KR20030003846A - Method of refining extra low carbon ferritic stainless steel - Google Patents
Method of refining extra low carbon ferritic stainless steel Download PDFInfo
- Publication number
- KR20030003846A KR20030003846A KR1020010039686A KR20010039686A KR20030003846A KR 20030003846 A KR20030003846 A KR 20030003846A KR 1020010039686 A KR1020010039686 A KR 1020010039686A KR 20010039686 A KR20010039686 A KR 20010039686A KR 20030003846 A KR20030003846 A KR 20030003846A
- Authority
- KR
- South Korea
- Prior art keywords
- decarburization
- slag
- stainless steel
- low carbon
- carbon
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/068—Decarburising
- C21C7/0685—Decarburising of stainless steel
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/005—Manufacture of stainless steel
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0087—Treatment of slags covering the steel bath, e.g. for separating slag from the molten metal
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Analytical Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
본 발명은 극저탄소 페라이트 스테인레스강의 정련방법에 관한 것으로서, 특히 VOD를 이용한 스테인레스강의 제조공정에서 저탄소 영역에서의 탈탄기 슬래그 조성 및 물성을 조절 함으로써 극저탄소 페라이트 스테인레스강을 정련하는 방법에 관한 것이다.The present invention relates to a method for refining ultra low carbon ferritic stainless steel, and more particularly, to a method for refining ultra low carbon ferritic stainless steel by controlling decarburizing slag composition and physical properties in a low carbon region in a manufacturing process of stainless steel using VOD.
일반적으로 스테인레스강 중의 탄소는 페라이트(Ferrite)계 스테인레스강의 내공식성, 인성 등을 나쁘게 하고, 오스테나이트(austenite)계 스테인레스강에서는응력부식균열등에 나쁜 영향을 미치는 것으로 알려져 있다. 최근에는 스테인레스강에 대한 사용 범위가 확대됨에 따라 가혹한 사용 조건에서도 우수한 품질 특성을 나타내는 다양한 용도의 스테인레스강이 개발되고 있고, 이에 따른 품질 특성을 만족시키기 위해서는 강중의 탄소를 극히 낮은 수준까지 낮추어야 한다. 따라서 극 저탄소 스테인레스강의 제조는 일반적으로 VOD(Vacuum Oxygen Decarburization)를 이용하여 제조하고 있다. 일례로서 최근 해안 지방의 건축 외장재로 널리 사용되는 26%Cr 함유 스테인레스강에서 탄소 농도가 높으면, 내식성 및 가공성이 떨어지므로 탄소농도를 매우 낮은 수준까지 요구하고 있다. 그러나 VOD와 같은 진공 탈탄공정에서도 200ppm 이하의 낮은 탄소 영역에서는 고 진공 상태의 산소 취입에 의해 탄소농도를 낮추는 것은 정련시간이 길어지고, 크롬 산화가 증가 할 뿐 만 아니라 부원료 등의 사용량이 증가하는 문제점이 있다.In general, carbon in stainless steel is poor in corrosion resistance, toughness, and the like of ferrite stainless steel, and in austenitic stainless steel, it is known to adversely affect stress corrosion cracking. Recently, as the range of use for stainless steel is expanded, stainless steels of various uses have been developed that exhibit excellent quality characteristics even under severe use conditions. In order to satisfy the quality characteristics, the carbon in the steel must be lowered to an extremely low level. Therefore, the ultra low carbon stainless steel is generally manufactured using VOD (Vacuum Oxygen Decarburization). As an example, the high carbon concentration in 26% Cr-containing stainless steel, which is widely used as a building cladding in coastal areas recently, requires a very low carbon concentration because of poor corrosion resistance and processability. However, even in vacuum decarburization processes such as VOD, lowering the carbon concentration by high vacuum injection of oxygen in the low carbon region below 200ppm increases the refining time, not only increases chromium oxidation but also increases the amount of auxiliary materials. There is this.
