WO2022124526A1 - Acier inoxydable à base de ferrite ayant une résistance au striage améliorée et son procédé de fabrication - Google Patents

Acier inoxydable à base de ferrite ayant une résistance au striage améliorée et son procédé de fabrication Download PDF

Info

Publication number
WO2022124526A1
WO2022124526A1 PCT/KR2021/011464 KR2021011464W WO2022124526A1 WO 2022124526 A1 WO2022124526 A1 WO 2022124526A1 KR 2021011464 W KR2021011464 W KR 2021011464W WO 2022124526 A1 WO2022124526 A1 WO 2022124526A1
Authority
WO
WIPO (PCT)
Prior art keywords
less
stainless steel
ferritic stainless
present
rolling
Prior art date
Application number
PCT/KR2021/011464
Other languages
English (en)
Korean (ko)
Inventor
공정현
이문수
Original Assignee
주식회사 포스코
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 주식회사 포스코 filed Critical 주식회사 포스코
Priority to US18/265,345 priority Critical patent/US20240035134A1/en
Priority to EP21903573.0A priority patent/EP4261319A1/fr
Priority to CN202180082869.3A priority patent/CN116635560A/zh
Publication of WO2022124526A1 publication Critical patent/WO2022124526A1/fr

Links

Images

Classifications

    • 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
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/002—Heat treatment of ferrous alloys containing Cr
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0273—Final recrystallisation annealing
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0405—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0426—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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0447—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment
    • C21D8/0473—Final recrystallisation annealing
    • 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
    • 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
    • C21D9/48—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals deep-drawing sheets
    • 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
    • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C22C38/28—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
    • C22C38/40—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
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite

