WO2020085855A1 - High manganese steel having excellent oxygen cutting properties, and manufacturing method therefor - Google Patents

High manganese steel having excellent oxygen cutting properties, and manufacturing method therefor Download PDF

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WO2020085855A1
WO2020085855A1 PCT/KR2019/014184 KR2019014184W WO2020085855A1 WO 2020085855 A1 WO2020085855 A1 WO 2020085855A1 KR 2019014184 W KR2019014184 W KR 2019014184W WO 2020085855 A1 WO2020085855 A1 WO 2020085855A1
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cutting
steel
manganese
oxygen
less
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PCT/KR2019/014184
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French (fr)
Korean (ko)
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이운해
이동호
조원태
이순기
최창식
강상덕
정영덕
김보성
석정훈
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주식회사 포스코
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Priority claimed from KR1020190118923A external-priority patent/KR102245226B1/en
Application filed by 주식회사 포스코 filed Critical 주식회사 포스코
Priority to EP19876472.2A priority Critical patent/EP3872214A4/en
Priority to CN201980069176.3A priority patent/CN112912526B/en
Publication of WO2020085855A1 publication Critical patent/WO2020085855A1/en

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    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/001Ferrous alloys, e.g. steel alloys containing N
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D6/00Heat treatment of ferrous alloys
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D6/00Heat treatment of ferrous alloys
    • C21D6/002Heat treatment of ferrous alloys containing Cr
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D6/00Heat treatment of ferrous alloys
    • C21D6/005Heat treatment of ferrous alloys containing Mn
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0205Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226Hot rolling
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/002Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/02Ferrous alloys, e.g. steel alloys containing silicon
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/06Ferrous alloys, e.g. steel alloys containing aluminium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/32Ferrous alloys, e.g. steel alloys containing chromium with boron
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese

Definitions

  • the present invention relates to a high-manganese steel material and a method for manufacturing the same, and more particularly, to an austenitic high-manganese steel material having excellent oxygen cutting property and a method for manufacturing the same.
  • the austenitic high-manganese steel material is characterized by having high toughness as the austenite is stable even at room temperature by adjusting the content of manganese (Mn) and carbon (C), which are elements that increase the stability of austenite.
  • Austenite is a paramagnetic material with low permeability and excellent non-magnetic properties compared to ferrite. In general, materials used for transformers, switchboards, etc. have a permeability of 1.05 or less, while austenitic high manganese steels have a permeability of 1.02 or less, so it can be seen that they have superior non-magnetic properties compared to conventional materials.
  • austenitic high-manganese steel As a structure, cutting and processing of the material by oxygen cutting are essential, but since high-manganese steel contains a large amount of alloying components, the cutting surface is caused by sparks during oxygen cutting. Heating problems exist. That is, it is not preferable from the viewpoint of productivity because the steel is pre-heated or the cutting speed is adjusted in advance to improve the cutability. Accordingly, there is a need to develop an austenitic high-manganese steel material having economical and effective oxygen cutting processing characteristics.
  • Patent Document 1 Republic of Korea Patent Publication No. 10-2010-0064473 (2010.06.15. Public)
  • a high-manganese steel material having excellent oxygen cutting properties and a method for manufacturing the same can be provided.
  • the high-manganese steel material having excellent oxygen-cutting properties according to an aspect of the present invention, in weight percent, carbon (C): 0.1-0.5%, manganese (Mn): 20-26%, silicon (Si): 0.05-0.4% , Aluminum (Al): 2.0% or less, Chromium (Cr): 4% or less, including residual Fe and other inevitable impurities, and the cutability sensitivity (Sc) calculated by the following [Relational Formula 1] is 430 or more, and 95 area % Or more of austenite.
  • the steel material by weight, may further include 0.0005 to 0.01% boron (B).
  • the magnetic permeability of the steel material may be 1.02 or less.
  • the yield strength of the steel material is 240MPa or more, the tensile strength is 720MPa or more, and the elongation may be 25% or more.
  • the average surface roughness of the steel cutting surface may be 0.5 mm or less.
  • a method of manufacturing a high-manganese steel material having excellent oxygen-cutting properties in weight percent, carbon (C): 0.1-0.5%, manganese (Mn): 20-26%, silicon (Si): 0.05 ⁇ 0.4%, aluminum (Al): 2.0% or less, chromium (Cr): 4% or less, including residual Fe and other unavoidable impurities, and the slab sensitivity (Sc) of 430 or more calculated by [Relational Formula 1] below Re-heating in the temperature range of 1050 ⁇ 1300 °C; Hot rolling the reheated slab to a finish rolling temperature of 800 to 1050 ° C to provide a hot rolled material; And cooling the hot rolled material to a temperature range of 600 ° C. or less at a cooling rate of 1 to 100 ° C./s.
  • the slab by weight, may further include 0.0005 to 0.01% boron (B).
  • an austenitic high-manganese steel material having excellent oxygen cutting properties and a method for manufacturing the same can be provided.
  • FIG. 1 (a) is a photograph of whether a spark is generated during oxygen cutting in Example 2 and a cut surface due to oxygen cutting
  • FIG. 1 (b) shows whether spark is generated during oxygen cutting in Comparative Example 2 and when oxygen is cut. This is a photograph of the cut surface.
  • the present invention relates to a high-manganese steel material having excellent oxygen-cutting properties and a method for manufacturing the same, and the following describes preferred embodiments of the present invention.
  • the embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. These embodiments are provided to those skilled in the art to further detail the present invention.
  • the high-manganese steel material having excellent oxygen-cutting properties according to an aspect of the present invention, in weight percent, carbon (C): 0.1-0.5%, manganese (Mn): 20-26%, silicon (Si): 0.05-0.4% , Aluminum (Al): 2.0% or less, chromium (Cr): 4% or less, the balance may include Fe and other unavoidable impurities.
  • Carbon (C) is an effective element for stabilizing austenite of steel and securing strength by solid solution strengthening, so the present invention can limit the lower limit of the carbon (C) content to a certain range in order to secure low-temperature toughness and strength. .
  • the stability of austenite is insufficient and stable austenite cannot be obtained at room temperature, and it is easily processed into ⁇ -martensite and ⁇ '-martensite by external stress. This is because it can reduce the toughness and strength of the steel. Therefore, the present invention can limit the lower limit of the carbon (C) content to 0.1%.
  • the lower limit of the preferred carbon (C) content is 0.15%, and the lower limit of the more preferred carbon (C) content may be 0.17%.
  • the carbon (C) content exceeds a certain range, the cutting surface may be deteriorated by the occurrence of sparks during oxygen cutting of the steel, or the productivity may be inferior by lowering the cutting speed.
  • the upper limit of can be limited to 0.5%.
  • the upper limit of the preferred carbon (C) content may be 0.47%, and the upper limit of the more preferred carbon (C) content may be 0.45%.
  • Manganese (Mn) is an important element that plays a role in stabilizing austenite, so the present invention can limit the lower limit of the manganese (Mn) content to 20% to achieve this effect. That is, the present invention can effectively increase the austenite stability because it contains 20% or more of manganese (Mn), thereby inhibiting the formation of ferrite, ⁇ -martensite and ⁇ '-martensite, and nonmagnetic properties of steel and It can effectively secure low-temperature toughness.
  • the manganese (Mn) content exceeds a certain level range, the effect of increasing the stability of austenite is saturated, while the manufacturing cost is greatly increased, and surface oxidation may be deteriorated due to excessive internal oxidation during hot rolling.
  • the present invention can limit the upper limit of the manganese (Mn) content to 26%. Therefore, the manganese (Mn) content of the present invention may be 20 to 26%, and a more preferable manganese (Mn) content may be 20 to 24%.
  • Silicon (Si) is an element that is indispensably added in trace amounts as a deoxidizer, such as aluminum (Al).
  • a deoxidizer such as aluminum (Al).
  • the present invention has an upper limit of the silicon (Si) content. It can be limited to 0.4%.
  • the upper limit of the more preferable silicon (Si) content may be 0.3%.
  • an excessive cost is required to reduce the silicon (Si) content in the steel, so the present invention can limit the lower limit of the silicon (Si) content to 0.05%.
  • the lower limit of the more preferable silicon (Si) content may be 0.1%.
  • Aluminum (Al) is a representative element added as a deoxidizer. However, aluminum (Al) may form precipitates by reacting with carbon (C) and nitrogen (N), and the hot workability may be deteriorated by these precipitates, and the present invention provides an upper limit of the aluminum (Al) content. It can be limited to 2.0%.
  • the preferred content of aluminum (Al) may be 0.01 to 2.0%, and the more preferred content of aluminum (Al) may be 0.01 to 1.95%.
  • Chromium (Cr) is a winso that stabilizes austenite up to a range of an appropriate addition amount, thereby contributing to the improvement of non-magnetic properties, and is employed in austenite to increase the strength of steel.
  • chromium (Cr) is also an element that improves the corrosion resistance of steel materials. Therefore, the present invention can add chromium (Cr) to achieve this effect.
  • chromium (Cr) increases the melting temperature of the oxide during oxygen cutting, and as the added content increases, the tendency for oxygen cutting property to deteriorate tends to deteriorate.
  • the upper limit of the chromium (Cr) content is limited to 4%. May be, the upper limit of the more preferred chromium (Cr) content may be 3.5%.
  • the non-magnetic high-manganese steel material having excellent oxygen-cutting properties may include residual Fe and other unavoidable impurities in addition to the above-described components.
  • unintended impurities from the raw material or the surrounding environment may inevitably be mixed, and therefore cannot be entirely excluded. Since these impurities are known to anyone skilled in the art, they are not specifically mentioned in this specification.
  • addition of effective ingredients other than the above composition is not entirely excluded.
  • the high-manganese steel material having excellent oxygen cutting property according to an aspect of the present invention may further include 0.0005 to 0.01% boron (B), and 0.03% or less phosphorus (P), 0.05% It may include one or more of the following sulfur (S) and less than 0.02% nitrogen (N).
  • Boron (B) is a grain boundary strengthening element for strengthening the austenite grain boundary, and is an element capable of effectively lowering the high temperature cracking sensitivity of steel materials by strengthening the austenite grain boundary even with a small amount added. Therefore, in order to achieve this effect, the present invention can limit the lower limit of the boron (B) content to 0.0005%.
  • the lower limit of the more preferred boron (B) content may be 0.001%.
  • the upper limit of the content can be limited to 0.01%.
