EP4343013A1 - Austenitic stainless steel and manufacturing method thereof - Google Patents

Austenitic stainless steel and manufacturing method thereof Download PDF

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EP4343013A1
EP4343013A1 EP22828661.3A EP22828661A EP4343013A1 EP 4343013 A1 EP4343013 A1 EP 4343013A1 EP 22828661 A EP22828661 A EP 22828661A EP 4343013 A1 EP4343013 A1 EP 4343013A1
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less
bent portion
stainless steel
austenitic stainless
cold
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German (de)
English (en)
French (fr)
Inventor
Sangseok KIM
Minam PARK
Kihoon Jo
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Posco Holdings Inc
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Posco Co Ltd
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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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58—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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
    • 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
    • C21D6/02—Hardening by precipitation
    • 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
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips 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
    • C21D8/0221—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
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—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
    • C22C38/02—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
    • C22C38/18—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
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • 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 disclosure relates to an austenitic stainless steel free of surface cracks and having excellent surface roughness in a bent portion and a manufacturing method thereof.
  • austenitic stainless steels have been applied for various uses to manufacture components for transportation and construction due to excellent formability, work hardenability, and weldability.
  • 304 series stainless steels or 301 series stainless steels have low yield strengths of 200 to 350 MPa, there are limits to apply these stainless steels to structural materials.
  • a skin pass rolling process is generally conducted to increase yield strength of 300 series stainless steels for common use.
  • the skin pass rolling process may cause problems in increasing manufacturing costs and significantly deteriorating elongation of materials.
  • Patent Document 0001 discloses a method of performing heat treatment for a long time over 48 hours in a temperature range of 600 to 700°C to obtain an average grain size of 10 ⁇ m or less.
  • the method disclosed in Patent Document 0001 may cause problems of deteriorating productivity in the case of implementing the method in an actual production line and increasing manufacturing costs.
  • Patent Document 0001 Japanese Patent Laid-open Publication No. 2020-050940A (Publication Date: April 2, 2020 )
  • an austenitic stainless steel free of surface cracks and having excellent surface roughness in a bent portion and a manufacturing method thereof by presenting a ultra-fine grain manufacturing technology that realizes bending formability and sound surface properties in the bent portion.
  • an austenitic stainless steel includes, in percent by weight (wt%), 0.005 to 0.03% of C, 0.1 to 1% of Si, 0.1 to 2% of Mn, 6 to 12% of Ni, 16 to 20% of Cr, 0.01 to 0.2% of N, 0.25% or less of Nb, and the balance of Fe and inevitable impurities, wherein an average grain size (d) of a central portion in a thickness direction is 5 ⁇ m or less, and a martensite area fraction measured in a bent portion after a 180° bending test may be 10% or less.
  • the austenitic stainless steel according to an embodiment of the present disclosure may have a center line average height Ra of 0.5 ⁇ m or less and a ten point average roughness Rz of 3 ⁇ m or less in the bent portion as surface roughness.
  • the austenitic stainless steel according to an embodiment of the present disclosure may have a pitting potential of 250 mV or more when measured by a 3.5% NaCl solution at 30°C.
  • a method of manufacturing an austenitic stainless steel includes hot rolling a slab including, in percent by weight (wt%), 0.005 to 0.03% of C, 0.1 to 1% of Si, 0.1 to 2% of Mn, 6 to 12% of Ni, 16 to 20% of Cr, 0.01 to 0.2% of N, 0.25% or less of Nb, and the balance of Fe and inevitable impurities, cold rolling the hot-rolled steel sheet at room temperature, and cold annealing the cold-rolled steel sheet to satisfy a ⁇ value represented by Equation (1) below to at least -10 but not more than 10.
  • ⁇ 406 ⁇ 2127 ⁇ C ⁇ 26.2 ⁇ Mn ⁇ 31.5 ⁇ Ni ⁇ 127 ⁇ N ⁇ 48.2 ⁇ Nb ⁇ 0.108 ⁇ Temp
  • Equation (1) [C], [Mn], [Ni], [N], and [Nb] represent weight percentages (wt%) of respective elements and Temp refers to cold annealing temperature (°C).
  • the cold rolling may be performed after the hot rolling without performing hot annealing.
  • an austenitic stainless steel free of surface cracks and having excellent surface roughness in a bent portion and a method of manufacturing the same may be provided by applying a ultra-fine grain manufacturing technology that realizes bending formability and sound surface properties in the bent portion.
