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
    • C21D2211/001—Austenite

Definitions

  • the present invention relates to a high strength and high ductility steel sheet suitable for structural members such as automobiles and railroad cars, and more particularly to a steel sheet which minimizes alloying elements such as Ni and which has a strength and ductility To a low alloy steel sheet and a manufacturing method thereof.
  • Transformational texture steel is represented by DP (Dual Phase) steel, TRIP (TRANSformation Induced Plasticity) steel, CP (Complex Phase) steel, etc. These transformed structure steels have mechanical properties, That is, the tensile strength and the elongation level are different.
  • TRIP steel which is one of the transformed structure steel, can control both the cooling rate and the cooling termination temperature during the cooling process after forming the austenite during the annealing process, thereby partially improving the strength and ductility by partially retaining the austenite at the room temperature.
  • the metastable retained austenite is transformed into martensite by deformation, thereby increasing elongation by delaying local stress concentration relaxation and necking with increasing strength. Therefore, it is important that TRIP steels retain austenite more than a certain fraction at room temperature.
  • austenite stabilizing element should be added together with a large amount of Mn to maintain a certain percentage of retained austenite at room temperature.
  • TWIP winning Induced Plasticity
  • PCT Published Patent Application No. 2012/077150 is a high Mn-containing TWIP steel having excellent mechanical properties and moldability, cold-rolled steel is subjected to cold-rolling annealing for recrystallization.
  • alloying elements such as C, Al and Si are additionally added to stabilize the austenite phase or to control the stacking defect energy (SFE).
  • the TRIP steel and the TWIP steel to which a large amount of the alloy component is added are solidified into austenite single phase at the time of manufacture, and the hot workability is weakened, and a defect caused by inclusions such as Al easily occurs in hot rolling.
  • manufacturing technology such as casting and rolling process is very difficult due to a problem, and a manufacturing cost is high due to a large increase of alloy cost.
  • the increase in the strength of the automotive steel sheet necessarily causes an increase in the yield strength and a decrease in the elongation percentage, which results in a significant decrease in moldability.
  • a hot press forming or hot forming forming method has been commercialized.
  • U.S. Patent No. 6,296,805 discloses an aluminum steel plate or an aluminum alloy plated steel sheet for suppressing an oxide film formed on the surface of a steel sheet during a heating process of a hot press forming process. Further, a technique of using a galvanized steel sheet or a zinc alloy plated steel sheet at a site where a sacrificial pattern characteristic is required, such as a wet portion of an automobile body, has been proposed.
  • An object of the present invention is to provide a low alloy steel sheet having a high strength and high ductility by minimizing the addition of alloying elements and realizing a TRIP shape.
  • the present invention also provides a low alloy steel sheet having high strength and high ductility by implementing an annealing technique including a plurality of microstructures by controlling a heat treatment process.
  • the low alloy steel sheet excellent in strength and ductility may contain, by weight%, C: 0.05 to 0.15%, Si: 0.7 to 2.5%, Mn: 8 to 9.9%, Cr: 13 to 15.0% : More than 0 and not more than 1.0%, N: 0.1 to 0.2%, Al: more than 0 and not more than 0.25%, Sn: more than 0 and not more than 0.05%, and the remainder contains Fe and other unavoidable impurities. 20% or less, and the remainder includes the austenite phase.
  • Ni may be further contained in an amount of 0.2% or less by weight.
  • it may further include Mo: less than 0.2% by weight.
  • the steel sheet may have an elongation of 30% or more.
  • the steel sheet may have a tensile strength of 1250 MPa or more.
  • the steel sheet may have a yield strength of 520 MPa or more.
