KR101253834B1 - Method for Manufacturing Galvannealed Steel Sheet with Low Permeability - Google Patents
Method for Manufacturing Galvannealed Steel Sheet with Low Permeability Download PDFInfo
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- KR101253834B1 KR101253834B1 KR1020100104200A KR20100104200A KR101253834B1 KR 101253834 B1 KR101253834 B1 KR 101253834B1 KR 1020100104200 A KR1020100104200 A KR 1020100104200A KR 20100104200 A KR20100104200 A KR 20100104200A KR 101253834 B1 KR101253834 B1 KR 101253834B1
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- steel sheet
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- dip galvanized
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- 238000000034 method Methods 0.000 title claims abstract description 90
- 230000035699 permeability Effects 0.000 title claims abstract description 65
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 24
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 135
- 239000010959 steel Substances 0.000 claims abstract description 135
- 238000010438 heat treatment Methods 0.000 claims abstract description 134
- 230000006698 induction Effects 0.000 claims abstract description 102
- 229910001335 Galvanized steel Inorganic materials 0.000 claims abstract description 45
- 239000008397 galvanized steel Substances 0.000 claims abstract description 45
- 238000005275 alloying Methods 0.000 claims abstract description 31
- 238000005246 galvanizing Methods 0.000 claims abstract description 26
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 20
- 238000007747 plating Methods 0.000 claims description 18
- 239000011572 manganese Substances 0.000 claims description 13
- 229910001566 austenite Inorganic materials 0.000 claims description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 7
- 229910052748 manganese Inorganic materials 0.000 claims description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 6
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 6
- 238000000137 annealing Methods 0.000 claims description 6
- 229910052799 carbon Inorganic materials 0.000 claims description 6
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 4
- 239000011651 chromium Substances 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 4
- 239000010936 titanium Substances 0.000 claims description 4
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 239000011574 phosphorus Substances 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- 239000010703 silicon Substances 0.000 claims description 3
- 229910052717 sulfur Inorganic materials 0.000 claims description 3
- 239000011593 sulfur Substances 0.000 claims description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 2
- 229910052804 chromium Inorganic materials 0.000 claims description 2
- 229910052757 nitrogen Inorganic materials 0.000 claims description 2
- 238000013021 overheating Methods 0.000 claims description 2
- 238000003303 reheating Methods 0.000 claims description 2
- 229910052719 titanium Inorganic materials 0.000 claims description 2
- 239000004615 ingredient Substances 0.000 claims 1
- 229910000937 TWIP steel Inorganic materials 0.000 description 12
- 239000011701 zinc Substances 0.000 description 10
- 229910052725 zinc Inorganic materials 0.000 description 7
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 239000000696 magnetic material Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 229910000765 intermetallic Inorganic materials 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 238000003908 quality control method Methods 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 239000013585 weight reducing agent Substances 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229910000794 TRIP steel Inorganic materials 0.000 description 1
- 229910000797 Ultra-high-strength steel Inorganic materials 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 229910000905 alloy phase Inorganic materials 0.000 description 1
- 230000037396 body weight Effects 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000002500 effect on skin Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000005211 surface analysis Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000009941 weaving Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
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Classifications
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/26—After-treatment
- C23C2/261—After-treatment in a gas atmosphere, e.g. inert or reducing atmosphere
-
- 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
- C21D1/34—Methods of heating
- C21D1/42—Induction heating
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/001—Austenite
Abstract
본 발명은 자동차용 부품 및 자동차나 가전제품의 내외판 등에 사용되는 합금화 용융아연도금강판을 제조하는 방법에 관한 것으로서,연속용융아연도금라인에서 용융아연도금강판을 강판 폭방향 유도가열방식에 의해 가열하여 합금화 함으로써 투자율이 낮은 강판을 대상으로 하여 합금화 용융아연도금강판의 제조를 가능하게 하는 합금화 용융아연도금강판의 제조방법을 제공하고자 하는 것이다.
본 발명의 일측면에 의하면, 강판을 용융아연도금한 후, 유도가열코일을 구비한 유도가열로에서 용융아연도금된 강판을 유도가열하고 합금화하여 합금화 용융아연도금강판을 제조하는 방법으로서, 상기 용융아연도금의 대상강판으로서 두께가 0.5~2.5mm인 저투자율 강판을 사용하고 그리고 상기 유도가열이 강판 폭방향 유도가열방식에 의하여 행해지는 것을 특징으로 하는 저투자율 합금화 용융아연도금강판의 제조방법이 제공된다.
본 발명에 의하면, 연속용융아연도금라인에서 저투자율 강판을 이용하여 유도가열방식에 의해 합금화 용융아연도금강판, 예를 들면, Fe함량이 4-15중량%인 합금화 용융아연도금강판을 제조할 수 있다. The present invention relates to a method for manufacturing an alloyed hot-dip galvanized steel sheet used for automotive parts and the inner and outer plates of automobiles and home appliances, heating the hot-dip galvanized steel sheet in the continuous hot dip galvanizing line by the widthwise induction heating method The present invention is to provide a method for producing an alloyed hot-dip galvanized steel sheet which enables the production of alloyed hot-dip galvanized steel sheet for steel sheets having low permeability by alloying.
According to one aspect of the present invention, after hot-dip galvanizing the steel sheet, induction heating furnace having an induction heating coil induction heating and alloying to produce an alloyed hot-dip galvanized steel sheet by induction heating and alloying, A low permeability steel sheet having a thickness of 0.5 to 2.5 mm is used as a target steel sheet for galvanizing, and the induction heating is performed by a steel sheet widthwise induction heating method. do.
According to the present invention, an alloyed hot dip galvanized steel sheet, for example, a Fe content of 4-15% by weight using a low permeability steel sheet in a continuous hot dip galvanizing line by an induction heating method, can be produced. have.
Description
본 발명은 자동차용 부품 및 자동차나 가전제품의 내외판 등에 사용되는 합금화 용융아연도금강판을 제조하는 방법에 관한 것으로서, 보다 상세하게는 연속용융아연도금라인에서 투자율이 낮은 강판을 대상으로 하여 용융아연도금한 도금강판을 강판 폭방향 유도가열방식에 의해 가열하여 합금화 용융아연도금강판을 제조하는 방법에 관한 것이다.
