KR101560902B1 - Hot rolled steel sheet having excellent corrosion resistance by sulfuric acid and hydrochloric acid and method for manufacturing the same - Google Patents
Hot rolled steel sheet having excellent corrosion resistance by sulfuric acid and hydrochloric acid and method for manufacturing the same Download PDFInfo
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- KR101560902B1 KR101560902B1 KR1020130151739A KR20130151739A KR101560902B1 KR 101560902 B1 KR101560902 B1 KR 101560902B1 KR 1020130151739 A KR1020130151739 A KR 1020130151739A KR 20130151739 A KR20130151739 A KR 20130151739A KR 101560902 B1 KR101560902 B1 KR 101560902B1
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- steel sheet
- hot
- rolled steel
- sulfuric acid
- hydrochloric acid
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 75
- 239000010959 steel Substances 0.000 title claims abstract description 75
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 title claims abstract description 48
- 230000007797 corrosion Effects 0.000 title claims abstract description 45
- 238000005260 corrosion Methods 0.000 title claims abstract description 45
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 title claims abstract description 42
- 238000000034 method Methods 0.000 title claims description 10
- 238000004519 manufacturing process Methods 0.000 title abstract description 14
- 229910052802 copper Inorganic materials 0.000 claims abstract description 18
- 229910052787 antimony Inorganic materials 0.000 claims abstract description 11
- 239000002131 composite material Substances 0.000 claims abstract description 11
- 239000012535 impurity Substances 0.000 claims abstract description 6
- 238000001816 cooling Methods 0.000 claims description 21
- 238000005098 hot rolling Methods 0.000 claims description 10
- 238000004804 winding Methods 0.000 claims description 6
- 229910017932 Cu—Sb Inorganic materials 0.000 claims description 4
- 238000010791 quenching Methods 0.000 claims description 4
- 230000000171 quenching effect Effects 0.000 claims description 4
- 239000010949 copper Substances 0.000 description 30
- 239000000203 mixture Substances 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 10
- 230000000694 effects Effects 0.000 description 9
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 8
- 239000011572 manganese Substances 0.000 description 8
- FZUJWWOKDIGOKH-UHFFFAOYSA-N sulfuric acid hydrochloride Chemical compound Cl.OS(O)(=O)=O FZUJWWOKDIGOKH-UHFFFAOYSA-N 0.000 description 7
- 239000010935 stainless steel Substances 0.000 description 6
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 5
- 230000007547 defect Effects 0.000 description 5
- 229910052717 sulfur Inorganic materials 0.000 description 5
- 239000011593 sulfur Substances 0.000 description 5
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 238000005275 alloying Methods 0.000 description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 3
- 238000006477 desulfuration reaction Methods 0.000 description 3
- 230000023556 desulfurization Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000003303 reheating Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 229910000655 Killed steel Inorganic materials 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- CADICXFYUNYKGD-UHFFFAOYSA-N sulfanylidenemanganese Chemical compound [Mn]=S CADICXFYUNYKGD-UHFFFAOYSA-N 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- VCUFZILGIRCDQQ-KRWDZBQOSA-N N-[[(5S)-2-oxo-3-(2-oxo-3H-1,3-benzoxazol-6-yl)-1,3-oxazolidin-5-yl]methyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C1O[C@H](CN1C1=CC2=C(NC(O2)=O)C=C1)CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F VCUFZILGIRCDQQ-KRWDZBQOSA-N 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 239000002803 fossil fuel Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 230000000979 retarding effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
Abstract
황산 및 염산 복합내식성이 우수한 열연강판 및 그 제조방법이 개시된다. 본 발명의 일 측면인 황산 및 염산 복합내식성이 우수한 열연강판은 중량%로, C: 0.05~0.1%, Mn: 0.5~1.5%, P: 0.02%이하, S: 0.02%이하, Al: 0.01%~0.1%, Cu: 0.2~0.7%, Sb: 0.05~0.1%, 잔부 Fe 및 기타 불가피한 불순물을 포함하고, 표면으로부터 두께 방향으로 500nm 이내에 Cu 및 Sb가 농축되어 있는 것을 특징으로 한다.A hot-rolled steel sheet excellent in sulfuric acid and hydrochloric acid combined corrosion resistance and a method for producing the same. A hot rolled steel sheet excellent in sulfuric acid and hydrochloric acid composite corrosion resistance, which is one aspect of the present invention, contains 0.05 to 0.1% of C, 0.5 to 1.5% of Mn, 0.02% or less of P, To about 0.1% of Cu, about 0.2 to about 0.7% of Cu, about 0.05 to about 0.1% of Sb, and the balance of Fe and other unavoidable impurities, wherein Cu and Sb are concentrated within 500 nm from the surface in the thickness direction.
Description
본 기술은 화력 발전소 탈황, 탈질설비, 예열기 및 이들의 부품 등의 소재로 사용되는 열연강판에 관한 것으로, 보다 상세하게는 황산 및 염산에 대한 복합내식성이 우수한 열연강판 및 그 제조방법에 관한 것이다.
TECHNICAL FIELD The present invention relates to a hot-rolled steel sheet used as a material for desulfurization, denitrification equipment, preheater, and parts thereof of a thermal power plant, and more particularly to a hot-rolled steel sheet having excellent corrosion resistance to sulfuric acid and hydrochloric acid and a method for manufacturing the same.
황산 또는 황산-염산 복합 내식강은 석탄 또는 석유 등 화석 연료를 연소하면서 생성되는 아황산가스 및 염소가스가 함유된 배기가스가 수분과 반응을 하여 황산 및 염산을 생성하여 황산 또는 황산-염산 복합 부식이 심각한 화력발전소 탈황 및 탈질설비 또는 복합 발전소의 배관 및 GGH(Gas Gas Heater)의 비교적 두꺼운 두께의 강판을 사용해야 하는 열소자(heat element) 소재 등으로 이용된다.