  • a method of manufacturing a low alloy steel sheet excellent in strength and ductility is characterized by comprising, by weight, 0.05 to 0.15% of C, 0.7 to 2.5% of Si, 8 to 9.9% of Mn, 13 to 15.0 of Cr %, More than 0% of Cu, not more than 1.0% of N, 0.1 to 0.2% of Al, more than 0 and not more than 0.25% of Sn, more than 0 and not more than 0.05% of Ni and not more than 0.2% of Sn, Hot rolling the slab, hot-annealing the hot-rolled steel sheet, cold-rolling the hot-rolled steel sheet, and cold-annealing the cold-rolled steel sheet at 750 to 900 ° C. .
  • a martensite phase may be contained in a microstructure at a volume fraction of 20% or less in the cold rolling and annealing step, and the remainder may include an austenite phase.
  • the cold rolling annealing may be performed by performing heat treatment at 750 to 900 ° C for 5 minutes, followed by air cooling.
  • the hot-rolling is reheated to a temperature range of 1100 to 1200 ° C, hot-rolled, and hot-rolled and annealed in a temperature range of 900 to 1100 ° C, and the cold- You can proceed with the rate.
  • the low alloy steel sheet having excellent strength and ductility according to the embodiment of the present invention can have a tensile strength of 1250 MPa or more, an elongation of 30% or more, and a yield strength of 520 MPa or more by realizing TRIP or TWIP development. Accordingly, various types of molded articles can be manufactured and used as automobile parts or other structural materials.
  • FIG. 1 is a photograph showing a microstructure of a low alloy steel sheet according to an embodiment of the present invention.
  • FIG. 2 is a photograph showing the microstructure of a low alloy steel sheet according to a comparative example.
  • FIG. 3 is a graph showing changes in mechanical properties according to a cold-annealing temperature in a method of manufacturing a low-alloy steel sheet according to an embodiment of the present invention.
  • FIG. 4 is a photograph of the microstructure of an inventive steel according to an embodiment of the present invention obtained by cold-annealing at 750 ° C., by EBSD (Electron Backscatter Diffraction).
  • FIG. 5 is a photograph of the microstructure of an inventive steel according to an embodiment of the present invention taken at 800.degree. C. at 800.degree. C. by Electron Backscatter Diffraction (EBSD).
  • EBSD Electron Backscatter Diffraction
  • FIG. 6 is a photograph of a microstructure obtained by cold rolling annealing at 900.degree. C. of an inventive steel according to an embodiment of the present invention by EBSD (Electron Backscatter Diffraction).
  • EBSD Electro Backscatter Diffraction
  • FIG. 1 is a view illustrating a state in which a plating layer is formed on a base material of a home appliance including a hair line according to an embodiment of the present invention, a hair line is processed, and a coating layer is formed.
  • a copper (Cu) plating layer 110 is formed on an upper surface of a base material 100 of a home appliance 1 according to an embodiment disclosed.
  • a nickel (Ni) plating layer 120 is formed on the copper plating layer 110.
  • a chromium (Cr) plating layer 130 is formed on the nickel plating layer 120.
  • Al aluminum
  • On the upper surface of the chromium plated layer 130 unevenness 130a for forming a pattern in the transverse direction is formed.
  • the irregularities 130a may be formed by hairline processing.
  • the horizontal direction means the horizontal direction. More specifically, the lateral direction means that the hair line is formed horizontally with the short side of the base material 100. [ Formation of the hair line will be described later.
  • the coating layer 140 may be formed on the upper surface of the chromium plating layer 130.
  • the coating layer 140 may be formed using one of acrylic, fluorine, and silane coating materials.
  • the copper plating layer 110, the nickel plating layer 120, and the chromium plating layer 130 may be sequentially formed from the base material 100.
  • the upper surface of the chromium plating layer 130 is provided with projections and depressions 130a and the coating layer 140 may be disposed on the upper surface of the chromium plating layer 130.
  • the thickness of aluminum as the base material 100 may be 10 to 30 mm.
  • the base material 100 may be manufactured using an extrusion technique.
  • the thickness of the copper plating layer 110 may be 5 to 30 ⁇ ⁇ .
  • the thickness of the nickel plating layer 120 may be 5 to 30 ⁇ ⁇ .
  • the thickness of the chromium plated layer 130 may be 0.15 to 0.5 mu m. This means the thickness of the chrome plated layer after hairline processing, which means the maximum thickness of the chrome plated layer.
