KR20220054862A - Alloy structural steel and its manufacturing method - Google Patents
Alloy structural steel and its manufacturing method Download PDFInfo
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- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 84
- 239000000956 alloy Substances 0.000 title claims abstract description 84
- 229910000746 Structural steel Inorganic materials 0.000 title claims abstract description 64
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 23
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 46
- 239000010959 steel Substances 0.000 claims abstract description 46
- 238000010438 heat treatment Methods 0.000 claims abstract description 18
- 238000007670 refining Methods 0.000 claims abstract description 15
- 238000010791 quenching Methods 0.000 claims abstract description 14
- 230000000171 quenching effect Effects 0.000 claims abstract description 14
- 229910052729 chemical element Inorganic materials 0.000 claims abstract description 12
- 238000005496 tempering Methods 0.000 claims abstract description 12
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 10
- 238000003723 Smelting Methods 0.000 claims abstract description 9
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 9
- 238000005266 casting Methods 0.000 claims abstract description 8
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 8
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 7
- 238000005098 hot rolling Methods 0.000 claims abstract description 7
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 5
- 239000012535 impurity Substances 0.000 claims abstract description 4
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 3
- 239000002245 particle Substances 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 11
- 238000001816 cooling Methods 0.000 claims description 7
- 229910052698 phosphorus Inorganic materials 0.000 claims description 5
- 229910001562 pearlite Inorganic materials 0.000 claims description 3
- 229910000859 α-Fe Inorganic materials 0.000 claims description 3
- 229910052746 lanthanum Inorganic materials 0.000 claims description 2
- 229910052702 rhenium Inorganic materials 0.000 claims description 2
- 229910052706 scandium Inorganic materials 0.000 claims description 2
- 229910052727 yttrium Inorganic materials 0.000 claims description 2
- 238000005275 alloying Methods 0.000 abstract description 7
- 239000011777 magnesium Substances 0.000 description 16
- 230000000694 effects Effects 0.000 description 13
- 229910052760 oxygen Inorganic materials 0.000 description 12
- 239000000243 solution Substances 0.000 description 11
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 10
- 229910052717 sulfur Inorganic materials 0.000 description 10
- 238000012360 testing method Methods 0.000 description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 8
- 239000011572 manganese Substances 0.000 description 8
- 239000001301 oxygen Substances 0.000 description 8
- 230000001276 controlling effect Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 230000008569 process Effects 0.000 description 6
- 229910052786 argon Inorganic materials 0.000 description 5
- 229910001566 austenite Inorganic materials 0.000 description 5
- 238000009749 continuous casting Methods 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 239000002826 coolant Substances 0.000 description 4
- 239000002480 mineral oil Substances 0.000 description 4
- 235000010446 mineral oil Nutrition 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 238000007711 solidification Methods 0.000 description 3
- 230000008023 solidification Effects 0.000 description 3
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 229910000838 Al alloy Inorganic materials 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910001018 Cast iron Inorganic materials 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- SNAAJJQQZSMGQD-UHFFFAOYSA-N aluminum magnesium Chemical compound [Mg].[Al] SNAAJJQQZSMGQD-UHFFFAOYSA-N 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 238000009863 impact test Methods 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 229910001404 rare earth metal oxide Inorganic materials 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 239000002436 steel type Substances 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 238000009864 tensile test Methods 0.000 description 2
- 150000003568 thioethers Chemical class 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 229910019018 Mg 2 Si Inorganic materials 0.000 description 1
- 229910000971 Silver steel Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000003009 desulfurizing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000003137 locomotive effect Effects 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 238000004626 scanning electron microscopy Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 238000007619 statistical method Methods 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
Classifications
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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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
- C21D1/58—Oils
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
- C21D1/60—Aqueous agents
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- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/008—Heat treatment of ferrous alloys containing Si
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/02—Hardening by precipitation
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
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- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
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- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
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- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
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- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
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- C21D2211/00—Microstructure comprising significant phases
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- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
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- C21D2211/00—Microstructure comprising significant phases
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Abstract
합금 구조용 스틸이 개시되며, 상기 스틸의 화학 원소는 질량 백분율로 0.35-0.45%의 C, 0.27-0.35%의 Si, 0.6-0.8%의 Mn, 0.015-0.05%의 Al, 0.06-0.1%의 V, 0.2-1.0%의 Zr, 0.001-0.005%의 Mg, 0.025% 이하의 P, 0.015% 이하의 S, 0.005% 이하의 N, 0.001% 이하의 O, 및 나머지의 Fe와 기타 불가피한 불순물이다. 또한, (1) 제련, 정련 및 주조 단계; (2) 블루밍 및 코깅 단계; (3) 제품을 형성하기 위한 2차 열간압연 단계; 및 (4) ??칭 및 템퍼링을 포함하는 열처리 단계를 포함하는 합금 구조용 스틸의 제조방법이 개시되어 있다. 미량의 합금원소를 첨가하여 설계하고, 합금 구조용 스틸을 더욱 강화시키고 인성을 부여하며 제조원가가 저렴하다.An alloy structural steel is disclosed, wherein the chemical elements of the steel are 0.35-0.45% C, 0.27-0.35% Si, 0.6-0.8% Mn, 0.015-0.05% Al, 0.06-0.1% V by mass percentage. , 0.2-1.0% Zr, 0.001-0.005% Mg, 0.025% or less P, 0.015% or less S, 0.005% or less N, 0.001% or less O, and the remainder Fe and other unavoidable impurities. Also, (1) smelting, refining and casting steps; (2) blooming and cogging steps; (3) a secondary hot rolling step to form a product; and (4) a heat treatment step including quenching and tempering is disclosed. It is designed by adding a small amount of alloying elements, and the steel for alloy structure is further strengthened and tough, and the manufacturing cost is low.
Description
본 발명은 스틸 타입 및 그 제조방법에 관한 것으로, 특히 합금 구조용 스틸 및 그 제조방법에 관한 것이다.The present invention relates to a steel type and a method for manufacturing the same, and more particularly, to a steel for an alloy structure and a method for manufacturing the same.
40CrV는 기관차 커넥팅 로드, 크랭크샤프트, 푸싱 로드, 프로펠러, 빔, 샤프트 슬리브 브래킷, 양단 스터드(double-ended stud), 나사, 무-침탄기어(non-carburized gear), 침탄처리된 각종 기어 및 핀, 고압보일러 워터펌프축(직경 30mm이하), 고압실린더, 강관, 볼트(작동온도가 420℃ 미만이고, 강도는 30MPa이다) 등과 같은 다양한 가변 하중 및 고하중 중요 부품 제조에 사용할 수 있다.40CrV includes locomotive connecting rods, crankshafts, pushing rods, propellers, beams, shaft sleeve brackets, double-ended studs, screws, non-carburized gears, carburized gears and pins, It can be used for manufacturing various variable load and high load important parts such as high pressure boiler water pump shaft (diameter less than 30mm), high pressure cylinder, steel pipe, bolt (operating temperature is less than 420℃, strength is 30MPa), etc.