The present invention relates to a method for manufacturing an alloyed hot-dip galvanized steel sheet used for automotive parts and the inner and outer plates of automobiles and home appliances, more specifically, hot-dip galvanized steel for low permeability in continuous hot-dip galvanizing line The present invention relates to a method for producing an alloyed hot dip galvanized steel sheet by heating a plated plated steel sheet by a steel plate widthwise induction heating method.
차체경량화와 안정성이 요구되는 자동차용 부품 등에 사용하기 위한 강판은 높은 강도, 연성 및 내식성 등이 요구되고 있다.Steel sheets for use in automobile parts and the like requiring body weight reduction and stability are required to have high strength, ductility and corrosion resistance.
이러한 차체 경량화 요구에 대응하기 위한 다양한 시도들이 진행되어 오고 있는데, 그 일례로서, 대한민국 특허출원 제2007-0018416호를 들 수 있다. Various attempts have been made to cope with such a demand for weight reduction of the vehicle body, and for example, Korean Patent Application No. 2007-0018416.
상기 대한민국 특허출원에서는 초고장력 및 고 연신율이 보장될 수 있도록 하기 위해 탄소(C)와 망간(Mn)을 기본으로 하되, 탄소(C) 0.15∼0.30 중량%, 실리콘(Si) 0.01∼0.03 중량%, 망간(Mn) 15∼25 중량%, 알루미늄(Al) 1.2∼3.0 중량%, 인(P) 0.020 중량% 이하, 황(S) 0.001∼0.002 중량%, 잔부 철(Fe) 및 기타 불가피한 불순물로 이루어지며, 강의 미세조직이 오스테나이트 상으로 이루어진 TWIP(TWin Induced Plasticity)형 초고강도 강판을 개시하고 있다.The Korean patent application is based on carbon (C) and manganese (Mn) in order to ensure ultra-high tensile strength and high elongation, carbon (C) 0.15 ~ 0.30% by weight, silicon (Si) 0.01 ~ 0.03% by weight , 15-25 wt% manganese (Mn), 1.2-3.0 wt% aluminum (Al), 0.020 wt% or less phosphorus (P), 0.001-0.002 wt% sulfur (S), residual iron (Fe) and other unavoidable impurities The present invention discloses a TWIP (TWin Induced Plasticity) type ultra high strength steel sheet having a microstructure of steel in an austenite phase.
한편, 강판의 내식성을 확보하기 위한 합금화 용융아연도금강판(이하, 'GA강판'이라고도 함)은 소재 중의 철이 도금층 내부로 확산을 일으켜 8~12% 정도로 분산된 피막을 형성함으로써 용접성과 도장성이 우수한 특성을 발휘하는 표면처리강판으로 주로 자동차나 가전제품의 내외판용으로 사용되고 있다.On the other hand, alloyed hot-dip galvanized steel sheet (hereinafter referred to as 'GA steel sheet') to secure the corrosion resistance of the steel sheet is formed by the diffusion of iron in the material into the plating layer to form a film dispersed by about 8 to 12% weldability and paintability It is a surface-treated steel sheet that shows excellent characteristics and is mainly used for interior and exterior plates of automobiles and home appliances.
이와 같이 우수한 용접성과 도장성을 가지는 GA강판을 제조하기 위해서는 0.12~0.14 wt%의 Al이 함유된 도금욕에서 용융 아연도금을 행하고, 도금부착량을 조절한 후 강판을 직접가열 또는 유도가열방법을 적용하여 도금층의 합금화 처리를 행하여야 한다. In order to manufacture a GA steel sheet having excellent weldability and paintability, hot dip galvanizing is performed in a plating bath containing 0.12 to 0.14 wt% of Al, and after adjusting the coating amount, the steel sheet is directly heated or induction heated. By alloying the plating layer.
일반적으로, 합금화 처리온도가 낮고 유지시간이 길어질수록 우수한 합금화 피막을 얻을 수 있으므로 작업속도가 낮을수록 합금화 품질제어가 유리하다. In general, the lower the alloying treatment temperature and the longer the holding time, the better the alloying film can be obtained, so the lower the working speed, the better the alloying quality control.
그러나, 합금화 용융아연도금강판은 한정된 설비를 통과하는 한정된 시간 내에서 합금화 품질을 확보하여야 하므로 용융아연도금강판 대비 생산성이 떨어져 제조원가가 올라가게 되는 문제를 안고 있다. However, the alloyed hot-dip galvanized steel sheet has a problem that the production cost is lowered because the alloying quality must be secured within a limited time passing through the limited equipment, compared to the hot-dip galvanized steel sheet.
따라서, 고속 가열 및 합금화 품질제어를 위해서는 유도가열방법이 유리하다.Therefore, the induction heating method is advantageous for high speed heating and alloying quality control.
현재, 연속용융아연도금라인에서 사용되는 유도가열 기술은 투자율이 높은 강판의 경우 가열효율이 좋지만, 오스테나이트 상분율이 많고 두께가 0.5~2.5 mm인 강판의 경우 투자율이 낮아서 유도가열을 위해서는 주파수가 대단히 높은 초고주파 전류가 필요하고 그 가열 효율이 낮다. At present, the induction heating technology used in continuous hot dip galvanizing line has good heating efficiency in high permeability steel plate, but in case of steel plate with a high austenite phase fraction and thickness of 0.5 ~ 2.5 mm, the permeability is low and the frequency is high for induction heating. Very high microwave current is required and its heating efficiency is low.
이러한 기술적인 문제로 인해 저투자율 강판에 대해서는 연속용융도금라인(CGL)에서 합금용융도금강판 생산이 사실상 불가능하다. Due to this technical problem, it is virtually impossible to produce hot-dip alloy steel sheets in a continuous hot dip plating line (CGL) for low permeability steel sheets.
따라서, 저투자율 강판을 대상으로 하여 합금화 용융아연도금강판을 제조할 수 있는 새로운 방법이 요구되고 있다.
Therefore, there is a need for a new method for producing an alloyed hot dip galvanized steel sheet for low permeability steel sheets.
본 발명은 연속용융아연도금라인에서 용융아연도금강판을 강판 폭방향 유도가열방식에 의해 가열하여 합금화 함으로써 투자율이 낮은 강판을 대상으로 하여 합금화 용융아연도금강판의 제조를 가능하게 하는 합금화 용융아연도금강판의 제조방법을 제공하고자 하는 것이다.
