KR20150057815A - Steel sheet for complex corrosion resistance to sulfuric acid and hydrochloric acid and method for manufacturing the same - Google Patents
Steel sheet for complex corrosion resistance to sulfuric acid and hydrochloric acid and method for manufacturing the same Download PDFInfo
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- KR20150057815A KR20150057815A KR1020130141627A KR20130141627A KR20150057815A KR 20150057815 A KR20150057815 A KR 20150057815A KR 1020130141627 A KR1020130141627 A KR 1020130141627A KR 20130141627 A KR20130141627 A KR 20130141627A KR 20150057815 A KR20150057815 A KR 20150057815A
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- steel sheet
- hot
- sulfuric acid
- corrosion resistance
- corrosion
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 97
- 239000010959 steel Substances 0.000 title claims abstract description 97
- 238000005260 corrosion Methods 0.000 title claims abstract description 68
- 230000007797 corrosion Effects 0.000 title claims abstract description 68
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 title claims abstract description 60
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims description 12
- 238000004519 manufacturing process Methods 0.000 title abstract description 13
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 238000001816 cooling Methods 0.000 claims description 31
- 239000010949 copper Substances 0.000 claims description 30
- 229910052802 copper Inorganic materials 0.000 claims description 12
- 239000011572 manganese Substances 0.000 claims description 12
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 11
- 229910017932 Cu—Sb Inorganic materials 0.000 claims description 11
- 238000004804 winding Methods 0.000 claims description 8
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 6
- 238000005098 hot rolling Methods 0.000 claims description 6
- 238000003303 reheating Methods 0.000 claims description 6
- 238000005096 rolling process Methods 0.000 claims description 6
- 229910052717 sulfur Inorganic materials 0.000 claims description 6
- 239000011593 sulfur Substances 0.000 claims description 6
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- 229910052748 manganese Inorganic materials 0.000 claims description 5
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 3
- 229910052787 antimony Inorganic materials 0.000 claims description 3
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 claims description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 239000011574 phosphorus Substances 0.000 claims description 3
- 239000002131 composite material Substances 0.000 abstract description 19
- 239000000463 material Substances 0.000 abstract description 5
- 238000006477 desulfuration reaction Methods 0.000 abstract description 4
- 230000023556 desulfurization Effects 0.000 abstract description 4
- 238000010438 heat treatment Methods 0.000 abstract description 4
- 230000000052 comparative effect Effects 0.000 description 14
- 239000010935 stainless steel Substances 0.000 description 12
- 239000000203 mixture Substances 0.000 description 11
- 239000000243 solution Substances 0.000 description 10
- FZUJWWOKDIGOKH-UHFFFAOYSA-N sulfuric acid hydrochloride Chemical compound Cl.OS(O)(=O)=O FZUJWWOKDIGOKH-UHFFFAOYSA-N 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 230000007547 defect Effects 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- CADICXFYUNYKGD-UHFFFAOYSA-N sulfanylidenemanganese Chemical compound [Mn]=S CADICXFYUNYKGD-UHFFFAOYSA-N 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 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
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 229910000655 Killed steel Inorganic materials 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 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
- 239000003245 coal Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 239000002803 fossil fuel Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 230000000979 retarding effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000006104 solid solution Substances 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
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- 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
- C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
Description
본 발명은 화력 발전소 탈황, 탈질설비, 예열기 및 이들의 부품 등의 소재로 사용되는 내식용 강판에 관한 것으로, 보다 상세하게는 황산 및 염산에 대한 복합내식성이 우수한 강판 및 이의 제조방법에 관한 것이다.
More particularly, the present invention relates to a steel sheet excellent in complex corrosion resistance to sulfuric acid and hydrochloric acid, and a method for producing the steel sheet. BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a steel sheet used as a material for desulfurization,
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 다량으로 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 a superior effect of significantly retarding the sulfuric acid corrosion rate compared to other additive elements. However, when added in a large amount, copper (Cu) is added in an appropriate amount to cause cracking of 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, .
따라서, 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 copper (Cu) content in sulfuric acid-hydrochloric acid combined corrosion resistant steel.
본 발명의 일 측면은, 황산-염산 복합 내식강에 있어서 동일 함량의 구리(Cu)를 첨가한 강에 비해 내식성이 우수한 저합금계 복합내식용 강판 및 이를 제조하는 방법을 제공하고자 하는 것이다.
An aspect of the present invention is to provide a low alloy type composite corrosion-resistant steel sheet excellent in corrosion resistance compared to a steel to which copper (Cu) is added in the same amount of sulfuric acid-hydrochloric acid combined corrosion resistant steel, and a method of manufacturing the same.
본 발명의 일 측면은, 중량%로, 탄소(C): 0.05~0.1%, 망간(Mn): 0.5~1.5%, 알루미늄(Al): 0.01%~0.1%, 구리(Cu): 0.2~0.7%, 안티몬(Sb): 0.05~0.1%, 인(P): 0.02% 이하, 황(S): 0.02% 이하, 잔부 Fe 및 불가피한 불순물을 포함하고, 표면에는 Sb 및/또는 Cu-Sb 산화물을 포함하는 것인 황산 및 염산 복합내식용 강판을 제공한다.