  • the upper limit of the more preferred boron (B) content may be 0.006%.
  • Phosphorus (P) is not only an element that is inevitably introduced into the steel, but is an element that is easily segregated and causes cracking during casting or degrades weldability. Therefore, the present invention may limit the upper limit of the phosphorus (P) content to 0.03% to prevent deterioration of castability and deterioration of weldability, and the upper limit of the more preferable phosphorus (P) content may be 0.02%.
  • Sulfur (S) is not only an element that is inevitably introduced into the steel, but is also an element that causes hot brittle defects by inclusion formation. Therefore, the present invention can limit the upper limit of the sulfur (S) content to 0.05% to suppress the occurrence of hot embrittlement, the upper limit of the more preferred sulfur (S) content may be 0.02%.
  • Nitrogen (N) is not only an element inevitably introduced into steel, but also an element contributing to solid solution strengthening. However, if the content of nitrogen (N) is excessive, there is a problem of lowering the strength of the steel by forming a coarse nitride, so the present invention can limit the upper limit of the nitrogen (N) content to 0.02%.
  • the cutability sensitivity (Sc) calculated by the following [Relational Formula 1] may be 430 or more. More preferably, the cutting sensitivity (Sc) calculated by the following [Relational Formula 1] may be 460 or more.
  • the inventors of the present invention have conducted an in-depth study in relation to the oxygen-cutting property of high-manganese steel, while aluminum (Al) is an element that positively affects the oxygen-cutting property of high-manganese steel, whereas carbon (C) and manganese (Mn) ) And chromium (Cr) were found to be elements that negatively affect the oxygen-cleavability of high-manganese steels.
  • the inventors of the present invention have conducted a study on the correlation of these carbon (C), manganese (Mn), chromium (Cr), and aluminum (Al) contents, and the sensitivity to cutability (Sc) ) was more than a certain level, it was confirmed that it has excellent oxygen cleavage.
  • the high manganese steel material having excellent oxygen cutting property controls the alloy composition content so that the cutability sensitivity (Sc) by [Relational Formula 1] satisfies 430 or more, so the average of the steel cutting surface during oxygen cutting
  • the surface roughness can be managed at a level of 0.5 mm or less.
  • a high-manganese steel material having excellent oxygen-cutting properties may include at least 95% by area of austenite as a microstructure, thereby effectively securing non-magnetic properties and low-temperature properties of the steel material.
  • the average grain size of austenite may be 5 to 150 ⁇ m.
  • the average grain size of austenite that can be implemented in the manufacturing process is 5 ⁇ m or more, and when the average grain size is greatly increased, the strength of the steel material may be lowered, so the grain size of austenite may be limited to 150 ⁇ m or less.
  • the austenitic high-manganese steel material having excellent oxygen cleavability may include carbide and / or ⁇ -martensite as a structure that may exist in addition to austenite.
  • carbide and / or ⁇ -martensite exceeds a certain level, the toughness and ductility of the steel may be rapidly reduced.
  • the fraction of carbide and / or ⁇ -martensite is less than 5 area%. Can be limited.
  • a high-manganese steel material having excellent oxygen cutting properties according to an aspect of the present invention is provided with an optimal alloy composition, and thus may have an excellent cutting surface during oxygen cutting. That is, since the occurrence of sparks is minimized when oxygen is cut, it is possible to minimize the phenomenon that the cut surface is non-uniform due to melting of the steel material.
  • the high-manganese steel material having excellent oxygen cutting property according to an aspect of the present invention can effectively prevent a decrease in cutting speed when cutting oxygen, thereby optimizing work efficiency and maximizing productivity.
  • a high-manganese steel material having excellent oxygen cutting properties according to an aspect of the present invention may have a permeability of 1.02 or less, a yield strength of 240 MPa or more, a tensile strength of 720 MPa or more, and an elongation of 25% or more.
  • a method of manufacturing a high-manganese steel material having excellent oxygen-cutting properties in weight percent, carbon (C): 0.1-0.5%, manganese (Mn): 20-26%, silicon (Si): 0.05 ⁇ 0.4%, aluminum (Al): 2.0% or less, chromium (Cr): 4% or less, including residual Fe and other unavoidable impurities, and the slab sensitivity (Sc) of 430 or more calculated by [Relational Formula 1] below Re-heating in the temperature range of 1050 ⁇ 1300 °C; Hot rolling the reheated slab to a finish rolling temperature of 800 to 1050 ° C to provide a hot rolled material; And cooling the hot rolled material to a temperature range of 600 ° C. or less at a cooling rate of 1 to 100 ° C./s.
  • the slab by weight, may further include 0.0005 to 0.01% boron (B), 0.03% or less phosphorus (P), 0.05% or less sulfur (S), and 0.02% or less nitrogen (N).
  • B boron
  • P phosphorus
  • S sulfur
  • N nitrogen
  • the description of the steel composition of the slab will be replaced by the description of the steel composition of the steel material described above. do.
  • the slab provided with the above-described steel composition can be reheated in a temperature range of 1050 to 1300 ° C.
  • the reheating temperature is less than a certain range, the problem of excessive rolling load during hot rolling may occur, or a problem that the alloy component is not sufficiently dissolved may occur, so that the present invention can limit the lower limit of the slab reheating temperature range to 1050 ° C. have.
  • the reheating temperature exceeds a certain range, the grains may grow excessively and the strength may decrease, or the re-heating may exceed the solidus temperature of the steel material, thereby deteriorating the hot rolling property of the steel material.
  • the upper limit of the range can be limited to 1300 ° C.
  • the hot rolling process includes a rough rolling process and a finish rolling process, and the reheated slab may be hot rolled and provided as a hot rolled material.
  • the hot finish rolling is preferably carried out in a temperature range of 800 ⁇ 1050 °C. If the hot finish rolling temperature is less than a certain range, excessive rolling load due to an increase in the rolling load may be a problem, and if the hot finish rolling temperature exceeds a certain range, the grains grow coarsely and the target strength cannot be obtained.
  • the hot rolled hot rolled material may be cooled to a cooling stop temperature of 600 ° C. or less at a cooling rate of 1 to 100 ° C./s. If the cooling rate is less than a certain range, the ductility of the steel may be reduced due to carbides precipitated at the grain boundary during cooling, and thus deterioration of abrasion resistance may be a problem. Therefore, the present invention can limit the cooling rate of the hot rolled material to 1 ° C / s or more. have. The lower limit of the more preferable cooling rate may be 10 ° C / s, and accelerated cooling may be applied.
  • the present invention sets the upper limit of the cooling rate to 100 ° C. Can be limited to / s.
  • the present invention limits the cooling stop temperature to 600 ° C. or less. You can.
  • the high-manganese steel with excellent oxygen-cutting properties prepared as described above contains 95% by area or more of austenite as a microstructure, has a permeability of 1.02 or less, a yield strength of 240MPa or more, a tensile strength of 720MPa or more, and an elongation of 25% or more, At the same time as having an excellent cutting surface during oxygen cutting, it is possible to effectively prevent a decrease in productivity of the oxygen cutting operation.
  • the slab that satisfies the alloy composition of Table 1 below was reheated at a temperature of 1200 ° C, hot rolled under the conditions of Table 2 to produce a hot rolled material having a thickness of 12mm, and then cooled to a cooling stop temperature of 100 ° C at a cooling rate of 20 ° C / s.
  • the specimen was prepared by accelerated cooling.
  • the yield strength, tensile strength and elongation of each specimen were measured, and the permeability, the maximum cutting speed, and the cutting surface state are shown together in Table 2 below.
  • the maximum cutting speed means the maximum cutting speed applicable when oxygen cutting is performed at an average gas pressure of 0.7 MPa.
  • the cut surface scores were evaluated by dividing them into 1, 1.5, and 2.
  • a rating of 1 means that the base material is not only melted during oxygen cutting, but also means that the average surface roughness of the cut surface is greater than 0.5 mm.
  • a rating of 1.5 means that some of the base material is melted during oxygen cutting, but the average surface roughness of the cut surface is 0.5 mm. The following means the case, and a rating of 1 means that the base material is not melted during oxygen cutting and the average surface roughness of the cut surface is 0.5 mm or less.
  • the cutability index in Table 2 means the value obtained by multiplying the maximum cutting speed of each specimen and the cutting surface rating.
  • Example 1 0.41 21.7 0.27 0.017 0.003 0.013 2.01 0.013 772.6
  • Example 2 0.18 22.3 0.14 0.019 0.010 1.80 0.00 0.013 1197.6
  • Example 3 0.44 24.6 0.26 0.019 0.007 0.020 3.45 0.018 495.4
  • Example 4 0.18 21.8 0.21 0.016 0.003 0.026 2.00 0.016 924.3
  • Example 5 0.41 21.8 0.22 0.019 0.003 0.016 1.95 0.013 779.0
  • Example 6 0.40 21.6 0.20 0.018 0.003 0.025 0.00 0.014 1062.5
  • Example 7 0.41 21.9 0.21 0.019 0.003 0.027 4.00 0.016 490.1
  • Example 8 0.39 22.3 0.15 0.018 0.009 1.93 1.92 0.016 789.9
  • Example 9 0.2 22 0.2 0.018 0.002 0.025 0 0.015 1187.2
  • Example 10 0.2 20 0.2
  • FIG. 1 (a) is a photograph of whether a spark is generated during oxygen cutting in Example 2 and a cut surface due to oxygen cutting
  • FIG. 1 (b) shows whether spark is generated during oxygen cutting in Comparative Example 2 and when oxygen is cut. This is a photograph of the cut surface.
  • FIG. 1 (b) of FIG. 1 in the case of Example 2, while having an excellent cutting surface, in the case of Comparative Example 2, excessive sparking occurs when oxygen is cut, resulting in melting of the base material, and thus not uniform It can be seen that an unsuccessful cut surface is realized.

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Abstract

The high manganese steel having excellent oxygen cutting properties, according to one aspect of the present invention, comprises 0.1-0.5 wt% of carbon (C), 20-26 wt% of manganese (Mn), 0.05-0.4 wt% of silicon (Si), at most 2.0 wt% of aluminum (Al), and at most 4 wt% of chromium (Cr), with the remainder being Fe and other unavoidable impurities, and has a cutting sensitivity (Sc), calculated according to [relational expression 1] below, of at least 430 and may comprise at least 95 area% of austenite as a microstructure. [Relational expression 1] Cutting sensitivity (Sc) = 1742 - 662*[C] - 19.2*[Mn] + 1.6*[Al] - 140*[Cr] (In [relational expression 1], [C], [Mn], [Al], and [Cr] represent the respective percentages by weight of C, Mn, Al, and Cr included in the steel and, if the elements concerned are not included, represent 0.)