The present invention is an alloyed hot-dip galvanized steel sheet which enables the production of alloyed hot-dip galvanized steel sheet for steel sheets with low permeability by heating and alloying the hot-dip galvanized steel sheet by the steel plate width direction induction heating method in the continuous hot-dip galvanizing line. It is to provide a method of manufacturing.
이하, 본 발명에 대하여 설명한다.EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated.
본 발명의 일측면에 의하면, 강판을 용융아연도금한 후, 유도가열코일을 구비한 유도가열로에서 용융아연도금된 강판을 유도가열하고 합금화하여 합금화 용융아연도금강판을 제조하는 방법으로서, 상기 용융아연도금의 대상강판으로서 두께가 0.5~2.5mm인 저투자율 강판을 사용하고 그리고 상기 유도가열이 강판 폭방향 유도가열방식에 의하여 행해지는 것을 특징으로 하는 저투자율 합금화 용융아연도금강판의 제조방법이 제공된다.According to one aspect of the present invention, after hot-dip galvanizing the steel sheet, induction heating furnace having an induction heating coil induction heating and alloying to produce an alloyed hot-dip galvanized steel sheet by induction heating and alloying, A low permeability steel sheet having a thickness of 0.5 to 2.5 mm is used as a target steel sheet for galvanizing, and the induction heating is performed by a steel sheet widthwise induction heating method. do.
상기 합금화 용융아연도금강판의 제조방법에서 강판의 유도가열 시 주파수는 0.5~300 kHz이고, 합금화 온도는 450~600℃이고, 그리고 합금화시간은 1~10초로 선정하는 것이 바람직하다.
In the method of manufacturing the alloyed hot-dip galvanized steel sheet, the induction heating frequency of the steel sheet is 0.5 ~ 300 kHz, the alloying temperature is 450 ~ 600 ℃, and the alloying time is preferably selected from 1 to 10 seconds.
본 발명에 의하면, 연속용융아연도금라인에서 저투자율 강판을 이용하여 유도가열방식에 의해 합금화 용융아연도금강판, 예를 들면, Fe함량이 4-15중량%인 합금화 용융아연도금강판을 제조할 수 있다.
According to the present invention, an alloyed hot dip galvanized steel sheet, for example, a Fe content of 4-15% by weight using a low permeability steel sheet in a continuous hot dip galvanizing line by an induction heating method, can be produced. have.
도 1은 자성체인 페라이트 상분율이 높은 고투자율강판과 비자성체인 오스테나이트 상분율이 높은 저투자율 강판을 연속용융아연도금라인에서 강판 길이방향 유도가열 방식에 의하여 가열할 때 유도가열 효율을 비교한 모식도.
도 2는 연속용융아연도금라인에서 저투자율 강판을 본 발명에 따라 강판 폭방향 유도가열 방식에 의하여 가열하는 것을 나타내는 모식도.
도 3은 본 발명에 따라 연속용융아연도금라인에서 강판 폭방향 유도가열 방식으로 저투자율 강판을 가열하였을 때 유도가열 효율을 나타내는 모식도.
도 4는 종래 강판길이방향 유도가열 방식과 본 발명의 강판폭방향 유도가열 방식을 사용하여 연속용융아연도금라인에서 합금화시켜 제조된 EDDQ와 TWIP강의 합금화용융안연도금강판의 도금층 표면 분석결과도.1 is a comparison of induction heating efficiency when a high permeability steel sheet having a high ferritic content of magnetic material and a low permeability steel sheet having a high austenite content of non-magnetic material is heated by a longitudinal induction heating method in a continuous hot dip galvanizing line. Schematic diagram.
Figure 2 is a schematic diagram showing the heating of the low permeability steel sheet in the continuous molten zinc plating line by the steel plate width direction induction heating method according to the present invention.
Figure 3 is a schematic diagram showing the induction heating efficiency when heating the low permeability steel sheet in the width direction induction heating method in the continuous molten zinc plating line according to the present invention.
4 is a surface analysis result of the plating layer surface of the alloyed molten annealing steel sheet of EDDQ and TWIP steel produced by alloying in the continuous molten zinc plating line using the conventional steel plate length direction induction heating method and the steel plate width direction induction heating method of the present invention.
이하, 본 발명에 대하여 상세히 설명한다.Hereinafter, the present invention will be described in detail.
본 발명은 강판을 용융아연도금한 후, 유도가열코일을 구비한 유도가열로에서 용융아연도금된 강판을 유도가열하고 합금화하여 합금화 용융아연도금강판을 제조하는 방법에 있어서 유도가열방식을 개선한 것이다.The present invention is to improve the induction heating method in the method of manufacturing an alloyed hot-dip galvanized steel sheet by induction heating and alloying the hot-dip galvanized steel sheet in an induction heating furnace having an induction heating coil after hot-dip galvanizing the steel sheet. .
본 발명의 대상강판은 특별히 한정되는 것은 아니지만, 저투자율 강판에 바람직하게 적용되는 것이다.The target steel sheet of the present invention is not particularly limited, but is preferably applied to a low permeability steel sheet.
상기한 저투자율 강판으로는 비투자율이 30이하인 강판이 바람직하며, 또한 오스테나이트 상분율이 50%이상인 저투자율 강판이 바람직하다.As said low permeability steel plate, the steel plate whose specific permeability is 30 or less is preferable, and the low permeability steel plate whose austenite phase fraction is 50% or more is preferable.
상기 비투자율은 공기의 투자율을 1로 두고 그 상대적인 값으로 나타낸 것이다.The specific permeability is expressed as a relative value with the air permeability set to one.
본 발명에 바람직하게 적용될 수 있는 저투자율 강판으로는 탄소(C): 0.10∼0.30 중량%, 망간(Mn): 10∼30 중량% 및 잔부 철(Fe)을 포함하는 강판을 들 수 있다.The low permeability steel sheet which can be preferably applied to the present invention includes a steel sheet containing carbon (C): 0.10 to 0.30% by weight, manganese (Mn): 10 to 30% by weight, and balance iron (Fe).