One aspect of the present invention is a copper alloy sheet comprising 0.05 to 0.1% of carbon (C), 0.5 to 1.5% of manganese (Mn), 0.01 to 0.1% of aluminum (Al) (S): 0.02% or less, the balance being Fe and unavoidable impurities, Sb and / or Cu-Sb oxide is added to the surface, And a sulfuric acid and hydrochloric acid composite corrosion resistant steel sheet.
본 발명의 다른 일 측면은, 상술한 성분조성을 만족하는 강 슬라브를 1100~1300℃에서 재가열하는 단계; 상기 재가열된 강 슬라브를 열간압연하고, 850~950℃에서 마무리 압연하여 열연강판을 제조하는 단계; 상기 열연강판을 80~150℃/s의 냉각속도로 제1 냉각하는 단계; 상기 냉각한 열연강판을 권취한 후 유지하여 상기 열연강판 표면이 700℃ 이상으로 복열되도록 하는 단계; 상기 권취 및 유지 후 30~50℃/h의 냉각속도로 제2 냉각하는 단계; 및 상기 제2 냉각 후 내식처리하는 단계를 포함하는 황산 및 염산 복합내식용 강판의 제조방법을 제공한다.
According to another aspect of the present invention, there is provided a method for manufacturing a steel slab, comprising the steps of: reheating a steel slab satisfying the above-described compositional composition at 1100 to 1300 캜; Hot-rolling the reheated steel slab and finishing rolling at 850 to 950 ° C to produce a hot-rolled steel sheet; Cooling the hot-rolled steel sheet at a cooling rate of 80 to 150 ° C / s; Winding and holding the cooled hot-rolled steel sheet so that the surface of the hot-rolled steel sheet is reheated to 700 ° C or more; A second cooling step at a cooling rate of 30 to 50 DEG C / h after the winding and holding; And a step of subjecting the steel sheet to a second heat treatment followed by a corrosion-resistant treatment.
본 발명에 의하면, 종래 황산-염산 복합 내식강에 비하여 저합금계이면서도 복합내식성이 우수하게 향상된 복합내식용 강판을 제공할 수 있다.INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a composite corrosion resistant steel sheet that is improved in composite corrosion resistance while being a low alloy steel as compared with conventional sulfuric acid-hydrochloric acid composite corrosion resistant steel.
또한, 본 발명의 복합내식용 강판은 황산 및 염산에 대한 복합부식이 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.
Further, the composite corrosion resistant steel sheet of the present invention can be suitably applied to materials requiring relatively thick thicknesses of denitrification plants, desulfurization facilities, flue gas pipes of boilers, and preheaters where complex corrosion of sulfuric acid and hydrochloric acid occurs , It has an effect of significantly extending the life span thereof.
본 발명자들은 기존 다량의 Cu를 포함하는 황산-염산 복합 내식강에 비해 합금조성을 최적화시키면서도 황산 및 염산에 대한 복합내식성이 우수한 강판을 얻기 위하여 깊이 연구하였으며, 그 결과 첨가되는 Cu의 함량을 최소화시키면서, 동시에 Sb를 첨가하여 이들로부터 형성되는 산화물을 이용하여 황산 및 염산에 대한 복합내식성을 효과적으로 개선할 수 있음을 확인하고, 본 발명을 완성하기에 이르렀다.
The inventors of the present invention have studied to obtain a steel sheet excellent in complex corrosion resistance against sulfuric acid and hydrochloric acid while optimizing the composition of the alloy compared with the conventional sulfuric acid-hydrochloric acid corrosion resistant steel containing Cu, and as a result, And Sb is added thereto to effectively improve the complex corrosion resistance against sulfuric acid and hydrochloric acid using the oxides formed therefrom. The present invention has been accomplished based on these findings.
이하, 본 발명에 대하여 상세히 설명한다.
Hereinafter, the present invention will be described in detail.
본 발명의 일 측면에 따른 황산 및 염산에 대한 복합내식성이 우수한 강판은, 중량%로, 탄소(C): 0.05~0.1%, 망간(Mn): 0.5~1.5%, 알루미늄(Al): 0.01%~0.1%, 구리(Cu): 0.2~0.7%, 안티몬(Sb): 0.05~0.1%, 인(P): 0.02% 이하, 황(S): 0.02% 이하로 포함하는 것이 바람직하다.
A steel sheet excellent in complex corrosion resistance against sulfuric acid and hydrochloric acid according to one aspect of the present invention comprises 0.05 to 0.1% of carbon (C), 0.5 to 1.5% of manganese (Mn), 0.01% of aluminum (Al) (P): 0.02% or less, and sulfur (S): 0.02% or less in terms of copper (Cu)
이하에서는, 본 발명의 복합내식용 강판의 성분조성을 상기와 같이 한정한 이유에 대하여 상세히 설명한다. 이때, 특별한 언급이 없는 한 각 성분의 함량은 중량%를 의미한다.
Hereinafter, the reason why the composition of the composite corrosion resistant steel sheet of the present invention is limited as described above will be described in detail. At this time, the content of each component means weight% unless otherwise specified.
C: 0.05~0.1%C: 0.05 to 0.1%
탄소(C)는 강판의 강도 확보에 유리한 원소로서, 그 함량이 0.05% 미만이면 목표 강도의 확보가 어려우며, 이로 인해 내마모특성이 저하하는 문제가 있다. 반면. 그 함량이 0.1%를 초과하게 되면 강판 용접시 용접성이 크게 나빠져 결함이 발생할 가능성이 높고, 내식성도 크게 저하하는 문제가 있다.Carbon (C) is an element favorable for securing the strength of a steel sheet. If the content of carbon (C) is less than 0.05%, it is difficult to secure the target strength, thereby deteriorating the abrasion resistance. On the other hand. If the content exceeds 0.1%, there is a problem that the weldability is greatly deteriorated during the steel plate welding, the possibility of occurrence of defects is high, and the corrosion resistance is greatly deteriorated.