Description

산소 절단성이 우수한 고망간 강재 및 그 제조방법High manganese steel with excellent oxygen cutting properties and method for manufacturing the same
본 발명은 고망간 강재 및 그 제조방법에 관한 것이며, 상세하게는 산소 절단성이 우수한 오스테나이트계 고망간 강재 및 그 제조방법에 관한 것이다. The present invention relates to a high-manganese steel material and a method for manufacturing the same, and more particularly, to an austenitic high-manganese steel material having excellent oxygen cutting property and a method for manufacturing the same.
오스테나이트계 고망간 강재는 오스테나이트의 안정성을 높여주는 원소인 망간(Mn)과 탄소(C)의 함량을 조율하여 상온에서도 오스테나이트가 안정하여 높은 인성을 가지는 특징이 있다. 오스테나이트는 상자성체로 투자율이 낮으며, 페라이트 대비 비자성 특성이 우수하다. 일반적으로 변압기, 배전반 등에 이용되는 소재는 1.05 이하 수준의 투자율을 가지는 반면, 오스테나이트계 고망간 강재는 1.02 이하 수준의 투자율을 가지므로, 기존의 소재 대비 우수한 비자성 특성을 가지는 것을 알 수 있다.The austenitic high-manganese steel material is characterized by having high toughness as the austenite is stable even at room temperature by adjusting the content of manganese (Mn) and carbon (C), which are elements that increase the stability of austenite. Austenite is a paramagnetic material with low permeability and excellent non-magnetic properties compared to ferrite. In general, materials used for transformers, switchboards, etc. have a permeability of 1.05 or less, while austenitic high manganese steels have a permeability of 1.02 or less, so it can be seen that they have superior non-magnetic properties compared to conventional materials.
더불어, 오스테나이트를 주 조직으로 가지는 고망간 강재의 경우, 저온에서의 연성 파괴 특성을 가지므로 우수한 저온 인성을 가지는 기술적 장점이 존재한다.In addition, in the case of a high-manganese steel having austenite as the main structure, it has a ductile fracture property at low temperature, and thus has a technical advantage of having excellent low-temperature toughness.
다만, 이와 같이 오스테나이트계 고망간 강재를 구조물로 이용하기 위해서는 산소 절단 등에 의한 소재의 절단 및 가공이 필수적이나, 고망간 강재는 다량의 합금 성분을 포함하므로 산소 절단 작업 시 불꽃 발생 등에 의해 절단면 상태가 열위한 문제점이 존재한다. 즉, 절단성 향상을 위해 강재를 사전 예열하거나 절단 속도를 하양 조절하는바, 생산성 측면에서 바람직하지 않다. 따라서, 경제적이면서도 효과적인 산소 절단 가공 특성을 가지는 오스테나이트계 고망간 강재의 개발이 요구되는 실정이다.However, in order to use austenitic high-manganese steel as a structure, cutting and processing of the material by oxygen cutting are essential, but since high-manganese steel contains a large amount of alloying components, the cutting surface is caused by sparks during oxygen cutting. Heating problems exist. That is, it is not preferable from the viewpoint of productivity because the steel is pre-heated or the cutting speed is adjusted in advance to improve the cutability. Accordingly, there is a need to develop an austenitic high-manganese steel material having economical and effective oxygen cutting processing characteristics.
(선행기술문헌)(Advanced technical literature)
(특허문헌 1) 대한민국 공개특허공보 제10-2010-0064473호 (2010.06.15. 공개)(Patent Document 1) Republic of Korea Patent Publication No. 10-2010-0064473 (2010.06.15. Public)
본 발명의 일 측면에 따르면 산소 절단성이 우수한 고망간 강재 및 그 제조방법이 제공될 수 있다According to an aspect of the present invention, a high-manganese steel material having excellent oxygen cutting properties and a method for manufacturing the same can be provided.
본 발명의 과제는 상술한 내용에 한정되지 않는다. 통상의 기술자라면 본 명세서의 전반적인 내용으로부터 본 발명의 추가적인 과제를 이해하는데 아무런 어려움이 없을 것이다.The subject of this invention is not limited to the above-mentioned content. Those skilled in the art will have no difficulty in understanding the additional subject matter of the present invention from the general contents of this specification.
본 발명의 일 측면에 따른 산소 절단성이 우수한 고망간 강재는, 중량%로, 탄소(C): 0.1~0.5%, 망간(Mn): 20~26%, 실리콘(Si): 0.05~0.4%, 알루미늄(Al): 2.0% 이하, 크롬(Cr): 4% 이하, 잔부 Fe 및 기타 불가피한 불순물을 포함하고, 하기 [관계식 1]로 계산되는 절단성 민감도(Sc)가 430 이상이며, 95면적% 이상의 오스테나이트를 미세조직으로 포함할 수 있다.The high-manganese steel material having excellent oxygen-cutting properties according to an aspect of the present invention, in weight percent, carbon (C): 0.1-0.5%, manganese (Mn): 20-26%, silicon (Si): 0.05-0.4% , Aluminum (Al): 2.0% or less, Chromium (Cr): 4% or less, including residual Fe and other inevitable impurities, and the cutability sensitivity (Sc) calculated by the following [Relational Formula 1] is 430 or more, and 95 area % Or more of austenite.
[관계식 1][Relationship 1]
절단성 민감도(Sc) = 1742 - 662*[C] - 19.2*[Mn] + 1.6*[Al] - 140*[Cr]Cutting sensitivity (Sc) = 1742-662 * [C]-19.2 * [Mn] + 1.6 * [Al]-140 * [Cr]
(상기 [관계식 1]에서 [C], [Mn], [Al] 및 [Cr]은 각각 강재에 포함되는 C, Mn, Al 및 Cr의 중량%를 의미하며, 해당 성분이 첨가되지 않는 경우 0을 의미한다.)(In [Relational Formula 1], [C], [Mn], [Al], and [Cr] mean the weight percent of C, Mn, Al, and Cr included in the steel, respectively, and 0 when the corresponding component is not added. Means.)
상기 강재는, 중량%로, 0.0005~0.01%의 보론(B)을 더 포함할 수 있다.The steel material, by weight, may further include 0.0005 to 0.01% boron (B).
상기 강재의 투자율은 1.02 이하일 수 있다.The magnetic permeability of the steel material may be 1.02 or less.
상기 강재의 항복강도는 240MPa 이상이고, 인장강도는 720MPa 이상이며, 연신율은 25% 이상일 수 있다.The yield strength of the steel material is 240MPa or more, the tensile strength is 720MPa or more, and the elongation may be 25% or more.
0.3~0.9Mpa의 가스압 및 300~700mm/min의 최대 절단속도로 상기 강재를 산소절단 하는 경우, 상기 강재 절단면의 평균 표면 조도는 0.5mm 이하일 수 있다.When oxygen-cutting the steel with a gas pressure of 0.3 to 0.9 Mpa and a maximum cutting speed of 300 to 700 mm / min, the average surface roughness of the steel cutting surface may be 0.5 mm or less.
본 발명의 일 측면에 따른 산소 절단성이 우수한 고망간 강재의 제조방법은, 중량%로, 탄소(C): 0.1~0.5%, 망간(Mn): 20~26%, 실리콘(Si): 0.05~0.4%, 알루미늄(Al): 2.0% 이하, 크롬(Cr): 4% 이하, 잔부 Fe 및 기타 불가피한 불순물을 포함하며, 하기 [관계식 1]로 계산되는 절단성 민감도(Sc)가 430 이상인 슬라브를 1050~1300℃의 온도범위에서 재가열하는 단계; 상기 재가열된 슬라브를 800~1050℃의 마무리 압연 온도로 열간압연하여 열연재를 제공하는 단계; 및 상기 열연재를 1~100℃/s의 냉각속도로 600℃ 이하의 온도범위까지 냉각하는 단계;를 포함할 수 있다.A method of manufacturing a high-manganese steel material having excellent oxygen-cutting properties according to an aspect of the present invention, in weight percent, carbon (C): 0.1-0.5%, manganese (Mn): 20-26%, silicon (Si): 0.05 ~ 0.4%, aluminum (Al): 2.0% or less, chromium (Cr): 4% or less, including residual Fe and other unavoidable impurities, and the slab sensitivity (Sc) of 430 or more calculated by [Relational Formula 1] below Re-heating in the temperature range of 1050 ~ 1300 ℃; Hot rolling the reheated slab to a finish rolling temperature of 800 to 1050 ° C to provide a hot rolled material; And cooling the hot rolled material to a temperature range of 600 ° C. or less at a cooling rate of 1 to 100 ° C./s.
[관계식 1] [Relationship 1]
절단성 민감도(Sc) = 1742 - 662*[C] - 19.2*[Mn] + 1.6*[Al] - 140*[Cr]Cutting sensitivity (Sc) = 1742-662 * [C]-19.2 * [Mn] + 1.6 * [Al]-140 * [Cr]
(상기 [관계식 1]에서 [C], [Mn], [Al] 및 [Cr]은 각각 강재에 포함되는 C, Mn, Al 및 Cr의 중량%를 의미하며, 해당 성분이 첨가되지 않는 경우 0을 의미한다.)(In [Relational Formula 1], [C], [Mn], [Al], and [Cr] mean the weight percent of C, Mn, Al, and Cr included in the steel, respectively, and 0 when the corresponding component is not added. Means.)
상기 슬라브는, 중량%로, 0.0005~0.01%의 보론(B)을 더 포함할 수 있다.The slab, by weight, may further include 0.0005 to 0.01% boron (B).
상기 과제의 해결 수단은 본 발명의 특징을 모두 열거한 것은 아니며, 본 발명의 다양한 특징과 그에 따른 장점과 효과는 아래의 구체적인 실시예를 참조하여 보다 상세하게 이해될 수 있을 것이다.The solving means of the above problems does not list all the features of the present invention, and various features of the present invention and the advantages and effects thereof may be understood in more detail with reference to specific embodiments below.
본 발명의 바람직한 일 측면에 따르면, 산소 절단성이 우수한 오스테나이트계 고망간 강재 및 그 제조방법이 제공될 수 있다.According to a preferred aspect of the present invention, an austenitic high-manganese steel material having excellent oxygen cutting properties and a method for manufacturing the same can be provided.