Sulfuric acid or sulfuric acid-hydrochloric acid composite corrosion resistant steel reacts with moisture in exhaust gas containing sulfurous acid gas and chlorine gas generated by burning fossil fuel such as coal or petroleum to generate sulfuric acid and hydrochloric acid, and sulfuric acid or sulfuric acid- It is used as a heat element material which requires the use of a relatively thick steel sheet of a pipe and GGH (Gas Gas Heater) of a severe thermal power plant desulfurization and denitrification facility or a combined power plant.
일반적으로 황산-염산 복합 내식강은 황산 및 염산 복합 분위기에서 일반강 보다 부식속도를 지연시키기 위하여 강중에 구리(Cu)를 다량 첨가하는 것으로 알려져 왔다.
In general, sulfuric acid - hydrochloric acid composite corrosion resistant steel has been known to add a large amount of copper (Cu) to the steel in order to delay the corrosion rate in a mixed atmosphere of sulfuric acid and hydrochloric acid.
구리(Cu)는 다른 첨가 원소에 비해 황산 부식속도를 크게 지연시키는 효과가 월등하지만 많이 첨가할 경우 열간압연시 강판의 크랙발생을 유발하는 등의 이유로 적당량의 구리(Cu)를 첨가하면서 다른 원소를 복합 첨가하는 강(특허문헌 1 내지 3)이 개발되었다.
Copper (Cu) has an effect of significantly retarding the sulfuric acid corrosion rate compared to other additive elements, but when added in large amounts, it causes cracks in the steel sheet during hot rolling. (Patent Documents 1 to 3) have been developed.
이와 같이, 황산-염산 복합 내식강에서 구리(Cu)의 함량이 높을수록 내식성의 향상이 가능한 반면, 구리(Cu)는 고가의 원소로서 함량이 증가할수록 제조원가가 높아질 뿐만 아니라 융점이 낮은 구리(Cu)가 편석되거나 농도가 높은 부위에서는 약간의 변형에 의해서도 크랙이 발생하기 쉬워, 연속 주조 과정에서 가공을 많이 받는 슬라브의 코너 등에 크랙이 발생하고 열간압연 후에는 표면결함으로 잔존하여 다른 부위보다 먼저 부식하는 문제점이 있다.
As described above, the higher the content of copper (Cu) in the sulfuric acid-hydrochloric acid combined corrosion resistant steel, the better the corrosion resistance. On the other hand, the copper (Cu) is an expensive element, ) Is segregated or cracked due to slight deformation at a high concentration region, cracks are generated in the corner of the slab which is subjected to a lot of processing in the continuous casting process, and the surface defect is left after the hot rolling, .
이에, 황산-염산 복합 내식강에서 구리(Cu)의 함량은 최소화하면서, 높은 복합내식성을 확보할 수 있는 방안이 요구되고 있는 실정이다.
Therefore, there is a demand for a method for securing high complex corrosion resistance while minimizing the content of copper (Cu) in sulfuric acid-hydrochloric acid combined corrosion resistant steel.
본 발명의 일 측면은, 성분계와 공정조건을 적절하게 제어함으로써 동일 함량의 Cu를 첨가한 강에 비해 황산 및 염산이 복합적으로 존재하는 부식환경에서 우수한 내식성을 갖는 열연강판 및 그 제조방법을 제공하고자 하는 것이다.
An aspect of the present invention is to provide a hot-rolled steel sheet having excellent corrosion resistance in a corrosive environment in which sulfuric acid and hydrochloric acid are present in a complex manner compared to a steel to which the same amount of Cu is added, .
본 발명의 일 측면인 황산 및 염산 복합내식성이 우수한 열연강판은 중량%로, C: 0.05~0.1%, Mn: 0.5~1.5%, P: 0.02%이하, S: 0.02%이하, Al: 0.01%~0.1%, Cu: 0.2~0.7%, Sb: 0.05~0.1%, 잔부 Fe 및 기타 불가피한 불순물을 포함하고, 표면으로부터 두께 방향으로 500nm 이내에 Cu 및 Sb가 농축되어 있는 것을 특징으로 한다.
A hot rolled steel sheet excellent in sulfuric acid and hydrochloric acid composite corrosion resistance, which is one aspect of the present invention, contains 0.05 to 0.1% of C, 0.5 to 1.5% of Mn, 0.02% or less of P, To about 0.1% of Cu, about 0.2 to about 0.7% of Cu, about 0.05 to about 0.1% of Sb, and the balance of Fe and other unavoidable impurities, wherein Cu and Sb are concentrated within 500 nm from the surface in the thickness direction.
또한, 본 발명의 다른 일 측면인 황산 및 염산 복합내식성이 우수한 열연강판의 제조방법은 중량%로, C: 0.05~0.1%, Mn: 0.5~1.5%, P: 0.02%이하, S: 0.02%이하, Al: 0.01%~0.1%, Cu: 0.2~0.7%, Sb: 0.05~0.1%, 잔부 Fe 및 기타 불가피한 불순물을 포함하는 강 슬라브를 1100~1300℃에서 재가열하는 단계; 상기 재가열된 강 슬라브를 열간압연하고, 850~950℃에서 마무리 열간압연하여 열연강판을 얻는 단계; 상기 열연강판을 80~150℃/s의 속도로 급냉하는 단계; 상기 냉각된 열연강판을 650~750℃에서 권취하는 단계; 및 상기 권취된 열연강판을 30~50℃/h의 속도로 서냉하는 단계를 포함한다.
Another aspect of the present invention is to provide a method for producing a hot rolled steel sheet excellent in sulfuric acid and hydrochloric acid complex corrosion resistance, which comprises 0.05 to 0.1% of C, 0.5 to 1.5% of Mn, 0.02% or less of P, Reheating a steel slab containing Al at 0.01 to 0.1%, Cu at 0.2 to 0.7%, Sb at 0.05 to 0.1%, and the balance Fe and other unavoidable impurities at 1100 to 1300 ° C; Hot-rolling the reheated steel slab and finishing hot-rolling at 850 to 950 ° C to obtain a hot-rolled steel sheet; Quenching the hot-rolled steel sheet at a rate of 80 to 150 ° C / s; Winding the cooled hot-rolled steel sheet at 650 to 750 ° C; And slowly cooling the rolled hot-rolled steel sheet at a speed of 30 to 50 ° C / h.