Definitions

  • the present invention relates to a ferritic stainless steel and a method for manufacturing the same, and more particularly, to a ferritic stainless steel with improved resistance to load and a method for manufacturing the same.
  • stainless steel is classified according to its chemical composition or metal structure. According to the metal structure, stainless steel is classified into austenitic (300 series), ferritic (400 series), martensitic, and ideal.
  • ferritic stainless steel is a steel with high price competitiveness compared to austenitic stainless steel because it contains less expensive alloying elements.
  • Ferritic stainless steel has good surface gloss, drawability and oxidation resistance, and is widely used in kitchenware, building exterior materials, home appliances, and electronic parts.
  • ferritic stainless steel is a steel type requiring high-quality surface gloss when used for exterior applications.
  • the ferritic stainless steel has a problem in that a ridge defect in the form of stripes occurs parallel to the rolling direction during forming such as deep drawing. Such a ridging defect deteriorates the appearance of the product, and when a ridging defect occurs severely, a polishing process is added after molding, thereby increasing the manufacturing cost.
  • the ⁇ 001 ⁇ //ND texture remains as a long colony structure in the rolling direction even after the final cold rolling.
  • the remaining colony tissue exhibits a relatively low plastic anisotropy (R value) compared to the tissue having other surrounding tissues. This difference in plastic anisotropy causes plastic imbalance between the two structures during molding, causing ridging defects in ferritic stainless steel.
  • the present invention relates to a ferritic stainless steel and a method for manufacturing the same, and an object of the present invention is to provide a ferritic stainless steel with improved resistance to load and a method for manufacturing the same.
  • Ferritic stainless steel with improved gripping resistance is, by weight, C: 0.001 to 0.3%, Si: 0.01 to 1.0%, Mn: 0.1 to 3.0%, Cr: 10 to 15%, N : 0.001 to 0.3%, P: 0.03% or less, Ni: 1.0% or less, Cu: 1.0% or less, Al: 1.0% or less, Mo: 0.003% or less, Ti: 1.0% or less.
  • C 0.001 to 0.3%
  • Si 0.01 to 1.0%
  • Mn 0.1 to 3.0%
  • Cr 10 to 15%
  • N 0.001 to 0.3%
  • P 0.03% or less
  • Mo: 0.003% or less Ti: 1.0% or less
  • the remaining Fe and other unavoidable impurities are included and ,
  • ⁇ S represented by the following formula (1) is 6 or more.
  • the ferritic stainless steel may have a ferrite grain size of 15 ⁇ m or less.
  • the ridging height (Wt) measured after the ferritic stainless steel is stretched by 15% at a thickness of 1.0 mm or less may satisfy 10 ⁇ m or less.
  • the method for manufacturing a ferritic stainless steel with improved resistance to loading is C: 0.001 to 0.3%, Si: 0.01 to 1.0%, Mn: 0.1 to 3.0%, Cr: 10 to 15%, N: 0.001 to 0.3%, P: 0.03% or less, Ni: 1.0% or less, Cu: 1.0% or less, Al: 1.0% or less, Mo: 0.003% or less, Ti: 1.0% or less
  • the remaining Fe and other inevitable Reheating the slab to 1050 to 1250° C., including impurities, and ⁇ S represented by the following formula (1) is 6 or more; hot rolling the reheated slab; and cold-rolling the hot-rolled material and cold-rolling annealing; including, in the reheating step, ⁇ Wt (T) defined as austenite weight % at temperature T is controlled to satisfy the following formula (2) .
  • Equation (2) ⁇ Wt (1200°C) ⁇ 19%
  • Equation (3) ⁇ S * ⁇ Wt (1200°C) ⁇ 114
  • the hot rolling may include the step of finish rolling at a temperature of 700 to 950 °C.
  • the hot rolling after the hot rolling, it may further include the step of hot rolling annealing at 600 to 900 °C.
  • the present invention can provide a ferritic stainless steel having a uniform surface quality by optimizing alloy components and component relationships as well as reheating and hot rolling conditions, and improved squeezing resistance, and a method for manufacturing the same.
  • 1A is a state diagram including ⁇ Wt (1200° C.) of Example 3 using JMatPro.
  • 1B is a state diagram including ⁇ Wt (1200° C.) of Example 10 using JMatPro.
  • 1c is a state diagram including ⁇ Wt (1200° C.) of Comparative Example 1 using JMatPro.
  • 1d is a state diagram including ⁇ Wt (1200° C.) of Comparative Example 6 using JMatPro.
  • Example 2A is a hot-rolled microstructure of Example 3 investigated with an IQ (Image Quality) map.
  • Example 2B is a hot-rolled microstructure of Example 10 investigated with an IQ (Image Quality) map.
  • 2C is a hot-rolled microstructure of Comparative Example 1 investigated by an IQ (Image Quality) map.
  • 2D is a hot-rolled microstructure of Comparative Example 6 investigated by an IQ (Image Quality) map.
  • Example 3A is a hot-rolled microstructure of Example 3 investigated with an Inverse Pole Figure (IPF) map.
  • IPF Inverse Pole Figure
  • Example 3B is a hot-rolled microstructure of Example 10 investigated with an Inverse Pole Figure (IPF) map.
  • IPF Inverse Pole Figure
  • 3C is a hot-rolled microstructure of Comparative Example 1 investigated by an Inverse Pole Figure (IPF) map.
  • IPF Inverse Pole Figure
  • 3D is a hot-rolled microstructure of Comparative Example 6 investigated with an Inverse Pole Figure (IPF) map.
  • IPF Inverse Pole Figure