본 발명에 바람직하게 적용될 수 있는 다른 저투자율 강판으로는 탄소(C): 0.10∼0.30중량%, 실리콘(Si): 0.01∼0.03중량%, 티타늄(Ti): 0.05~0.2중량%, 망간(Mn): 10∼30중량%, 알루미늄(Al): 0.5∼3.0중량%, 니켈(Ni): 0.001~10중량%, 크롬(Cr): 0.001~10중량%, 질소(N): 0.001~0.05중량%, 인(P): 0.020중량% 이하, 황(S): 0.001∼0.005중량%, 잔부 철(Fe) 및 기타 불가피한 불순물을 포함하고 그리고 오스테나이트 상분율이 50 %이상인 강판을 들 수 있다.Other low permeability steel sheets which can be preferably applied to the present invention include carbon (C): 0.10 to 0.30 wt%, silicon (Si): 0.01 to 0.03 wt%, titanium (Ti): 0.05 to 0.2 wt%, manganese (Mn) ): 10 to 30% by weight, aluminum (Al): 0.5 to 3.0% by weight, nickel (Ni): 0.001 to 10% by weight, chromium (Cr): 0.001 to 10% by weight, nitrogen (N): 0.001 to 0.05% by weight %, Phosphorus (P): 0.020% by weight or less, sulfur (S): 0.001 to 0.005% by weight, residual iron (Fe) and other unavoidable impurities, and an austenite phase percentage of 50% or more.
본 발명의 대상강판의 두께는 특별히 한정되는 것은 아니지만, 0.5~2.5mm이 바람직하다.Although the thickness of the target steel plate of this invention is not specifically limited, 0.5-2.5 mm is preferable.
본 발명에서는 유도가열로에서 강판 폭방향 유도가열방식에 의하여 용융아연도금강판을 가열한다.In the present invention, the hot-dip galvanized steel sheet is heated by a steel plate widthwise induction heating method in an induction heating furnace.
본 발명은 종래의 연속용융아연도금라인의 강판 길이방향 유도가열방식을 강판 폭 방향 유도가열방식으로 변경한 것이다. The present invention is to change the steel sheet longitudinal induction heating method of the conventional continuous molten zinc plating line to the steel plate width direction induction heating method.
도 1에는 자성체인 페라이트 상분율이 높은 고투자율 강판과 비자성체인 오스테나이트 상분율이 높은 저투자율 강판을 연속용융아연도금라인에서 강판 길이방향 유도가열 방식에 의하여 가열할 때 유도가열 효율을 비교한 모식도가 나타나 있다.Figure 1 compares the induction heating efficiency when heating a high permeability steel sheet having a high ferritic content of magnetic material and a low permeability steel sheet having a high austenite content of non-magnetic material by continuous induction heating method in a continuous hot dip galvanizing line. A schematic is shown.
상기 고투자율강판으로는 일반강(IF), DP강 및 TRIP강 등을 들 수 있고, 상기 저투자율 강판으로는 1180CP 강 및 TWIP강 등을 들 수 있다.Examples of the high permeability steel sheet include ordinary steel (IF), DP steel, and TRIP steel. Examples of the low permeability steel sheet include 1180CP steel and TWIP steel.
도 1에 나타난 바와 같이, 종래의 강판 길이방향 유도가열 방식에서는 고투자율 강판의 경우 단면적에 대한 자속 집적이 높아 그 유도가열 효율이 높지만, 저투자율 강판의 경우는 단면적에 대한 자속 집적이 적어 그 유도가열 효율이 적다. As shown in FIG. 1, in the conventional steel plate longitudinal induction heating method, high magnetic permeability of the high permeability steel plate has high magnetic flux accumulation with respect to the cross-sectional area, and thus induction heating efficiency is high. Low heating efficiency
좀더 자세히 설명하기 위해 표피효과(Skin effect)로 설명하면, 우선 표피깊이(Skin Depth)는 표면전류의 38.7 %가 흐르는 깊이로 발열의 90 %가 발생하며 주파수에 반비례한다. To explain in more detail the skin effect, the skin depth is 38.7% of the surface current and 90% of the heat is inversely proportional to frequency.
또한, 가열체의 직경이 표피깊이의 3배 이상이고 코일내 가열체 단면적 비율이 크면 효율이 크다. In addition, if the diameter of the heating body is at least three times the skin depth and the ratio of the heating body cross-sectional area in the coil is large, the efficiency is high.
δ = 503.3√(ρ/μr f) [δ: 표피깊이(Skin Depth), ρ: 저항율, μr: 비투자율, f: 주파수]δ = 503.3√ (ρ / μ r f ) [δ: Skin Depth, ρ: resistivity, μ r : specific permeability, f : frequency]
현재 연속용융도금라인(CGL)의 합금화(GA)유도가열로(강판 길이방향 유도가열 방식)에서는 50kHz의 주파수를 사용하고 있으며 투자율이 높은 일반강이나 AHSS(Advance High Strength Steel)의 경우(강판의 페라이트 상분율이 100%일 때 비투자율: ~200)는 표피 깊이가 약 70㎛이지만, 저투자율 강판의 경우(강판의 오스테나이트 상분율이 100%일 때 비투자율: ~1, 공기의 비투자율: 1)는 표피깊이가 1,000㎛를 넘으므로 두께가 0.5~2.5mm인 강판을 유도가열할 때 서로 상쇄되어 그 효율이 떨어진다. At present, the alloy (GA) induction furnace (steel plate longitudinal induction heating method) of the continuous hot-dip galvanizing line (CGL) uses a frequency of 50 kHz, and has a high permeability for general steel or AHSS (Advance High Strength Steel). The specific permeability: ~ 200 when the ferrite content is 100%, the skin depth is about 70㎛, but in the case of low permeability steel sheet (the specific permeability: ~ 1, the specific permeability of air when the austenite content of steel sheet is 100% : 1) the skin depth is over 1,000㎛, so when induction heating of 0.5 ~ 2.5mm thick steel plate, they are offset each other and the efficiency is inferior.
실제로 저투자율 강판인 TWIP강을 합금화(GA) 유도가열을 하였을 경우 그 효율이 20~30%로 유도가열이 되지 않는다. Indeed, when alloyed (GA) induction heating of TWIP steel, which is a low permeability steel sheet, the efficiency is not 20 to 30%.