  • the thickness of the chromium plating layer before the hairline processing may be 0.3 to 0.8 mu m. This will be described in more detail in the following Examples.
  • FIG. 2 is a view illustrating a process of manufacturing a home appliance according to an embodiment of the present invention.
  • At least one plating layer 110, 120, or 130 is formed on the base material 100, and the upper surface of the plating layer 110, 120, And a coating layer 140 is formed on the hair line 130a.
  • the coating layer may be coated using a silane-based, fluorine-based, or acrylic-based coating material. According to the disclosed embodiment, the silane-based cycloalkoxyalkylsilane can be coated.
  • Plating is performed on the upper surface of the base material 100 in the order of the copper plating layer 110, the nickel plating layer 120, and the chromium plating layer 130. Thereafter, hair lines are formed on the upper surface of the chromium plated layer 130 to form irregularities 130a. Thereafter, the coating is performed to coat the upper surface of the unevenness 130a to form the coating layer 140.
  • FIG. 3 is a view showing a state in which an axis of a hairline processing wheel for processing a hair line on a base material is tilted according to an embodiment disclosed.
  • the hairline processing of the disclosed embodiment proceeds using the hairline processing wheel 2.
  • the polishing brush 3 for machining the hair line of the hairline processing wheel 2 is a polishing brush 3 made of high purity alumina (Al 2 O 3 ( purity : 90% or more)) bonded to the inspection surface of Nylon 6.6 or polyester through an adhesive (3) is used.
  • the hair line processing wheel 2 processes the hair line in a state of being tilted at a predetermined angle.
  • the rotary shaft 4 of the hairline processing wheel 2 is installed to be tilted at a predetermined angle with respect to the short side of the base material 100.
  • the polishing brush 3 of the hairline processing wheel 2 is also tilted at a predetermined angle.
  • the polishing brush 3 of the hairline processing wheel 2 can be tilted 4 to 10 degrees with respect to the horizontal plane. That is, the angle? Shown in FIG. 3 may be 4 to 10 degrees.
  • the generation of the hairline in the transverse direction causes centrifugal force to act on the base material 100 because the hairline is processed while the base material moves.
  • a low alloy steel sheet excellent in strength and ductility comprises 0.05 to 0.15% of C, 0.7 to 2.5% of Si, 8 to 9.9% of Mn, 13 to 15% of Cr, Cu: more than 0 to 1.0%, N: 0.1 to 0.2%, Al: more than 0 to 0.25%, Sn: more than 0 to 0.25%, and the balance of Fe and other unavoidable impurities.
  • the low alloy steel sheet having excellent strength and ductility according to an embodiment of the present invention may further contain Ni of 0.2% or less by weight.
  • the low alloy steel sheet having excellent strength and ductility according to an embodiment of the present invention may further contain less than 0.2% Mo by weight.
  • the content of C is 0.05% to 0.15% or less.
  • C is an austenite forming element and is an effective element for increasing the strength of a material by solid solution strengthening. Although it is advantageous to add a large amount of C in order to secure the yield strength, the corrosion resistance is lowered when it is added in excess, and the upper limit is limited to 0.15% or less. On the other hand, in the case of lower limit, the lower limit is limited to 0.05% in order to take the load of decarburization during smelting and to obtain the effect of increasing the strength by the minimum C. It is preferable to add C in the range of 0.05 to 0.15% in order to stably manufacture and secure the strength by C.
  • the content of Si is not less than 0.7% and not more than 2.5%.
  • Si is partially added because it acts as a deoxidizing effect and a ferrite stabilizing element. However, if it is added in excess, the mechanical properties related to the corrosion resistance and the impact toughness are lowered.
  • the upper limit is limited to 2.5%.
  • the lower limit is limited to 0.7% in order to control the stability of the austenite phase by Si addition, control of fired organic martensite formation, and ease of production.
  • the content of Mn is 8% or more and 9.9% or less.
  • Mn is an austenite-forming element, and is a major element constituting the austenite phase in the Cr-added steel.
  • the same effect as Ni is utilized as a substitute for Ni.