덧붙여 상기한 과제의 해결수단은, 본 발명의 특징을 모두 열거한 것은 아니다. 본 발명의 다양한 특징과 그에 따른 장점과 효과는 아래의 구체적인 실시형태를 참조하여 보다 상세하게 이해될 수 있을 것이다.
In addition, the solution of the above-mentioned problems does not list all the features of the present invention. The various features of the present invention and the advantages and effects thereof will be more fully understood by reference to the following specific embodiments.
본 발명에 따르면, 종래 황산-염산 복합 내식강에 비하여 저합금계이면서도 우수한 복합내식성을 가지는 열연강판을 제공할 수 있다. 또한, 본 발명의 열연강판은 황산 및 염산에 대한 복합 부식이 발생하는 발전소 탈질, 탈황설비, 보일러의 배연가스 배관 및 예열기의 비교적 두꺼운 두께를 요구하는 소재에 적합하게 적용할 수 있을 뿐만 아니라, 이들의 수명을 크게 연장하는 효과가 있다.
According to the present invention, it is possible to provide a hot-rolled steel sheet having a low corrosion resistance and excellent corrosion resistance compared with conventional sulfuric acid-hydrochloric acid combined corrosion resistant steel. In addition, the hot-rolled steel sheet of the present invention can be suitably applied to materials requiring relatively thick thicknesses of denitrification plants, desulfurization facilities, flue gas piping of boilers, and preheaters where complex corrosion of sulfuric acid and hydrochloric acid occurs, It is possible to greatly extend the life of the battery.
본 발명자들은 황산-염산 복합 내식강에서 구리(Cu)의 함량은 최소화하면서, 높은 복합내식성을 확보할 수 있는 방법에 대하여 강판의 조성 및 제조방법의 양 측면으로 연구를 거듭한 결과, 강판의 일 조성으로 Sb를 첨가함과 동시에, 열간압연 후 냉각조건을 적절히 제어할 경우 강판의 표면에 Cu 및 Sb 농축층이 형성되어 높은 복합내식성을 확보할 수 있음을 확인하고, 본 발명을 완성하기에 이르렀다.
The inventors of the present invention have conducted studies on the composition and production method of steel sheet for a method capable of ensuring high complex corrosion resistance while minimizing the content of copper (Cu) in sulfuric acid-hydrochloric acid composite corrosion resistant steel. As a result, Sb is added to the steel sheet and Cu and Sb concentrated layers are formed on the surface of the steel sheet when the cooling conditions after the hot rolling are appropriately controlled to secure a high composite corrosion resistance and the present invention has been completed .
이하, 본 발명의 일 측면인 황산 및 염산 복합내식성이 우수한 열연강판에 대하여 상세히 설명한다.
Hereinafter, a hot rolled steel sheet excellent in sulfuric acid and hydrochloric acid combined corrosion resistance, which is one aspect of the present invention, will be described in detail.
먼저, 본 발명 열연강판의 합금조성에 대하여 상세히 설명한다.First, the alloy composition of the hot-rolled steel sheet of the present invention will be described in detail.
탄소(C): 0.05~0.1중량%Carbon (C): 0.05 to 0.1 wt%
탄소(C)는 강판의 강도 확보에 유리한 원소로서, 그 함량이 0.05 중량% 미만이면 목표 강도의 확보가 어려우며 내마모 특성이 저하되는 문제가 있다. 반면 그 함량이 0.1중량%를 초과하게 되면 강판 용접시 용접성이 크게 나빠져 결함이 발생할 가능성이 높고, 내식성도 크게 저하하는 문제가 있다. 따라서, 본 발명에서는 상기 탄소의 함량은 0.05~0.1중량%로 제한함이 바람직하다.
Carbon (C) is an element favorable in securing strength of a steel sheet. When the content is less than 0.05% by weight, it is difficult to secure a desired strength and there is a problem that wear resistance characteristics are deteriorated. On the other hand, if the content exceeds 0.1% by weight, the weldability is greatly deteriorated in the case of welding the steel sheet, so that the possibility of occurrence of defects is high, and the corrosion resistance is greatly deteriorated. Therefore, in the present invention, the carbon content is preferably limited to 0.05 to 0.1 wt%.
망간(Mn): 0.5~1.5중량%Manganese (Mn): 0.5 to 1.5 wt%
망간(Mn)은 강중 고용되어 있는 황을 망간황화물로 석출함으로써 상기 고용 황에 의한 적열취성(hot shortness)을 방지하는 역할을 하며, 고용강화 효과를 발현하는 원소이다. 상기 망간의 함량이 0.5중량% 미만인 경우에는 망간황화물이 충분히 석출되지 못하여 고용 황에 의한 적열취성이 발생한 우려가 있으며, 목표 강도의 확보가 어려운 문제가 있다. 반면, 그 함량이 1.5중량%를 초과하는 경우에는 상술한 효과가 포화되며, 제조원가가 급격히 상승하는 문제가 있으므로, 본 발명에서는 상기 망간의 함량은 0.5~1.5중량%로 제한함이 바람직하다.
Manganese (Mn) is an element that acts to prevent hot shortness caused by the solid solution sulfur by precipitating sulfur dissolved in the steel into manganese sulfide, and exhibiting the solid solution strengthening effect. When the content of manganese is less than 0.5% by weight, manganese sulfide can not be sufficiently precipitated, and there is a fear that a hot brittleness due to solid sulfur is generated, and it is difficult to secure a target strength. On the other hand, when the content exceeds 1.5% by weight, the above-mentioned effect is saturated and the production cost increases sharply. Therefore, in the present invention, the content of manganese is preferably limited to 0.5 to 1.5% by weight.
인(P): 0.02 중량% 이하Phosphorus (P): not more than 0.02% by weight
인(P)은 강 중 불가피하게 첨가되는 원소이며, 그 함량이 0.02 중량%를 초과하게 되면 목표로 하는 복합내식성이 크게 저하되는 문제가 있다. 따라서, P의 함량을 0.02 중량% 이하로 관리하는 것이 바람직하다.