만약, 현재 합금화(GA)유도가열방식(강판 길이방향 유도가열 방식)으로 저투자율 강판을 유도가열한다면 주파수를 약 1,000 kHz까지 올려야 하지만, 이 경우 전자파인체보호기준 및 주변기기에 영향을 미치므로 사용할 수 없다. If induction heating of low permeability steel plate by the current alloy (GA) induction heating method (steel plate longitudinal induction heating method), the frequency should be raised to about 1,000 kHz, but in this case, it can be used because it affects electromagnetic wave protection standards and peripheral devices. none.
한편, 폭방향 유도가열 방식에 의하여 강판을 가열하는 기술이 대한민국 특허공개 1995-0025406호 및 2010-0071761호에 개시되어 있다. On the other hand, a technique for heating the steel sheet by the widthwise induction heating method is disclosed in Korean Patent Publication Nos. 1995-0025406 and 2010-0071761.
그러나, 이들 특허에는 단순히 강판을 유도가열하는 기술이 개시되어 있을 뿐, 저투자율 강판의 합금화를 위한 유도가열에 대해서는 개시되어 있지 않다. However, these patents merely disclose a technique of induction heating of a steel sheet, and do not disclose induction heating for alloying a low permeability steel sheet.
또한, 저투자율 강판을 합금화 하기 위한 방법으로 직접가열방법을 사용할 수도 있다. 그 대표적인 방법으로는 직화방법 및 적외선 램프를 이용하는 방법이 있다. In addition, a direct heating method may be used as a method for alloying a low permeability steel sheet. Representative methods include a direct fire method and a method using an infrared lamp.
상기 직화방법은 표면에 결함을 유발할 수 있고, 강판 온도제어가 힘들기 때문에 GA강판의 파우더링성 및 가공성 등이 악화될 수 있어 적합하지 않다. The direct weaving method may cause defects on the surface and is difficult to control the temperature of the steel sheet, so that the powdering property and workability of the GA steel sheet may be deteriorated.
상기 적외선 램프를 이용하는 방법은 강판 온도제어가 용이하여 GA 강판제조에 용이하지만, 가열속도가 느리기 때문에(적외선 램프가열속도: ~10℃/s, 유도가열속도: ~70℃/s) 가열구간이 기존대비 몇 배가 된다. The method using the infrared lamp is easy to manufacture the GA steel sheet because the temperature control of the steel sheet is easy, but the heating section is slow because the heating rate is slow (infrared lamp heating rate: ~ 10 ° C / s, induction heating rate: ~ 70 ° C / s). It is several times higher than before.
또한, 가열구간에서 강판은 아연으로 도금되어 있으므로 복사율(Emissivity)이 0.2이하이므로(흑체의 복사율: 1.0), 가열원인 적외선을 반사시키므로 그 효율이 떨어진다. In addition, since the steel sheet is plated with zinc in the heating section, the emissivity is 0.2 or less (emissivity of the black body: 1.0), and the efficiency is lowered because it reflects infrared rays as the heating source.
실제로 용융아연도금한 저투자율 강판(TWIP강)을 13초 동안 가열하여도 (100 mpm에서 유도가열시간: 2.2초) 합금화가 되지 않았다. 따라서, 직접가열방법도 저투자율 강판을 합금화하기 위한 방법으로는 적합하지 않다.Indeed, hot-dip galvanized low permeability steel sheets (TWIP steel) were not alloyed even when heated for 13 seconds (induction heating time at 100 mpm: 2.2 seconds). Therefore, the direct heating method is also not suitable as a method for alloying a low permeability steel sheet.
도 2에는 연속용융아연도금라인의 유도가열로에서 저투자율 강판을 본 발명에 따라 강판 폭방향 유도가열 방식에 의하여 가열하는 것을 나타내는 모식도가 나타나 있고, 도 3에는 본 발명에 따라 연속용융아연도금라인의 유도가열로에서에서 강판 폭방향 유도가열 방식으로 저투자율 강판을 가열하였을 때 유도가열 효율을 나타낸 모식도가 나타나 있다.Figure 2 is a schematic diagram showing the heating of the low permeability steel sheet in the steel sheet width direction induction heating method according to the present invention in the induction heating furnace of continuous hot dip galvanizing line, Figure 3 is a continuous hot dip galvanizing line in accordance with the present invention The schematic diagram showing the induction heating efficiency when the low permeability steel plate was heated in the widthwise induction heating method in the induction heating furnace of is shown.
도 2 및 도 3에 나타난 바와 같이, 본 발명의 폭 방향 유도가열 방식에 따라 저투자율 강판을 가열하는 경우 코일내 가열체 단면적이 넓어 효율이 증가된다. As shown in Figures 2 and 3, when heating the low permeability steel sheet according to the widthwise induction heating method of the present invention, the cross section of the heating body in the coil is wide, the efficiency is increased.
실제로 본 발명의 유도가열 방식으로 저투자율 강판인 TWIP강을 가열하였을 때 약 3 초안에 450℃에서 최대 600℃까지 유도가열이 가능하였다. In fact, when the TWIP steel, which is a low permeability steel sheet, was heated by the induction heating method of the present invention, induction heating was possible from 450 ° C. to 600 ° C. in about 3 seconds.
본 발명에 따라 강판을 폭 방향 유도가열방식에 의해 가열하기 위해서는 도 2 및 도 3에 나타난 바와 같이 한쌍의 유도가열코일을 강판을 사이에 두고 서로 마주보고 위치시키는 것이 필요하다. 상가 한쌍의 유도가열코일을 유도 가열 유니트라고 한다. 상기 유도 가열 유니트는 다수개 설치되어 있다. 상기 한쌍의 유도가열코일사이를 강판이 지나감으로써 가열된다.In order to heat the steel sheet by the widthwise induction heating method according to the present invention, it is necessary to place a pair of induction heating coils facing each other with the steel plates interposed therebetween as shown in FIGS. 2 and 3. A pair of induction heating coils in the mall is called an induction heating unit. A plurality of induction heating units are provided. The steel sheet is heated between the pair of induction heating coils.
그러나, 강판 폭 방향 유도가열 방식은 코일의 형상과 위치에 따라 강판이 가열되는 정도가 서로 다르며 에지가 지나치게 과열될 수 있다. However, the steel plate width direction induction heating method is different in the degree to which the steel sheet is heated depending on the shape and position of the coil and the edge may be excessively overheated.
따라서, 이러한 강판 에지의 지난친 과열을 방지하기 위하여 도 2에도 나타나 있는 바와 같이 강판의 에지 부근에 차폐판을 설치하는 것이 바람직하다.Therefore, in order to prevent such overheating of the steel sheet edge, it is preferable to provide a shielding plate near the edge of the steel sheet as shown in FIG. 2.