  • Mn is contained in a large amount at the time of production, oxide-based inclusions cause defects in production or deterioration in corrosion resistance.
  • An additional technique for reducing the employment oxygen of the special refining or the like is required for the inclusion reduction, and the manufacturing cost is increased. Therefore, the upper limit is limited to 9.5%.
  • the minimum amount for Ni addition and the minimum amount for securing the austenite single phase or some ferrite or martensite structure is about 8%. Therefore, the range of Mn is preferably limited to 8 to 9.9%.
  • the content of Cr is 13.0% or more and 15.0% or less.
  • Cr is a representative ferrite-forming element and is an element that increases corrosion resistance. In particular, it is an element that greatly affects N employment.
  • the trace elements particularly S and P which are intergranular segregated elements
  • the upper limit of Cr is limited to 15.0% or less.
  • the content of Cr is too low, it will solidify at the austenite phase during solidification at a high temperature, and control a trace amount of P and S which are intergranular segregation factors. In case of insufficient control, Occurs.
  • at least 13.0% is required to have minimum corrosion resistance and superior corrosion resistance over carbon steel. Therefore, Cr is preferably limited to 13.0 to 15.0% in order to solidify the primer into ferrite within the range of the desired alloying element and to maintain the corrosion resistance of the minimum stainless steel level.
  • the content of Cu is more than 0 and not more than 1.0%.
  • Cu is an austenite-forming element similar to Mn and Ni. As an element to be added in place of Ni, when it is added in excess, it is precipitated as metal Cu in excess of solubility and causes grain boundary embrittlement upon heating. Therefore, the maximum amount that can control the stability of austenite without exceeding the solubility is 1.0%. Therefore, Cu is preferably limited to more than 0 and 1.0%.
  • the content of N is 0.1% or more and 0.2% or less.
  • N is a representative austenite forming element along with Ni, and it is an element which improves the corrosion resistance of the material together with Cr and Mo.
  • the effect of N addition is shown, and the minimum amount that improves the strength of the material with interstitial elements along with C is 0.1%.
  • Most of the pressure is applied to increase the solubility of N in order to employ a large amount of N in the material.
  • Cr and Mn which are representative elements for increasing the solubility of N, are present in a large amount, the amount that can maximally employ N without applying atmospheric pressure is 0.2%. Therefore, it is preferable that the appropriate amount of N is limited within the range of 0.1 to 0.2%.
  • the content of Al is 0% or more and 0.25% or less.
  • Al is a ferrite-forming element in Cr-added stainless steels. It is a useful element for deoxidation in steelmaking and simultaneously increases the energy of lamination defects of austenite phase to form fired organic martensite or mechanical twinning. It is known that it improves the delayed fracture resistance, which is a crack which is caused by cracking. If the content exceeds 0.25%, large-sized Al inclusions are generated and cause surface defects. Further, when it is added excessively, it contains a large amount of ferrite phase at a high temperature and causes cracking in hot rolling. Therefore, the content of Al is limited to a range of 0% to 0.25%. According to one embodiment of the present invention, Al can be contained at 0.13% or less.
  • the content of Sn is 0% or more and 0.05% or less.
  • Sn is known as an element improving the corrosion resistance of the material and improving the pickling property by controlling the thickness of the annealing scale at annealing. That is, when a large amount of Si is added, the effect of suppressing the formation of SiO 2 oxide on the scale surface layer generated in the cold rolling or hot-rolling annealing process can be increased, and the efficiency of the cold rolling annealing process can be increased.
  • excessive addition of Sn causes a decrease in hot workability and a decrease in the top of the production process, so that the upper limit is limited to 0.05%.
  • the corrosion resistance when Sn is added, Sn is added to the surface of the passivation layer of the stainless steel to increase the resistance of the coating. Therefore, the content of Sn is limited to a range of 0.05% or less.