Phosphorus (P) is an element which is inevitably added in the steel, and when the content exceeds 0.02% by weight, there is a problem that the intended composite corrosion resistance is largely lowered. Therefore, it is preferable to control the P content to 0.02 wt% or less.
황(S): 0.02 중량% 이하Sulfur (S): 0.02 wt% or less
황(S)은 강 중 고용되어 적열취성을 유발하는 원소이므로, 그 함량을 가능한 낮게 제어하는 것이 바람직하다. 그 함량이 0.02 중량%를 초과하게 되면 적열취성에 의한 결함발생 가능성이 높아지는 문제가 있으므로, S의 함량을 0.02 중량% 이하로 관리하는 것이 바람직하다.
Sulfur (S) is an element which is dissolved in the steel and causes red embrittlement. Therefore, it is desirable to control the content as low as possible. When the content exceeds 0.02% by weight, there is a problem that the possibility of occurrence of defects due to the heat-induced brittleness is increased. Therefore, it is preferable to control the S content to 0.02% by weight or less.
알루미늄(Al): 0.01~0.1 중량%Aluminum (Al): 0.01 to 0.1 wt%
알루미늄(Al)은 알루미늄 킬드강(Al-killed) 강 제조시 불가피하게 첨가되는 원소로서, 탈산효과를 위해 0.01중량% 이상 첨가됨이 바람직하다. 다만, 상기 알루미늄의 함량이 0.1중량%를 초과하는 경우에는 강판의 표면결함을 유발할 가능성이 높아질 뿐만 아니라 용접성이 저하되는 문제가 있다. 따라서, 본 발명에서는 Al의 함량을 0.01~0.1 중량%로 제한하는 것이 바람직하다.
Aluminum (Al) is an element which is inevitably added in the production of aluminum killed steel (Al-killed steel), and is preferably added in an amount of 0.01 wt% or more for deoxidizing effect. However, when the content of aluminum exceeds 0.1% by weight, there is a problem that not only the possibility of causing surface defects of the steel sheet increases but also the weldability is deteriorated. Therefore, in the present invention, the content of Al is preferably limited to 0.01 to 0.1% by weight.
구리(Cu): 0.2~0.7 중량%Copper (Cu): 0.2 to 0.7 wt%
구리(Cu)는 내황산 및 내염산의 복합부식특성을 고려하여 첨가하는 원소로서, 그 함량이 0.2 중량% 미만이면 목표로 하는 복합내식성을 확보하기 어려우므로, 0.2% 이상으로 첨가하는 것이 바람직하다. 복합내식성은 Cu의 함량이 증가할수록 향상되지만, 그 함량이 0.7 중량%를 초과하게 되면 내식성 증가폭이 크게 저하하고, 제조원가가 급격히 상승하는 문제가 있다. 따라서, 본 발명에서는 Cu의 함량을 0.2~0.7 중량%로 제한하는 것이 바람직하다.
Copper (Cu) is an element to be added in consideration of the complex corrosion property of sulfuric acid and hydrochloric acid. When the content is less than 0.2% by weight, it is difficult to secure the desired complex corrosion resistance. . The composite corrosion resistance increases as the content of Cu increases, but when the content exceeds 0.7% by weight, the increase in the corrosion resistance significantly decreases and the manufacturing cost increases sharply. Therefore, in the present invention, the content of Cu is preferably limited to 0.2 to 0.7 wt%.
안티몬(Sb): 0.05~0.1중량%Antimony (Sb): 0.05 to 0.1 wt%
안티몬(Sb)은 상기 Cu와 함께 복합내식성을 향상시키기 위해 필수로 첨가하는 원소로서, 특히 부식환경에서 Sb 산화물 또는 Cu-Sb 복합산화물을 형성시킴으로써 복합내식성을 효과적으로 향상시킬 수 있는 원소이다. 상기 안티몬의 함량이 0.05중량% 미만이면 상술한 효과를 얻기 어려우며, 반면 0.1중량%를 초과하게 되면 상술한 효과가 포화될 뿐만 아니라, 제조원가가 급격히 상승하는 문제가 있으므로, 이를 고려하여 0.1중량% 이하로 첨가하는 것이 바람직하다.
Antimony (Sb) is an element that is added as an indispensable element in order to improve complex corrosion resistance together with Cu. It is an element that can effectively improve complex corrosion resistance by forming Sb oxide or Cu-Sb composite oxide particularly in a corrosive environment. If the content of antimony is less than 0.05% by weight, it is difficult to obtain the above-mentioned effect. On the other hand, if it exceeds 0.1% by weight, the above-mentioned effect is saturated and the production cost increases sharply. .
상기 조성 이외에 나머지는 Fe 및 불가피한 불순물로 이루어진다. 다만, 상기 조성이외에 다른 조성이 포함될 수 없음을 배제하는 것은 아니다.
In addition to the above composition, the remainder is composed of Fe and unavoidable impurities. However, it is not excluded that compositions other than the above composition can not be included.
한편, 본 발명의 열연강판은 그 표면으로부터 두께 방향으로 500nm 이내에 Cu 및 Sb가 농축되어 있는 것이 바람직하다. 이들 원소들은 강판의 제조시에는 표면에 농화된 상태로 존재하다가 황산 및 염산에 의한 부식환경에 노출될 경우, Cu 산화물, Sb 산화물, Cu-Sb 복합산화물의 형태로 변함으로써 열연강판의 내식성을 매우 우수한 수준으로 향상시킨다.On the other hand, in the hot-rolled steel sheet of the present invention, it is preferable that Cu and Sb are concentrated within 500 nm in the thickness direction from the surface. These elements are present in concentrated state on the surface during the manufacture of the steel sheet, and when they are exposed to the corrosive environment by sulfuric acid and hydrochloric acid, they change into the forms of Cu oxide, Sb oxide and Cu-Sb composite oxide, Improvement to excellent level.