합금 구조 스틸 표준(GB/T 3077-2015)에 따르면 기존 40CrV의 성분 범위는 다음과 같다: 0.37-0.44wt%의 C; 0.17-0.37wt%의 Si; 0.5-0.8wt%의 Mn; 0.015wt% 이하의 S; 0.025wt% 이하의 P; 0.8-1.1wt%의 Cr; 0.1-0.2wt%의 V; 및 0.015wt 이상의 Al. 스틸 유형의 기계적 특성은 다음과 같다: 항복강도(yield strength, Rel)는 735MPa 이상이고; 인장강도(tensile strength, Rm)는 885MPa 이상이며; 연신율(elongation percentage)은 10% 이상이고; 경도는 241HB 이상이며; 충격인성(impact toughness)은 71J 이상이다.According to the alloy structural steel standard (GB/T 3077-2015), the composition range of the existing 40CrV is as follows: 0.37-0.44 wt% C; 0.17-0.37 wt % Si; 0.5-0.8 wt % Mn; 0.015 wt% or less of S; 0.025 wt% or less of P; 0.8-1.1 wt % Cr; 0.1-0.2 wt% V; and 0.015 wt or more of Al. The mechanical properties of the steel type are as follows: the yield strength (Rel) is greater than 735 MPa; Tensile strength (Rm) is not less than 885 MPa; the elongation percentage is at least 10%; The hardness is 241HB or more; The impact toughness is greater than 71J.
현재 기술의 발달로 스틸의 기계적 물성은 실제 적용 및 제조의 요구사항을 완전히 충족시킬 수 없으며, 이를 바탕으로 실제 적용의 요구 사항을 충족시키기 위해 기계적 물성이 더 높고 충격인성이 더 높으며 비용면에서 더 합리적인 합금 구조용 스틸을 얻을 것으로 예상된다.With the development of current technology, the mechanical properties of steel cannot fully meet the requirements of practical application and manufacturing. It is expected to obtain reasonable alloy structural steel.
본 발명의 하나의 목적은 합금 구조용 스틸을 제공하는 것이다. 합금 구조용 스틸은 미량 합금 원소를 첨가하여 설계되었다. Zr과 Mg를 적당량 첨가하고 총산소의 저함유량을 조절하며 첨가된 미량 합금원소의 특성을 이용하여 합금 구조용 스틸을 더욱 강화하고 인성을 주어 합금 구조용 스틸은 높은 강도를 가지고 저렴한 재료비를 가진다.One object of the present invention is to provide a steel for alloy structure. Alloy structural steel is designed by adding trace alloying elements. By adding appropriate amounts of Zr and Mg, controlling the low content of total oxygen, and using the properties of the added trace alloying elements to further strengthen and toughen the alloy structural steel, the alloy structural steel has high strength and low material cost.
상기 목적을 달성하기 위해, 본 발명은 다음의 화학 원소를 질량 백분율로 포함하는 합금 구조용 스틸을 제공한다:In order to achieve the above object, the present invention provides an alloy structural steel comprising the following chemical elements in mass percentages:
0.35-0.45%의 C, 0.27-0.35%의 Si, 0.6-0.8%의 Mn, 0.015-0.05%의 Al, 0.06-0.1%의 V, 0.2-1.0%의 Zr, 0.001-0.005%의 Mg, 0.025% 이하의 P, 0.015% 이하의 S, 0.005% 이하의 N, 0.001% 이하의 O, 및 나머지의 Fe와 기타 불가피한 불순물.0.35-0.45% C, 0.27-0.35% Si, 0.6-0.8% Mn, 0.015-0.05% Al, 0.06-0.1% V, 0.2-1.0% Zr, 0.001-0.005% Mg, 0.025 % P or less, 0.015% or less S, 0.005% or less N, 0.001% or less O, and the remainder Fe and other unavoidable impurities.
본 발명에 따른 합금 구조용 스틸에 있어서, 각 화학원소의 설계원리는 다음과 같다:In the alloy structural steel according to the present invention, the design principle of each chemical element is as follows:
C: 본 발명에 따른 합금 구조용 스틸에서 C는 주로 탄화물의 석출량 및 석출온도 범위에 영향을 미친다. C의 상대적으로 낮은 질량 백분율을 제어하는 것은 본 발명에 따른 합금 구조용 스틸의 기계적 특성을 개선하는 데 유리하다. 또한, C는 특정 강화 효과가 있지만 C의 질량 비율이 지나치게 높으면 재료의 내식성이 저하될 수 있다. 제련설비의 생산능력 측면에서 재료의 기계적 성질 및 충격인성을 고려하여 본 발명에 따른 합금 구조용 스틸에서 C의 질량 백분율은 0.35~0.45%의 범위 내에서 제어된다.C: In the alloy structural steel according to the present invention, C mainly affects the precipitation amount of carbides and the precipitation temperature range. Controlling the relatively low mass percentage of C is advantageous for improving the mechanical properties of the alloy structural steel according to the present invention. In addition, although C has a certain reinforcing effect, if the mass ratio of C is too high, the corrosion resistance of the material may be deteriorated. In consideration of the mechanical properties and impact toughness of the material in terms of the production capacity of the smelting facility, the mass percentage of C in the alloy structural steel according to the present invention is controlled within the range of 0.35 to 0.45%.
Si: Si는 스틸의 강도를 향상시킬 수 있지만 스틸의 성형성 및 인성에 불리하다. 또한, 제련 과정에서 Si가 잔류하는 경우가 많기 때문에 Si의 함량을 적절하게 선택하는 것이 매우 중요하다. 이를 바탕으로 본 발명에 따른 합금 구조용 스틸에서 Si의 질량 백분율은 0.27~0.35% 범위 내에서 제어된다.Si: Si can improve the strength of steel, but is disadvantageous to the formability and toughness of the steel. In addition, it is very important to appropriately select the content of Si because Si is often left in the smelting process. Based on this, the mass percentage of Si in the alloy structural steel according to the present invention is controlled within the range of 0.27 to 0.35%.
Mn: Mn은 상대적으로 약한 오스테나이트 원소이며 합금 구조에 대한 스틸의 황의 부작용을 억제하고 열가소성을 향상시킬 수 있다. 그러나 Mn의 질량 백분율이 지나치게 높으면 스틸의 내식성을 확보하는데 불리하다. 제련 공정에서 Mn이 잔류하는 경우가 많다는 점을 고려하여, 본 발명의 기술적 해결방안에서 Mn의 질량 백분율은 0.6~0.8% 범위 내에서 제어된다.Mn: Mn is a relatively weak austenitic element and can suppress the adverse effect of sulfur in steel on the alloy structure and improve the thermoplasticity. However, if the mass percentage of Mn is too high, it is disadvantageous in securing the corrosion resistance of the steel. Considering that Mn is often left in the smelting process, the mass percentage of Mn in the technical solution of the present invention is controlled within the range of 0.6 to 0.8%.