따라서, 본 발명에서는 C의 함량을 0.05~0.1%로 제한하는 것이 바람직하다.
Therefore, in the present invention, the content of C is preferably limited to 0.05 to 0.1%.
Mn: 0.5~1.5%Mn: 0.5 to 1.5%
망간(Mn)은 강 중 고용 황을 망간황화물로 석출하여 고용 황에 의한 적열취성(Hot shortness)을 방지하는 역할을 위하여 첨가하는 원소이다.Manganese (Mn) is an element added to precipitate solid sulfur in manganese sulfide in the steel and to prevent hot shortness caused by solid sulfur.
본 발명에서는 상술한 적열취성 방지 효과와 함께 고용강화를 위하여 첨가하며, 그 Mn의 함량이 0.5% 미만이면 강도가 낮고, 망간황화물이 충분히 형성되지 못하여 고용 황에 의한 적열취성이 발생할 우려가 있으며, 반면 1.5%를 초과하게 되면 상술한 효과가 포화되며, 제조비용을 고려하여 상한값을 1.5%로 제한하는 것이 바람직하다.
In the present invention, in addition to the effect of preventing the above-mentioned red-hot brittleness, it is added for reinforcement of the solid solution. If the content of Mn is less than 0.5%, the strength is low and manganese sulfide is not sufficiently formed, On the other hand, if it exceeds 1.5%, the above effect is saturated and it is preferable to limit the upper limit value to 1.5% in consideration of the manufacturing cost.
Al: 0.01%~0.1%Al: 0.01% to 0.1%
알루미늄(Al)은 통상 탈산효과를 위해 첨가하는 원소로서, 본 발명에서는 Al-킬드(killed)강 제조시 첨가되는 함량의 0.01%를 하한으로 한다. 다만, Al의 함량이 0.1%를 초과하게 되면 강판의 표면결함을 유발할 확률이 높아질 뿐만 아니라 용접성이 저하되는 문제가 있다.Aluminum (Al) is usually added for deoxidation. In the present invention, the lower limit of 0.01% of the content added in the production of Al-killed steel is set. However, if the content of Al exceeds 0.1%, not only the probability of causing surface defects of the steel sheet increases but also the weldability is deteriorated.
따라서, 본 발명에서는 Al의 함량을 0.01~0.1%로 제한하는 것이 바람직하다.
Therefore, in the present invention, the content of Al is preferably limited to 0.01 to 0.1%.
Cu: 0.2~0.7%Cu: 0.2 to 0.7%
구리(Cu)는 황산 및 염산에 대한 복합부식성을 향상시키기 위하여 첨가하는 원소로서, 그 함량이 0.2% 미만이면 목표로 하는 복합내식성을 확보하기 어려우므로, 0.2% 이상으로 첨가하는 것이 바람직하다. 복합내식성은 Cu의 함량이 증가할수록 향상되지만, 그 함량이 0.7%를 초과하게 되면 내식성 증가폭이 크게 저하하고, 제조원가가 급격히 상승하는 문제가 있다.Copper (Cu) is an element added to improve the complex corrosion resistance to sulfuric acid and hydrochloric acid. When the content is less than 0.2%, it is difficult to secure the intended complex corrosion resistance. The composite corrosion resistance increases as the content of Cu increases, but when the content exceeds 0.7%, the increase in corrosion resistance significantly decreases and the manufacturing cost increases sharply.
따라서, 본 발명에서는 Cu의 함량을 0.2~0.7%로 제한하는 것이 바람직하다.
Therefore, in the present invention, it is preferable to limit the Cu content to 0.2 to 0.7%.
Sb: 0.05~0.1%Sb: 0.05 to 0.1%
안티몬(Sb)은 강의 복합내식성 향상을 위해 첨가하는 원소로서, 특히 Sb은 부식 중에 Sb 산화물 또는 상술한 Cu와 반응하여 Cu-Sb 복합산화물을 형성함으로써 황산 및 염산에 대한 복합내식성을 크게 향상시키는 역할을 한다.Antimony (Sb) is an element added to improve the composite corrosion resistance of steel. In particular, Sb reacts with Sb oxide or Cu mentioned above during corrosion to form Cu-Sb composite oxide, thereby greatly improving complex corrosion resistance against sulfuric acid and hydrochloric acid .
상술한 효과를 얻기 위해서는 0.05% 이상으로 Sb을 첨가할 필요가 있으며, Sb의 함량이 증가할수록 복합내식성이 향상되지만, 그 함량이 0.1%를 초과하게 되면 복합내식성 증가폭이 크게 저하하게 된다.In order to obtain the above-mentioned effect, it is necessary to add Sb to 0.05% or more. As the content of Sb increases, the complex corrosion resistance improves. However, when the content exceeds 0.1%, the width of the increase in complex corrosion resistance greatly decreases.
따라서, 본 발명에서는 Sb의 함량을 0.05~0.1%로 제한하는 것이 바람직하다.
Therefore, in the present invention, the content of Sb is preferably limited to 0.05 to 0.1%.