  • Figure 4a is a photograph showing the surface microstructure after cold rolling annealing of Example 3.
  • Figure 4b is a photograph showing the surface microstructure after cold rolling annealing of Example 10.
  • Figure 4c is a photograph showing the surface microstructure after cold rolling annealing of Comparative Example 1.
  • 4d is a photograph showing the surface microstructure after cold rolling annealing of Comparative Example 6.
  • Ferritic stainless steel with improved gripping resistance is, by weight, C: 0.001 to 0.3%, Si: 0.01 to 1.0%, Mn: 0.1 to 3.0%, Cr: 10 to 15%, N : 0.001 to 0.3%, P: 0.03% or less, Ni: 1.0% or less, Cu: 1.0% or less, Al: 1.0% or less, Mo: 0.003% or less, Ti: 1.0% or less.
  • C 0.001 to 0.3%
  • Si 0.01 to 1.0%
  • Mn 0.1 to 3.0%
  • Cr 10 to 15%
  • N 0.001 to 0.3%
  • P 0.03% or less
  • Mo: 0.003% or less Ti: 1.0% or less
  • the remaining Fe and other unavoidable impurities are included and ,
  • ⁇ S represented by the following formula (1) is 6 or more.
  • Ferritic stainless steel with improved resistance to rubbing according to the present invention is, by weight, C: 0.001 to 0.3%, Si: 0.01 to 1.0%, Mn: 0.1 to 3.0%, Cr: 10 to 15%, N: 0.001 to 0.3% %, P: 0.03% or less, Ni: 1.0% or less, Cu: 1.0% or less, Al: 1.0% or less, Mo: 0.003% or less, Ti: 1.0% or less Including remaining Fe and other unavoidable impurities
  • the content of carbon (C) is 0.001 to 0.3%.
  • C is an interstitial solid solution strengthening element that improves the strength of ferritic stainless steel.
  • the content of C is less than 0.001%, sufficient strength cannot be obtained by reducing the amount of carbide produced.
  • the upper limit is to be limited to 0.3%.
  • the content of silicon (Si) is 0.01 to 1.0%.
  • Si is an alloying element that is essential for deoxidation of molten steel during steel making, and at the same time improves strength and corrosion resistance, and at the same time stabilizes the ferrite phase, it can be added in an amount of 0.01% or more in the present invention.
  • the upper limit is to be limited to 1.0%.
  • the content of manganese (Mn) is 0.1 to 3.0%.
  • Mn is an austenite phase stabilizing element, and may promote grain refinement by inducing austenite nucleation during hot rolling. However, if the content is excessive, corrosion resistance is lowered, manganese-based fume is generated during welding, and it causes MnS phase precipitation to reduce elongation. Therefore, in the present invention, it is intended to control the Mn content to 0.1 to 3.0%.
  • the content of chromium (Cr) is 10 to 15%.
  • the upper limit of the Cr content is to be limited to 15%.
  • the content of nitrogen (N) is 0.001 to 0.3%.
  • N is an interstitial solid solution strengthening element that not only improves the strength of ferritic stainless steel, but also precipitates an austenite phase during hot rolling to promote recrystallization.
  • the N content is controlled to 0.001 to 0.3%.
  • the content of phosphorus (P) is 0.03% or less.
  • P is an impurity that is unavoidably contained in steel, and is an element that causes intergranular corrosion during pickling or inhibits hot workability. Therefore, it is desirable to control its content as low as possible. Therefore, in the present invention, the content of P is controlled to 0.03% or less.
  • the content of nickel (Ni) is 1.0% or less.
  • Ni has an effect of improving corrosion resistance, there is a problem in that when a large amount is added, impurities in the material increase and elongation decreases.
  • Ni is a typical austenite stabilizing element, but as an expensive element, it increases the manufacturing cost. Therefore, in the present invention, the Ni content is controlled to 1.0% or less.
  • the content of copper (Cu) is 1.0% or less.
  • the Cu is an effective element for improving corrosion resistance, workability and ridging properties. However, when a large amount is added, there is a problem in that workability is reduced. Therefore, in the present invention, the Cu content is controlled to 1.0% or less.
  • the content of aluminum (Al) is 1.0% or less.
  • Al is a ferrite phase stabilizing element and serves to lower the oxygen content in molten steel as a strong deoxidizer.
  • the Al content is controlled to 1.0% or less.
  • the content of molybdenum (Mo) is 0.003% or less.
  • Mo is an effective element for improving the corrosion resistance of stainless steel.
  • Mo is an expensive element, it causes an increase in raw material cost and degrades workability when added in a large amount. Therefore, in the present invention, the content of Mo is controlled to 0.003% or less.
  • the content of titanium (Ti) is 1.0% or less.
  • Ti is an element effective in reducing the amount of solid solution C and solid solution N in steel and securing corrosion resistance of steel by preferentially combining with interstitial elements such as carbon (C) and nitrogen (N) to form precipitates (carbonitrides).
  • interstitial elements such as carbon (C) and nitrogen (N) to form precipitates (carbonitrides).
  • the content of titanium is controlled to 1.0% or less.
  • the remaining component of the present invention is iron (Fe).
  • Fe iron
  • ⁇ S expressed by the following formula (1) is 6 or more.
  • ⁇ S (Austenite (gamma-phase) stability) is an index of austenite phase stability corresponding to the maximum amount of austenite at high temperature.
  • ⁇ S value 6 or more.