도 1의 (a)는 실시예 2의 산소 절단 시 불꽃 발생 여부 및 산소 절단에 의한 절단면을 촬영한 사진이며, 도 1의 (b)는 비교예 2의 산소 절단 시 불꽃 발생 여부 및 산소 절단에 의한 절단면을 촬영한 사진이다. FIG. 1 (a) is a photograph of whether a spark is generated during oxygen cutting in Example 2 and a cut surface due to oxygen cutting, and FIG. 1 (b) shows whether spark is generated during oxygen cutting in Comparative Example 2 and when oxygen is cut. This is a photograph of the cut surface.
본 발명은 산소 절단성이 우수한 고망간 강재 및 그 제조방법에 관한 것으로, 이하에서는 본 발명의 바람직한 구현예들을 설명하고자 한다. 본 발명의 구현예들은 여러 가지 형태로 변형될 수 있으며, 본 발명의 범위가 아래에서 설명되는 구현예들에 한정되는 것으로 해석되어서는 안된다. 본 구현예들은 당해 발명이 속하는 기술분야에서 통상의 지식을 가지는 자에게 본 발명을 더욱 상세하기 위하여 제공되는 것이다.The present invention relates to a high-manganese steel material having excellent oxygen-cutting properties and a method for manufacturing the same, and the following describes preferred embodiments of the present invention. The embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. These embodiments are provided to those skilled in the art to further detail the present invention.
이하, 본 발명의 강 조성에 대하여 보다 상세히 설명한다. 이하, 특별히 달리 표시하지 않는 한 각 원소의 함량을 나타내는 %는 중량을 기준으로 한다.Hereinafter, the steel composition of the present invention will be described in more detail. Hereinafter, unless otherwise indicated,% representing the content of each element is based on weight.
본 발명의 일 측면에 따른 산소 절단성이 우수한 고망간 강재는, 중량%로, 탄소(C): 0.1~0.5%, 망간(Mn): 20~26%, 실리콘(Si): 0.05~0.4%, 알루미늄(Al): 2.0% 이하, 크롬(Cr): 4% 이하, 잔부 Fe 및 기타 불가피한 불순물을 포함할 수 있다. The high-manganese steel material having excellent oxygen-cutting properties according to an aspect of the present invention, in weight percent, carbon (C): 0.1-0.5%, manganese (Mn): 20-26%, silicon (Si): 0.05-0.4% , Aluminum (Al): 2.0% or less, chromium (Cr): 4% or less, the balance may include Fe and other unavoidable impurities.
탄소(C): 0.1~0.5%Carbon (C): 0.1 ~ 0.5%
탄소(C)는 강재의 오스테나이트를 안정화시키고, 고용강화에 의해 강도를 확보하는데 효과적인 원소이므로, 본 발명은 저온인성 및 강도 확보를 위하여 탄소(C) 함량의 하한을 일정 범위로 제한할 수 있다. 즉, 탄소(C) 함량이 일정 수준에 이하인 경우, 오스테나이트의 안정도가 부족하여 상온에서 안정한 오스테나이트를 얻을 수 없으며, 외부 응력에 의해 쉽게 ε-마르텐사이트 및 α'-마르텐사이트로 가공유기변태를 일으켜 강재의 인성 및 강도를 감소시킬 수 있기 때문이다. 따라서, 본 발명은 탄소(C) 함량의 하한을 0.1%로 제한할 수 있다. 바람직한 탄소(C) 함량의 하한은 0.15%이며, 보다 바람직한 탄소(C) 함량의 하한은 0.17%일 수 있다. 반면, 탄소(C) 함량이 일정 범위를 초과하는 경우, 강재의 산소 절단 시 불꽃 발생에 의해 절단면이 열위해지거나, 절단 속도를 낮추어 생산성이 열위해질 수 있는바, 본 발명은 탄소(C) 함량의 상한을 0.5%로 제한할 수 있다. 바람직한 탄소(C) 함량의 상한은 0.47%일 수 있으며, 보다 바람직한 탄소(C) 함량의 상한은 0.45%일 수 있다.Carbon (C) is an effective element for stabilizing austenite of steel and securing strength by solid solution strengthening, so the present invention can limit the lower limit of the carbon (C) content to a certain range in order to secure low-temperature toughness and strength. . In other words, when the carbon (C) content is below a certain level, the stability of austenite is insufficient and stable austenite cannot be obtained at room temperature, and it is easily processed into ε-martensite and α'-martensite by external stress. This is because it can reduce the toughness and strength of the steel. Therefore, the present invention can limit the lower limit of the carbon (C) content to 0.1%. The lower limit of the preferred carbon (C) content is 0.15%, and the lower limit of the more preferred carbon (C) content may be 0.17%. On the other hand, when the carbon (C) content exceeds a certain range, the cutting surface may be deteriorated by the occurrence of sparks during oxygen cutting of the steel, or the productivity may be inferior by lowering the cutting speed. The upper limit of can be limited to 0.5%. The upper limit of the preferred carbon (C) content may be 0.47%, and the upper limit of the more preferred carbon (C) content may be 0.45%.
망간(Mn): 20~26%Manganese (Mn): 20-26%
망간(Mn)은 오스테나이트를 안정화시키는 역할을 하는 중요한 원소이므로, 본 발명은 이와 같은 효과 달성을 위해 망간(Mn) 함량의 하한을 20%로 제한할 수 있다. 즉, 본 발명은 20% 이상의 망간(Mn)을 포함하므로 오스테나이트 안정도를 효과적으로 증가시킬 수 있으며, 그에 따라 페라이트, ε-마르텐사이트 및 α'-마르텐사이트의 형성을 억제하여 강재의 비자성 특성 및 저온인성을 효과적으로 확보할 수 있다. 반면, 망간(Mn) 함량이 일정 수준 범위를 초과하는 경우, 오스테나이트의 안정도 증가 효과는 포화되는 반면 제조원가가 크게 증가하고, 열간압연 중 내부산화가 과도하게 발생하여 표면품질이 열위해질 수 있는바, 본 발명은 망간(Mn) 함량의 상한을 26%로 제한할 수 있다. 따라서, 본 발명의 망간(Mn) 함량은 20~26%일 수 있으며, 보다 바람직한 망간(Mn) 함량은 20~24%일 수 있다.Manganese (Mn) is an important element that plays a role in stabilizing austenite, so the present invention can limit the lower limit of the manganese (Mn) content to 20% to achieve this effect. That is, the present invention can effectively increase the austenite stability because it contains 20% or more of manganese (Mn), thereby inhibiting the formation of ferrite, ε-martensite and α'-martensite, and nonmagnetic properties of steel and It can effectively secure low-temperature toughness. On the other hand, when the manganese (Mn) content exceeds a certain level range, the effect of increasing the stability of austenite is saturated, while the manufacturing cost is greatly increased, and surface oxidation may be deteriorated due to excessive internal oxidation during hot rolling. , The present invention can limit the upper limit of the manganese (Mn) content to 26%. Therefore, the manganese (Mn) content of the present invention may be 20 to 26%, and a more preferable manganese (Mn) content may be 20 to 24%.
규소(Si): 0.05~0.4%Silicon (Si): 0.05 ~ 0.4%
규소(Si)는 알루미늄(Al)과 같이 탈산제로서 필수불가결하게 미량 첨가되는 원소이다. 다만, 규소(Si)가 과도하게 첨가되는 경우 입계에 산화물을 형성하여 고온연성을 감소시키고, 크랙 등을 유발하여 표면품질을 저하시킬 우려가 있는바, 본 발명은 규소(Si) 함량의 상한을 0.4%로 제한할 수 있다. 보다 바람직한 규소(Si) 함량의 상한은 0.3%일 수 있다. 반면, 강 중에서 규소(Si) 함량을 줄이기 위해서는 과도한 비용이 소요되는바, 본 발명은 규소(Si) 함량의 하한을 0.05%로 제한할 수 있다. 보다 바람직한 규소(Si) 함량의 하한은 0.1%일 수 있다. Silicon (Si) is an element that is indispensably added in trace amounts as a deoxidizer, such as aluminum (Al). However, when silicon (Si) is excessively added, an oxide is formed at a grain boundary to reduce high temperature ductility, and there is a fear that surface quality may be lowered by causing cracks, etc., so that the present invention has an upper limit of the silicon (Si) content. It can be limited to 0.4%. The upper limit of the more preferable silicon (Si) content may be 0.3%. On the other hand, an excessive cost is required to reduce the silicon (Si) content in the steel, so the present invention can limit the lower limit of the silicon (Si) content to 0.05%. The lower limit of the more preferable silicon (Si) content may be 0.1%.
알루미늄(Al): 2.0% 이하Aluminum (Al): 2.0% or less
알루미늄(Al)은 탈산제로 첨가되는 대표적인 원소이다. 다만, 알루미늄(Al)은 탄소(C) 및 질소(N)와 반응하여 석출물을 형성할 수 있으며, 이들 석출물에 의해 열간 가공성이 저하될 수 있는바, 본 발명은 알루미늄(Al) 함량의 상한을 2.0%로 제한할 수 있다. 바람직한 알루미늄(Al)의 함량은 0.01~2.0% 일 수 있으며, 보다 바람직한 알루미늄(Al)의 함량은 0.01~1.95%일 수 있다.Aluminum (Al) is a representative element added as a deoxidizer. However, aluminum (Al) may form precipitates by reacting with carbon (C) and nitrogen (N), and the hot workability may be deteriorated by these precipitates, and the present invention provides an upper limit of the aluminum (Al) content. It can be limited to 2.0%. The preferred content of aluminum (Al) may be 0.01 to 2.0%, and the more preferred content of aluminum (Al) may be 0.01 to 1.95%.