Al: 본 발명에 따른 합금 구조용 스틸에서 Al은 합금 구조를 강화시키기 위해 스틸 내의 산소함량을 조절함으로써 전위거동에 주로 영향을 미친다. Al의 총량의 증가는 분명히 용액 온도를 증가시키고 기계적 특성을 향상시킬 수 있지만 가소성 손실을 유발할 수 있다. 또한, Al을 첨가하는 것은 스틸의 연신 변형 성능에 유리하고 스틸의 가공 성능을 향상시키는 데 유리하다. Al 함량이 지나치게 높으면 스틸의 충격인성을 감소시킬 수 있다. 이를 바탕으로 본 발명에 따른 합금 구조용 스틸에서 Al의 질량 백분율은 0.015~0.05%의 범위 내에서 제어된다.Al: In the alloy structural steel according to the present invention, Al mainly affects the dislocation behavior by controlling the oxygen content in the steel to strengthen the alloy structure. Increasing the total amount of Al can obviously increase the solution temperature and improve the mechanical properties, but cause plasticity loss. In addition, the addition of Al is advantageous for the stretch deformation performance of the steel and for improving the processing performance of the steel. If the Al content is too high, the impact toughness of the steel may be reduced. Based on this, the mass percentage of Al in the alloy structural steel according to the present invention is controlled within the range of 0.015 to 0.05%.
V: 본 발명의 기술적 해결방안에서 V는 탄소 및 산소에 대해 매우 강한 친화력을 가지며 상응하는 안정한 화합물을 형성할 수 있다. V는 주로 스틸에서 탄화물 형태로 존재하며, V는 스틸의 조직 및 결정립을 미세화하고 스틸의 강도 및 인성을 저하시키는 주요 효과를 갖는다. V가 고온에서 고용체(solid solution)에 용해되면 ??칭 정도(quenching degree)가 향상된다. 반대로 V가 탄화물의 형태로 존재하면 ??칭 정도가 감소한다. 또한, V는 ??칭된 스틸의 템퍼링 안정성을 향상시키고 2차 경화 효과를 생성할 수 있다. 합금 구조용 스틸의 바나듐은 일반적인 열처리 조건에서 ??칭 정도를 감소시킬 수 있으므로 일반적으로 망간 및 크롬 원소와 결합하여 합금 구조용 스틸에 사용한다. 바나듐은 주로 스틸의 강도 및 항복강도비를 개선하고 결정립을 미세화하며 ??칭 및 템퍼링된 스틸의 과열 민감도를 줄이는 데 사용된다. 이에 기초하여, 본 발명에 따른 합금 구조용 스틸에서 V의 질량 백분율은 0.06~0.1%의 범위 내로 제어된다.V: In the technical solution of the present invention, V has a very strong affinity for carbon and oxygen and can form the corresponding stable compound. V mainly exists in the form of carbide in steel, and V has the main effect of refining the structure and grain of the steel and lowering the strength and toughness of the steel. When V is dissolved in a solid solution at high temperature, the quenching degree is improved. Conversely, when V exists in the form of a carbide, the quenching degree decreases. In addition, V can improve the tempering stability of quenched steel and create a secondary hardening effect. Vanadium in alloy structural steel can reduce the quenching degree under normal heat treatment conditions, so it is generally used in alloy structural steel in combination with manganese and chromium elements. Vanadium is mainly used to improve the strength and yield strength ratio of steel, to refine grains, and to reduce the overheating sensitivity of quenched and tempered steel. Based on this, the mass percentage of V in the alloy structural steel according to the present invention is controlled within the range of 0.06 to 0.1%.
Zr: 본 발명에 따른 합금 구조용 스틸에서 Zr은 강한 탄화물 형성 원소로서 스틸에서의 니오븀, 탄탈륨, 바나듐과 유사한 효과를 갖는다. 소량의 Zr을 첨가하면 결정립의 탈기, 정제 및 미세화 효과를 얻을 수 있으며 이는 스틸의 저온 성능에 유리하고 스탬핑 성능(stamping performance)을 향상시킨다. 또한, 소량의 Zr이 첨가되고, Zr의 일부가 스틸에 용체화(solutionized)되어 적절한 양의 ZrC 및 ZrN을 형성하여 결정립 미세화 및 스탬핑 성능 향상을 용이하게 한다. 이를 바탕으로 본 발명에 따른 합금 구조용 스틸에서 Zr의 질량 백분율은 0.2~1.0% 범위 내로 제어된다.Zr: In the alloy structural steel according to the present invention, Zr is a strong carbide-forming element and has similar effects to niobium, tantalum and vanadium in steel. When a small amount of Zr is added, the effect of degassing, refining and refining the grains can be obtained, which is advantageous for the low-temperature performance of the steel and improves the stamping performance. In addition, a small amount of Zr is added, and a part of Zr is solutionized in the steel to form appropriate amounts of ZrC and ZrN, thereby facilitating grain refinement and stamping performance improvement. Based on this, the mass percentage of Zr in the alloy structural steel according to the present invention is controlled within the range of 0.2 to 1.0%.
Mg: Mg는 매우 활성이 큰 금속 원소이며 O, N 및 S에 대한 친화력이 매우 강하다. 따라서 Mg는 철강 제련에서 우수한 탈산 및 탈황제이며 동시에 주철에 대한 우수한 구상화제(nodulizing agent)이기도 하다. 그러나 Mg는 주철에 용해하기 매우 어렵고, MgS, MgO, Mg3N2, Mg2Si의 화합물 상태로 존재한다. 또한, Mg 및 C는 MgC2 및 Mg2C3와 같은 일련의 화합물을 형성할 수도 있다. 이에 기초하여, 본 발명에 따른 합금 구조용 스틸에서 Mg의 질량 백분율은 0.001~0.005% 범위 내로 제어된다.Mg: Mg is a very active metal element and has a very strong affinity for O, N and S. Therefore, Mg is an excellent deoxidizing and desulfurizing agent in steel smelting, and at the same time an excellent nodulizing agent for cast iron. However, Mg is very difficult to dissolve in cast iron, and exists as a compound of MgS, MgO, Mg 3 N 2 , and Mg 2 Si. Mg and C may also form a series of compounds such as MgC 2 and Mg 2 C 3 . Based on this, the mass percentage of Mg in the alloy structural steel according to the present invention is controlled within the range of 0.001 to 0.005%.
P 및 S: P와 S는 모두 본 발명의 합금 구조용 스틸의 기계적 성질 및 기계가공 성능에 심각한 영향을 미칠 수 있으며 P와 S의 질량 백분율은 엄격하게 제어되어야 하므로 P는 0.025% 이하, S는 0.015% 이하이다.P and S: Both P and S can seriously affect the mechanical properties and machining performance of the alloy structural steel of the present invention, and the mass percentage of P and S must be strictly controlled, so that P is 0.025% or less, S is 0.015 % or less.