이 때, 농축된 Cu 및 Sb의 함량에 대해서는 특별히 한정하지 아니하며, 하기에서 설명할 바와 같이, 황산 및 염산에 의한 부식환경에서 열연강판의 표면으로부터 200nm 두께 이상의 산화물층을 형성할 수 있을 정도라면 무방하다. 상기 산화물층의 두께가 200nm 미만인 경우에는 본 발명이 목표로 하는 내식성 확보가 곤란하다. 한편, 상기 산화물층의 두께가 두꺼워질수록 내식성이 보다 향상되므로, 본 발명에서는 상기 산화물층 두께의 상한에 대해서는 특별히 한정하지 않는다. 다만, 400nm를 초과하는 경우에는 다량의 합금 첨가 대비 내식성 향상 효과가 낮을 뿐만 아니라, 제조원가가 과도하게 상승하는 문제가 있으므로, 상기 산화물층의 두께는 200~400nm인 것이 보다 바람직하다.
At this time, the content of concentrated Cu and Sb is not particularly limited. As will be described below, if the oxide layer having a thickness of 200 nm or more can be formed from the surface of the hot-rolled steel sheet in a corrosive environment by sulfuric acid and hydrochloric acid, Do. When the thickness of the oxide layer is less than 200 nm, it is difficult to secure the intended corrosion resistance of the present invention. On the other hand, since the corrosion resistance is improved as the thickness of the oxide layer is increased, the upper limit of the thickness of the oxide layer is not particularly limited in the present invention. However, when the thickness is more than 400 nm, the effect of improving the corrosion resistance of a large amount of alloying addition is low, and the manufacturing cost is excessively increased. Therefore, the thickness of the oxide layer is more preferably 200 to 400 nm.
본 발명의 열연강판은 황산 16.9부피% + 염산 0.35부피% 용액에 대한 부식 감량이 2.0mg/cm2/hr 이하로서 매우 우수한 복합내식성을 갖는다.
The hot-rolled steel sheet of the present invention has a corrosion resistance loss of 2.0 mg / cm 2 / hr or less with respect to 16.9% by volume sulfuric acid + 0.35% by volume hydrochloric acid solution.
이하, 본 발명의 다른 일측면인 황산 및 염산 복합내식성이 우수한 열연강판의 제조방법에 대하여 상세히 설명한다.
Hereinafter, a method of manufacturing a hot-rolled steel sheet having excellent corrosion resistance to sulfuric acid and hydrochloric acid, which is another aspect of the present invention, will be described in detail.
우선, 상술한 조성을 만족하는 강 슬라브를 준비한 뒤, 1100~1300℃에서 재가열한다. 재가열 온도가 1100℃ 미만인 경우에는 후속되는 열간압연시의 온도를 확보하기 어려운 문제가 있으며, 반면, 재가열 온도가 1300℃를 초과하는 경우에는 융점이 낮은 Cu가 용출하여 슬라브 표면에 크랙(crack)이 발생할 가능성이 높다는 문제가 있다.
First, a steel slab satisfying the above composition is prepared and reheated at 1100 to 1300 ° C. When the reheating temperature is less than 1100 ° C, there is a problem that it is difficult to secure the temperature during subsequent hot rolling. On the other hand, when the reheating temperature exceeds 1300 ° C, Cu having a low melting point elutes and cracks There is a problem that the possibility of occurrence is high.
이후, 상기 재가열된 강 슬라브를 열간압연하고, 850~950℃에서 마무리 열간압연하여 열연강판을 얻는다. 마무리 열간압연 온도가 850℃ 미만인 경우에는 연신된 결정립의 생성으로 인해 연신율이 크게 저하하고, 방향별 재질편차가 불균일해지는 문제가 있으며, 반면 950℃를 초과하게 되면 오스테나이트 결정립이 조대해져 경화능이 크게 증가하는 문제가 있다.
Thereafter, the reheated steel slab is hot-rolled and finishing hot-rolled at 850 to 950 ° C to obtain a hot-rolled steel sheet. When the final hot rolling temperature is lower than 850 ° C, there is a problem that the elongation rate is greatly lowered due to the formation of the elongated crystal grains and the material deviation is uneven in each direction. On the other hand, when it exceeds 950 ° C, the austenite grains become coarse, There is an increasing problem.
이후, 상기 열연강판을 강판의 표면온도를 기준으로 80~150℃/s로 급냉한다. 상기와 같은 급냉을 통하여 권취 후 내식성에 유리한 합금원소가 강판의 표면으로 이동하는데 필요한 추진력을 제공할 수 있다. 냉각속도가 80℃/s 미만이면 열연강판의 표면온도가 너무 높아 강 내부에 존재하는 산화물 형성 원소들이 표면으로 이동하는 추진력이 낮아, 최종적으로 강판이 복합적인 부식환경에 노출되었을 때 충분한 산화물이 형성되기 어려운 문제가 있다. 반면, 냉각속도가 150℃/s를 초과하게 되면 강판내부의 온도가 너무 낮아져 권취 후 목적하는 온도까지 복열이 이루어지지 않아 산화물층 형성에 유리한 합금원소의 이동이 원활하게 이루어지지 않는 문제가 있다. 따라서, 상기 냉각속도는 80~150℃/s이 바람직하다. 상기 냉각속도는 90~150℃/s인 것이 보다 바람직하며, 100~150℃/s인 것이 보다 더 바람직하다.
Thereafter, the hot-rolled steel sheet is quenched to 80 to 150 ° C / s based on the surface temperature of the steel sheet. By the quenching as described above, it is possible to provide the driving force necessary for the alloying element which is advantageous in corrosion resistance after winding to move to the surface of the steel sheet. When the cooling rate is less than 80 ° C / s, the surface temperature of the hot-rolled steel sheet is too high, so that the driving force of the oxide-forming elements present in the steel to the surface is low. Finally, when the steel sheet is exposed to a complex corrosive environment, There is a problem that is difficult to be done. On the other hand, when the cooling rate exceeds 150 ° C / s, the temperature inside the steel sheet becomes too low, so that there is a problem that the alloying element which is advantageous for the formation of the oxide layer is not smoothly moved. Therefore, the cooling rate is preferably 80 to 150 DEG C / s. The cooling rate is more preferably 90 to 150 DEG C / s, and still more preferably 100 to 150 DEG C / s.