  • the steel sheet may further contain Ni in an amount of 0.2% or less by weight.
  • Ni is an austenite-forming element and plays the same role as Mn. Most of Ni is replaced with Mn, and some of them are present as impurities by scrap or the like. The residual amount is limited to 0.2% or less.
  • the steel sheet may further contain less than 0.2% by weight of Mo
  • Mo is an expensive element that increases the corrosion resistance and forms ferrite. In the absence of addition, the amount is limited to 0.2% or less.
  • the steel sheet according to the present invention satisfying the above alloy element composition range has a microstructure in which the martensite phase has a volume fraction of 20% or less and the remainder contains the austenite phase.
  • the low alloy steel sheet according to the present invention can be produced through a process such as reheating, hot rolling, hot rolling, cold rolling, cold annealing and pickling of slabs according to a conventional production method.
  • the cold-rolling annealing according to an embodiment of the present invention can be performed at a temperature of 750 to 900 ° C.
  • the low alloy steel sheet excellent in strength and ductility according to the present invention can be used for general products for molding, for example, and can be used as a strip, a bar, a plate, a sheet, a pipe, ), Or a tube (tube).
  • Specimens of steels corresponding to the composition range of the composition according to the present invention were prepared, and the elongation, yield strength and tensile strength of the material were measured after hot rolling, hot rolling annealing, cold rolling and cold annealing.
  • Table 1 below shows the alloy composition (wt%) for the experimental steel types.
  • the hot rolled steel sheets were hot rolled at ordinary rolling temperature, and cold rolled and cold rolled annealed at various temperatures to evaluate the microstructure and related strength and elongation.
  • Table 2 shows the yield strength, tensile strength and elongation obtained after annealing the inventive steel at respective cold rolling annealing temperatures for about 5 minutes.
  • Table 3 shows the yield strength, tensile strength and elongation obtained after heat treatment of the comparative steels at respective cold rolling annealing temperatures for about 5 minutes.
  • Annealing temperature Yield strength (Mpa) Tensile Strength (Mpa) Elongation (%) 700 795 1203 26.3 750 784 1214 39.6 800 691 1136 41.9 850 689 1112 46.1 900 515 962 52.2 950 495 1013 54.6 1000 471 1014 55.8 1100 414 944 59.2
  • FIG. 3 is a graph showing changes in mechanical properties according to a cold-annealing temperature in a method of manufacturing a low-alloy steel sheet according to an embodiment of the present invention.
  • the yield strength increases and the tensile sensitivity decreases as the cold-rolled annealing temperature decreases.
  • a decrease in the annealing temperature may adversely affect the workability.
  • Fig. 3 shows that the yield strength increases and the tensile sensitivity decreases as the cold-rolled annealing temperature decreases.
  • a decrease in the annealing temperature may adversely affect the workability.
  • the comparative steel has a yield strength of 520 MPa or higher at a temperature of 750 to 900 ° C., but it can be confirmed that the desired mechanical properties can not be secured because the tensile strength is 1250 MPa or less.
  • FIG. 4 is a photograph of a microstructure obtained by cold rolling and annealing at 750 ° C. of an inventive steel according to an embodiment of the present invention by EBSD (Electron Backscatter Diffraction)
  • FIG. 6 is a photograph of a microstructure obtained by cold-rolling annealing at 800 ° C. by EBSD (Electron Backscatter Diffraction).
  • FIG. 6 is a photograph of EBSD (Electron Backscatter Diffraction). 4 to 6, the grain size and composition of austenite according to the cold-rolling annealing temperature can be confirmed.
  • the cold-rolling annealing temperature shown in Fig. 6 is 900 ° C, it can be confirmed that the crystal grains are composed of coarse austenite and a small amount of martensite. Accordingly, when the cold-rolling annealing temperature exceeds 900 ° C, it is confirmed that the yield strength is lowered.
  • the inventive steel according to one embodiment of the present application can have a yield strength of 520 MPa, a tensile strength of 1250 MPa, and an elongation of 30% or more within the range of the cold annealing temperature of 750 to 900 ⁇ .