N: N은 오스테나이트를 안정화시키는 원소이다. N의 상대적으로 낮은 질량 백분율을 제어하는 것은 본 발명에 따른 합금 구조용 스틸의 충격인성을 개선하는 데 유리하다. 또한, 질소의 상대적으로 높은 질량 백분율은 스틸의 인성 및 가단성(malleability)을 저하시키는 원인이 될 수 있으며, 열간 가공성(hot workability)을 저하시킬 수도 있다. 이에 기초하여, 본 발명에 따른 합금 구조용 스틸은 N의 질량 백분율을 0.005% 이하의 범위 내로 제어한다.N: N is an element that stabilizes austenite. Controlling the relatively low mass percentage of N is advantageous for improving the impact toughness of the alloy structural steel according to the present invention. In addition, the relatively high mass percentage of nitrogen may cause deterioration of toughness and malleability of the steel, and may deteriorate hot workability. Based on this, the alloy structural steel according to the present invention controls the mass percentage of N within the range of 0.005% or less.
O: 본 발명에 따른 합금 구조용 스틸에서, O는 주로 산화물 개재물의 형태로 존재하며, 높은 총산소 함량은 높은 개재물 함량을 나타낸다. 총 산소 함량의 감소는 재료의 종합적인 성능을 향상시키는 데 도움이 된다. 재료의 우수한 기계적 물성 및 내식성을 확보하기 위해, 본 발명의 기술적 해결방안에서 O의 질량 백분율은 0.001% 이하의 범위 내로 제어된다.O: In the alloy structural steel according to the present invention, O is mainly present in the form of oxide inclusions, and a high total oxygen content indicates a high inclusion content. Reduction of the total oxygen content helps to improve the overall performance of the material. In order to ensure excellent mechanical properties and corrosion resistance of the material, in the technical solution of the present invention, the mass percentage of O is controlled within the range of 0.001% or less.
또한, 본 발명에 따른 합금 구조용 스틸은 Ce, Hf, La, Re, Sc 및 Y로 구성된 군에서 선택된 하나 이상의 화학 원소를 추가로 포함하고, 상기 원소의 총 첨가량이 1% 이하이다.In addition, the alloy structural steel according to the present invention further includes one or more chemical elements selected from the group consisting of Ce, Hf, La, Re, Sc and Y, and the total amount of the elements added is 1% or less.
본 발명의 기술적 해결방안에 있어서, 바람직하게는 상기 희토류 원소를 소량 첨가하여 강 중의 산소 및 황 원소와 결합하여 희토류 산화물 및 황화물을 형성함으로써 용강을 정제하고 개재물의 크기를 줄일 수 있다. 또한, 형성된 희토류 산화물 및 황화물은 초기 응고된 결정립을 미세화하기 위한 응고 과정에서 핵형성 입자로 사용될 수 있으며, 또한 스틸의 성능 향상에 일정한 도움이 된다.In the technical solution of the present invention, preferably, the rare earth element is added in a small amount to combine with oxygen and sulfur elements in the steel to form rare earth oxides and sulfides, so that the molten steel can be refined and the size of inclusions can be reduced. In addition, the formed rare earth oxides and sulfides may be used as nucleating particles in the solidification process for refining the initially solidified grains, and also help to improve the performance of steel.
또한, 본 발명에 따른 합금 구조용 스틸에 있어서, 원소의 질량 함량이 하기 중 적어도 하나를 만족한다:Further, in the alloy structural steel according to the present invention, the mass content of the element satisfies at least one of the following:
0.08-0.1%의 V;V of 0.08-0.1%;
0.3-0.7% Zr; 및0.3-0.7% Zr; and
0.001-0.003%의 Mg.0.001-0.003% Mg.
또한, 본 발명에 따른 합금 구조용 스틸에 있어서, 상기 원소의 함유량의 질량비는 하기 중 적어도 하나를 더 만족한다:Further, in the alloy structural steel according to the present invention, the mass ratio of the content of the elements further satisfies at least one of the following:
Zr/N=40-200;Zr/N=40-200;
Zr/V=2-16.7; 및Zr/V=2-16.7; and
Zr/C=0.4-2.8.Zr/C=0.4-2.8.
용액에서 Zr, N, V 및 C의 질량 백분율은 ZrC 및 ZrN의 형성량 조절이 용이하도록 제어되며, ZrC 및 ZrN의 형성은 결정립을 미세화하고 스틸의 기계적 특성 및 스탬핑 저항성을 개선하는 효과를 가질 수 있으며, 한편, 스틸에서 N의 일부를 응고시키고 용체화된 N의 질량 백분율을 줄이는 효과도 가질 수 있다.The mass percentages of Zr, N, V and C in the solution are controlled to facilitate control of the amount of ZrC and ZrN formation, and the formation of ZrC and ZrN can have the effect of refining grains and improving the mechanical properties and stamping resistance of steel. On the other hand, it may also have the effect of solidifying a part of N in the steel and reducing the mass percentage of solutionized N.
또한, 본 발명에 따른 합금 구조용 스틸에 있어서, 상기 원소의 함유량의 질량비는 하기 중 적어도 하나를 더 만족한다:Further, in the alloy structural steel according to the present invention, the mass ratio of the content of the elements further satisfies at least one of the following:
Mg/O=0.5~3; 및Mg/O=0.5~3; and
Mg/S=0.6~5.0.Mg/S=0.6~5.0.
해결방안에서 Mg 및 O 및 S의 질량 백분율에 대한 제어는 냉각 응고 과정에서 합금에서 형성된 MgO 및 MgS의 양을 촉진할 수 있고, MgS 및 MgO의 형성은 한 측면에서 결정 입자를 더욱 미세화하고 오스테나이트 결정 입자를 안정화시키는 효과를 가질 수 있고, 다른 측면에서 합금에서 O 및 S의 위험을 결정 경계까지 감소시켜 본 발명의 합금 구조용 스틸의 충격인성을 개선할 수 있다.Control of the mass percentage of Mg and O and S in the solution can promote the amount of MgO and MgS formed in the alloy during the cooling solidification process, and the formation of MgS and MgO further refines the crystal grains and austenite on one side. It may have an effect of stabilizing crystal grains, and in another aspect, it is possible to improve the impact toughness of the alloy structural steel of the present invention by reducing the risk of O and S in the alloy to the crystal boundary.
또한, 본 발명에 따른 합금 구조용 스틸에서 그 미세조직(microstructure)이 페라이트(ferrite) + 펄라이트(pearlite)이고, 합금 구조용 스틸은 ZrC, ZrN, MgO 및 MgS 입자를 포함한다.In addition, in the alloy structural steel according to the present invention, the microstructure is ferrite + pearlite, and the alloy structural steel includes ZrC, ZrN, MgO and MgS particles.