  • An austenitic stainless steel may include, in percent by weight (wt%), 0.005 to 0.03% of C, 0.1 to 1% of Si, 0.1 to 2% of Mn, 6 to 12% of Ni, 16 to 20% of Cr, 0.01 to 0.2% of N, 0.25% or less of Nb, and the balance of Fe and inevitable impurities, wherein an average grain size (d) of a central portion in a thickness direction may be 5 ⁇ m or less, and a martensite area fraction measured in the bent portion after a 180° bending test may be 10% or less.
  • An austenitic stainless steel may include, in percent by weight (wt%), 0.005 to 0.03% of C, 0.1 to 1% of Si, 0.1 to 2% of Mn, 6 to 12% of Ni, 16 to 20% of Cr, 0.01 to 0.2% of N, 0.25% or less of Nb, and the balance of Fe and inevitable impurities.
  • the content of carbon (C) may be from 0.005 to 0.03%.
  • C is an austenite phase-stabilizing element.
  • C may be added in an amount of 0.005% or more.
  • an excess of C may cause a problem of forming a chromium carbide during low-temperature annealing to deteriorate grain boundary corrosion resistance.
  • an upper limit of the C content may be controlled to 0.03 wt%.
  • the content of silicon (Si) may be from 0.1 to 1.0%.
  • Si is an element added as a deoxidizer during a steel-making process and has an effect on improving corrosion resistance of a steel by forming an Si oxide in a passivated layer in the case of performing a bright annealing process.
  • Si may be added in an amount of 0.1 wt% or more.
  • an excess of Si may cause a problem of deteriorating ductility.
  • an upper limit of the Si content may be controlled to 1.0 wt%.
  • the content of manganese (Mn) may be from 0.1 to 2.0%.
  • Mn is an austenite phase-stabilizing element.
  • Mn may be added in an amount of 0.1% or more.
  • an excess of Mn may cause a problem of deteriorating corrosion resistance.
  • an upper limit of the Mn content may be controlled to 2.0%.
  • the content of nickel (Ni) may be from 6.0 to 12.0%.
  • Ni is an austenite phase-stabilizing element and has an effect on softening a steel material.
  • Ni may be added in an amount of 6.0% or more.
  • an excess of Ni may cause a problem of increasing manufacturing costs.
  • an upper limit of Ni may be controlled to 12.0%.
  • the content of chromium (Cr) may be from 16.0 to 20.0%.
  • Cr is a major element for improving corrosion resistance of a stainless steel.
  • Cr may be added in an amount of 16.0 wt% or more.
  • an excess of Cr may cause problems of hardening a steel material and inhibiting strain-induced martensite transformation during cold rolling.
  • an upper limit of the Cr content may be controlled to 20.0%.
  • the content of nitrogen (N) may be from 0.01 to 0.2%.
  • N is an austenite phase-stabilizing element and enhances strength of a steel material.
  • N may be added in an amount of 0.01% or more.
  • an excess of N may cause problems such as hardening of a steel material and deterioration of hot workability.
  • an upper limit of the N content may be controlled to 0.2%.
  • the content of niobium (Nb) may be from 0.25% or less. Addition of Nb that induces formation of Nb-based Z-phase precipitates has an effect on inhibiting the growth of crystal grains. However, an excess of Nb may cause a problem of increasing manufacturing costs. In consideration thereof, an upper limit of the Nb content may be controlled to 0.25%.
  • the remaining component of the composition of the present disclosure is iron (Fe).
  • the composition may include unintended impurities inevitably incorporated from raw materials or surrounding environments, and thus addition of other alloy components is not excluded.
  • the impurities are not specifically mentioned in the present disclosure, as they are known to any person skilled in the art of manufacturing.
  • the average grain size (d) of a central portion in a thickness direction may be 5 ⁇ m or less, and a martensite area fraction measured in the bent portion after a 180° bending test may be 10% or less.
  • a method of promoting TRIP transformation to transform an austenite phase to a martensite phase is used to implement a ultra-fine grain microstructure.
  • an amount of strain-induced martensite transformation increases during cold deformation.
  • a hardness of a material increases, and surface properties of a processed portion may deteriorate in the case of processing the material.
  • a ultra-fine grain microstructure may be implemented and a martensite area fraction measured in a bent portion may be reduced, so that an austenitic stainless steel with excellent surface properties may be provided.