크롬(Cr): 4% 이하Chromium (Cr): 4% or less
크롬(Cr)은 적정 첨가량의 범위까지는 오스테나이트를 안정화시켜 비자성 특성 향상에 기여하며, 오스테나이트 내에 고용되어 강재의 강도를 증가시키는 윈소이다. 또한, 크롬(Cr)은 강재의 내식성을 향상시키는 원소이기도 하다. 따라서, 본 발명은 이와 같은 효과를 달성하기 위하여 크롬(Cr)을 첨가할 수 있다. 다만, 크롬(Cr)은 산소 절단 시 산화물의 용융온도를 높여 첨가 함량이 증가할수록 열위한 산소 절단성이 열위해지는 경향을 나타내는바, 본 발명은 크롬(Cr) 함량의 상한을 4%로 제한할 수 있으며, 보다 바람직한 크롬(Cr) 함량의 상한은 3.5%일 수 있다.Chromium (Cr) is a winso that stabilizes austenite up to a range of an appropriate addition amount, thereby contributing to the improvement of non-magnetic properties, and is employed in austenite to increase the strength of steel. In addition, chromium (Cr) is also an element that improves the corrosion resistance of steel materials. Therefore, the present invention can add chromium (Cr) to achieve this effect. However, chromium (Cr) increases the melting temperature of the oxide during oxygen cutting, and as the added content increases, the tendency for oxygen cutting property to deteriorate tends to deteriorate. In the present invention, the upper limit of the chromium (Cr) content is limited to 4%. May be, the upper limit of the more preferred chromium (Cr) content may be 3.5%.
본 발명의 일 측면에 따른 산소 절단성이 우수한 비자성 고망간 강재는 상기한 성분 이외에 잔부 Fe 및 기타 불가피한 불순물을 포함할 수 있다. 다만, 통상의 제조과정에서는 원료 또는 주위 환경으로부터 의도되지 않는 불순물이 불가피하게 혼입될 수 있으므로, 이들을 전면적으로 배제할 수는 없다. 이들 불순물들은 본 기술분야에서 통상의 지식을 가진 자라면 누구라도 알 수 있는 것이기 때문에 그 모든 내용을 본 명세서에서 특별히 언급하지는 않는다. 더불어, 상기 조성 이외에 유효한 성분의 첨가가 전면적으로 배제되는 것은 아니다.The non-magnetic high-manganese steel material having excellent oxygen-cutting properties according to an aspect of the present invention may include residual Fe and other unavoidable impurities in addition to the above-described components. However, in the normal manufacturing process, unintended impurities from the raw material or the surrounding environment may inevitably be mixed, and therefore cannot be entirely excluded. Since these impurities are known to anyone skilled in the art, they are not specifically mentioned in this specification. In addition, addition of effective ingredients other than the above composition is not entirely excluded.
또한, 본 발명의 일 측면에 따른 산소 절단성이 우수한 고망간 강재는, 중량%로, 0.0005~0.01%의 보론(B)을 더 포함할 수 있으며, 0.03% 이하의 인(P), 0.05% 이하의 황(S) 및 0.02% 이하의 질소(N) 중 1종 이상을 포함할 수 있다.In addition, the high-manganese steel material having excellent oxygen cutting property according to an aspect of the present invention, by weight, may further include 0.0005 to 0.01% boron (B), and 0.03% or less phosphorus (P), 0.05% It may include one or more of the following sulfur (S) and less than 0.02% nitrogen (N).
붕소(B): 0.0005~0.01%Boron (B): 0.0005 ~ 0.01%
붕소(B)은 오스테나이트 입계를 강화하는 입계 강화 원소로서, 소량 첨가에 의하더라도 오스테나이트 입계를 강화하여 강재의 고온 균열 민감도를 효과적으로 낮출 수 있는 원소이다. 따라서, 이와 같은 효과를 달성하기 위하여, 본 발명은 붕소(B) 함량의 하한을 0.0005%로 제한할 수 있다. 보다 바람직한 붕소(B) 함량의 하한은 0.001%일 수 있다. 반면, 붕소(B)의 함량이 일정 범위를 초과하는 경우, 오스테나이트 입계에 편석을 유발하여 강재의 고온 균열 민감도를 증가시키므로, 강재의 표면 품질이 저하될 수 있는바, 본 발명은 붕소(B) 함량의 상한을 0.01%로 제한할 수 있다. 보다 바람직한 붕소(B) 함량의 상한은 0.006%일 수 있다.Boron (B) is a grain boundary strengthening element for strengthening the austenite grain boundary, and is an element capable of effectively lowering the high temperature cracking sensitivity of steel materials by strengthening the austenite grain boundary even with a small amount added. Therefore, in order to achieve this effect, the present invention can limit the lower limit of the boron (B) content to 0.0005%. The lower limit of the more preferred boron (B) content may be 0.001%. On the other hand, when the content of boron (B) exceeds a certain range, it causes segregation at the austenite grain boundary, thereby increasing the sensitivity of high temperature cracking of the steel, so the surface quality of the steel may be lowered. ) The upper limit of the content can be limited to 0.01%. The upper limit of the more preferred boron (B) content may be 0.006%.
인(P): 0.03% 이하Phosphorus (P): 0.03% or less
인(P)은 강 중에 불가피하게 유입되는 원소일 뿐만 아니라, 쉽게 편석되는 원소로서 주조 시 균열발생을 유발하거나, 용접성을 저하시키는 원소이다. 따라서, 본 발명은 주조성 악화 및 용접성 저하를 방지하기 위하여 인(P) 함량의 상한을 0.03%로 제한할 수 있으며, 보다 바람직한 인(P) 함량의 상한은 0.02%일 수 있다. Phosphorus (P) is not only an element that is inevitably introduced into the steel, but is an element that is easily segregated and causes cracking during casting or degrades weldability. Therefore, the present invention may limit the upper limit of the phosphorus (P) content to 0.03% to prevent deterioration of castability and deterioration of weldability, and the upper limit of the more preferable phosphorus (P) content may be 0.02%.
황(S): 0.05% 이하Sulfur (S): 0.05% or less
황(S) 역시 강 중에 불가피하게 유입되는 원소일 뿐만 아니라, 개재물 형성에 의해 열간취성 결함을 유발한 원소이다. 따라서, 본 발명은 열간취성 발생을 억제하기 위하여 황(S) 함량의 상한을 0.05%로 제한할 수 있으며, 보다 바람직한 황(S) 함량의 상한은 0.02%일 수 있다.Sulfur (S) is not only an element that is inevitably introduced into the steel, but is also an element that causes hot brittle defects by inclusion formation. Therefore, the present invention can limit the upper limit of the sulfur (S) content to 0.05% to suppress the occurrence of hot embrittlement, the upper limit of the more preferred sulfur (S) content may be 0.02%.
질소(N) 0.02% 이하Nitrogen (N) 0.02% or less
질소(N) 역시 강 중에 불가피하게 유입되는 원소일 뿐만 아니라, 고용강화에 기여하는 원소이기도 한다. 다만, 질소(N)의 함량이 과다한 경우 조대한 질화물을 형성하여 오히려 강재의 강도를 저하시키는 문제가 존재하므로, 본 발명은 질소(N) 함량의 상한을 0.02%로 제한할 수 있다.Nitrogen (N) is not only an element inevitably introduced into steel, but also an element contributing to solid solution strengthening. However, if the content of nitrogen (N) is excessive, there is a problem of lowering the strength of the steel by forming a coarse nitride, so the present invention can limit the upper limit of the nitrogen (N) content to 0.02%.
본 발명의 일 측면에 따른 산소 설단성이 우수한 고망간 강재는, 하기의 [관계식 1]에 의해 계산되는 절단성 민감도(Sc)가 430 이상일 수 있다. 보다 바람직하게는 하기의 [관계식 1]에 의해 계산되는 절단성 민감도(Sc)가 460 이상일 수 있다.In the high-manganese steel material having excellent oxygen snow-setting properties according to an aspect of the present invention, the cutability sensitivity (Sc) calculated by the following [Relational Formula 1] may be 430 or more. More preferably, the cutting sensitivity (Sc) calculated by the following [Relational Formula 1] may be 460 or more.
[관계식 1][Relationship 1]
절단성 민감도(Sc) = 1742 - 662*[C] - 19.2*[Mn] + 1.6*[Al] - 140*[Cr]Cutting sensitivity (Sc) = 1742-662 * [C]-19.2 * [Mn] + 1.6 * [Al]-140 * [Cr]
(상기 [관계식 1]에서 [C], [Mn], [Al] 및 [Cr]은 각각 강재에 포함되는 C, Mn, Al 및 Cr의 중량%를 의미하며, 해당 성문이 첨가되지 않는 경우 0을 의미한다.)(In [Relational Formula 1], [C], [Mn], [Al], and [Cr] mean the weight percent of C, Mn, Al, and Cr included in the steel, respectively, and 0 is not added. Means.)
본 발명의 발명자는 고망간 강재의 산소 절단성과 관련하여 심도 있는 연구를 수행하였으며, 알루미늄(Al)은 고망간 강재의 산소 절단성에 긍정적인 영향을 미치는 원소인 반면, 탄소(C), 망간(Mn) 및 크롬(Cr)은 고망간 강재의 산소 절단성에 부정적인 영향을 미치는 원소인 것을 알 수 있었다. The inventors of the present invention have conducted an in-depth study in relation to the oxygen-cutting property of high-manganese steel, while aluminum (Al) is an element that positively affects the oxygen-cutting property of high-manganese steel, whereas carbon (C) and manganese (Mn) ) And chromium (Cr) were found to be elements that negatively affect the oxygen-cleavability of high-manganese steels.
또한, 본 발명의 발명자는 이들 탄소(C), 망간(Mn), 크롬(Cr) 및 알루미늄(Al) 함량의 상관관계에 대한 연구를 수행하였으며, [관계식 1]로 표시되는 절단성 민감도(Sc)가 일정 수준 이상인 경우, 우수한 산소 절단성을 가지는 것을 확인할 수 있었다. In addition, the inventors of the present invention have conducted a study on the correlation of these carbon (C), manganese (Mn), chromium (Cr), and aluminum (Al) contents, and the sensitivity to cutability (Sc) ) Was more than a certain level, it was confirmed that it has excellent oxygen cleavage.
즉, 본 발명의 이 측면에 따른 산소 절단성이 우수한 고망간 강재는 [관계식 1]에 의한 절단성 민감도(Sc)가 430 이상을 만족하도록 합금 조성 함량을 제어하므로, 산소 절단 시 강재 절단면의 평균 표면 조도를 0.5mm 이하의 수준으로 관리할 수 있다.That is, the high manganese steel material having excellent oxygen cutting property according to this aspect of the present invention controls the alloy composition content so that the cutability sensitivity (Sc) by [Relational Formula 1] satisfies 430 or more, so the average of the steel cutting surface during oxygen cutting The surface roughness can be managed at a level of 0.5 mm or less.