ZrC, ZrN, MgO, MgS 입자는 ZrC, ZrN, MgO, MgS가 합금 구조용 스틸에 미세한 입자 형태로 존재함을 의미한다. 입자는 연속 주조 및 냉각 응고 공정 및 열간 압연 공정에서 오스테나이트 결정 입자의 크기를 더욱 미세화하고 안정화하여 블랭크 또는 완제품 표면에 결함이 형성되는 것을 방지하고 한편, 제품의 기계적 특성도 향상시킨다.ZrC, ZrN, MgO, and MgS grains mean that ZrC, ZrN, MgO, and MgS exist in the form of fine grains in the alloy structural steel. The grains further refine and stabilize the size of the austenite crystal grains in the continuous casting and cold solidification process and hot rolling process to prevent defects from forming on the surface of the blank or finished product, while also improving the mechanical properties of the product.
또한, 본 발명에 따른 합금 구조용 스틸은 ZrC와 ZrN 입자의 개수의 합이 3-15 pieces/㎟이다.In addition, in the alloy structural steel according to the present invention, the sum of the number of ZrC and ZrN particles is 3-15 pieces/mm 2 .
이 해결방안에서, 본 발명자는 ZrC 및 ZrN 입자의 수의 합을 3-15 pieces/mm2 범위 내로 조절하는 것이 결정립을 미세화하고 스틸의 기계적 특성 및 스탬핑 성능을 개선하고 스틸에서 N의 일부를 응고시키고 용체화된 N의 질량 백분율을 감소시키는 것에 더 나은 효과를 갖는다는 것을 발견하였다.In this solution, the present inventors found that adjusting the sum of the number of ZrC and ZrN particles within the range of 3-15 pieces/mm 2 refines the grains, improves the mechanical properties and stamping performance of the steel, and solidifies a part of the N in the steel and has a better effect on reducing the mass percentage of solutionized N.
또한, 본 발명에 따른 합금 구조용 스틸에서, MgO 및 MgS 입자의 수의 합은 5-20 pieces/㎟이다.Further, in the alloy structural steel according to the present invention, the sum of the number of MgO and MgS particles is 5-20 pieces/mm 2 .
상기 용액에서, 본 발명자는 MgO 및 MgS 입자의 수의 합을 5-20 pieces/㎟의 범위 내로 제어하는 것이 결정립을 더욱 미세화시키고, 오스테나이트 결정립을 안정화시키며, 본 발명의 합금 구조용 스틸의 충격인성을 개선하기 위해 결정 경계에 대한 합금 내의 O 및 S의 위험을 감소시키는 데에 더 나은 효과를 가져온다는 것을 발견하였다.In the solution, the present inventors found that controlling the sum of the number of MgO and MgS particles within the range of 5-20 pieces/mm2 further refines the grains, stabilizes the austenite grains, and improves the impact toughness of the alloy structural steel of the present invention It was found that it has a better effect on reducing the risk of O and S in the alloy to the crystal boundary to improve the
또한, 본 발명에 따른 합금 구조용 스틸은 ZrC, ZrN, MgO, MgS 입자의 입경이 0.2~7㎛이다.In addition, in the alloy structural steel according to the present invention, the particle diameter of ZrC, ZrN, MgO, and MgS particles is 0.2 to 7 μm.
또한, 본 발명에 따른 합금 구조용 스틸은 755 MPa 이상의 항복강도(yield strength), 900 MPa 이상의 인장강도(tensile strength), 12% 이상의 연신율(elongation percentage) 및 100J 이상의 충격인성(impact toughness)을 가진다.In addition, the alloy structural steel according to the present invention has a yield strength of 755 MPa or more, a tensile strength of 900 MPa or more, an elongation percentage of 12% or more, and an impact toughness of 100J or more.
이에 따라, 본 발명의 다른 목적은 합금 구조용 스틸의 제조방법을 제공하는 것이다. 제조방법에 의해 기계적 물성이 더 높고 충격인성이 우수하며 비용면에서 더 합리적인 합금 구조용 스틸을 얻을 수 있다.Accordingly, another object of the present invention is to provide a method of manufacturing an alloy structural steel. By the manufacturing method, it is possible to obtain alloy structural steel with higher mechanical properties, excellent impact toughness, and more reasonable cost.
상기 목적을 달성하기 위하여, 본 발명은 다음 단계를 포함하는 합금 구조용 스틸의 제조방법을 제공한다:In order to achieve the above object, the present invention provides a method for manufacturing an alloy structural steel comprising the following steps:
(1) 제련(smelting), 정련(refining) 및 주조(casting) 단계;(1) smelting, refining and casting steps;
(2) 블루밍(blooming) 및 코깅(cogging) 단계;(2) blooming (blooming) and cogging (cogging) step;
(3) 제품을 형성하기 위한 2차 열간압연(hot rolling) 단계; 및(3) a secondary hot rolling step to form a product; and
(4) ??칭(quenching) 및 템퍼링(tempering)을 포함하는 열처리 단계.(4) a heat treatment step including quenching and tempering.
본 발명이 제공하는 제조방법에서, 전기로 제련 및 LF 및 VD (또는 RH) 정련은 단계 (1)에서 채택될 수 있고, VD (또는 RH) 정련의 최종 단계에서, 소량의 페로지르코늄과 소량의 마그네슘 알루미늄 합금을 순차적으로 첨가할 수 있으며, 스틸 중의 각 화학 원소의 질량 백분율이 본 발명에서 정의된 범위를 만족하고 아르곤 유량이 충족된 후 아르곤 취입과 함께 부드러운 교반을 수행하고, 아르곤 유량이 5-8L/min의 범위 내에서 제어된다.In the manufacturing method provided by the present invention, electric furnace smelting and LF and VD (or RH) refining may be adopted in step (1), and in the final step of VD (or RH) refining, a small amount of ferrozirconium and a small amount of Magnesium aluminum alloy may be added sequentially, and the mass percentage of each chemical element in the steel meets the range defined in the present invention, and after the argon flow rate is met, gentle stirring is performed with argon blowing, and the argon flow rate is 5- Controlled within the range of 8L/min.
일부 바람직한 실시예에서, 단계 (1)에서 주조는 블룸 연속 주조(bloom continuous casting)를 채택할 수 있으며 주조 속도(casting speed)는 0.45-0.65m/min의 범위 내에서 제어되며; 몰드 플럭스(mould fluxes)가 채택되고, 몰드 전자기 교반이 채택되며, 전류는 500A, 주파수는 2.5-3.5Hz이고, 연속 주조 블룸의 등축 입자 비율은 20% 이상이다.In some preferred embodiments, the casting in step (1) may adopt bloom continuous casting and the casting speed is controlled within the range of 0.45-0.65 m/min; The mold fluxes are adopted, the mold electromagnetic stirring is adopted, the current is 500A, the frequency is 2.5-3.5Hz, and the equiaxed particle proportion of the continuous casting bloom is more than 20%.