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)

Abstract

La présente invention concerne : une tôle d'acier faiblement allié conservant une résistance élevée, une limite d'élasticité élevée et une ductilité élevée, tout en possédant une teneur minimale en éléments d'alliage ajoutés ; et un procédé de fabrication d'une tôle d'acier faiblement allié. Selon un mode de réalisation de la présente invention, la feuille d'acier faiblement allié possédant une résistance et une ductilité excellentes comprend, en % en poids, une teneur de 0,05 à 0,15 % de C, une teneur de 0,7 à 2,5 % de Si, une teneur de 8 à 9,9 % de Mn, une teneur de 13 à 15,0 % de Cr, une teneur supérieure à 0 % et inférieure ou égale à 1,0 % de Cu, une teneur de 0,1 à 0,2 % de N, une teneur supérieure à 0 % et inférieure ou égale à 0,25 % d'Al, une teneur supérieure à 0 % et inférieure ou égale à 0,05 % de Sn, le complément étant du Fe et d'autres impuretés inévitables, une microstructure comprenant une phase martensitique inférieure ou égale à 20 % en volume, le reste étant une phase austénitique.
PCT/KR2018/011097 2017-09-25 2018-09-20 Tôle d'acier faiblement allié possédant une résistance et une ductilité excellentes et procédé de fabrication s'y rapportant Ceased WO2019059660A1 (fr)

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CN201880062303.2A CN111133122B (zh) 2017-09-25 2018-09-20 具有优异的强度和延展性的低合金钢板及其制造方法
EP18857908.0A EP3674435A1 (fr) 2017-09-25 2018-09-20 Tôle d'acier faiblement allié possédant une résistance et une ductilité excellentes et procédé de fabrication s'y rapportant

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3978643A4 (fr) * 2019-07-17 2022-08-17 Posco Acier inoxydable austénitique ayant une résistance améliorée et procédé de fabrication associé
US20230124298A1 (en) * 2018-04-02 2023-04-20 Samsung Electronics Co., Ltd. Home appliance including hairline and manufacturing method thereof
US20230142021A1 (en) * 2020-04-22 2023-05-11 Posco Low-cost austenitic stainless steel having high strength and high formability, and method for manufacturing same

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115305412B (zh) * 2021-05-05 2024-02-06 通用汽车环球科技运作有限责任公司 具有优异耐腐蚀性和超高强度的组合的压制硬化钢

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6296805B1 (en) 1998-07-09 2001-10-02 Sollac Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment
KR20080034839A (ko) * 2005-05-23 2008-04-22 피오트르 알. 쉘러 오스테나이트계 경량 스틸 및 이의 용도
KR20080106200A (ko) * 2006-12-27 2008-12-04 닛폰 스틸 앤드 스미킨 스테인레스 스틸 코포레이션 충격 흡수 특성이 우수한 구조 부재용 스테인리스 강판
KR20090035710A (ko) * 2006-07-20 2009-04-10 아크테크 게엠베하 오스테나이트 스테인레스 주강과 그 제조 방법 및 사용
KR20110052749A (ko) * 2008-09-11 2011-05-18 티센크룹 니로스타 게엠베하 스테인리스강, 그 스테인리스강으로 제조한 냉간 스트립, 및 그 스테인리스강으로 평탄형 강 제품을 제조하는 방법
WO2012077150A2 (fr) 2010-12-07 2012-06-14 Centro Sviluppo Materiali S.P.A. Procédé de fabrication d'un acier à haute teneur en manganèse présentant une résistance mécanique et une aptitude au formage élevées, et acier obtenu par le procédé
KR20140105849A (ko) * 2012-03-09 2014-09-02 닛폰 스틸 앤드 스미킨 스테인레스 스틸 코포레이션 면내 이방성이 작은 페라이트·오스테나이트 2상 스테인리스 강판 및 그 제조 방법
KR20180068088A (ko) * 2016-12-13 2018-06-21 주식회사 포스코 강도 및 연성이 우수한 저합금 강판