본 발명의 일 측면에 따른 산소 절단성이 우수한 고망간 강재는 95면적% 이상의 오스테나이트를 미세조직으로 포함할 수 있으며, 그에 따라 강재의 비자성 특성 및 저온물성을 효과적으로 확보할 수 있다. 또한, 오스테나이트의 평균 결정립도는 5~150㎛일 수 있다. 제조 공정상 구현 가능한 오스테나이트의 평균 결정립도는 5㎛ 이상이며, 평균 결정립도가 크게 증가하는 경우 강재의 강도 저하가 우려되는바, 오스테나이트의 결정립도는 150㎛ 이하로 제한될 수 있다.A high-manganese steel material having excellent oxygen-cutting properties according to an aspect of the present invention may include at least 95% by area of austenite as a microstructure, thereby effectively securing non-magnetic properties and low-temperature properties of the steel material. In addition, the average grain size of austenite may be 5 to 150 μm. The average grain size of austenite that can be implemented in the manufacturing process is 5 µm or more, and when the average grain size is greatly increased, the strength of the steel material may be lowered, so the grain size of austenite may be limited to 150 µm or less.
본 발명의 일 측면에 따른 산소 절단성이 우수한 오스테나이트계 고망간 강재는 오스테나이트 이외에 존재 가능한 조직으로서 탄화물 및/또는 ε-마르텐사이트를 포함할 수 있다. 탄화물 및/또는 ε-마르텐사이트의 분율이 일정 수준을 초과하는 경우, 강재의 인성 및 연성이 급격히 저하될 수 있는바, 본 발명은 탄화물 및/또는 ε-마르텐사이트의 분율을 5면적% 이하로 제한할 수 있다.The austenitic high-manganese steel material having excellent oxygen cleavability according to an aspect of the present invention may include carbide and / or ε-martensite as a structure that may exist in addition to austenite. When the fraction of carbide and / or ε-martensite exceeds a certain level, the toughness and ductility of the steel may be rapidly reduced. In the present invention, the fraction of carbide and / or ε-martensite is less than 5 area%. Can be limited.
앞서 설명한 바와 같이, 본 발명의 일 측면에 따른 산소 절단성이 우수한 고망간 강재는 최적의 합금조성으로 구비되는바, 산소 절단 시 우수한 절단면을 가질 수 있다. 즉, 산소 절단 시 불꽃 발생을 최소화하는바, 강재의 용융에 따라 절단면이 불균일해지는 현상을 최소화할 수 있다. 더불어, 본 발명의 일 측면에 따른 산소 절단성이 우수한 고망간 강재는 산소 절단 시 절단속도의 저하를 효과적으로 방지 가능하므로, 작업 효율을 최적화하여 생산성을 극대화할 수 있다. As described above, a high-manganese steel material having excellent oxygen cutting properties according to an aspect of the present invention is provided with an optimal alloy composition, and thus may have an excellent cutting surface during oxygen cutting. That is, since the occurrence of sparks is minimized when oxygen is cut, it is possible to minimize the phenomenon that the cut surface is non-uniform due to melting of the steel material. In addition, the high-manganese steel material having excellent oxygen cutting property according to an aspect of the present invention can effectively prevent a decrease in cutting speed when cutting oxygen, thereby optimizing work efficiency and maximizing productivity.
본 발명의 일 측면에 따른 산소 절단성이 우수한 고망간 강재는, 1.02 이하의 투자율, 240MPa 이상의 항복강도, 720MPa 이상의 인장강도, 25% 이상의 연신율을 구비할 수 있다.A high-manganese steel material having excellent oxygen cutting properties according to an aspect of the present invention may have a permeability of 1.02 or less, a yield strength of 240 MPa or more, a tensile strength of 720 MPa or more, and an elongation of 25% or more.
이하, 본 발명의 제조방법에 대해 보다 상세히 설명한다.Hereinafter, the manufacturing method of the present invention will be described in more detail.
본 발명의 일 측면에 따른 산소 절단성이 우수한 고망간 강재의 제조방법은, 중량%로, 탄소(C): 0.1~0.5%, 망간(Mn): 20~26%, 실리콘(Si): 0.05~0.4%, 알루미늄(Al): 2.0% 이하, 크롬(Cr): 4% 이하, 잔부 Fe 및 기타 불가피한 불순물을 포함하며, 하기 [관계식 1]로 계산되는 절단성 민감도(Sc)가 430 이상인 슬라브를 1050~1300℃의 온도범위에서 재가열하는 단계; 상기 재가열된 슬라브를 800~1050℃의 마무리 압연 온도로 열간압연하여 열연재를 제공하는 단계; 및 상기 열연재를 1~100℃/s의 냉각속도로 600℃ 이하의 온도범위까지 냉각하는 단계;를 포함할 수 있다.A method of manufacturing a high-manganese steel material having excellent oxygen-cutting properties according to an aspect of the present invention, in weight percent, carbon (C): 0.1-0.5%, manganese (Mn): 20-26%, silicon (Si): 0.05 ~ 0.4%, aluminum (Al): 2.0% or less, chromium (Cr): 4% or less, including residual Fe and other unavoidable impurities, and the slab sensitivity (Sc) of 430 or more calculated by [Relational Formula 1] below Re-heating in the temperature range of 1050 ~ 1300 ℃; Hot rolling the reheated slab to a finish rolling temperature of 800 to 1050 ° C to provide a hot rolled material; And cooling the hot rolled material to a temperature range of 600 ° C. or less at a cooling rate of 1 to 100 ° C./s.
[관계식 1][Relationship 1]
절단성 민감도(Sc) = 1742 - 662*[C] - 19.2*[Mn] + 1.6*[Al] - 140*[Cr]Cutting sensitivity (Sc) = 1742-662 * [C]-19.2 * [Mn] + 1.6 * [Al]-140 * [Cr]
(상기 [관계식 1]에서 [C], [Mn], [Al] 및 [Cr]은 각각 강재에 포함되는 C, Mn, Al 및 Cr의 중량%를 의미하며, 해당 성분이 첨가되지 않는 경우 0을 의미한다.)(In [Relational Formula 1], [C], [Mn], [Al], and [Cr] mean the weight percent of C, Mn, Al, and Cr included in the steel, respectively, and 0 when the corresponding component is not added. Means.)
또한, 상기 슬라브는, 중량%로, 0.0005~0.01%의 보론(B)을 더 포함할 수 있 있으며, 0.03% 이하의 인(P), 0.05% 이하의 황(S) 및 0.02% 이하의 질소(N) 중 1종 이상을 포함할 수 있다.In addition, the slab, by weight, may further include 0.0005 to 0.01% boron (B), 0.03% or less phosphorus (P), 0.05% or less sulfur (S), and 0.02% or less nitrogen (N).
슬라브 재가열Slab reheating
본 발명의 제조방법에 제공되는 슬라브의 강 조성은, 전술한 산소 절단성이 우수한 고망간 강재의 강 조성과 대응하므로, 슬라브의 강 조성에 대한 설명은 전술한 강재의 강 조성에 대한 설명으로 대신한다.Since the steel composition of the slab provided in the manufacturing method of the present invention corresponds to the steel composition of the high-manganese steel material having excellent oxygen-cutting property, the description of the steel composition of the slab will be replaced by the description of the steel composition of the steel material described above. do.
전술한 강 조성으로 제공되는 슬라브를 1050~1300℃의 온도범위에서 재가열 할 수 있다. 재가열 온도가 일정 범위 미만인 경우, 열간압연 중에 과도한 압연부하가 걸리는 문제가 발생하거나, 합금성분이 충분히 고용되지 않는 문제가 발생할 수 있으므로, 본 발명은 슬라브 재가열 온도범위의 하한을 1050℃로 제한할 수 있다. 반면, 재가열 온도가 일정 범위를 초과하는 경우, 결정립이 과도하게 성장하여 강도가 저하되거나, 강재의 고상선 온도를 초과하여 재가열 됨으로써 강재의 열간압연성이 열위해질 수 있으므로, 본 발명은 슬라브 재가열 온도범위의 상한을 1300℃로 제한할 수 있다.The slab provided with the above-described steel composition can be reheated in a temperature range of 1050 to 1300 ° C. When the reheating temperature is less than a certain range, the problem of excessive rolling load during hot rolling may occur, or a problem that the alloy component is not sufficiently dissolved may occur, so that the present invention can limit the lower limit of the slab reheating temperature range to 1050 ° C. have. On the other hand, if the reheating temperature exceeds a certain range, the grains may grow excessively and the strength may decrease, or the re-heating may exceed the solidus temperature of the steel material, thereby deteriorating the hot rolling property of the steel material. The upper limit of the range can be limited to 1300 ° C.
열간압연Hot rolled
열간압연 공정은 조압연 공정 및 마무리 압연 공정을 포함하며, 재가열된 슬라브는 열간압연되어 열연재로 제공될 수 있다. 이때 열간 마무리 압연은 800~1050℃의 온도범위에서 수행되는 것이 바람직하다. 열간 마무리 압연 온도가 일정 범위 미만인 경우 압연 하중 증가에 따른 과도한 압연부하가 문제될 수 있으며, 열간 마무리 압연 온도가 일정 범위를 초과하는 경우 결정립이 조대하게 성장하여 목표하는 강도를 얻을 수 없기 때문이다.The hot rolling process includes a rough rolling process and a finish rolling process, and the reheated slab may be hot rolled and provided as a hot rolled material. At this time, the hot finish rolling is preferably carried out in a temperature range of 800 ~ 1050 ℃. If the hot finish rolling temperature is less than a certain range, excessive rolling load due to an increase in the rolling load may be a problem, and if the hot finish rolling temperature exceeds a certain range, the grains grow coarsely and the target strength cannot be obtained.