  • the hot-rolled band structure of the ferritic stainless steel is not removed and remains, and a ridging defect occurs severely.
  • the present invention induced austenite phase transformation in hot rolling by optimizing the alloy composition of ferritic stainless steel. Accordingly, in the ferritic stainless steel according to an embodiment of the present invention, it is possible to secure fine grains of a single ferrite phase without a band structure or a colony structure.
  • the size of the single-phase ferrite grains may be 15 ⁇ m or less.
  • ⁇ S expressed by the following formula (1) is 6 or more, reheating the slab to 1050 to 1250 ° C., hot rolling the reheated slab, and cold rolling and cold annealing the hot rolled material, and in the reheating step, the temperature Controlled so that ⁇ Wt (T) defined as austenite weight % at T satisfies the following formula (2).
  • Equation (2) ⁇ Wt (1200°C) ⁇ 19%
  • ⁇ Wt (T) (Austenite (gamma-phase) Weight at temperature T) is the weight % of austenite at temperature T in the reheating step. Even if ⁇ S satisfies 6 or more, when the reheating temperature is high, the austenite phase stability is lowered. When the stability of the austenite phase is lowered, the austenite phase transformation does not occur sufficiently during hot rolling, so that the hot-rolled band structure remains on the surface of the ferritic stainless steel.
  • Equation (3) ⁇ S * ⁇ Wt (1200°C) ⁇ 114
  • finish rolling may be performed at 700 to 950°C.
  • hot rolling should be performed at 700°C or higher.
  • the temperature of the finish rolling exceeds 900°C, relatively large ferrite grains are formed. Therefore, in the present invention, the temperature of the finish rolling is controlled to 900° C. or less so that fine ferrite grains can be formed after hot rolling.
  • Hot rolled material is surface pickled for cold rolling. In this case, hot rolling annealing may be omitted. However, when excessively fine ferrite grains are formed or the elongation is lowered due to residual dislocation, the hot-rolled material may be hot-rolled and annealed.
  • the step of hot rolling annealing may be further included.
  • Hot-rolling annealing is preferably performed at 600 to 900° C. in order to remove the stress formed during hot rolling without regenerating the austenite phase.
  • a slab was prepared by a continuous casting process, and reheated at 1,050 to 1,200 ° C. Next, the reheated slab was finish-rolled at a temperature of 700 to 950 °C.
  • Example 1 0.011 0.24 0.48 0.024 11.2 0.78 0 0 0.02 0.18 0 0.01
  • Example 2 0.007 0.23 0.5 0.023 11 0.79 0.19 0 0.017 0.17 0 0.01
  • Example 3 0.007 0.15 0.9 0.02 10.6 0 0.3 0 0 0.15 0 0.008
  • Example 4 0.011 0.2 One 0.02 10.8 0 0.31 0 0 0.22 0 0.01
  • Example 5 0.011 0.15 One 0.02 10.6 0 0.31 0 0 0.15 0 0.01
  • Example 6 0.007 0.1 0.9 0.02 10.5 0 0.3 0 0 0.135 0 0.008
  • Example 7 0.011 0.1 One 0.02 10.5 0 0.31 0 0 0.135 0 0.01
  • Example 8 0.005 0.1 0.82 0.02 10.5 0 0.21 0 0 0.135 0 0.004
  • Example 9 0.005 0.15 0.82 0.02 10.6 0 0.21
  • the hot-rolled material was pickled, cold-rolled to a thickness of 1.0t or less, and then cold-rolled and annealed at 700 to 900° C. to prevent the austenite phase from being regenerated. After that, the cold-rolled annealed material was stretched by 15% in the rolling direction, and the height of the ridging curve was measured with a surface roughness device.
  • Table 2 shows the values of ⁇ S, ⁇ Wt (1200° C.), ⁇ S * ⁇ Wt (1200° C.) and ridging height ( ⁇ m) of Examples and Comparative Examples.
  • ⁇ S is 6 or more
  • ⁇ Wt (1200° C.) is 19% or more
  • ⁇ S * ⁇ Wt (1200° C.) satisfies 114 or more. Accordingly, in Examples 1 to 10, the ridging height was 10 ⁇ m or less, and the surface quality was good.
  • ⁇ S is -22.1 less than 6
  • ⁇ Wt (1200° C.) is 0%, less than 19%
  • ⁇ S * ⁇ Wt (1200° C.) is 0 and less than 114. Accordingly, in Comparative Example 1, a ridging defect having a height of 22.9 ⁇ m occurred.
  • ⁇ S is 15.6, which satisfies 6 or more presented in the present invention, and ⁇ S * ⁇ Wt (1200° C.) has a value of 280.8 or more.
  • ⁇ Wt (1200° C.) was 18% and had a value of less than 19%, and a ridging defect of 13.8 ⁇ m larger than 10 ⁇ m occurred.
  • ⁇ Wt (1200° C.) was 24% and 19% or more.
  • ⁇ S was -7.2 and less than 6
  • ⁇ S * ⁇ Wt (1200° C.) was -172.8 and less than 114. Accordingly, in comparison 7, a ridging defect of 12.4 ⁇ m larger than 10 ⁇ m occurred.
  • Table 3 shows the measured values of whether the band structure was observed after hot rolling, whether the band structure was observed after cold rolling annealing, and the ferrite grain size for Examples 3, 10, Comparative Example 1 and Comparative Example 6.
  • the ferrite grain size of Example 3 was 10.8 ⁇ m, and the ferrite grain size of Example 10 was 11.2 ⁇ m.
  • the ferrite grain size of Comparative Example 1 was 35.1 ⁇ m, and the ferrite grain size of Comparative Example 6 was 18.9 ⁇ m.
  • the band structure or colony structure does not appear on the surface, and the ridging height is suppressed to 10 ⁇ m or less, so that the uniformity of the ferritic stainless steel A surface quality can be ensured.
  • a ferritic stainless steel having a uniform surface quality and improved resistance to hardening by optimizing not only alloy components and component relationships, but also reheating and hot rolling conditions. Therefore, it can be used in various industrial fields.