또한, 연속용융아연도금라인에서 조업하는 강판의 폭과 두께 및 목표온도가 다양하므로 균일한 합금화 용융아연도금강판을 제조하는데 어려움이 있다.In addition, since the width and thickness of the steel sheet operating in the continuous hot-dip galvanizing line and the target temperature varies, it is difficult to produce a uniform alloyed hot-dip galvanized steel sheet.
따라서, 유도 가열 유니트 및 차폐판을 설치하는 경우 차폐판을 가열대상강판에 대하여 수평 및 수직방향으로 이동가능하도록 구성하는 것이 바람직하다.Therefore, when installing the induction heating unit and the shielding plate, it is preferable to configure the shielding plate to be movable in the horizontal and vertical directions with respect to the steel sheet to be heated.
상기와 같이 유도 가열 유니트 및 차폐판을 구성하는 경우에는 가열 온도 증감과 가열 대상 강판의 폭 변화에 따른 다양한 압연 조건에도 정밀하게 대응이 가능하다. In the case of configuring the induction heating unit and the shielding plate as described above, it is possible to precisely cope with various rolling conditions according to the increase and decrease of the heating temperature and the width change of the steel sheet to be heated.
또한, 본 발명에서는 가열 대상 강판이 유도가열유니트의 유도 가열 코일을 지나기 전의 강판 중앙과 에지부분의 온도를 측정하는 입측 온도계 및 가열 대상 강판이 유도 가열 코일을 지난 후의 강판 중앙과 에지부분의 온도를 측정하는 출측 온도계를 추가로 설치할 수 있다.In addition, in the present invention, the entrance thermometer measuring the temperature of the center and the edge portion of the steel sheet before the heating target steel sheet passes the induction heating coil of the induction heating unit, and the temperature of the center and the edge portion of the steel sheet after the heating target steel sheet passes the induction heating coil. An additional exit thermometer can be installed.
상기와 같이 설치된 입측 온도계 및 출측 온도계에서 측정된 강판의 온도에 기초하여 가열 대상 강판에 대한 연속용융아연도금라인의 유도 가열 전류를 적절히 제어하여 저투자율 용융도금 강판의 합금화를 보다 정밀하게 제어할 수 있다.The alloying of the low permeability hot-dip galvanized steel sheet can be more precisely controlled by appropriately controlling the induction heating current of the continuous hot-dip galvanizing line for the steel sheet to be heated based on the temperature of the steel sheet measured by the entrance thermometer and the exit thermometer installed as described above. have.
이하, 저투자율 강판을 대상으로 하여 본 발명에 따라 합금화 용융아연도금강판을 제조하는 방법에 대하여 설명한다.Hereinafter, a method for producing an alloyed hot dip galvanized steel sheet according to the present invention for a low permeability steel sheet will be described.
본 발명의 강판폭방향 유도가열 방식에 의하여 강판을 가열하기 전의 공정들(예를 들면, 용융아연도금강판을 제조하는 공정까지의 공정들)은 특별히 한정되는 것은 아니며, 이하에서는 바람직한 일례를 들어 설명한다.Processes before heating the steel sheet by the steel sheet width direction induction heating method of the present invention (for example, processes up to the process of manufacturing a hot-dip galvanized steel sheet) are not particularly limited, and the following description will be given by way of preferred examples. do.
우선, 대상강판 표면의 청정화를 행하고 필요에 따라 표면의 이물질이나 산화막을 제거한다.First, the surface of the target steel sheet is cleaned, and foreign matter or oxide film on the surface is removed as necessary.
강판을 H2-N2 환원성 분위기로에서 700~900℃까지 1.5 ~ 6℃/s의 속도로 가열한 후, 20초 이상 유지하여 소둔한 다음, 소둔된 강판을 400~500℃까지 -14 ~ -5 ℃/s의 냉각속도로 냉각한다. The steel sheet is heated in a H 2 -N 2 reducing atmosphere furnace at a rate of 1.5 to 6 ° C./s from 700 to 900 ° C., followed by annealing for at least 20 seconds, followed by annealing of the steel sheet to 400 to 500 ° C. Cool at a cooling rate of -5 ° C / s.
상기한 냉각공정은 강판의 기계적 성질을 구현하기 위해 미세조직에 변태조직을 제조하는 방법으로 고강도 고연성 고강도강 제조에 필요하다. The cooling process is required to manufacture high strength high ductility high strength steel by the method of manufacturing the transformation structure in the microstructure to realize the mechanical properties of the steel sheet.
그 후 도금욕 온도보다 최대 50℃까지 높은 온도까지 냉각한 강판을 재가열한다. Thereafter, the steel sheet cooled to a temperature up to 50 ° C. above the plating bath temperature is reheated.
상기 냉각한 강판의 재가열 온도가 도금욕 온도보다 50℃를 초과하는 경우에는 강판의 Fe가 도금욕에 용출되는 양이 많아져 드로스가 다량 발생하기 때문에 바람직하지 않다. When the reheating temperature of the cooled steel sheet exceeds 50 ° C. above the plating bath temperature, the amount of Fe eluted into the plating bath increases, which is not preferable.
다음에, 온도가 430~480 ℃이고 0.1~0.3 wt%의 Al 및 불가피하게 함유된 성분을 함유한 용융 아연 도금욕에서 2.5 ~ 8초 유지한 후 꺼내 에어 와이핑(Air wiping)에 의해 원하는 도금량으로 맞춘 후 냉각한다. Next, after the temperature is 430 to 480 ° C. and maintained for 2.5 to 8 seconds in a hot dip galvanizing bath containing 0.1 to 0.3 wt% of Al and inevitably contained components, the desired coating amount is removed by air wiping. To cool and cool.