이후, 상기 냉각된 열연강판을 650~750℃에서 권취한다. 권취온도가 650℃ 미만일 경우에는 권취공정에서 원자의 이동이 용이하지 않아 농축층의 형성이 곤란하여 부식환경에서 산화물층이 형성되지 않아 충분한 내식성을 확보하기 어려울 수 있다. 상기 권취온도가 750℃를 초과하는 경우에는 복열되는 온도가 너무 높아 권취된 강판이 찌그러지는 등 결함이 발생할 수 있으므로, 상기 권취온도는 650~750℃의 범위를 갖는 것이 바람직하다.
Thereafter, the cooled hot-rolled steel sheet is rolled at 650 to 750 ° C. When the coiling temperature is less than 650 캜, the movement of atoms is not easy in the winding step, so that formation of a dense layer is difficult, and an oxide layer is not formed in a corrosive environment, so that it is difficult to secure sufficient corrosion resistance. If the coiling temperature exceeds 750 캜, the coiling temperature may be too high to cause defects such as warping of the wound steel plate. Therefore, the coiling temperature preferably ranges from 650 to 750 캜.
한편, 상기 권취시에는 상기 강판의 표면이 복열현상에 의해 700℃ 이상이 되도록 하는 것이 바람직하다. 상기 냉각 공정을 통해 강판 내부의 온도가 670~750℃의 범위를 갖도록 하더라도 상기 강판의 표면은 급냉에 의해 상기 온도범위보다 낮은 온도를 가지게 된다. 따라서, 상기 복열 과정을 거침으로써 산화물층 형성에 유리한 합금원소의 이동이 활발해지도록 하고, 이를 통해 농축층이 충분한 두께로 형성되도록 할 수 있다. 상기 효과를 충분히 얻기 위해서는 상기 복열을 거친 강판의 표면 온도가 700℃ 이상인 것이 바람직하다. 다만, 충분한 복열 과정을 거치라도 강판의 표면온도가 750℃를 초과하기는 어렵다.
On the other hand, at the time of winding, it is preferable that the surface of the steel sheet is heated to 700 ° C or more by double heat. The surface of the steel sheet has a temperature lower than the temperature range by quenching even if the temperature inside the steel sheet is in the range of 670 to 750 ° C through the cooling process. Therefore, by moving the alloying element favorable for the formation of the oxide layer through the repetition process, the concentrated layer can be formed to have a sufficient thickness. In order to sufficiently obtain the above effect, it is preferable that the surface temperature of the steel sheet subjected to the double heat treatment is 700 ° C or higher. However, it is difficult for the surface temperature of the steel sheet to exceed 750 ° C even after sufficient repetition.
상기 권취된 강판을 30~50℃/hr의 속도로 300~400℃까지 서냉한다. 상기 냉각속도가 과도하게 빠른 경우에는 농축층을 형성하는 원소인 Cu의 이동이 충분하지 못하여 충분한 두께의 농축층 형성이 곤란할 수 있으므로, 상기 냉각속도는 50℃/hr 이하의 범위를 갖는 것이 바람직하다. 반면, 30℃/hr미만일 경우에는 결정립의 크기가 과도하게 커져 강도가 낮아질 수 있으므로, 상기 냉각속도는 30~50℃/hr의 범위를 갖는 것이 바람직하다. 따라서, 상기 냉각속도는 30~50℃/hr의 범위인 것이 바람직하다. 상기 냉각속도는 30~40℃/hr인 것이 보다 바람직하다. 한편, 상기 냉각정지온도가 300℃ 미만일 경우에는 냉각시간이 너무 길어 생산성에 문제가 있고, 반면 400℃를 초과하는 경우에는 농축층의 두께가 충분하지 못하여 내식성이 열위하는 문제가 있을 수 있다. 따라서, 상기 냉각정지온도는 300~400℃의 범위인 것이 바람직하다.
The rolled steel sheet is slowly cooled to 300 to 400 ° C at a rate of 30 to 50 ° C / hr. If the cooling rate is excessively high, the movement of Cu, which is an element forming the dense layer, may not be sufficient and it may be difficult to form a dense layer having a sufficient thickness. Therefore, the cooling rate is preferably 50 ° C / hr or less . On the other hand, when the cooling rate is less than 30 ° C / hr, the grain size becomes excessively large and the strength may be lowered. Therefore, the cooling rate is preferably in the range of 30 to 50 ° C / hr. Therefore, the cooling rate is preferably in the range of 30 to 50 DEG C / hr. The cooling rate is more preferably 30 to 40 ° C / hr. On the other hand, when the cooling stop temperature is less than 300 ° C, the cooling time is too long to cause a problem in productivity. On the other hand, when the cooling stop temperature is more than 400 ° C, the thickness of the concentrated layer is insufficient. Therefore, the cooling stop temperature is preferably in the range of 300 to 400 ° C.
이하, 실시예를 통하여 본 발명을 보다 구체적으로 설명하고자 한다. 다만, 하기의 실시예는 본 발명을 예시하여 보다 상세하게 설명하기 위한 것일 뿐, 본 발명의 권리범위를 한정하기 위한 것이 아니라는 점에 유의할 필요가 있다. 본 발명의 권리범위는 특허청구범위에 기재된 사항과 이로부터 합리적으로 유추되는 사항에 의해 결정되는 것이기 때문이다.
Hereinafter, the present invention will be described more specifically by way of examples. It should be noted, however, that the following examples are intended to illustrate the invention in more detail and not to limit the scope of the invention. The scope of the present invention is determined by the matters set forth in the claims and the matters reasonably inferred from them.
(( 실시예Example ))
하기 표 1에 나타낸 바와 같은 성분조성으로 용해하여 제조한 강괴를 1200℃ 가열로에서 1시간 유지한 후 열간압연하였다. 이때, 마무리 열간압연은 900℃에서 실시하였으며, 최종 4.5mm의 두께를 갖는 열연강판을 제조하였다. 이후, 하기 표 2에 나타낸 조건으로 냉각 및 권취한 후 유지하였다. 그 다음, 40℃/h의 속도로 냉각하여, 최종 열연강판을 제조하였다.