P: 0.02% 이하P: not more than 0.02%
인(P)은 강 중 불가피하게 첨가되는 원소이며, 그 함량이 0.02%를 초과하게 되면 청열취성의 우려가 있으며, 목표로 하는 복합내식성이 크게 저하되는 문제가 있다. 따라서, P의 함량을 0.02% 이하로 제한하는 것이 바람직하다.
Phosphorus (P) is an element which is inevitably added in the steel. When the content exceeds 0.02%, there is a fear of brittle brittleness and a target compound corrosion resistance is greatly deteriorated. Therefore, it is preferable to limit the content of P to 0.02% or less.
S: 0.02% 이하S: not more than 0.02%
황(S)은 강 중 고용되어 적열취성을 유발하는 원소이므로, 그 함량을 가능한 낮게 제어하는 것이 바람직하다. 그 함량이 0.02%를 초과하게 되면 적열취성에 의한 결함발생 가능성이 높아지는 문제가 있으므로, S의 함량을 0.02% 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. If the content exceeds 0.02%, there is a problem that the possibility of occurrence of defects due to the heat-induced embrittlement increases. Therefore, it is preferable to control the S content to 0.02% or less.
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.
상술한 성분조성을 만족하는 본 발명의 강판은 그 표면에 Sb 및/또는 Cu-Sb 산화물을 포함하는 것을 특징으로 한다.
The steel sheet of the present invention satisfying the above-mentioned composition of the present invention is characterized by containing Sb and / or Cu-Sb oxide on its surface.
상기 산화물층 일종의 내식층으로서, 부식환경에서 강판을 보호하는 역할을 함으로써, 결과적으로 황산 및 염산에 대한 복합내식성을 향상시킬 수 있는 것이다.As the corrosion resistant layer as a kind of the oxide layer, it plays a role of protecting the steel sheet in the corrosive environment, and as a result, the composite corrosion resistance against sulfuric acid and hydrochloric acid can be improved.
보다 구체적으로, 상기 Sb 및/또는 Cu-Sb 산화물은 상기 강판 표면으로부터 두께방향으로 400nm 이상의 두께로 형성되는 것이 바람직하며, 일정 두께의 층으로 산화물을 포함할 경우 황산-염산 복합 부식환경에서 강판을 우수하게 보호할 수 있다. 보다 바람직하게, 상기 산화물은 400~500nm의 두께로 형성될 때, 복합내식성을 더 우수하게 향상시킬 수 있다.
More specifically, the Sb and / or Cu-Sb oxides are preferably formed to a thickness of 400 nm or more in the thickness direction from the surface of the steel sheet, and when the oxide is contained in the layer of a certain thickness, the steel sheet in the sulfuric acid- Can be excellent protection. More preferably, when the oxide is formed to a thickness of 400 to 500 nm, the composite corrosion resistance can be further improved.
상기한 바와 같이 일정 두께로 Sb 및/또는 Cu-Sb 산화물을 포함하는 본 발명의 강판은 황산 16.9부피% + 염산 0.35부피% 용액에 대한 부식 감량이 1.0mg/Cm2/hr 이하로서 매우 우수한 복합내식성을 갖는다.
As described above, the steel sheet of the present invention containing Sb and / or Cu-Sb oxide with a predetermined thickness has a corrosion loss of not more than 1.0 mg / Cm 2 / hr to 16.9% by volume sulfuric acid + 0.35% It has corrosion resistance.
이하, 본 발명의 황산 및 염산에 대한 복합내식성이 우수한 강판을 제조하는 바람직한 방법에 대하여, 하기에 일 구현예로서 상세히 설명한다.
Hereinafter, a preferred method for producing a steel sheet having excellent corrosion resistance against sulfuric acid and hydrochloric acid of the present invention will be described in detail as one embodiment below.
먼저, 재가열된 강 슬라브를 열간압연-냉각-권취-냉각의 공정을 거쳐 열연강판으로 제조한 후, 상기 제조된 열연강판에 대해 내식처리를 행함으로써 목적하는 복합내식용 강판을 제조할 수 있으며, 이하에서는 각각의 제조공정에 대하여 상세히 설명한다.
First, the reheated steel slab is formed into a hot-rolled steel sheet through a hot rolling-cooling-winding-cooling-cooling process, and then the steel sheet is subjected to an erosion treatment to produce a desired composite steel sheet. Hereinafter, each manufacturing process will be described in detail.
(재가열 단계)(Reheating step)
먼저, 상술한 성분조성을 만족하는 강 슬라브를 준비한 후, 재가열하는 공정을 거친다. 통상, 재가열 공정은 후속되는 압연을 원활히 하기 위하여 행해지는 것으로서, 압연 온도를 확보할 수 있는 온도범위에서 행해지는 것이 바람직하다.First, a steel slab satisfying the above-mentioned composition is prepared and then reheated. In general, the reheating step is performed in order to smooth subsequent rolling, and is preferably performed in a temperature range in which the rolling temperature can be ensured.
본 발명에서는 1100~1300℃의 범위에서 재가열 공정을 행하는 것이 바람직하며, 이때 재가열 온도가 1300℃를 초과하게 되면 융점이 낮은 Cu가 용출하여 슬라브 표면에 크랙(crack)이 발생할 가능성이 높으며, 반면 1100℃ 미만이면 후속되는 열간압연시의 온도를 확보하기 어려운 문제가 있다.