Landscapes

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

Abstract

La présente invention concerne un acier inoxydable à base de ferrite ayant une résistance au striage améliorée. Selon un mode de réalisation de l'acier inoxydable à base de ferrite ayant une résistance au striage améliorée de l'invention, en % en poids, 0,001 à 0,3 % de C ; 0,01 à 1,0 % de Si ; 0,1 à 3,0 % de Mn ; 10 à 15 % de Cr ; 0,001 à 0,3 % de N ; 0,03 % ou moins de P ; 1,0 % ou moins de Ni ; 1,0 % ou moins de Cu ; 1,0 % ou moins d'Al ; 0,003 % ou moins de Mo ; 1,0 % ou moins de Ti ; le reste de Fe ; et d'autres impuretés inévitables, sont compris, et γS représenté par l'équation (1) ci-dessous satisfait à 6 ou plus. Équation (1) : γS = 900C - 30 Si + 12 Mn + 23 Ni - 17 Cr - 12 Mo + 12 Cu - 49 Ti - 52 Al + 950 N + 178 (où C, Si, Mn, Ni, Cr, Mo, Cu, Ti, Al et N représentent des teneurs [% en poids] des éléments respectifs).
PCT/KR2021/011464 2020-12-09 2021-08-26 Acier inoxydable à base de ferrite ayant une résistance au striage améliorée et son procédé de fabrication WO2022124526A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US18/265,345 US20240035134A1 (en) 2020-12-09 2021-08-26 Ferritic stainless steel with improved ridging resistance and its manufacturing method
EP21903573.0A EP4261319A1 (fr) 2020-12-09 2021-08-26 Acier inoxydable à base de ferrite ayant une résistance au striage améliorée et son procédé de fabrication
CN202180082869.3A CN116635560A (zh) 2020-12-09 2021-08-26 具有改善的抗起皱性的基于铁素体的不锈钢及其制造方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1020200171165A KR102497439B1 (ko) 2020-12-09 2020-12-09 내리징성이 향상된 페라이트계 스테인리스강 및 그 제조방법
KR10-2020-0171165 2020-12-09