상기 용융 아연 도금욕중의 Al함량이 0.1wt% 미만인 경우에는 Fe-Al 억제층이 적어 Fe와 Zn의 반응이 빨라지고 감마상(Fe 함량이 17~28 wt%)이 많아짐에 따라 파우더링성 및 가공성이 악화되기 쉽고, 0.3 wt%를 초과하게 되는 경우에는 Al함량이 지나치게 많아 Fe-Al 억제층이 너무 많이 형성되어 Fe와 Zn의 반응이 느려져 적절한 델타상(Fe 함량이 7~12 wt%) 분율이 줄어들어 플래킹성이 악화되기 쉽다. When the Al content in the hot dip galvanizing bath is less than 0.1wt%, the Fe-Al suppression layer is less, so that the reaction between Fe and Zn is faster and the gamma phase (Fe content is 17 to 28 wt%) increases, so that powdering and workability are possible. In this case, it is easy to deteriorate, and when it exceeds 0.3 wt%, the Al content is excessively large so that the Fe-Al suppression layer is formed so that the reaction between Fe and Zn is slowed down, so that the appropriate delta phase (Fe content is 7-12 wt%) This decreases and the flaking is likely to deteriorate.
그 후 용융 아연도금강판을 도금욕에서 꺼내 에어 와이핑에 의해 원하는 도금량으로 맞춘 후 본 발명의 강판폭방향 유도가열 방식에 의하여 용융 아연도금강판을 유도가열하여 합금화시킨다. Thereafter, the hot-dip galvanized steel sheet is removed from the plating bath and adjusted to a desired coating amount by air wiping, and then the hot-dip galvanized steel sheet is induction heated and alloyed by the steel sheet width direction induction heating method of the present invention.
이때, 주파수는 0.5 ~ 200kHz가 바람직하고, 합금화 온도는 450 ~ 600℃가 바람직하고, 합금화 시간(유도가열시간)은 1~10초로 선정하는 것이 바람직하다.At this time, the frequency is preferably 0.5 to 200 kHz, the alloying temperature is preferably 450 to 600 ° C, and the alloying time (induction heating time) is preferably selected to 1 to 10 seconds.
상기 주파수가 0.5kHz 미만인 경우에는 표피 깊이가 너무 길어져 적합하지 않고, 200kHz를 초과하는 경우에는 전자파인체보호기준 및 주변기기에 영향을 미칠 수 있다. If the frequency is less than 0.5kHz, the skin depth is too long to be suitable, and if it exceeds 200kHz may affect the electromagnetic wave protection standards and peripherals.
또한, 합금화온도 및 합금화(가열)시간이 각각 450℃미만 및 1초 미만에서는 연속 용융아연도금라인에서 Fe-Zn 금속간 화합물 생성이 힘들고, 600℃ 초과 및 10초 초과한 경우에는 감마상(Fe 함량이 17~28 wt%)이 많아짐에 따라 파우더링성 및 가공성이 악화되기 쉽다. In addition, when the alloying temperature and the alloying (heating) time is less than 450 ℃ and less than 1 second, respectively, it is difficult to form Fe-Zn intermetallic compounds in the continuous hot dip galvanizing line. As the content is 17 to 28 wt%), the powdering property and processability tend to deteriorate.
본 발명에 의해서는 예를 들면, 합금화 용융아연도금층의 Fe함량이 4-15중량%인 합금화 용융아연도금강판이 제조될 수 있다.
According to the present invention, for example, an alloyed hot-dip galvanized steel sheet having a Fe content of the alloyed hot-dip galvanized layer of 4-15% by weight can be produced.
이하, 실시예를 통해 본 발명을 보다 구체적으로 설명한다. Hereinafter, the present invention will be described more specifically by way of examples.
(실시예)(Example)
고투자율강판인 일반강(EDDQ)과 다량의 Mn, Al과 Ni 등이 함유된 저투자율 강판인 TWIP강을 냉간압연하고 소둔하여 알칼리 탈지 및 산세처리로 청정화한 후 5%H2-N2, -65℃ 이슬점 분위기하에서 800℃까지 가열하고 소둔한 후 일반강은 500℃까지 냉각하고, TWIP강은 400℃까지 급냉하고 다시 500℃까지 재가열하였다. 그 후 용융 아연 도금욕에 침지하고 약 3초 유지 후 와이핑(wiping)하여 도금량을 45 g/m2으로 하였다.After cold rolling and annealing of general steel (EDDQ), which is a high permeability steel sheet, and TWIP steel, which is a low permeability steel sheet containing a large amount of Mn, Al, and Ni, it is cleaned by alkaline degreasing and pickling, and then 5% H 2 -N 2 , After heating and annealing to 800 ° C. in a dew point atmosphere of −65 ° C., the general steel was cooled to 500 ° C., and the TWIP steel was quenched to 400 ° C. and then reheated to 500 ° C. Thereafter, it was immersed in a hot dip galvanizing bath, and maintained for about 3 seconds and then wiped to make the plating amount 45 g / m 2 .
상기 일반강(EDDQ)은 합금화(GA) 유도가열시 오스테나이트 상분율이 0%로 고투자율 강판이고, TWIP강은 오스테나이트 상분율이 100%로 저투자율 강판이다. The general steel (EDDQ) is a high permeability steel sheet having an austenite phase fraction of 0% during alloying (GA) induction heating, and a low permeability steel sheet of TWIP steel having an austenite phase fraction of 100%.
상기와 같이 제조된 용융아연도금강판을 하기 표 1의 조건으로 가열하여 합금화시켜 합금화용융아연도금강판을 제조하였으며, 실 합금화(GA)온도를 하기 표 2에 나타내었다.The hot-dip galvanized steel sheet prepared as described above was heated and alloyed under the conditions of Table 1 to produce an alloyed hot-dip galvanized steel sheet, and the actual alloy (GA) temperature is shown in Table 2 below.
하기 표 1에서 기존(종래)방식은 강판 길이방향 유도가열방식을 의미하는 것이고, 본 발명방식은 강판 폭방향 유도가열방식을 의미한다.In the following Table 1, the conventional (conventional) method means a steel plate longitudinal induction heating method, the present invention means a steel plate width direction induction heating method.