In the present invention, it is preferable to carry out the reheating process at a temperature in the range of 1100 to 1300 ° C. At this time, when the reheating temperature exceeds 1300 ° C., there is a high possibility that cracking occurs on the surface of the slab due to elution of Cu having a low melting point, Lt; 0 > C, there is a problem that it is difficult to secure the temperature at the time of subsequent hot rolling.
(열간압연 단계)(Hot rolling step)
상기 재가열된 강 슬라브를 열간압연하고, 마무리 압연하여 열연강판으로 제조할 수 있다.The reheated steel slab may be hot rolled and finishing rolled to obtain a hot rolled steel sheet.
상기 열간압연시 마무리 온도는 850~950℃에서 실시함이 바람직하다. 열간 마무리 온도가 850℃ 미만이면 연신립 조직이 형성되어 연신율이 크게 저하하고, 방향별 재질편차가 불균일해지는 문제가 있으며, 반면 950℃를 초과하게 되면 오스테나이트 결정립이 조대해져 경화능이 크게 증가하는 문제가 있다.
The finish rolling temperature is preferably 850 to 950 캜. If the hot finish temperature is less than 850 ° C, a drawstring lag is formed to cause a significant decrease in elongation and unevenness of the material in each direction. On the other hand, when the hot finish temperature exceeds 950 ° C, the austenite grains become coarse, .
(제1 냉각 단계)(First cooling step)
상기 제조된 열연강판을 강냉하는 공정을 거치는 것이 바람직하다. It is preferable that the produced hot-rolled steel sheet undergoes a step of cooling hardly.
본 발명은 최종적으로 열연강판 표면에 산화물을 형성시키고자 하는 것으로서, 이때 산화물을 형성하는 원소들을 상기 냉각에 의해 표면으로 이동시킬 수 있다. The present invention aims to finally form an oxide on the surface of the hot-rolled steel sheet, and the elements forming the oxide can be moved to the surface by the cooling.
이때, 냉각속도를 제어함으로써 산화물 형성 원소들의 표면으로의 이동을 원활히 할 수 있으며, 바람직하게 80~150℃/s로 제어하는 것이 바람직하다.At this time, the oxide-forming elements can be smoothly moved to the surface by controlling the cooling rate, and it is preferable to control the temperature to 80 to 150 ° C / s.
냉각속도가 80℃/s 미만이면 열연강판의 표면온도가 너무 높아 강 내부에 존재하는 산화물 형성 원소들이 표면으로 이동하는 추진력이 낮아, 최종적으로 충분한 산화물을 형성하기 어려운 문제가 있다. 반면, 냉각속도가 150℃/s를 초과하게 되면 강판내부의 온도가 너무 낮아져 권취 후 목적하는 온도까지 복열이 이루어지지 않게 되는 문제가 있다.
If 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 for the oxide-forming elements existing in the steel to move to the surface is low, and finally, sufficient oxide is difficult to form. On the other hand, if the cooling rate exceeds 150 ° C / s, the temperature inside the steel sheet becomes too low, and the double heating is not achieved until the desired temperature after winding.
(권취 및 유지 단계)(Winding and holding step)
상기한 바에 따라 냉각된 열연강판을 권취한 다음, 권취온도에서 유지함으로써 열연강판 표면을 복열시키는 것이 바람직하다. 상기 복열에 의해 산화물 형성원소들을 강판 표면으로 효과적으로 이동시킬 수 있다.It is preferable that the surface of the hot-rolled steel sheet is reheated by holding the cooled hot-rolled steel sheet at the coiling temperature after winding it. The oxide forming elements can be effectively transferred to the steel sheet surface by the double heat.
이때, 열연강판의 표면이 700℃ 이상으로 복열되도록 하는 것이 바람직하며, 이를 위해서는 권취온도를 650~750℃로 제어하는 것이 바람직하다. 권취온도가 650℃ 미만이면 권취 후 복열되는 온도가 너무 낮아 산화물 형성 원소들이 표면으로 충분히 이동하지 못하게 되는 문제가 있으며, 반면 권취온도가 750℃를 초과하게 되면 복열되는 온도가 너무 높아 권취된 강판이 찌그러지는 등 결함이 발생할 우려가 있다.
At this time, it is preferable that the surface of the hot-rolled steel sheet is heated to a temperature of 700 ° C or higher. To this end, it is preferable to control the coiling temperature to 650 to 750 ° C. If the coiling temperature is less than 650 캜, the temperature at which the co-fired is too low to allow the oxide forming elements to move sufficiently to the surface. On the other hand, if the coiling temperature exceeds 750 캜, There is a fear that defects such as squeezing may occur.
(제2 냉각 단계)(Second cooling step)
상기 권취 및 유지하여 목표온도로 강판 표면이 복열된 열연강판을 냉각하여 최종 목표로 하는 열연강판을 제조할 수 있다. 이때, 냉각은 최종 제조되는 열연강판 표면에 충분한 두께로 산화물이 형성되도록 서냉하는 것이 바람직하다.It is possible to manufacture a hot rolled steel sheet as a final target by cooling the hot rolled steel sheet in which the surface of the steel sheet is reheated to the target temperature by winding and holding. At this time, it is preferable that the cooling be gradual cooling so that an oxide is formed to a sufficient thickness on the surface of the hot-rolled steel sheet to be finally produced.