Publications (1)

Publication Number Publication Date
WO2022124526A1 true WO2022124526A1 (fr) 2022-06-16

Family

ID=81973664

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2021/011464 WO2022124526A1 (fr) 2020-12-09 2021-08-26 Acier inoxydable à base de ferrite ayant une résistance au striage améliorée et son procédé de fabrication

Country Status (5)

Country Link
US (1) US20240035134A1 (fr)
EP (1) EP4261319A1 (fr)
KR (1) KR102497439B1 (fr)
CN (1) CN116635560A (fr)
WO (1) WO2022124526A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07268461A (ja) * 1994-03-29 1995-10-17 Kawasaki Steel Corp 面内異方性が小さいフェライト系ステンレス鋼帯の製造方法
JP2000256750A (ja) * 1999-03-05 2000-09-19 Nippon Yakin Kogyo Co Ltd 耐リジング性に優れたフェライト系ステンレス鋼板の製造方法
JP2004197197A (ja) * 2002-12-20 2004-07-15 Jfe Steel Kk 加工性および耐リジング性に優れたフェライト系ステンレス鋼板およびその製造方法
KR20140080348A (ko) * 2012-12-20 2014-06-30 주식회사 포스코 내리징성이 우수한 페라이트계 스테인리스강 및 그 제조 방법
WO2015099459A1 (fr) * 2013-12-24 2015-07-02 (주)포스코 Acier inoxydable ferritique présentant des propriétés améliorées de formabilité et de résistance au striage, et son procédé de production

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100406406B1 (ko) 1999-08-24 2003-11-19 주식회사 포스코 내리징과 내스티킹이 우수한 페라이트 스테인레스강의 열간압연방법
KR100467719B1 (ko) * 2000-12-08 2005-01-24 주식회사 포스코 리징 저항성 및 스피닝 가공성이 우수한 페라이트계스테인리스강 및 그 제조 방법

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07268461A (ja) * 1994-03-29 1995-10-17 Kawasaki Steel Corp 面内異方性が小さいフェライト系ステンレス鋼帯の製造方法
JP2000256750A (ja) * 1999-03-05 2000-09-19 Nippon Yakin Kogyo Co Ltd 耐リジング性に優れたフェライト系ステンレス鋼板の製造方法
JP2004197197A (ja) * 2002-12-20 2004-07-15 Jfe Steel Kk 加工性および耐リジング性に優れたフェライト系ステンレス鋼板およびその製造方法
KR20140080348A (ko) * 2012-12-20 2014-06-30 주식회사 포스코 내리징성이 우수한 페라이트계 스테인리스강 및 그 제조 방법
WO2015099459A1 (fr) * 2013-12-24 2015-07-02 (주)포스코 Acier inoxydable ferritique présentant des propriétés améliorées de formabilité et de résistance au striage, et son procédé de production

Also Published As

Publication number Publication date
KR102497439B1 (ko) 2023-02-08
CN116635560A (zh) 2023-08-22
US20240035134A1 (en) 2024-02-01
KR20220081556A (ko) 2022-06-16
EP4261319A1 (fr) 2023-10-18