일부 바람직한 실시예에서, 단계 (2)에서 블랭크는 블루밍 및 코깅 전에 전처리될 수 있고, 예를 들어 표면 마무리 및 연마를 거쳐 가시적인 표면 결함을 제거하여 높은 표면 품질을 보장할 수 있다.In some preferred embodiments, the blank in step (2) may be pretreated prior to blooming and cogging, for example, surface finishing and polishing to remove visible surface defects to ensure high surface quality.
또한, 본 발명에 의해 제공되는 제조방법에서, 단계 (2) 및 (3)에서, 가열 온도는 블루밍 및 코깅 동안 1,150-1,250℃이고; 제품을 형성하기 위한 2차 열간압연시 가열온도는 1,150~1,250℃이다.Further, in the manufacturing method provided by the present invention, in steps (2) and (3), the heating temperature is 1,150-1,250° C. during blooming and cogging; The heating temperature during secondary hot rolling to form a product is 1,150~1,250℃.
또한, 본 발명이 제공하는 제조방법에 있어서, 상기 (4) 단계에서, ??칭 시 가열 온도는 855-890℃ 범위 내로 조절되고, ??칭 시 냉각 속도는 50-90℃/s 범위 내로 조절되며; 템퍼링 시 가열 온도는 645-670℃ 범위 내로 조절되고, 템퍼링 시 냉각 속도는 50-90℃/s로 조절된다.In addition, in the manufacturing method provided by the present invention, in the step (4), the heating temperature during quenching is adjusted within the range of 855-890 ℃, and the cooling rate during quenching is within the range of 50-90 ℃/s. regulated; The heating temperature during tempering is controlled within the range of 645-670°C, and the cooling rate during tempering is controlled at 50-90°C/s.
상기 (4) 단계에서 ??칭에 사용되는 냉각제는 광유일 수 있고, 템퍼링에 사용되는 냉각제는 광유 또는 물일 수 있음에 유의해야 한다.It should be noted that the coolant used for quenching in step (4) may be mineral oil, and the coolant used for tempering may be mineral oil or water.
본 발명에 따르면, 종래 기술에 비해 합금 구조용 스틸 및 그 제조방법은 다음과 같은 이점 및 유익한 효과를 갖는다:According to the present invention, compared with the prior art, the alloy structural steel and the method for producing the same have the following advantages and beneficial effects:
본 발명에 따르면, 합금 구조용 스틸은 미량 합금 원소를 첨가하고; Zr과 Mg를 적당량 첨가하고 총산소의 저함유량을 조절하며 첨가된 미량 합금원소의 특성을 이용함으로써 디자인되고, 합금 구조용 스틸을 더욱 강화시키고 인성을 주어 합금 구조용 스틸은 고강도를 가지고 재료 비용은 저렴하다.According to the present invention, the alloy structural steel is added with trace alloying elements; It is designed by adding an appropriate amount of Zr and Mg, controlling the low content of total oxygen, and using the properties of the added trace alloying elements. .
또한, 본 발명에서 제공하는 제조방법에 의해 기계적 물성이 초고강도이고 충격인성이 우수하며 제조 비용이 저렴한 합금 구조용 스틸을 얻을 수 있다.In addition, by the manufacturing method provided in the present invention, it is possible to obtain an alloy structural steel having excellent mechanical properties, excellent impact toughness, and low manufacturing cost.
본 발명에 의해 제공되는 합금 구조용 스틸 및 그 제조방법은 구체적인 실시예와 함께 이하에서 더 설명 및 예시될 것이지만, 설명 및 예시는 본 발명의 기술적 해결방안에 대한 부적절한 제한을 구성하지 않는다.The alloy structural steel provided by the present invention and its manufacturing method will be further described and illustrated below together with specific embodiments, but the description and illustration do not constitute an improper limitation to the technical solution of the present invention.
실시예 1-6 및 비교예 1-3Examples 1-6 and Comparative Examples 1-3
실시예 1-6에 의해 제공되는 합금 구조용 스틸은 다음 단계를 채택하여 제조된다:The alloy structural steel provided by Examples 1-6 was prepared by employing the following steps:
(1) 전기로에 의한 제련, LF 정련 및 주조.(1) Smelting by electric furnace, LF refining and casting.
(2) 블루밍 및 코깅: 가열 온도는 1,150-1,250℃이다.(2) Blooming and cogging: The heating temperature is 1,150-1,250°C.
(3) 2차 열간압연하여 제품 성형: 가열 온도는 1,150-1,250℃이다.(3) Secondary hot rolling to form a product: The heating temperature is 1,150-1,250°C.
(4) ??칭 및 템퍼링을 포함하는 열처리로서, ??칭 시 가열 온도는 855-890℃ 범위 내로 조절되고, ??칭 시 냉각 속도는 50-90℃/s 범위 내로 조절되며, 냉각제로 광유를 채택한다; 템퍼링 시 가열 온도는 645-670℃ 범위 내로 조절되고, 템퍼링 시 냉각 속도는 50-90℃/s 범위로 조절되며, 냉각제는 광유 또는 물을 사용한다.(4) as a heat treatment including quenching and tempering, the heating temperature during quenching is controlled within the range of 855-890 ℃, the cooling rate during quenching is controlled within the range of 50-90 ℃ / s, with a coolant Adopt mineral oil; The heating temperature during tempering is controlled within the range of 645-670°C, the cooling rate during tempering is controlled within the range of 50-90°C/s, and the coolant is mineral oil or water.
일부 다른 실시예에서 정련은 RH 정련을 채택할 수도 있고 VD (또는 RH) 정련의 최종 단계에서 소량의 페로지르코늄-철 및 소량의 마그네슘 알루미늄 합금을 순차적으로 첨가할 수 있고, 아르곤 취입에 의한 부드러운 교반은 스틸의 각 화학 원소의 질량 백분율이 본 발명에서 정의된 범위를 만족한 후 수행되며, 아르곤 유량은 5-8L/min의 범위 내에서 제어된다는 것을 유의해야 한다.In some other embodiments, the refining may adopt RH refining, and in the final stage of VD (or RH) refining, a small amount of ferrozirconium-iron and a small amount of magnesium aluminum alloy may be sequentially added, and gentle stirring by argon blowing It should be noted that the silver steel is performed after the mass percentage of each chemical element satisfies the range defined in the present invention, and the argon flow rate is controlled within the range of 5-8 L/min.
일부 바람직한 실시예에서, 단계 (1)에서 주조는 블룸 연속 주조를 채택할 수 있으며 주조 속도는 0.45-0.65m/min의 범위 내에서 제어되며; 몰드 플럭스가 채택되고, 몰드 전자기 교반이 채택되며, 전류는 500A, 주파수는 2.5-3.5Hz이고, 연속 주조 블룸의 등축 입자 비율은 20% 이상이다.In some preferred embodiments, the casting in step (1) may adopt bloom continuous casting, and the casting speed is controlled within the range of 0.45-0.65 m/min; The mold flux is adopted, the mold electromagnetic stirring is adopted, the current is 500A, the frequency is 2.5-3.5Hz, and the equiaxed particle proportion of the continuous casting bloom is more than 20%.