보다 구체적으로, 상기 냉각은 30~50℃/h의 냉각속도로 300~400℃까지 냉각하는 것이 바람직하며, 이때 냉각속도가 50℃/h를 초과하게 되면 표면 산화물 형성 원소들의 이동이 충분하지 못하여 목표로 하는 두께의 산화물층이 형성되지 못하여, 결과적으로 복합내식성 향상효과가 충분치 못하게 된다. 반면, 냉각속도가 30℃/h 미만이면 냉각을 완료하는데에 너무 오랜 시간이 소요되어 제조원가가 상승하는 문제가 있다. 또한, 냉각종료온도가 300℃ 미만이면 냉각시간이 너무 길어 생산성에 문제가 있고, 반면 400℃를 초과하게 되면 산화물층의 두께가 충분하지 못하여 내식성이 열위하는 문제가 있을 수 있다.
More specifically, the cooling is preferably carried out at a cooling rate of 30 to 50 ° C / h to 300 to 400 ° C. When the cooling rate exceeds 50 ° C / h, the movement of the surface oxide forming elements is not sufficient An oxide layer having a desired thickness can not be formed, resulting in an insufficient effect of improving the complex corrosion resistance. On the other hand, if the cooling rate is less than 30 DEG C / h, it takes too much time to complete the cooling and the manufacturing cost increases. If the cooling end temperature is less than 300 ° C, the cooling time is too long to cause a problem in productivity. If the cooling end temperature exceeds 400 ° C, the thickness of the oxide layer is insufficient and the corrosion resistance may be insufficient.
(내식처리)(Corrosion treatment)
이후, 상기 강판에 대하여 내식처리를 실시하는 것이 바람직한데, 이는 제조된 열연강판 극표면에 Sb 및/또는 Cu-Sb 산화물로 이루어진 내식층이 형성되도록 함으로써 강판 전체에 내식성을 향상시키기 위한 것이다. 즉, 상기 제2 냉각까지 완료된 열연강판의 표면에는 Sb 및/또는 Cu가 농축되어 있는 상태로서, 이러한 열연강판에 내식처리를 행하는 것으로부터 Sb 및/또는 Cu-Sb 산화물을 형성할 수 있다.Thereafter, the steel sheet is preferably subjected to a corrosion treatment so as to improve the corrosion resistance of the entire steel sheet by forming a corrosion resistant layer of Sb and / or Cu-Sb oxide on the surface of the produced hot-rolled steel sheet. That is, Sb and / or Cu is concentrated on the surface of the hot-rolled steel sheet that has been subjected to the second cooling, and Sb and / or Cu-Sb oxide can be formed from such hot-rolled steel sheet by performing the corrosion-resistant treatment.
상기 내식처리는 상기 제조된 열연강판을 40~60℃의 황산용액에 침전하는 과정을 거치는 것이 바람직하다. It is preferable that the corrosion-resistant treatment is performed by precipitating the hot-rolled steel sheet in a sulfuric acid solution at 40 to 60 ° C.
이때, 황산용액의 농도가 너무 낮으면 부식환경에서 생성되는 내식층의 두께가 너무 얇아 내식성이 저하하므로 15% 이상의 농도를 갖는 황산용액을 이용하는 것이 바람직하다. 다만, 황산용액의 농도가 너무 높으면 생성된 내식층이 오히려 얇아지는 문제가 있으므로 그 상한값을 25%로 제어하는 것이 바람직하다.At this time, if the concentration of the sulfuric acid solution is too low, the thickness of the corrosion resistant layer formed in the corrosive environment is too thin to reduce the corrosion resistance, so that it is preferable to use a sulfuric acid solution having a concentration of 15% or more. However, if the concentration of the sulfuric acid solution is too high, there is a problem that the formed corrosion resistant layer becomes rather thin, so that the upper limit value is preferably controlled to 25%.
그리고, 황산용액의 온도가 너무 낮거나 너무 높으면 산화물이 충분히 형성되지 않아 원하는 두께로 내식층이 형성되지 못하는 문제가 있으며, 이때 바람직한 온도 범위는 40~60℃이다.If the temperature of the sulfuric acid solution is too low or too high, there is a problem that the oxide is not sufficiently formed and the corrosion resistant layer can not be formed to a desired thickness. The preferable temperature range is 40 to 60 ° C.
상기한 황산용액에 상기 강판을 침적시킴에 있어서, 그 침적시간이 너무 짧거나 너무 길면 생성되는 내식층의 두께가 너무 얇아 내식성을 충분히 확보할 수 없다. 이에, 상기 침적은 충분한 내식층을 형성시킬 정도로 실시하여야 하며, 보다 구체적으로는 침적시간을 5~10분으로 한정하는 것이 바람직하다.
When the immersion time is too short or too long in immersing the steel sheet in the sulfuric acid solution, the thickness of the corrosion resistant layer that is formed is too thin, so that corrosion resistance can not be sufficiently secured. Thus, the deposition should be performed to a sufficient extent to form a corrosion resistant layer, and more specifically, the deposition time should preferably be limited to 5 to 10 minutes.
상술한 제조방법에 의해 제조된 강판은 그 표면에 Sb 및/또는 Cu-Sb 산화물을 400nm 이상의 두께로 포함하고 있으므로, 황산 및 염산 부식환경에서 황산 및 염산에 대한 복합내식성을 우수하게 확보할 수 있는 효과가 있다.