이와같은 VOD정련은 탈탄 단계와 환원 단계로 구분되는데, 탈탄 단계는 진공 상태에서 산소를 불어 넣어 탄소를 제거하는 과정이고, 환원 단계는 탈탄 단계에서 생성된 크롬 산화물을 환원시키고, 유황을 제거하는 과정이다. 상기의 탈탄 단계에서는 산소 취입 탈탄 단계와 진공 탈탄 단계로 다시 세분 할 수 있는데, 산소 취입에 의한 탈탄 단계에서는 크롬 등 유가금속의 산화를 최대한 억제하면서, 탄소를 제거해야 하지만, 탄소 농도가 낮은 영역에서는 공급된 산소의 대부분이 크롬과 반응하는데 소비되므로 슬래그중 크롬산화물의 농도가 크게 증가하게 된다. 또 진공 탈탄 단계에서는 하기 1식과 같은 산소 취입에 의해 생성된 크롬 산화물 등의 금속 산화물을 이용하여 탄소를 제거하는 과정으로 산소 취입 단계에서 생성된 슬래그조성에 따라 탈탄 효율이 크게 달라진다.The VOD refining is divided into a decarburization step and a reduction step. A decarburization step is a process of removing carbon by blowing oxygen in a vacuum state, and a reducing step is a process of reducing chromium oxide generated in a decarburization step and removing sulfur. to be. In the above decarburization step, it can be subdivided into oxygen blowing decarburization step and vacuum decarburization step. In the decarburization step by oxygen injection, carbon should be removed while suppressing oxidation of valuable metals such as chromium as much as possible. Since most of the supplied oxygen is consumed to react with chromium, the concentration of chromium oxide in the slag is greatly increased. In addition, in the vacuum decarburization step, carbon removal is performed by using a metal oxide such as chromium oxide generated by oxygen blowing as shown in the following equation, and the decarburization efficiency greatly varies depending on the slag composition generated in the oxygen blowing step.
(Cr2O3)+[C]=[Cr]+{CO}(gas) -------- (1)(Cr 2 O 3 ) + [C] = [Cr] + {CO} (gas) -------- (1)
탄소 농도가 낮은 영역에서는 슬래그 층을 통한 크롬산화물의 확산 속도가 탈탄반응의 율속단계이므로 슬래그의 융점이 너무 높은 것은 크롬산화물에 의한 탈탄반응에 크게 효과적으로 기여하지 못한다.In the region where the carbon concentration is low, the diffusion rate of chromium oxide through the slag layer is a rate decarburization step, so that the high slag melting point does not contribute significantly to the decarburization reaction by chromium oxide.
이에 본 발명의 발명자들은 상기한 종래방법의 문제점을 개선하기 위해 연구 및 실험을 중점 수행하고, 그 결과에 근거하여 본 발명을 제안하게 되었다.Accordingly, the inventors of the present invention focused on research and experiment to improve the problems of the conventional method described above, and proposed the present invention based on the results.
본 발명은 극저탄소 페라이트 스테인레스강의 재조시에 저탄소 영역에서 슬래그 조성을 제어하여 슬래그중 크롬산화물에 의한 탈탄반응을 촉진하고, 생석회를 진공탈탄 단계에서 첨가함으로써 생석회에 의한 탄소 픽업을 감소시켜 극저탄소 페라이트 스테인레스강의 정련방법을 제공하는 데 그 목적이 있다.The present invention controls the slag composition in the low carbon region during remanufacturing of ultra low carbon ferrite stainless steel to promote the decarburization reaction by chromium oxide in the slag, and by reducing the carbon pickup by the quicklime by adding the quicklime in the vacuum decarburization step The purpose is to provide a steel refining method.
도 1은 본 발명의 탈탄반응 속도에 미치는 (CaO)/(Al2O3)의 영향을 나타낸 그래프.1 is a graph showing the effect of (CaO) / (Al 2 O 3 ) on the decarburization rate of the present invention.
도 2는 본 발명의 생석회 투입방법에 따른 탄소농도 변화를 나타낸 그래프.Figure 2 is a graph showing a change in carbon concentration according to the quicklime input method of the present invention.