  • the austenitic stainless steel according to an embodiment of the present disclosure may have a center line average height Ra of 0.5 ⁇ m or less and a ten point average roughness Rz of 3 ⁇ m or less in a bent portion after a 180° bending test.
  • the 180° bending test may be performed by setting a curvature R value of a bent portion to be identical to a thickness of a material and conducting a bending process once.
  • the pitting potential is a critical potential at which corrosion occurs in the form of holes in a passivated metal material
  • the austenitic stainless steel according to an embodiment of the present disclosure may have a pitting potential of 250 mV or more when measured by immersing the stainless steel in a NaCl solution and applying a potential thereto.
  • a temperature of the NaCl may be 30°C and a concentration thereof may be 3.5%.
  • a method of manufacturing an austenitic stainless steel according to an embodiment of the present disclosure may include hot rolling a slab including, in percent by weight (wt%), 0.005 to 0.03% of C, 0.1 to 1% of Si, 0.1 to 2% of Mn, 6 to 12% of Ni, 16 to 20% of Cr, 0.01 to 0.2% of N, 0.25% or less of Nb, and the balance of Fe and inevitable impurities, cold rolling the hot-rolled slab at room temperature, and cold annealing the cold-rolled steel sheet to satisfy a ⁇ value represented by Equation (1) below to at least -10 but not more than 10.
  • ⁇ 406 ⁇ 2127 ⁇ C ⁇ 26.2 ⁇ Mn ⁇ 31.5 ⁇ Ni ⁇ 127 ⁇ N ⁇ 48.2 ⁇ Nb ⁇ 0.108 ⁇ Temp
  • Equation (1) [C], [Mn], [Ni], [N], and [Nb] represent weight percentages (wt%) of respective elements and Temp refers to cold annealing temperature (°C).
  • a slab having the composition of alloying elements may be processed to prepare a hot-rolled steel sheet by a hot rolling process. Then, the hot-rolled steel sheet may be cold-rolled at room temperature to prepare a cold-rolled steel sheet.
  • the prepared cold-rolled steel sheet may be cold-annealed.
  • the cold annealing may be performed in a temperature range of 700 to 850°C such that the ⁇ value represented by Equation (1) above satisfies at least -10 but not more than 10.
  • the cold rolling process may be performed after the hot rolling process without performing a hot annealing process.
  • productivity may be increased and manufacturing costs may be reduced.
  • Equation (1) of the prepared cold-annealed steel sheets are shown in Table 1 below.
  • Equation (1) [C], [Mn], [Ni], [N], and [Nb] represent weight percentages (wt%) of respective elements and Temp refers to cold annealing temperature (°C).
  • Table 1 Category Composition of alloying elements (wt%) Equati on (1) ⁇ Tern p (°C) C Si Mn Cr Ni Cu Mo N Nb Inventive Example 1 0.02 0.31 0.5 18.2 8.02 0.27 0.1 0.041 0.053 9.8 742 Inventive Example 2 0.02 0.31 0.5 18.2 8.02 0.27 0.1 0.041 0.053 8.9 751 Inventive Example 3 0.02 0.31 0.5 18.2 8.02 0.27 0.1 0.041 0.053 3.5 801 Inventive Example 4 0.019 0.31 0.5 18.1 8.05 0.25 0.1 0.1 0 5.2 750 Inventive Example 5 0.019 0.31 0.5 18.1 8.05 0.25 0.1 0.1 0 0 798 Inventive Example 6 0.019 0.31 0.5 18.1 8.05 0.25 0.1
  • the prepared cold-annealed steel sheet were cut into samples with a thickness of 0.1 to 3.0 mm. Then, for each sample, an average grain size (d) of a central portion in a thickness direction, a pitting potential, a martensite area fraction of a bent portion, cracks in the bent portion, surface properties of the bent portion, a center line average height Ra of the bent portion, and a ten point average roughness Rz of the bent portion were measured and the results are shown in Table 2 below.
  • the average grain size (d) was measured by electron backscatter diffraction (EBSD) (model no. e-Flash FS) by analyzing an orientation of the central portion.
  • EBSD electron backscatter diffraction
  • the pitting potential refers to a potential value at which pits are formed after immersing the sample in a NaCl solution and applying a potential thereto.