일부 바람직한 실시예에서, 단계 (2)에서 블랭크는 블루밍 및 코깅 전에 전처리될 수 있고, 예를 들어 표면 마무리 및 연마를 거쳐 가시적인 표면 결함을 제거하여 높은 표면 품질을 보장할 수 있다.In some preferred embodiments, the blank in step (2) may be pretreated prior to blooming and cogging, for example, surface finishing and polishing to remove visible surface defects to ensure high surface quality.
비교예 1-3은 선행기술의 성분 및 제조공정을 적용하여 얻어진 것이다.Comparative Examples 1-3 were obtained by applying the components and manufacturing process of the prior art.
실시예 1~6의 합금 구조용 스틸과 비교예 1~3의 종래 합금 구조용 스틸의 각 화학 원소의 질량 백분율을 표 1에 나타낸다.Table 1 shows the mass percentage of each chemical element of the alloy structural steels of Examples 1 to 6 and the conventional alloy structural steels of Comparative Examples 1 to 3.
[표 1] (wt%, Fe 및 기타 불가피한 불순물의 잔량)[Table 1] (wt%, remaining amount of Fe and other unavoidable impurities)
표 2는 실시예 1~6에서 얻은 합금 구조용 스틸의 미세조직 및 비교예 1-3에서 얻은 합금 구조용 종래 스틸의 미세조직의 조건을 나열한 것이다.Table 2 lists the conditions of the microstructure of the alloy structural steel obtained in Examples 1 to 6 and the microstructure of the conventional steel for alloy structure obtained in Comparative Examples 1-3.
[표 2][Table 2]
표 3은 실시예 1~6의 합금 구조용 스틸 및 비교예 1-3의 합금 구조용 종래 스틸의 특정 공정 파라미터를 나열한 것이다.Table 3 lists specific process parameters of the alloy structural steels of Examples 1 to 6 and the conventional steels for alloy structural use of Comparative Examples 1-3.
[표 3][Table 3]
본 발명의 실시효과를 검증함과 동시에, 선행기술인 실시예 1~6의 합금 구조용 스틸 및 비교예 1~3의 종래 합금 구조용 스틸에 대하여 본 발명의 우수한 효과를 입증하기 위하여 기계적 테스트를 거친다. 테스트를 위해 25mm 두께의 스틸이 채택되었다.At the same time verifying the effect of the present invention, mechanical tests are performed to prove the excellent effect of the present invention on the alloy structural steel of Examples 1 to 6 and the conventional alloy structural steel of Comparative Examples 1 to 3, which are prior art. 25mm thick steel was adopted for testing.
본 발명에 따르면 인장시험(항복강도 Rel, 인장강도 Rm 및 연신율에 대한 시험)은 zwick/roell Z330 인장시험기를 사용하여 시험을 수행하고 시험기준은 국가표준 GB/T 228.1-2010를 채택하는데, 여기서 항복강도 Rel, 인장 강도 Rm 및 연신율에 대한 시험은 이 표준의 3.10.1, 3.10.2 및 3.6.1에 정의된 표준에 따라 각각 수행된다.According to the present invention, the tensile test (test for yield strength R el , tensile strength R m and elongation) is performed using a zwick/roell Z330 tensile testing machine, and the test standard adopts the national standard GB/T 228.1-2010. , where the tests for yield strength R el , tensile strength R m and elongation are performed according to the standards defined in 3.10.1, 3.10.2 and 3.6.1 of this standard, respectively.
충격인성은 Zwick/Roell PSW 750 충격 시험기에 의해 시험되고, 시험 표준은 국가 표준 GB/T 229-2007을 채택하고 충격인성의 값은 샤르피 충격 시험에서 합금 구조용 스틸에 의해 흡수되는 에너지를 시험함으로써 얻어진다.Impact toughness is tested by Zwick/Roell PSW 750 impact testing machine, the test standard adopts national standard GB/T 229-2007, and the value of impact toughness is obtained by testing the energy absorbed by alloy structural steel in Charpy impact test lose
ZrC 및 ZrN 입자의 개수, MgO 및 MgS 입자의 개수, ZrC, ZrN, MgO 및 MgS 입자의 입자 직경에 대한 통계 및 시험 방법은 Oxford 에너지 분산 분광법 oxford X-max 20과 일치하는 주사 전자 현미경(SEM)으로 수행하고, 여기서, 주사 전자 현미경의 모델은 Zeiss scanning electron microscope EVO 18이고 테스트 표준은 표준 GB/T30834-2014를 채택한다.Statistical and test methods for the number of ZrC and ZrN particles, the number of MgO and MgS particles, and the particle diameters of ZrC, ZrN, MgO and MgS particles are by scanning electron microscopy (SEM) consistent with Oxford energy dispersive spectroscopy oxford X-max 20 , where the model of the scanning electron microscope is Zeiss scanning electron microscope EVO 18 and the test standard adopts the standard GB/T30834-2014.
실시예 및 비교예의 시험 결과를 표 4에 나타내었다.Table 4 shows the test results of Examples and Comparative Examples.
[표 4][Table 4]
표 2 및 표 4와 함께 본 발명의 실시예에 따른 합금 구조용 스틸에 따르면 미세조직은 페라이트 + 펄라이트이고, 스틸은 ZrC, ZrN, MgO 및 MgS 입자의 결정립을 포함하고, 이들 입자는 오스테나이트 결정립을 미세화 및 안정화시키는 효과가 있으며, 재료의 기계적 물성을 향상시키는 데 유리하므로, 종래 기술의 비교예 1-3의 합금 구조용 스틸에 비해, 본 발명의 실시예의 합금 구조는 더 나은 기계적 특성을 나타내며, 실시예의 합금 구조용 스틸은 항복강도가 755MPa 이상, 인장강도가 900MPa 이상, 연신율이 12% 이상이고 충격인성은 100J 이상이다.According to the alloy structural steel according to an embodiment of the present invention together with Tables 2 and 4, the microstructure is ferrite + pearlite, and the steel includes grains of ZrC, ZrN, MgO and MgS grains, and these grains form austenite grains. Since it has an effect of refining and stabilizing and is advantageous for improving the mechanical properties of the material, compared to the alloy structural steel of Comparative Examples 1-3 of the prior art, the alloy structure of the embodiment of the present invention exhibits better mechanical properties, Example alloy structural steel has a yield strength of 755 MPa or more, a tensile strength of 900 MPa or more, an elongation of 12% or more, and an impact toughness of 100 J or more.