상기의 목적을 달성하기 위한 본 발명은 VOD를 이용한 극 저탄소 스테인레스강의 제조과정에서 슬래그중 크롬산화물의 이동을 용이하게 하여 슬래그에 의한 탈탄반응을 촉진하고, 탈탄 반응 종료 후의 탄소 픽업을 억제시킬 수 있는 극저탄소 페라이트 스테인레스강의 정련방법에 있어서,In order to achieve the above object, the present invention facilitates the movement of chromium oxide in the slag during the production of ultra low carbon stainless steel using VOD, thereby promoting decarburization by slag, and suppressing carbon pick-up after the decarburization reaction is completed. In the refining method of ultra low carbon ferritic stainless steel,
VOD의 산소 취입 종료후의 슬래그의 조성을 Cr2O3가 25∼45%이면서, (CaO)/(Al2O3)의 비가 1 이하가 되도록 제어하고, 탈탄 단계에서 생석회를 투입하여, 용강의 고열에 의해 생석회중 잔류 탄소 성분을 제거하고 탄소픽업을 억제하여 극저탄소 페리이트 스테인레스강을 효과적으로 제조하는 방법에 관한 것이다.The composition of slag after completion of the VOD oxygen injection is controlled so that the ratio of (CaO) / (Al 2 O 3 ) is 1 or less while Cr 2 O 3 is 25 to 45%, and quicklime is added in the decarburization step to heat the molten steel. The present invention relates to a method for effectively producing ultra-low carbon ferritic stainless steel by removing residual carbon component in quicklime and suppressing carbon pickup.
이하, 본 발명을 상세히 설명한다.Hereinafter, the present invention will be described in detail.
탈탄기 슬래그 제어에 의한 극 저탄소강의 제조에 관해서는 대한민국 특허 등록 번호 117825호에는 용강량을 기준으로 하여 4.5∼5.5Kg/T의 형석과 7.5∼10Kg/T의 Fe-Si를 탈탄 말기에 투입하는 방법이 제시되어 있다. 그러나 본 발명은 고 크롬 함유 스테인레스강의 진공 탈탄 방법에 있어서, 진공 탈탄에서 탄소를 극저탄소로 낮추기 위해 고진공하에서 산소를 취입하여 탈탄하는 과정에서 슬래그의 조성을 제어함으로써 상기 진공 탈탄에서 이용되는 산소로서 슬래그중 크롬산화물을 이용하여 탈탄 반응 속도를 향상시키고, 탈탄 반응 후의 탄소의 픽업(Pick up)을 억제함으로써, 보다 효율적인 극저탄소 스테인레스강 제조방법을 제공하고자 한 것이다.Regarding the manufacture of ultra low carbon steel by controlling the decarburizer slag, Korean Patent Registration No. 117825 describes the addition of fluorite of 4.5 to 5.5 Kg / T and 7.5 to 10 Kg / T of Fe-Si based on molten steel at the end of decarburization. The method is presented. However, the present invention is a vacuum decarburization method of high chromium-containing stainless steel, in which the oxygen is used as the oxygen used in the vacuum decarburization by controlling the composition of the slag in the process of blowing the oxygen under high vacuum in order to lower the carbon to ultra low carbon. The purpose of the present invention is to provide a more efficient method for producing ultra-low carbon stainless steel by improving the rate of decarburization using chromium oxide and suppressing pick-up of carbon after decarburization.
이하, 상술한 슬래그 조성 범위의 한정 이유와 생석회 조기 투입 이유에 대해 설명한다.Hereinafter, the reason for limitation of the slag composition range mentioned above and the reason for premature injection of quicklime are demonstrated.
극 저탄소강 제조시에 탈탄 말기에는 탄소농도가 매우 낮기 때문에 용강중에 공급된 산소는 크롬과 반응하여 슬래그중 크롬산화물이 증가하면, 슬래그의 융점이 급격히 증가하여 슬래그에 의한 탈탄반응이 어렵기 때문에 적정조성의 슬래그를 만들어 주는 것이 중요하다.Since carbon concentration is very low at the end of decarburization in the production of ultra low carbon steel, oxygen supplied to molten steel reacts with chromium and increases the chromium oxide in the slag, so that the melting point of slag increases rapidly and decarburization reaction by slag is difficult. It is important to make the slag of the composition.