  • a NaCl solution maintained at 30°C and having a concentration of 3.5% was used.
  • the martensite area fraction of the bent portion (%) refers to an area fraction of martensite in the bent portion after the 180° bending test.
  • the martensite area fraction (%) was measured by using a ferrite content measuring device (model no. FMP30).
  • the cracks in the bent portion, the surface properties of the bent portion, the center line average height Ra of the bent portion, and the ten point average roughness Rz of the bent portion were measured after the 180° bending test.
  • the 180° bending test was performed by setting a curvature R value of a bent portion to be identical to the thickness of the cold-annealed steel sheet and conducting a bending process once.
  • 'O' indicates a fine state of cracks in bent portion.
  • 'X' indicates occurrence of cracks in the bent portion.
  • the S2 values of Equation (1) satisfied the range of at least -10 but not more than 10, and the average grain size (d) satisfied 5 ⁇ m or less.
  • the martensite area fraction (%) measured in the bent portion after the 180° bending test satisfied 10% or less in Inventive Examples 1 to 13.
  • Comparative Examples 12 to 14 Because the contents of Ni, which softens steel materials, of Comparative Examples 12 to 14 were more than that of Comparative Examples 1 to 11, surface cracks did not occur in the bent portion. However, bend-shaped uncrystallized portions were formed in Comparative Examples 12 to 14 due to low cold annealing temperatures. Therefore, Comparative Examples 12 to 14 exhibited poor surface properties because the center line average heights Ra were 1.16 to 3.92 ⁇ m and the ten point average roughnesses Rz were 7.05 to 16.20 ⁇ m in the bent portion as surface roughnesses.
  • FIGS. 1 and 2 are photographs for comparison of occurrence of cracks in a bent portion after a 180° bending test between an inventive example and a comparative example.
  • FIG. 1 is a photograph of Inventive Example 5
  • FIG. 2 is a photograph Comparative Example 4.
  • FIGS. 1 and 2 it was confirmed that surface cracks did not occur in the austenitic stainless steel according to an embodiment of the present disclosure.
  • FIGS. 3 and 4 are photographs for comparison of surface properties of a bent portion after a 180° bending test between an inventive example and a comparative example.
  • FIG. 3 is a photograph of Inventive Example 5
  • FIG. 4 is a photograph of Comparative Example 14. Upon comparison between FIGS. 3 and 4 , it was confirmed that the austenitic stainless steel according to an embodiment of the present disclosure had excellent surface properties.
  • FIGS. 5 and 6 are photographs of a central portion in the thickness direction of an inventive example and a comparative example measured by electron backscatter diffraction (EBSD).
  • FIG. 5 is a photograph of Inventive Example 5
  • FIG. 6 is a photograph of Comparative Example 14.
  • EBSD electron backscatter diffraction
  • an austenitic stainless steel free of surface cracks and having excellent surface roughness in a bent portion and a manufacturing method may be provided by presenting a ultra-fine grain manufacturing technology that realizes bending formability and sound surface properties in the bent portion.

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EP22828661.3A 2021-06-21 2022-06-15 Austenitic stainless steel and manufacturing method thereof Pending EP4343013A1 (en)

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KR1020210080002A KR20220169655A (ko) 2021-06-21 2021-06-21 오스테나이트계 스테인리스강 및 그 제조방법
PCT/KR2022/008454 WO2022270814A1 (ko) 2021-06-21 2022-06-15 오스테나이트계 스테인리스강 및 그 제조방법

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KR101550738B1 (ko) * 2015-04-29 2015-09-08 성기천 연성이 우수한 스테인리스강 및 이를 이용한 냉매 배관용 스테인리스 파이프
KR20170069338A (ko) * 2015-12-10 2017-06-21 주식회사 포스코 절곡능이 향상된 듀플렉스 스테인리스강 및 그 제조방법
KR101735007B1 (ko) * 2015-12-23 2017-05-15 주식회사 포스코 주름 저항성이 우수한 오스테나이트계 스테인리스 강관
KR101964314B1 (ko) * 2017-08-21 2019-08-07 주식회사포스코 가공성 및 내시효균열성이 우수한 오스테나이트계 스테인리스강 및 이를 이용한 드로잉 가공품
JP2020050940A (ja) 2018-09-28 2020-04-02 国立研究開発法人日本原子力研究開発機構 オーステナイト系微細粒ステンレス鋼の製造方法

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