Since the steel sheet produced by the above-described manufacturing method contains Sb and / or Cu-Sb oxide in a thickness of 400 nm or more on the surface thereof, it is possible to obtain excellent corrosion resistance against sulfuric acid and hydrochloric acid in a sulfuric acid and hydrochloric acid corrosion environment It is effective.
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 therefrom.
(( 실시예Example ))
하기 표 1에 나타낸 바와 같은 성분조성으로 용해하여 제조한 강괴를 1200℃ 가열로에서 1시간 유지한 후 열간압연하였다. 이때, 마무리 압연은 900℃에서 실시하였으며, 최종 4.5mm의 두께를 갖는 열연강판을 제조하였다. 이후, 100℃/s의 냉각속도로 냉각하여 700℃에서 권취 및 유지한 다음, 다시 40℃/hr로 냉각하여, 최종 열연강판을 제조하였다. 이후, 각각의 열연강판에 대해 하기 표 1에 나타낸 조건으로 내식처리를 행하였다.
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, the finish rolling was performed at 900 캜, and a hot rolled steel sheet having a thickness of 4.5 mm was produced. Thereafter, the steel sheet was cooled at a cooling rate of 100 deg. C / s, wound and held at 700 deg. C, and cooled to 40 deg. C / hr again to prepare a final hot rolled steel sheet. Then, the respective hot-rolled steel sheets were subjected to the corrosion treatment under the conditions shown in Table 1 below.
상기 내식처리 후 강판 표면에 형성된 Sb 및/또는 Cu-Sb 산화물층의 두께를 측정하여 하기 표 2에 나타내었다.
The thickness of the Sb and / or Cu-Sb oxide layer formed on the surface of the steel sheet after the corrosion-resistant treatment was measured and shown in Table 2 below.
그리고, 상기에 따라 제조된 강판의 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 steel sheet manufactured according to the above, each specimen was immersed in a solution of 16.9% by volume sulfuric acid at 60 ° C + 0.35% by volume hydrochloric acid for 6 hours, and then the corrosion loss of each specimen was measured. The results are shown in Table 2 below.
상기 표 1 및 2에 나타낸 바와 같이, 본 발명에 따른 강판(발명강 1 내지 3)은 부식감량이 1.0mg/cm2/hr 이하로 매우 우수한 복합내식성을 나타내는 것을 확인할 수 있다. 이는, 내식처리 후 형성된 산화물층의 두께가 모두 400nm 이상으로 형성된 것으로부터 기인한 것으로 사료된다.
As shown in Tables 1 and 2, it can be confirmed that the steel sheets (invention steels 1 to 3) according to the present invention exhibit excellent corrosion resistance with a corrosion loss of 1.0 mg / cm 2 / hr or less. This is considered to be attributable to the fact that the thickness of the oxide layer formed after the corrosion-resistant treatment was all 400 nm or more.
반면, Sb을 전혀 첨가하지 않은 비교강 1은 본 발명에서 제안하는 방법으로 제조하였더라도 부식감량이 6.2mg/cm2/hr로 복합내식성이 열위한 것을 확인할 수 있다. 특히, 비교강 1은 산화물층의 두께가 280nm 정도로 비교적 두껍게 형성되었더라도, 복합내식성 향상에 유리한 Sb 및/또는 Cu-Sb 산화물이 전혀 없어 내식성이 열화한 것이다.On the other hand, it can be confirmed that the comparative steel 1 without any addition of Sb has a corrosion loss of 6.2 mg / cm 2 / hr to produce a composite corrosion resistance even if it is manufactured by the method proposed in the present invention. In particular, comparative steel 1 has no Sb and / or Cu-Sb oxides favorable for improving the composite corrosion resistance even if the oxide layer is formed to have a comparatively large thickness of about 280 nm, and the corrosion resistance is deteriorated.
비교강 2 내지 4는 강의 성분조성이 각각 발명강 1 내지 3과 동일한 것이나, 비교강 2는 내식처리를 행하지 않는 경우이고, 비교강 3은 내식처리 용액의 농도가 낮고, 침적시간도 충분하지 못한 경우이고, 비교강 4는 내식처리 용액의 농도가 너무 높고, 침적시간도 너무 긴 경우에 해당한다. 이러한 비교강 2 내지 4는 산화물층이 모두 100nm 미만으로 충분히 형성되지 못하였으며, 그로 인해 부식감량이 각각 1.9mg/cm2/hr, 2.2mg/cm2/hr, 1.9mg/cm2/hr로서 복합내식성이 열위하였다.
The comparative steels 2 to 4 have the same composition as the inventive steels 1 to 3 respectively, but the comparative steels 2 are not subjected to the corrosion resistant treatment. The comparative steels 3 have a low concentration of the corrosion resistant treatment solution, , And the comparative steel 4 corresponds to a case where the concentration of the corrosion-resistant solution is too high and the immersion time is too long. The comparison steel 2 to 4, the oxide layer is not sufficiently formed in the both were not less than 100nm, whereby a corrosion-decrease, respectively 1.9mg / cm 2 / hr, 2.2mg / cm 2 / hr, 1.9mg / cm 2 / hr as The composite corrosion resistance was weakened.
Claims (7)
표면에는 Sb 및/또는 Cu-Sb 산화물을 포함하는 것인 황산 및 염산 복합내식용 강판.