따라서 본 발명의 VOD 정련에서 진공 탈탄기 슬래그는 CaO-Cr2O3-Al2O3로 구성되는데, Cr2O3는 용강중 크롬과 산소의 반응에 의해 생성되며, Al2O3는 용강의 온도를 높여주기 위해 첨가하는 Al의 산화생성물이며, CaO는 이들 산화물들과 슬래그를 만들어 주기 위해 첨가한다. 이들 슬래그에서 Cr2O3가 25∼45%의 조성으로 제어하여야 하는 이유는 Cr2O3가 25%이하인 경우는 탈탄에 필요한 산소가 충분하지 못해 탈탄 반응에 불리하며, Cr2O3가 45%이상에서는 슬래그의 융점이 너무 높아져 Cr2O3의 이동이 곤란하기 때문에 탈탄 반응 속도가 느려지게 된다.Therefore, in the VOD refining of the present invention, vacuum decarburizer slag is composed of CaO-Cr 2 O 3 -Al 2 O 3 , Cr 2 O 3 is produced by the reaction of chromium and oxygen in the molten steel, Al 2 O 3 of the molten steel It is an oxidation product of Al that is added to raise the temperature, and CaO is added to make these oxides and slag. If the reason that Cr 2 O 3 in the slag, these are to be controlled by the composition of 25-45% Cr 2 O 3 is not more than 25% is disadvantageous to the decarburization reaction and the oxygen necessary for decarburization can not insufficient, Cr 2 O 3 is 45 Above%, the melting point of the slag becomes too high, making it difficult to move Cr 2 O 3 , resulting in a slow decarburization reaction rate.
또 (CaO)/(Al2O3)의 비가 1 이하가 되어야 하는 이유는 1이상에서는 Al2O3와 화학 양론적으로 CaO.Al2O3를 만들고 남은 잉여의 CaO가 슬래그중 Cr2O3와 결합하여 Cr2O3의 활동도를 감소시켜 탈탄반응이 불리해지기 때문이다.The reason why the ratio of (CaO) / (Al 2 O 3 ) should be 1 or less is that at least 1, Ca 2 O 3 and stoichiometric CaO.Al 2 O 3 and the excess CaO remaining in the slag Cr 2 O bond and 3 to reduce the activity of Cr 2 O 3 is because the decarburization reaction to this disadvantage.
또한 본 발명에서 CaO를 진공 탈탄 단계에서 첨가하는 이유는 다음과 같다. 제강공정에서 사용되는 생석회는 석회석을 소성(sintering)하여 만드는데, 100%의 소성은 거의 불가능하기 때문에 보통 생석회 중심부에 CaCO3를 함유하고 있으며, 공업적인 생석회중에는 약 0.5-2.0%의 탄소 농도에 해당하는 CaCO3를 함유하게 된다. 따라서 생석회가 용강중에 투입되면 CaCO3는 하기 (2)-(4)식으로 나타낸 과정에 의해 용강의 탄소농도를 높이게 된다. 그러나 진공 탈탄 단계에서는 용강중 산소 농도가 충분히 높고, Si 또는 Al과 같은 탈산제가 없기 때문에 (3) 또는 (4)식의 반응이 일어나지 않으므로 탄소 농도가 증가하는 것을 억제할 수 있게 된다.In addition, the reason for adding CaO in the vacuum decarburization step in the present invention is as follows. The quicklime used in the steelmaking process is made by sintering limestone, which usually contains CaCO 3 in the center of quicklime because it is almost impossible to calcinate it and corresponds to a carbon concentration of about 0.5-2.0% in industrial quicklime. CaCO 3 to be contained. Therefore, when quicklime is added to molten steel, CaCO 3 increases the carbon concentration of molten steel by the process represented by the following formula (2)-(4). However, in the vacuum decarburization step, since the oxygen concentration in the molten steel is sufficiently high and there is no deoxidizer such as Si or Al, the reaction of formula (3) or (4) does not occur, and thus the increase in the carbon concentration can be suppressed.
CaCO3=(CaO)+{CO2} (2)CaCO 3 = (CaO) + {CO 2 } (2)
{CO2}+[Si}=(SiO2)+[C] (3){CO 2 } + [Si} = (SiO 2 ) + [C] (3)
3{CO2}+4[Al]=2(Al2O3)+3[C] (4)3 {CO 2 } +4 [Al] = 2 (Al 2 O 3 ) +3 [C] (4)
이하, 실시예를 통해 본 발명을 상세히 설명한다.Hereinafter, the present invention will be described in detail through examples.