냉각Cooling
열간압연된 열연재는 1~100℃/s의 냉각속도로 600℃ 이하의 냉각정지 온도까지 냉각될 수 있다. 냉각속도가 일정 범위 미만인 경우 냉각 도중 입계에 석출된 탄화물에 의해 강재의 연성 감소 및 이로 인한 내마모성의 열화가 문제될 수 있으므로, 본 발명은 열연재의 냉각속도를 1℃/s 이상으로 제한할 수 있다. 보다 바람직한 냉각속도의 하한은 10℃/s일 수 있으며, 가속냉각이 적용될 수 있다. 다만, 냉각속도가 빠를수록 탄화물 석출 억제 효과에는 유리하나, 통상의 냉각에 있어서 100℃/s를 초과하는 냉각속도는 설비 특성상 구현하기 어려운 사정을 고려하여, 본 발명은 냉각속도의 상한을 100℃/s로 제한할 수 있다. The hot rolled hot rolled material may be cooled to a cooling stop temperature of 600 ° C. or less at a cooling rate of 1 to 100 ° C./s. If the cooling rate is less than a certain range, the ductility of the steel may be reduced due to carbides precipitated at the grain boundary during cooling, and thus deterioration of abrasion resistance may be a problem. Therefore, the present invention can limit the cooling rate of the hot rolled material to 1 ° C / s or more. have. The lower limit of the more preferable cooling rate may be 10 ° C / s, and accelerated cooling may be applied. However, the faster the cooling rate is, the more advantageous the effect of suppressing the precipitation of carbides, but considering the circumstances in which the cooling rate exceeding 100 ° C / s in normal cooling is difficult to implement due to the characteristics of the facility, the present invention sets the upper limit of the cooling rate to 100 ° C. Can be limited to / s.
또한, 10℃/s 이상의 냉각속도를 적용하여 열연재를 냉각하더라도, 높은 온도에서 냉각이 정지되는 경우 탄화물이 생성 및 성장될 가능성이 높으므로, 본 발명은 냉각 정지 온도를 600℃ 이하로 제한할 수 있다.In addition, even if the hot-rolled material is cooled by applying a cooling rate of 10 ° C./s or more, when the cooling is stopped at a high temperature, there is a high possibility that carbides are generated and grown, so the present invention limits the cooling stop temperature to 600 ° C. or less. You can.
상기와 같이 제조된 산소 절단성이 우수한 고망간 강재는 95면적% 이상의 오스테나이트를 미세조직으로 포함하고, 1.02 이하의 투자율, 240MPa 이상의 항복강도, 720MPa 이상의 인장강도 및 25% 이상의 연신율을 구비하며, 산소 절단 시 우수한 절단면을 가짐과 동시에 산소 절단 작업의 생산성 저하를 효과적으로 방지할 수 있다.The high-manganese steel with excellent oxygen-cutting properties prepared as described above contains 95% by area or more of austenite as a microstructure, has a permeability of 1.02 or less, a yield strength of 240MPa or more, a tensile strength of 720MPa or more, and an elongation of 25% or more, At the same time as having an excellent cutting surface during oxygen cutting, it is possible to effectively prevent a decrease in productivity of the oxygen cutting operation.
이하, 실시예를 통하여 본 발명을 보다 구체적으로 설명한다. 다만, 후술하는 실시예는 본 발명을 예시하여 보다 구체화하기 위한 것일 뿐, 본 발명의 권리범위를 제한하기 위한 것은 아니라는 점에 유의할 필요가 있다.Hereinafter, the present invention will be described in more detail through examples. However, it is necessary to note that the embodiments described below are only intended to further illustrate the present invention and are not intended to limit the scope of the present invention.
(실시예)(Example)
하기 표 1의 합금조성을 만족하는 슬라브를 1200℃의 온도에서 재가열하고, 표 2의 조건으로 열간압연하여 12mm 두께의 열연재를 제조한 후 20℃/s의 냉각속도로 100℃의 냉각정지온도까지 가속냉각하여 시편을 제작하였다. 각 시편의 항복강도, 인장강도 및 연신율을 측정하고, 투자율과 최대 절단속도 및 절단면 상태를 하기 표 2에 함께 나타내었다. 최대 절단속도는 평균 0.7MPa의 가스압으로 산소 절단을 실시하는 경우, 적용 가능한 최대 절단 속도를 의미한다. 절단면의 평점은 1, 1.5 및 2로 구분하여 평가하였다. 평점 1은 산소 절단 중 모재가 용융되었을 뿐만 아니라, 절단면의 평균 표면 조도가 0.5mm 초과인 경우를 의미하고, 평점 1.5는 산소 절단 중 모재의 일부 용융이 발생하였으나, 절단면의 평균 표면 조도가 0.5mm 이하인 경우를 의미하며, 평점 1은 산소 절단 중 모재의 용융이 발생하지 않았을 뿐만 아니라 절단면의 평균 표면 조도가 0.5mm 이하인 경우를 의미한다. 표 2의 절단성 지수는 각 시편의 최대 절단속도와 절단면 평점을 곱한 값을 의미한다.The slab that satisfies the alloy composition of Table 1 below was reheated at a temperature of 1200 ° C, hot rolled under the conditions of Table 2 to produce a hot rolled material having a thickness of 12mm, and then cooled to a cooling stop temperature of 100 ° C at a cooling rate of 20 ° C / s. The specimen was prepared by accelerated cooling. The yield strength, tensile strength and elongation of each specimen were measured, and the permeability, the maximum cutting speed, and the cutting surface state are shown together in Table 2 below. The maximum cutting speed means the maximum cutting speed applicable when oxygen cutting is performed at an average gas pressure of 0.7 MPa. The cut surface scores were evaluated by dividing them into 1, 1.5, and 2. A rating of 1 means that the base material is not only melted during oxygen cutting, but also means that the average surface roughness of the cut surface is greater than 0.5 mm. A rating of 1.5 means that some of the base material is melted during oxygen cutting, but the average surface roughness of the cut surface is 0.5 mm. The following means the case, and a rating of 1 means that the base material is not melted during oxygen cutting and the average surface roughness of the cut surface is 0.5 mm or less. The cutability index in Table 2 means the value obtained by multiplying the maximum cutting speed of each specimen and the cutting surface rating.
구분division 합금조성(중량%)Alloy composition (% by weight) [관계식 1][Relationship 1]
CC MnMn SiSi PP SS AlAl CrCr NN
실시예1Example 1 0.41 0.41 21.7 21.7 0.27 0.27 0.017 0.017 0.003 0.003 0.013 0.013 2.01 2.01 0.013 0.013 772.6772.6
실시예2Example 2 0.18 0.18 22.3 22.3 0.14 0.14 0.019 0.019 0.010 0.010 1.80 1.80 0.00 0.00 0.013 0.013 1197.61197.6
실시예3Example 3 0.44 0.44 24.6 24.6 0.26 0.26 0.019 0.019 0.007 0.007 0.020 0.020 3.45 3.45 0.018 0.018 495.4495.4
실시예4Example 4 0.18 0.18 21.8 21.8 0.21 0.21 0.016 0.016 0.003 0.003 0.026 0.026 2.00 2.00 0.016 0.016 924.3924.3
실시예5Example 5 0.41 0.41 21.8 21.8 0.22 0.22 0.019 0.019 0.003 0.003 0.016 0.016 1.95 1.95 0.013 0.013 779.0779.0
실시예6Example 6 0.40 0.40 21.6 21.6 0.20 0.20 0.018 0.018 0.003 0.003 0.025 0.025 0.00 0.00 0.014 0.014 1062.51062.5
실시예7Example 7 0.41 0.41 21.9 21.9 0.21 0.21 0.019 0.019 0.003 0.003 0.027 0.027 4.00 4.00 0.016 0.016 490.1490.1
실시예8Example 8 0.39 0.39 22.3 22.3 0.15 0.15 0.018 0.018 0.009 0.009 1.93 1.93 1.92 1.92 0.016 0.016 789.9789.9
실시예9Example 9 0.20.2 2222 0.20.2 0.0180.018 0.0020.002 0.0250.025 00 0.0150.015 1187.21187.2
실시예10Example 10 0.20.2 2020 0.20.2 0.0180.018 0.0020.002 0.0250.025 00 0.0150.015 1225.61225.6
실시예11Example 11 0.20.2 2525 0.20.2 0.0180.018 0.0020.002 0.0250.025 00 0.0150.015 1129.61129.6
비교예1Comparative Example 1 0.45 0.45 24.4 24.4 0.22 0.22 0.019 0.019 0.003 0.003 0.012 0.012 3.95 3.95 0.018 0.018 422.6422.6
비교예2Comparative Example 2 0.610.61 22.122.1 0.20.2 0.0160.016 0.0060.006 0.0230.023 5.955.95 0.020.02 80.980.9
비교예3Comparative Example 3 0.80.8 2222 0.210.21 0.0150.015 0.0080.008 0.0260.026 3.653.65 0.0190.019 279.0279.0
구분division 마무리압연온도(℃)Finish rolling temperature (℃) YS(Mpa)YS (Mpa) TS(Mpa)TS (Mpa) El(%)El (%) 투자율Permeability 최대절단속도(mm/min)Cutting speed (mm / min) 절단면평점Cutting plane 절단성지수Cleavage index
실시예1Example 1 925925 457457 980980 5252 1.0031.003 400400 1.51.5 600600
실시예2Example 2 920920 386386 728728 5353 1.0011.001 700700 22 14001400
실시예3Example 3 930930 489489 906906 5454 1.0011.001 350350 1.51.5 525525
실시예4Example 4 917917 399399 834834 3333 1.0031.003 400400 1.51.5 600600
실시예5Example 5 925925 493493 10501050 6262 1.0021.002 400400 1.51.5 600600
실시예6Example 6 854854 394394 948948 5757 1.0031.003 500500 22 10001000
실시예7Example 7 915915 493493 969969 5151 1.0011.001 300300 1.51.5 450450
실시예8Example 8 920920 495495 803803 5454 1.0041.004 400400 1.51.5 600600
실시예9Example 9 900900 265265 890890 2727 1.0011.001 700700 22 14001400
실시예10Example 10 850850 280280 942942 2525 1.0011.001 700700 22 14001400
실시예11Example 11 940940 241241 762762 5454 1.0011.001 600600 22 12001200
비교예1Comparative Example 1 920920 452452 919919 5151 1.0001.000 300300 1One 300300
비교예2Comparative Example 2 920920 633633 10941094 5252 1.0011.001 300300 1One 300300
비교예3Comparative Example 3 925925 629629 11701170 4949 1.0011.001 300300 1One 300300
표 1 및 표 2에 나타난 바와 같이, 본 발명의 범위를 만족하는 실시예 1 내지 11의 경우, 절단면의 평균 표면 조도가 0.5mm 이하일 뿐만 아니라, 절단성 지수가 400 이상으로 우수한 산소 절단성을 구비하는 반면, 본 발명의 범위를 만족하지 않는 비교예 1 내지 3의 경우, 절단면의 평균 표면 조도가 0.5mm를 초과할 뿐만 아니라, 절단성 지수가 300 수준으로 산소 절단성이 열위한 것을 확인할 수 있다. As shown in Table 1 and Table 2, in the case of Examples 1 to 11 satisfying the scope of the present invention, not only the average surface roughness of the cut surface is 0.5 mm or less, but also has excellent oxygen cutting property with a cutability index of 400 or more. On the other hand, in the case of Comparative Examples 1 to 3 that do not satisfy the scope of the present invention, it can be seen that not only the average surface roughness of the cut surface exceeds 0.5 mm, but also the cutability index is inferior to the oxygen cutability of 300 levels. .