A steel ingot prepared by dissolving in a composition as shown in Table 1 was held in a heating furnace at 1200 占 폚 for 1 hour and then hot-rolled. At this time, finishing hot rolling was performed at 900 캜, and a hot rolled steel sheet having a final thickness of 4.5 mm was produced. Thereafter, it was cooled and wound up under the conditions shown in Table 2, and then held. Then, the steel sheet was cooled at a rate of 40 DEG C / h to produce a final hot-rolled steel sheet.
상기에 따라 제조된 열연강판의 부식특성을 관찰하기 위하여, 각각의 시편을 60℃의 황산 16.9부피% + 염산 0.35부피% 용액에 6시간 동안 침적한 후 각 시편의 부식감량을 측정하고, 그 결과를 하기 표 2에 나타내었다. In order to observe the corrosion characteristics of the hot-rolled steel sheet manufactured according to the above, the specimens were immersed in a solution of 16.9 vol% sulfuric acid at 60 ° C and 0.35 vol% hydrochloric acid for 6 hours, and then the corrosion loss of each specimen was measured. Are shown in Table 2 below.
또한, 황산-염산 복합부식조건에서의 침적 완료 후 강판 표면에 형성된 산화물층(내식층)의 두께를 측정하여 표 2에 나타내었다.
Further, the thickness of the oxide layer (corrosion resistant layer) formed on the surface of the steel sheet after completion of the deposition under the sulfuric acid-hydrochloric acid complex corrosion condition was measured and shown in Table 2.
Steel grade
(℃/s)
Cooling rate
(° C / s)
(℃)
Coiling temperature
(° C)
(℃/s)Cooling rate
(° C / s)
(℃)Coiling temperature
(° C)
상기 표 1 및 2에서 알 수 있듯이, 본 발명이 제안하는 합금조성과 제조조건을 만족하는 발명예 1 내지 3의 경우에는 320nm 이상의 산화물층이 형성됨으로써 황산 및 염산에 의한 부식환경하에서 부식감량이 2.0mg/㎠/Hr이하로 매우 우수한 내식특성을 가지고 있음을 알 수 있다.
As can be seen from Tables 1 and 2, in the case of Inventive Examples 1 to 3 satisfying the alloy composition and manufacturing conditions proposed by the present invention, an oxide layer having a thickness of 320 nm or more is formed, and the corrosion loss is 2.0 mg / ㎠ / Hr or less.
비교예 1은 본 발명의 합금조성을 만족하나, 권취온도가 500℃로 낮아 산화물층이 충분히 형성되지 않았으며, 이로 인해 부식감량이 4.5mg/㎠/hr로서 내식성이 매우 낮은 것을 알 수 있다.
The comparative example 1 satisfies the alloy composition of the present invention, but the oxide layer is not sufficiently formed because the coiling temperature is as low as 500 占 폚 and the corrosion loss is 4.5 mg / cm2 / hr, which indicates that the corrosion resistance is very low.
비교예 2 내지 4는 본 발명의 합금조성을 만족하나, 냉각속도가 10℃/s로서 낮은 수준이어서, 산화물층이 충분히 형성되지 않았으며, 이로 인해 부식감량이 3.2mg/㎠/hr 이상으로서 내식성이 매우 낮은 것을 알 수 있다.
Comparative Examples 2 to 4 satisfied the alloy composition of the present invention but the cooling rate was as low as 10 占 폚 / s, so that the oxide layer was not sufficiently formed, and the corrosion loss was 3.2 mg / It can be seen that it is very low.
비교예 5의 경우에는 본 발명의 제조조건을 만족하나, Sb가 첨가되지 않아 황산 및 염산에 의한 부식환경에서 부식감량 8.8 mg/cm2/hr로서 내식성이 매우 낮은 수준임을 알 수 있다. 이는 산화물층 내 내식성이 우수한 Cu-Sb 산화물 및 Sb 산화물이 존재하지 않기 때문이다.
In the case of Comparative Example 5, the production conditions of the present invention are satisfied, but Sb is not added, and the corrosion resistance is 8.8 mg / cm 2 / hr in the corrosive environment by sulfuric acid and hydrochloric acid. This is because Cu-Sb oxide and Sb oxide, which are excellent in the corrosion resistance in the oxide layer, are not present.
이상 실시예를 참조하여 설명하였지만, 해당 기술 분야의 숙련된 통상의 기술자는 하기의 특허 청구의 범위에 기재된 본 발명의 사상 및 영역으로부터 벗어나지 않는 범위 내에서 본 발명을 다양하게 수정 및 변경시킬 수 있음을 이해할 수 있을 것이다.While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. .
Claims (6)
표면으로부터 두께 방향으로 500nm 이내에 Cu 및 Sb가 농축되어 있으며,
황산 16.9부피% + 염산 0.35부피% 용액에 대한 부식 감량이 2.0mg/cm2/hr 이하인 황산 및 염산 복합내식성이 우수한 열연강판.
0.05 to 0.1% of C, 0.5 to 1.5% of Mn, 0.02% or less of P, 0.02% or less of S, 0.01 to 0.1% of Al, 0.2 to 0.7% %, The balance Fe and other unavoidable impurities,
Cu and Sb are concentrated within 500 nm from the surface in the thickness direction,
Sulfuric acid and hydrochloric acid composite having a corrosion loss of 2.0 mg / cm 2 / hr or less for 16.9% by volume sulfuric acid + 0.35% by volume hydrochloric acid solution.
상기 농축된 Cu 및 Sb는 황산 및 염산 부식환경에서 Cu 산화물, Sb 산화물 및 Cu-Sb 산화물로 이루어진 그룹에서 선택된 1종 이상을 포함하는 산화물층을 형성하는 것을 특징으로 하는 황산 및 염산 복합내식성이 우수한 열연강판.