(실시예 1)(Example 1)
VOD의 산소 취입 종점에서의 슬래그 조성 제어에 의한 26중량% 크롬 함유 페라이트 스테인레스강의 탈탄 거동 조사를 위해 200kg용량의 진공유도로 실험을 실시하였다. 슬래그 조성을 변화시키면서 200ppm이하의 탄소농도에서 탈탄 거동을 비교하였다. 실험 조건은 표 1에 나타내었다. 0.015∼0.02중량%의 탄소를 함유한 100kg의 스테인레스강을 용해한 후 1.5kg의 슬래그를 용강 상부에 투입하였다. 이때 슬래그중 Cr2O3, CaO 및 Al2O3농도를 변화시키면서 탈탄 방응 속도를 측정하였다.In order to investigate the decarburization behavior of 26 wt% chromium-containing ferritic stainless steel by controlling the slag composition at the oxygen injection end point of the VOD, an experiment was conducted with a vacuum induction capacity of 200 kg. The decarburization behavior was compared at carbon concentrations below 200 ppm with varying slag composition. The experimental conditions are shown in Table 1. After dissolving 100 kg of stainless steel containing 0.015 to 0.02% by weight of carbon, 1.5 kg of slag was added to the upper part of the molten steel. At this time, the decarburization response rate was measured while changing the concentration of Cr 2 O 3 , CaO and Al 2 O 3 in the slag.
도 1은 상기 실험결과로서 탈탄반응 속도에 미치는 (CaO)/(Al2O3)의 영향을 나타낸 것이다. 도 1에서 탈탄 반응속도는 상기 (1)식의 반응이 슬래그중 크롬산화물의 이동 속도에 의해 율속 된다는 가정하에 하기의 식에 의해 구한 것이다.Figure 1 shows the effect of (CaO) / (Al 2 O 3) on the decarburization reaction rate as the experimental results. In Fig. 1, the decarburization reaction rate is obtained by the following equation under the assumption that the reaction of the above formula (1) is rate controlled by the moving speed of chromium oxide in slag.
-dC/dt=K([C]-[C]e) (5)-dC / dt = K ([C]-[C] e) (5)
도 1에서 보면 슬래그중 Cr2O3농도가 높을수록 탈탄 속도는 향상되며, 45%Cr2O3에서 최대의 탈탄 속도를 나타내고, CaO/Al2O3의 비가 낮을수록 탈탄속도는 향상되지만, 1이상에서는 현저히 탈탄 속도가 저하되는 것을 볼 수 있다.1, the higher the concentration of Cr 2 O 3 in the slag, the higher the decarburization rate, the maximum decarburization rate at 45% Cr 2 O 3 , and the lower the ratio of CaO / Al 2 O 3, the higher the decarburization rate. At one or more, it can be seen that the decarburization rate is significantly reduced.
따라서 본 발명의 탈탄 반응에는 CaO/Al2O3의 비가 1이하이면서 Cr2O3의 농도가 25∼45%의 범위를 만족하는 슬래그가 효과가 있다는 것을 알 수 있다.Therefore, it can be seen that the slag satisfying the range of 25-45% of Cr 2 O 3 concentration while the ratio of CaO / Al 2 O 3 is 1 or less is effective in the decarburization reaction of the present invention.
(실시예 2)(Example 2)
생석회 투입 방법에 따른 탄소 픽업 저감을 확인하기 위해 실제 스테인레스강을 생산하고 있는 80ton VOD에서 극저탄소 스테인레스강인 STS 446M(26%Cr)을 대상으로 본 발명의 적용시험을 실시하였다. 생석회 투입시기는 종래법(환원단계 투입)과 본발명(진공 탈탄단계 투입)에서 생석회 1.5 ton/heat를 각각 투입하고, 용강중 탄소농도를 비교하여 도 2에 나타내었다. 도 2에서 보듯이 탄소농도는 종래법의 94ppm과 비교하여 본 발명을 적용한 경우 79ppm으로 나타나 본 발명에 의해 15ppm의 탄소 농도를 낮추는 효과가 있는 것으로 나타났다.In order to confirm the reduction of carbon pick-up according to the quicklime input method, the application test of the present invention was performed on STS 446M (26% Cr), which is an ultra low carbon stainless steel, at 80ton VOD which is actually producing stainless steel. The quicklime input time is shown in FIG. 2 by comparing 1.5 ton / heat of quicklime in the conventional method (reduction step input) and the present invention (vacuum decarburization step input), and comparing the carbon concentration in molten steel. As shown in Figure 2, the carbon concentration is 79ppm when the present invention is applied as compared to 94ppm of the conventional method appeared to have an effect of lowering the carbon concentration of 15ppm by the present invention.