도 1의 (a)는 실시예 2의 산소 절단 시 불꽃 발생 여부 및 산소 절단에 의한 절단면을 촬영한 사진이며, 도 1의 (b)는 비교예 2의 산소 절단 시 불꽃 발생 여부 및 산소 절단에 의한 절단면을 촬영한 사진이다. 도 1의 (a) 및 (b)에 나타난 바와 같이, 실시예 2의 경우 우수한 절단면을 가지는 반면, 비교예 2의 경우 산소 절단 시 과도한 불꽃이 발생하여 모재의 용융이 발생하며, 그에 따라 균일하지 못한 절단면이 구현되는 것을 확인할 수 있다. FIG. 1 (a) is a photograph of whether a spark is generated during oxygen cutting in Example 2 and a cut surface due to oxygen cutting, and FIG. 1 (b) shows whether spark is generated during oxygen cutting in Comparative Example 2 and when oxygen is cut. This is a photograph of the cut surface. As shown in (a) and (b) of FIG. 1, in the case of Example 2, while having an excellent cutting surface, in the case of Comparative Example 2, excessive sparking occurs when oxygen is cut, resulting in melting of the base material, and thus not uniform It can be seen that an unsuccessful cut surface is realized.
이상에서 실시예를 통하여 본 발명을 상세하게 설명하였으나, 이와 다른 형태의 실시예들도 가능하다. 그러므로, 이하에 기재된 청구항들의 기술적 사상과 범위는 실시예들에 한정되지 않는다.Although the present invention has been described in detail through the above embodiments, other types of embodiments are possible. Therefore, the technical spirit and scope of the claims set forth below are not limited to the embodiments.

Claims (7)

  1. 중량%로, 탄소(C): 0.1~0.5%, 망간(Mn): 20~26%, 실리콘(Si): 0.05~0.4%, 알루미늄(Al): 2.0% 이하, 크롬(Cr): 4% 이하, 잔부 Fe 및 기타 불가피한 불순물을 포함하고, In weight percent, carbon (C): 0.1-0.5%, manganese (Mn): 20-26%, silicon (Si): 0.05-0.4%, aluminum (Al): 2.0% or less, chromium (Cr): 4% Hereinafter, the remaining Fe and other inevitable impurities are included,
    하기 [관계식 1]로 계산되는 절단성 민감도(Sc)가 430 이상이며,The cutting sensitivity (Sc) calculated by the following [Relational Formula 1] is 430 or more,
    95면적% 이상의 오스테나이트를 미세조직으로 포함하는, 산소 절단성이 우수한 고망간 강재.A high-manganese steel with excellent oxygen-cutting properties, containing more than 95% by area of austenite as a microstructure.
    [관계식 1][Relationship 1]
    절단성 민감도(Sc) = 1742 - 662*[C] - 19.2*[Mn] + 1.6*[Al] - 140*[Cr]Cutting sensitivity (Sc) = 1742-662 * [C]-19.2 * [Mn] + 1.6 * [Al]-140 * [Cr]
    (상기 [관계식 1]에서 [C], [Mn], [Al] 및 [Cr]은 각각 강재에 포함되는 C, Mn, Al 및 Cr의 중량%를 의미하며, 해당 성분이 첨가되지 않는 경우 0을 의미한다.)(In [Relational Formula 1], [C], [Mn], [Al], and [Cr] mean the weight percent of C, Mn, Al, and Cr included in the steel, respectively, and 0 when the corresponding component is not added. Means.)
  2. 제1항에 있어서,According to claim 1,
    상기 강재는, 중량%로, 0.0005~0.01%의 보론(B)을 더 포함하는, 산소 절단성이 우수한 고망간 강재.The steel material, by weight%, further comprising 0.0005 to 0.01% boron (B), a high-manganese steel excellent in oxygen cutting.
  3. 제1항에 있어서,According to claim 1,
    상기 강재의 투자율은 1.02 이하인, 산소 절단성이 우수한 고망간 강재.The permeability of the steel is 1.02 or less, a high-manganese steel excellent in oxygen cutting property.
  4. 제1항에 있어서,According to claim 1,
    상기 강재의 항복강도는 240MPa 이상이고, 인장강도는 720MPa 이상이며, 연신율은 25% 이상인, 산소 절단성이 우수한 고망간 강재.The yield strength of the steel material is 240MPa or more, the tensile strength is 720MPa or more, and the elongation is 25% or more, a high-manganese steel excellent in oxygen cutting property.
  5. 제1항에 있어서,According to claim 1,
    0.3~0.9Mpa의 가스압 및 300~700mm/min의 최대 절단속도로 상기 강재를 산소절단 하는 경우, 상기 강재 절단면의 평균 표면 조도는 0.5mm 이하인, 산소 절단성이 우수한 고망간 강재.When oxygen-cutting the steel with a gas pressure of 0.3 to 0.9 Mpa and a maximum cutting speed of 300 to 700 mm / min, the average surface roughness of the steel cutting surface is 0.5 mm or less, and a high-manganese steel with excellent oxygen cutting properties.
  6. 중량%로, 탄소(C): 0.1~0.5%, 망간(Mn): 20~26%, 실리콘(Si): 0.05~0.4%, 알루미늄(Al): 2.0% 이하, 크롬(Cr): 4% 이하, 잔부 Fe 및 기타 불가피한 불순물을 포함하며, 하기 [관계식 1]로 계산되는 절단성 민감도(Sc)가 430 이상인 슬라브를 1050~1300℃의 온도범위에서 재가열하는 단계;In weight percent, carbon (C): 0.1-0.5%, manganese (Mn): 20-26%, silicon (Si): 0.05-0.4%, aluminum (Al): 2.0% or less, chromium (Cr): 4% Hereinafter, a step of reheating a slab having a residual Fe and other unavoidable impurities and having a cutability sensitivity (Sc) of 430 or more calculated as [Relational Formula 1] at a temperature range of 1050 to 1300 ° C;
    상기 재가열된 슬라브를 800~1050℃의 마무리 압연 온도로 열간압연하여 열연재를 제공하는 단계; 및Hot rolling the reheated slab to a finish rolling temperature of 800 to 1050 ° C to provide a hot rolled material; And
    상기 열연재를 1~100℃/s의 냉각속도로 600℃ 이하의 온도범위까지 냉각하는 단계;를 포함하는 산소 절단성이 우수한 고망간 강재의 제조방법.Cooling the hot rolled material to a temperature range of 600 ℃ or less at a cooling rate of 1 ~ 100 ℃ / s; Method for producing a high-manganese steel material having excellent oxygen cutting.
    [관계식 1][Relationship 1]
    절단성 민감도(Sc) = 1742 - 662*[C] - 19.2*[Mn] + 1.6*[Al] - 140*[Cr]Cutting sensitivity (Sc) = 1742-662 * [C]-19.2 * [Mn] + 1.6 * [Al]-140 * [Cr]
    (상기 [관계식 1]에서 [C], [Mn], [Al] 및 [Cr]은 각각 강재에 포함되는 C, Mn, Al 및 Cr의 중량%를 의미하며, 해당 성분이 첨가되지 않는 경우 0을 의미한다.)(In [Relational Formula 1], [C], [Mn], [Al], and [Cr] mean the weight percent of C, Mn, Al, and Cr included in the steel, respectively, and 0 when the corresponding component is not added. Means.)
  7. 제1항에 있어서,According to claim 1,
    상기 슬라브는, 중량%로, 0.0005~0.01%의 보론(B)을 더 포함하는, 산소 절단성이 우수한 고망간 강재의 제조방법.The slab, by weight%, further comprising 0.0005 to 0.01% boron (B), a method of manufacturing a high-manganese steel excellent in oxygen cutting.
PCT/KR2019/014184 2018-10-25 2019-10-25 High manganese steel having excellent oxygen cutting properties, and manufacturing method therefor WO2020085855A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993013233A1 (en) * 1991-12-30 1993-07-08 Pohang Iron & Steel Co., Ltd. Austenitic high manganese steel having superior formability, strength and weldability, and manufacturing process therefor
KR20060040718A (en) * 2003-07-22 2006-05-10 위시노 Method of producing austenitic iron/carbon/manganese steel sheets having a high strength and excellent toughness and being suitable for cold forming, and sheets thus produced
KR20090043508A (en) * 2006-07-11 2009-05-06 아르셀러미탈 프랑스 Process for manufacturing iron-carbon-manganese austenitic steel sheet with excellent resistance to delayed cracking, and sheet thus produced
KR20100064473A (en) 2008-12-05 2010-06-15 (주) 아이엔티 A cutting device using oxygen
JP2013023742A (en) * 2011-07-22 2013-02-04 Kobe Steel Ltd Non-magnetic steel wire material or rod steel
KR20170075657A (en) * 2015-12-23 2017-07-03 주식회사 포스코 Nonmagnetic steel having superior hot workability and method for manufacturing the same

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993013233A1 (en) * 1991-12-30 1993-07-08 Pohang Iron & Steel Co., Ltd. Austenitic high manganese steel having superior formability, strength and weldability, and manufacturing process therefor
KR20060040718A (en) * 2003-07-22 2006-05-10 위시노 Method of producing austenitic iron/carbon/manganese steel sheets having a high strength and excellent toughness and being suitable for cold forming, and sheets thus produced
KR20090043508A (en) * 2006-07-11 2009-05-06 아르셀러미탈 프랑스 Process for manufacturing iron-carbon-manganese austenitic steel sheet with excellent resistance to delayed cracking, and sheet thus produced
KR20100064473A (en) 2008-12-05 2010-06-15 (주) 아이엔티 A cutting device using oxygen
JP2013023742A (en) * 2011-07-22 2013-02-04 Kobe Steel Ltd Non-magnetic steel wire material or rod steel
KR20170075657A (en) * 2015-12-23 2017-07-03 주식회사 포스코 Nonmagnetic steel having superior hot workability and method for manufacturing the same

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