상기와 같이 제조된 합금화 용융아연도금강판의 도금층의 합금상 분율 및 Fe 함량(%)을 조사하고, 그 결과를 하기 표 2에 나타내고, 또한, 도금층 표면을 SEM 분석하고 그 결과를 도 4에 나타내었다. 도 4에서, 기존 유도가열방식의 EDDQ는 표 2의 실시예 2를 나타내고, 본 발명방식의 EDDQ는 표 2의 실시예 4를 나타내고, 기존 유도가열방식의 TWIP는 표 2의 실시예 6을 나타내고, 본 발명방식의 TWIP는 표 2의 실시예 10을 나타낸다.The alloy phase fraction and Fe content (%) of the plating layer of the alloyed hot-dip galvanized steel sheet prepared as described above were investigated, and the results are shown in Table 2 below, and the surface of the plating layer was SEM analyzed and the results are shown in FIG. 4. It was. In FIG. 4, the EDDQ of the conventional induction heating method represents Example 2 of Table 2, the EDDQ of the present invention system represents Example 4 of Table 2, and the TWIP of the conventional induction heating method represents Example 6 of Table 2. , TWIP of the present invention mode shows Example 10 of Table 2.
EDDQ
EDDQ
TWIP
TWIP
가열안됨
Not heated
(상기 에타상: Fe가 3wt%이하 고용된 Zn, 제타상: Fe 함량이 5~6 wt%임)(The eta phase: Zn in which Fe is less than or equal to 3 wt%, the zeta phase is 5 to 6 wt% of Fe content)
상기 표 2에 나타난 바와 같이, 종래의 유도가열 방식에서 EDDQ의 경우 목표 가열온도까지 유도가열 되는데 반해 TWIP강은 약 440~446℃로 목표 가열온도까지 유도가열되지 않았다. 또한, 주파수를 변경하거나 가열시간을 변경하여도 가열되지 않았다. As shown in Table 2, in the conventional induction heating method, induction heating to the target heating temperature in the case of EDDQ, while TWIP steel is not induction heating to the target heating temperature at about 440 ~ 446 ℃. In addition, heating was not performed even by changing the frequency or the heating time.
이에 반하여, 본 발명의 유도가열방식에서는 EDDQ와 TWIP강 모두 목표 가열온도까지 가열이 가능하고, 합금화도(Fe wt%)도 약 4.5~10.1%정도로 합금화 용융아연도금강판 제조가 가능함을 알 수 있다.On the contrary, in the induction heating method of the present invention, both EDDQ and TWIP steel can be heated to a target heating temperature, and the alloying degree (Fe wt%) is about 4.5 to 10.1%. .
또한, 도 4에 나타난 바와 같이, 일반강은 기존의 유도가열방식이든 본 발명의 유도가열방식이든 표면에 정형적인 Fe-Zn 금속간화합물인 델타상이 관찰된다. 그러나, TWIP강을 기존의 유도가열방식으로 가열한 경우에는 GI강판 표면과 같이 아연응고조직인 스팽글이 관찰되지만, 본 발명의 유도가열방식으로 가열하는 경우에는 표면에 델타상이 관찰됨을 알 수 있다.
In addition, as shown in Figure 4, whether the conventional steel induction heating method or conventional induction heating method of the present invention, the delta phase of a typical Fe-Zn intermetallic compound is observed on the surface. However, when the TWIP steel is heated by the conventional induction heating method, sequins of zinc-coagulated structure are observed like the surface of the GI steel sheet, but when the TWIP steel is heated by the induction heating method of the present invention, a delta phase is observed on the surface.
Claims (8)
상기 용융아연도금의 대상강판으로서 두께가 0.5~2.5mm이고, 비투자율이 30이하인 저투자율 강판을 사용하고, 상기 유도가열이 강판 폭방향 유도가열방식에 의하여 행해지고, 그리고 유도가열 시 주파수가 0.5~200 kHz인 것을 특징으로 하는 저투자율 합금화 용융아연도금강판의 제조방법.After hot-dip galvanizing the steel sheet, a method of producing an alloyed hot-dip galvanized steel sheet by induction heating and alloying the hot-dip galvanized steel sheet in an induction heating furnace having an induction heating coil,
A low permeability steel sheet having a thickness of 0.5 to 2.5 mm and a specific permeability of 30 or less is used as the target steel sheet for hot dip galvanizing, and the induction heating is performed by the steel plate width direction induction heating method, and the frequency at induction heating is 0.5 to A low permeability alloyed hot dip galvanized steel sheet, characterized in that 200 kHz.
The method for producing a low permeability alloyed hot dip galvanized steel sheet according to any one of claims 1 to 7, wherein the Fe content of the alloyed hot dip galvanized layer of the alloyed hot dip galvanized steel sheet is 4-15% by weight.
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| FR3014449B1 (en) | 2013-12-06 | 2020-12-04 | Fives Celes | POST-GALVANIZING ANCURING SECTION CONTAINING A TRANSVERSE-FLOW INDUCER HEATING UNIT |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR940007374B1 (en) * | 1992-07-24 | 1994-08-16 | 포항종합제철 주식회사 | Method of manufacturing austenite stainless steel |
| JP2002173714A (en) * | 2000-09-29 | 2002-06-21 | Kawasaki Steel Corp | High tensile strength hot dip plated steel sheet and its production method |
| KR100899550B1 (en) | 2007-11-01 | 2009-05-26 | 현대하이스코 주식회사 | Manufacturing process of galvannealed hot dip coated steel sheet |
| KR20100071761A (en) * | 2008-12-19 | 2010-06-29 | 재단법인 포항산업과학연구원 | In-line induction heating apparatus and method of in-line induction heating by using the same |
-
2010
- 2010-10-25 KR KR1020100104200A patent/KR101253834B1/en active IP Right Grant
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR940007374B1 (en) * | 1992-07-24 | 1994-08-16 | 포항종합제철 주식회사 | Method of manufacturing austenite stainless steel |
| JP2002173714A (en) * | 2000-09-29 | 2002-06-21 | Kawasaki Steel Corp | High tensile strength hot dip plated steel sheet and its production method |
| KR100899550B1 (en) | 2007-11-01 | 2009-05-26 | 현대하이스코 주식회사 | Manufacturing process of galvannealed hot dip coated steel sheet |
| KR20100071761A (en) * | 2008-12-19 | 2010-06-29 | 재단법인 포항산업과학연구원 | In-line induction heating apparatus and method of in-line induction heating by using the same |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20180069567A (en) * | 2016-12-15 | 2018-06-25 | 주식회사 포스코 | High manganese galvannealed steel sheet having excellent weldability and method for manufacturing same |
| KR101917442B1 (en) * | 2016-12-15 | 2018-11-09 | 주식회사 포스코 | High manganese galvannealed steel sheet having excellent weldability and method for manufacturing same |
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| KR20120042488A (en) | 2012-05-03 |
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