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1323919A (en) * 1969-12-27 1973-07-18 Nisshin Steel Co Ltd Austenitic stainless steels
BE754371A (fr) * 1970-01-13 1971-01-18 Nisshin Steel Co Ltd Aciers inoxydables austenitiques
JPS5420444B2 (fr) * 1971-08-18 1979-07-23
JPS61124556A (ja) * 1984-11-20 1986-06-12 Kawasaki Steel Corp 低ニツケルオ−ステナイト系ステンレス鋼板およびその製造方法
US4946644A (en) * 1989-03-03 1990-08-07 Baltimore Specialty Steels Corporation Austenitic stainless steel with improved castability
DE102005030413C5 (de) * 2005-06-28 2009-12-10 Technische Universität Bergakademie Freiberg Hochfester austenitisch-martensitischer Leichtbaustahl und seine Verwendung
JP2011219809A (ja) * 2010-04-08 2011-11-04 Honda Motor Co Ltd 高強度鋼板
FI125442B (fi) * 2010-05-06 2015-10-15 Outokumpu Oy Matalanikkelinen austeniittinen ruostumaton teräs ja teräksen käyttö
FI127274B (en) * 2014-08-21 2018-02-28 Outokumpu Oy HIGH-STRENGTH AUSTENITE STAINLESS STEEL AND ITS PRODUCTION METHOD
CN105200340B (zh) * 2015-09-23 2020-11-17 宝钢德盛不锈钢有限公司 800～1600MPa级高强度奥氏体不锈钢及制造方法和温成型方法
CN106319343B (zh) * 2016-10-10 2021-08-17 宝钢德盛不锈钢有限公司 一种低成本的高强度不锈钢及其焊管制造方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6296805B1 (en) 1998-07-09 2001-10-02 Sollac Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment
KR20080034839A (ko) * 2005-05-23 2008-04-22 피오트르 알. 쉘러 오스테나이트계 경량 스틸 및 이의 용도
KR20090035710A (ko) * 2006-07-20 2009-04-10 아크테크 게엠베하 오스테나이트 스테인레스 주강과 그 제조 방법 및 사용
KR20080106200A (ko) * 2006-12-27 2008-12-04 닛폰 스틸 앤드 스미킨 스테인레스 스틸 코포레이션 충격 흡수 특성이 우수한 구조 부재용 스테인리스 강판
KR20110052749A (ko) * 2008-09-11 2011-05-18 티센크룹 니로스타 게엠베하 스테인리스강, 그 스테인리스강으로 제조한 냉간 스트립, 및 그 스테인리스강으로 평탄형 강 제품을 제조하는 방법
WO2012077150A2 (fr) 2010-12-07 2012-06-14 Centro Sviluppo Materiali S.P.A. Procédé de fabrication d'un acier à haute teneur en manganèse présentant une résistance mécanique et une aptitude au formage élevées, et acier obtenu par le procédé
KR20140105849A (ko) * 2012-03-09 2014-09-02 닛폰 스틸 앤드 스미킨 스테인레스 스틸 코포레이션 면내 이방성이 작은 페라이트·오스테나이트 2상 스테인리스 강판 및 그 제조 방법
KR20180068088A (ko) * 2016-12-13 2018-06-21 주식회사 포스코 강도 및 연성이 우수한 저합금 강판

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3674435A4

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20230124298A1 (en) * 2018-04-02 2023-04-20 Samsung Electronics Co., Ltd. Home appliance including hairline and manufacturing method thereof
EP3978643A4 (fr) * 2019-07-17 2022-08-17 Posco Acier inoxydable austénitique ayant une résistance améliorée et procédé de fabrication associé
US20230142021A1 (en) * 2020-04-22 2023-05-11 Posco Low-cost austenitic stainless steel having high strength and high formability, and method for manufacturing same

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EP3674435A1 (fr) 2020-07-01
CN111133122A (zh) 2020-05-08
KR101952818B1 (ko) 2019-02-28
CN111133122B (zh) 2022-08-16

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