Similar Documents

Publication Publication Date Title
WO2022050635A1 (fr) Acier inoxydable austénitique et son procédé de fabrication
WO2019117430A1 (fr) Acier inoxydable ferritique ayant une excellente résistance à l'oxydation à haute température et procédé de fabrication associé
WO2017051998A1 (fr) Tôle d'acier plaquée et procédé de fabrication associé
WO2021085800A1 (fr) Acier inoxydable austénitique ayant un rapport limite d'élasticité plus élevé et procédé pour sa fabrication
WO2019004540A1 (fr) Pièce estampée à chaud et son procédé de fabrication
WO2021010599A2 (fr) Acier inoxydable austénitique ayant une résistance améliorée et procédé de fabrication associé
WO2022124526A1 (fr) Acier inoxydable à base de ferrite ayant une résistance au striage améliorée et son procédé de fabrication
WO2022131504A1 (fr) Acier inoxydable austénitique doté d'une résistance au ramollissement à haute température améliorée
WO2010074458A2 (fr) Tôle d'acier laminée à froid de haute résistance présentant une aptitude à l'emboutissage profond améliorée et un rapport d'élasticité élevé, tôle d'acier galvanisée utilisant celle-ci, tôle d'acier allié galvanisée et procédé de fabrication correspondant
WO2019117432A1 (fr) Acier inoxydable à base de ferrite à excellente ténacité à l'impact, et son procédé de production
WO2019125025A1 (fr) Matériau en acier à teneur élevée en manganèse, à base d'austénite, à résistance élevée, et son procédé de fabrication
WO2019124729A1 (fr) Acier inoxydable ferritique utilitaire possédant une excellente aptitude au façonnage à chaud et son procédé de fabrication
WO2021125564A1 (fr) Acier inoxydable ferritique à haute résistance pour collier de serrage et son procédé de fabrication
WO2021261884A1 (fr) Acier inoxydable austénitique à haute résistance présentant une excellente productivité et un excellent effet de réduction des coûts et son procédé de production
WO2022119134A1 (fr) Acier inoxydable ferritique présentant une érosion de joint de grain améliorée, et son procédé de fabrication
WO2023075287A1 (fr) Acier inoxydable ferritique et son procédé de fabrication
WO2020085687A1 (fr) Acier inoxydable ferritique à haute résistance pour collier de serrage et son procédé de production
WO2019039774A1 (fr) Acier inoxydable ferritique ayant une ténacité à l'impact à basse température améliorée et son procédé de production
WO2019124690A1 (fr) Acier inoxydable ferritique ayant une aptitude au façonnage améliorée pour la dilatation de tubes et son procédé de fabrication
WO2020130257A1 (fr) Tôle d'acier à haute résistance ayant une excellente ductilité et une excellente aptitude au façonnage, et son procédé de fabrication
WO2021025248A1 (fr) Acier inoxydable ferritique présentant une résistance au fluage à haute température améliorée et son procédé de fabrication
WO2018110866A1 (fr) Acier inoxydable à base de ferrite à résistance au choc améliorée, et son procédé de production
WO2023113558A1 (fr) Tôle d'acier laminée à froid et tôle d'acier galvanisée présentant une excellente aptitude au formage à la presse et procédé de fabrication associé
WO2024029679A1 (fr) Acier inoxydable à haute tenue à la corrosion et à haute résistance ainsi que son procédé de fabrication
WO2021221245A1 (fr) Acier inoxydable à base de ferrite ayant des caractéristiques de surface améliorées et son procédé de fabrication

Legal Events

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

Ref document number: 21903573

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 18265345

Country of ref document: US

WWE Wipo information: entry into national phase

Ref document number: 202180082869.3

Country of ref document: CN

WWE Wipo information: entry into national phase

Ref document number: 2301003489

Country of ref document: TH

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2021903573

Country of ref document: EP

Effective date: 20230710