(C): 0.05 to 0.1%, manganese (Mn): 0.5 to 1.5%, aluminum (Al): 0.01 to 0.1%, copper (Cu): 0.2 to 0.7%, antimony (Sb) 0.05 to 0.1%, phosphorus (P): 0.02% or less, sulfur (S): 0.02% or less, the balance Fe and unavoidable impurities,
Wherein the surface comprises Sb and / or Cu-Sb oxide.
상기 산화물은 상기 강판 표면으로부터 두께방향으로 400~500nm의 두께로 포함하는 것인 황산 및 염산 복합내식용 강판.
The method according to claim 1,
Wherein the oxide is contained in a thickness of 400 to 500 nm in a thickness direction from the surface of the steel sheet.
상기 강판은 황산 16.9부피% + 염산 0.35부피% 용액에 대한 부식 감량이 1.0mg/Cm2/hr 이하인 황산 및 염산 복합내식용 강판.
The method according to claim 1,
Wherein the steel sheet has a corrosion loss of 1.0 mg / Cm 2 / hr or less with respect to 16.9% by volume sulfuric acid + 0.35% by volume hydrochloric acid solution.
상기 재가열된 강 슬라브를 열간압연하고, 850~950℃에서 마무리 압연하여 열연강판을 제조하는 단계;
상기 열연강판을 80~150℃/s의 냉각속도로 제1 냉각하는 단계;
상기 냉각한 열연강판을 권취한 후 유지하여 상기 열연강판 표면이 700℃ 이상으로 복열되도록 하는 단계;
상기 권취 및 유지 후 30~50℃/h의 냉각속도로 제2 냉각하는 단계; 및
상기 제2 냉각 후 내식처리하는 단계
를 포함하는 황산 및 염산 복합내식용 강판의 제조방법.
(C): 0.05 to 0.1%, manganese (Mn): 0.5 to 1.5%, aluminum (Al): 0.01 to 0.1%, copper (Cu): 0.2 to 0.7%, antimony (Sb) Reheating a steel slab containing 0.05 to 0.1%, phosphorus (P) to 0.02% or less, sulfur (S) to 0.02% or less, the remainder Fe and unavoidable impurities at 1100 to 1300 ° C;
Hot-rolling the reheated steel slab and finishing rolling at 850 to 950 ° C to produce a hot-rolled steel sheet;
Cooling the hot-rolled steel sheet at a cooling rate of 80 to 150 ° C / s;
Winding and holding the cooled hot-rolled steel sheet so that the surface of the hot-rolled steel sheet is reheated to 700 ° C or more;
A second cooling step at a cooling rate of 30 to 50 DEG C / h after the winding and holding; And
After the second cooling step,
By weight based on the total weight of the steel sheet.
상기 권취는 650~750℃에서 실시하는 것인 황산 및 염산 복합내식용 강판의 제조방법.
5. The method of claim 4,
Wherein the coiling is carried out at 650 to 750 占 폚.
상기 내식처리는 40~60℃, 15~25% 농도의 황산용액에서 5~10분간 침적하여 실시하는 것인 황산 및 염산 복합내식용 강판의 제조방법.
5. The method of claim 4,
Wherein the corrosion-resistant treatment is carried out by immersing in a sulfuric acid solution having a concentration of 15 to 25% for 5 to 10 minutes at 40 to 60 占 폚.
상기 제2 냉각 후 상기 열연강판 표면에 Sb 및/또는 Cu가 농축되어 있는 것인 황산 및 염산 복합내식용 강판의 제조방법.
5. The method of claim 4,
And Sb and / or Cu is concentrated on the surface of the hot-rolled steel sheet after the second cooling.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105018866A (en) * | 2015-08-18 | 2015-11-04 | 国电科学技术研究院 | Novel acid-resisting low alloy steel |
| JPWO2021095185A1 (en) * | 2019-11-13 | 2021-05-20 | ||
| JP2022054486A (en) * | 2020-09-28 | 2022-04-07 | Ｊｆｅスチール株式会社 | Thick steel plate and method for producing the same |
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| JP4997808B2 (en) * | 2006-03-30 | 2012-08-08 | Ｊｆｅスチール株式会社 | Sulfuric acid dew-point corrosion steel with excellent hydrochloric acid resistance |
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| JP5862323B2 (en) * | 2011-01-31 | 2016-02-16 | Ｊｆｅスチール株式会社 | Corrosion resistant steel for holding coal ships or coal / ore combined ships |
| KR101372794B1 (en) * | 2011-08-26 | 2014-03-10 | 주식회사 포스코 | Steel sheet having excellent corrosion resistance by sulfuric acid and hydrochloric acid and weldability and method for manufacturing the same |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105018866A (en) * | 2015-08-18 | 2015-11-04 | 国电科学技术研究院 | Novel acid-resisting low alloy steel |
| US11939489B2 (en) | 2016-09-28 | 2024-03-26 | Posco Co., Ltd | Solution composition for surface treatment of steel sheet and surface-treated steel sheet using same |
| JPWO2021095185A1 (en) * | 2019-11-13 | 2021-05-20 | ||
| WO2021095185A1 (en) * | 2019-11-13 | 2021-05-20 | 日本製鉄株式会社 | Hot-rolled steel |
| JP2022054486A (en) * | 2020-09-28 | 2022-04-07 | Ｊｆｅスチール株式会社 | Thick steel plate and method for producing the same |
| JP2022054487A (en) * | 2020-09-28 | 2022-04-07 | Ｊｆｅスチール株式会社 | Thick steel plate and method for producing the same |
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