요약하면, 본 발명에 따르면, 합금 구조용 스틸은 미량 합금 원소를 첨가하고 Zr과 Mg를 적당량 첨가하며 총산소의 저함유량을 조절하고 첨가된 미량 합금원소의 특성을 이용하여 합금 구조용 스틸를 더욱 강화시키고 인성을 줌으로써 디자인되어 합금 구조용 스틸이 고강도를 가지고 재료비가 저렴해진다.In summary, according to the present invention, the alloy structural steel is made by adding trace alloying elements, adding appropriate amounts of Zr and Mg, controlling the low content of total oxygen, and using the properties of the added trace alloying elements to further strengthen and toughen the alloy structural steel. It is designed by giving the alloy structural steel with high strength and the material cost is low.
또한, 본 발명에서 제공하는 제조방법에 의해 기계적 물성이 초고강도이고 충격인성이 우수하며 제조 비용이 저렴한 합금 구조용 스틸을 얻을 수 있다.In addition, by the manufacturing method provided in the present invention, it is possible to obtain an alloy structural steel having excellent mechanical properties, excellent impact toughness, and low manufacturing cost.
본 발명의 보호 범위에 있는 선행 기술 부분은 출원명세서에 의해 제공된 실시예에 제한되지 않으며, 선행 특허 문헌, 선행 간행물, 선행 공개 사용 등을 포함하지만 이에 국한되지 않는, 본 발명의 해결방안과 충돌되지 않는 모든 선행 기술은 본 발명의 보호 범위에 속한다.The prior art part within the protection scope of the present invention is not limited to the embodiments provided by the application specification, and does not conflict with the solutions of the present invention, including but not limited to prior patent documents, prior publications, prior publication use, etc. All prior art that does not fall within the protection scope of the present invention.
또한, 본 발명의 모든 기술적 특징의 조합 형태는 본 발명의 특허청구범위에 기재된 조합 형태 또는 특정 실시형태에 기재된 조합 형태에 한정되지 않으며, 본 발명에 기재된 모든 기술적 특징은 자유롭게 조합될 수 있거나 또는 서로 충돌하지 않는 한 모든 형태로 통합된다.In addition, the combination form of all technical features of the present invention is not limited to the combination form described in the claims of the present invention or the combination form described in specific embodiments, and all technical features described in the present invention can be freely combined or each other It is integrated in all its forms as long as they do not conflict.
또한, 위에 열거된 실시예들은 단지 본 발명의 특정한 실시예들임을 주목해야 한다. 본 발명은 상기 실시예에 한정되지 않고, 이와 유사한 변경 또는 수정이 본 발명에 의해 개시된 내용으로부터 직접 얻어질 수 있거나, 또는 당해 기술분야의 통상의 지식을 가진 자가 매우 쉽게 생각할 수 있음은 자명하며, 이는 모두 본 발명의 보호 범위 내에서 속한다.It should also be noted that the above-listed embodiments are merely specific embodiments of the present invention. It is apparent that the present invention is not limited to the above embodiments, and similar changes or modifications can be obtained directly from the content disclosed by the present invention, or can be readily conceived by those of ordinary skill in the art, All of these fall within the protection scope of the present invention.
Claims (13)
0.35-0.45%의 C, 0.27-0.35%의 Si, 0.6-0.8%의 Mn, 0.015-0.05%의 Al, 0.06-0.1%의 V, 0.2-1.0%의 Zr, 0.001-0.005%의 Mg, 0.025% 이하의 P, 0.015% 이하의 S, 0.005% 이하의 N, 0.001% 이하의 O, 및 나머지의 Fe와 기타 불가피한 불순물.
Alloy structural steel containing the following chemical elements in mass percentages:
0.35-0.45% C, 0.27-0.35% Si, 0.6-0.8% Mn, 0.015-0.05% Al, 0.06-0.1% V, 0.2-1.0% Zr, 0.001-0.005% Mg, 0.025 % P or less, 0.015% or less S, 0.005% or less N, 0.001% or less O, and the remainder Fe and other unavoidable impurities.
The steel for alloy structure according to claim 1, further comprising one or more chemical elements selected from the group consisting of Ce, Hf, La, Re, Sc and Y, and the total amount of the elements added is 1% or less.
0.08-0.1%의 V;
0.3-0.7% Zr; 및
0.001-0.003%의 Mg.
The steel for alloy structure according to claim 1, wherein the mass percentage content of the chemical element satisfies at least one of the following:
V of 0.08-0.1%;
0.3-0.7% Zr; and
0.001-0.003% Mg.
Zr/N=40~200;
Zr/V=2~16.7; 및
Zr/C=0.4~2.8.
The steel for alloy structure according to claim 1, wherein the mass ratio of the content of the chemical element further satisfies at least one of the following.
Zr/N=40~200;
Zr/V=2~16.7; and
Zr/C=0.4~2.8.
Mg/O=0.5~3; 및
Mg/S=0.6~5.0.
The steel for alloy structure according to claim 1, wherein the mass ratio of the content of the chemical element further satisfies at least one of the following:
Mg/O=0.5~3; and
Mg/S=0.6~5.0.
The alloy structural steel according to claim 1, wherein the microstructure of the alloy structural steel is ferrite + pearlite, and the alloy structural steel includes ZrC, ZrN, MgO and MgS particles.
The alloy structural steel according to claim 6, wherein the sum of the numbers of the ZrC and ZrN particles is 3-15 pieces/mm 2 .
[Claim 7] The steel for alloy structure according to claim 6, wherein the sum of the number of MgO and MgS particles is 5-20 pieces/mm2.
[Claim 7] The steel for alloy structure according to claim 6, wherein the ZrC, ZrN, MgO and MgS particles have a diameter of 0.2 to 7 μm.
10. The method of any one of claims 1 to 9, wherein a yield strength of at least 755 MPa, a tensile strength of at least 900 MPa, an elongation percentage of at least 12% and an impact toughness of at least 100 J ), characterized in that it has an alloy structural steel.
(1) 제련(smelting), 정련(refining) 및 주조(casting) 단계;
(2) 블루밍(blooming) 및 코깅(cogging) 단계;
(3) 제품을 형성하기 위한 2차 열간압연(hot rolling) 단계; 및
(4) ??칭(quenching) 및 템퍼링(tempering)을 포함하는 열처리 단계.
A method for producing an alloy structural steel according to any one of claims 1 to 10, comprising the steps of:
(1) smelting, refining and casting steps;
(2) blooming (blooming) and cogging (cogging) steps;
(3) a secondary hot rolling step to form a product; and
(4) a heat treatment step including quenching and tempering.
According to claim 11, wherein the heating temperature in the blooming and cogging step is 1,150 ~ 1,250 ℃; The heating temperature in the secondary hot rolling step for forming the product is a manufacturing method, characterized in that 1,150 ~ 1,250 ℃.
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| CN201910920640.7 | 2019-09-27 | ||
| CN201910920640.7A CN112575242B (en) | 2019-09-27 | 2019-09-27 | Steel for alloy structure and manufacturing method thereof |
| PCT/CN2020/118043 WO2021057954A1 (en) | 2019-09-27 | 2020-09-27 | Steel for alloy structure and manufacturing method therefor |
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| KR20220054862A true KR20220054862A (en) | 2022-05-03 |
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