The method according to claim 1,
Wherein the concentrated Cu and Sb form an oxide layer containing at least one selected from the group consisting of Cu oxide, Sb oxide and Cu-Sb oxide in a sulfuric acid and hydrochloric acid corrosion environment. Hot rolled steel sheet.
상기 산화물층은 상기 열연강판 표면으로부터 두께 방향으로 200~400nm의 두께로 형성되는 것을 특징으로 하는 황산 및 염산 복합내식성이 우수한 열연강판.
3. The method of claim 2,
Wherein the oxide layer is formed to a thickness of 200 to 400 nm in a thickness direction from a surface of the hot-rolled steel sheet.
상기 재가열된 강 슬라브를 열간압연하고, 850~950℃에서 마무리 열간압연하여 열연강판을 얻는 단계;
상기 열연강판을 80~150℃/s의 속도로 급냉하는 단계;
상기 냉각된 열연강판을 650~750℃에서 권취하는 단계; 및
상기 권취된 열연강판을 30~50℃/h의 속도로 300~400℃까지 서냉하는 단계를 포함하는 황산 및 염산 복합내식성이 우수한 열연강판의 제조방법.
0.05 to 0.1% of C, 0.5 to 1.5% of Mn, 0.02% or less of P, 0.02% or less of S, 0.01 to 0.1% of Al, 0.2 to 0.7% %, Remainder Fe and other unavoidable impurities at 1100-1300 캜;
Hot-rolling the reheated steel slab and finishing hot-rolling at 850 to 950 ° C to obtain a hot-rolled steel sheet;
Quenching the hot-rolled steel sheet at a rate of 80 to 150 ° C / s;
Winding the cooled hot-rolled steel sheet at 650 to 750 ° C; And
And slowly cooling the wound hot-rolled steel sheet at a temperature of 30 to 50 占 폚 / h to 300 to 400 占 폚.
상기 권취시, 상기 강판의 표면이 복열 현상에 의해 700℃ 이상이 되도록 하는 황산 및 염산 복합내식성이 우수한 열연강판의 제조방법.6. The method of claim 5,
Wherein the surface of the steel sheet is 700 占 폚 or higher due to a double heat phenomenon at the time of winding the steel sheet.
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|---|---|---|---|---|
| KR20180027534A (en) * | 2015-05-28 | 2018-03-14 | 주식회사 포스코 | Hot-rolled steel sheet excellent in corrosion resistance of sulfuric acid and hydrochloric acid complex and method for manufacturing the same |
| WO2020032557A1 (en) | 2018-08-08 | 2020-02-13 | 주식회사 포스코 | Composition for steel sheet surface coating and steel sheet surface-coated with same |
| KR20200096189A (en) | 2018-08-08 | 2020-08-11 | 주식회사 포스코 | Composition for coating surface of steel sheet and surface-coated steel sheet using the same |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| KR102045881B1 (en) | 2016-09-28 | 2019-11-19 | 주식회사 포스코 | Solution composition for surface treating of steel sheet, steel sheet using the same, and manufacturing method of the same |
| KR20200065990A (en) * | 2018-11-30 | 2020-06-09 | 주식회사 포스코 | Corrosion resistant steel having high resistance to corrosion at sulfuric and sulfuric/hydrochloric acid condensing environment and manufacturing method the same |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003105488A (en) | 2001-10-01 | 2003-04-09 | Nippon Steel Corp | Steel having excellent molten acid ammonium sulfate corrosion resistance |
| JP2003213367A (en) * | 2001-11-19 | 2003-07-30 | Nippon Steel Corp | Low alloy steel having excellent hydrochloric acid- corrosion and sulfuric acid-corrosion resistance and welded joint thereof |
| JP2007262558A (en) * | 2006-03-30 | 2007-10-11 | Jfe Steel Kk | Sulfuric acid dew point corrosion resistant steel having excellent hydrochloric acid resistance |
| JP2012180546A (en) | 2011-02-28 | 2012-09-20 | Nisshin Steel Co Ltd | Sulfuric acid dew point corrosion resistant steel and exhaust gas flow-path constructional element |
-
2013
- 2013-12-06 KR KR1020130151739A patent/KR101560902B1/en active IP Right Grant
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003105488A (en) | 2001-10-01 | 2003-04-09 | Nippon Steel Corp | Steel having excellent molten acid ammonium sulfate corrosion resistance |
| JP2003213367A (en) * | 2001-11-19 | 2003-07-30 | Nippon Steel Corp | Low alloy steel having excellent hydrochloric acid- corrosion and sulfuric acid-corrosion resistance and welded joint thereof |
| JP2007262558A (en) * | 2006-03-30 | 2007-10-11 | Jfe Steel Kk | Sulfuric acid dew point corrosion resistant steel having excellent hydrochloric acid resistance |
| JP2012180546A (en) | 2011-02-28 | 2012-09-20 | Nisshin Steel Co Ltd | Sulfuric acid dew point corrosion resistant steel and exhaust gas flow-path constructional element |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20180027534A (en) * | 2015-05-28 | 2018-03-14 | 주식회사 포스코 | Hot-rolled steel sheet excellent in corrosion resistance of sulfuric acid and hydrochloric acid complex and method for manufacturing the same |
| KR102098511B1 (en) * | 2015-05-28 | 2020-04-07 | 주식회사 포스코 | Hot rolled steel sheet with excellent corrosion resistance of sulfuric acid and hydrochloric acid and its manufacturing method |
| WO2020032557A1 (en) | 2018-08-08 | 2020-02-13 | 주식회사 포스코 | Composition for steel sheet surface coating and steel sheet surface-coated with same |
| KR20200017108A (en) | 2018-08-08 | 2020-02-18 | 주식회사 포스코 | Composition for coating surface of steel sheet and surface-coated steel sheet using the same |
| KR20200096189A (en) | 2018-08-08 | 2020-08-11 | 주식회사 포스코 | Composition for coating surface of steel sheet and surface-coated steel sheet using the same |
| KR102310526B1 (en) | 2018-08-08 | 2021-10-08 | 주식회사 포스코 | Composition for coating surface of steel sheet and surface-coated steel sheet using the same |
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