이상에서 살펴본 바와 같이 본 발명은 VOD정련에서 진공 탈탄 단계에서 슬래그 조성을 조절하고, 생석회를 투입함으로써 탈탄 효율을 향상시키고, 탄소 픽업을 억제하여 극저탄소 페라이트 스테인레스 강을 용이하게 제조할 수 있는 것이다.As described above, the present invention is to adjust the slag composition in the vacuum decarburization step in VOD refining, improve the decarburization efficiency by adding quicklime, and can suppress the carbon pickup to easily produce ultra-low carbon ferrite stainless steel.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR10-2001-0039686A KR100523105B1 (en) | 2001-07-04 | 2001-07-04 | Method of refining extra low carbon ferritic stainless steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR10-2001-0039686A KR100523105B1 (en) | 2001-07-04 | 2001-07-04 | Method of refining extra low carbon ferritic stainless steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20030003846A true KR20030003846A (en) | 2003-01-14 |
| KR100523105B1 KR100523105B1 (en) | 2005-10-19 |
Family
ID=27713306
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR10-2001-0039686A Expired - Fee Related KR100523105B1 (en) | 2001-07-04 | 2001-07-04 | Method of refining extra low carbon ferritic stainless steel |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR100523105B1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009075464A1 (en) * | 2007-12-12 | 2009-06-18 | Posco | Method of manufacturing ultra low carbon ferritic stainless steel |
| CN101768656B (en) * | 2008-12-31 | 2011-08-24 | 宝山钢铁股份有限公司 | Method for refining ultra-low carbon ferritic stainless steel under vacuum |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2707783B2 (en) * | 1990-03-08 | 1998-02-04 | 住友金属工業株式会社 | Refining method of ultra low carbon stainless steel |
| JPH07173515A (en) * | 1993-12-20 | 1995-07-11 | Nippon Steel Corp | Decarburization and refining method for stainless steel |
| JP3903603B2 (en) * | 1998-07-21 | 2007-04-11 | 住友金属工業株式会社 | Melting method of ultra-low carbon steel with excellent cleanability |
| KR100361778B1 (en) * | 1998-12-21 | 2003-01-24 | 주식회사 포스코 | Manufacturing method of ultra low carbon stainless steel by slag control |
| KR100406403B1 (en) * | 1999-07-13 | 2003-11-19 | 주식회사 포스코 | Method of throwing Al into molten stainless steel at VOD refining process |
| JP2001172715A (en) * | 1999-12-13 | 2001-06-26 | Nippon Steel Corp | Manufacturing method of ultra-low carbon stainless steel molten steel |
-
2001
- 2001-07-04 KR KR10-2001-0039686A patent/KR100523105B1/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009075464A1 (en) * | 2007-12-12 | 2009-06-18 | Posco | Method of manufacturing ultra low carbon ferritic stainless steel |
| US8277537B2 (en) | 2007-12-12 | 2012-10-02 | Posco | Method of manufacturing ultra low carbon ferritic stainless steel |
| CN101768656B (en) * | 2008-12-31 | 2011-08-24 | 宝山钢铁股份有限公司 | Method for refining ultra-low carbon ferritic stainless steel under vacuum |
Also Published As
| Publication number | Publication date |
|---|---|
| KR100523105B1 (en) | 2005-10-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101259374B1 (en) | Method for manufacturing high cleaness bearing steel | |
| KR100523105B1 (en) | Method of refining extra low carbon ferritic stainless steel | |
| KR102733371B1 (en) | method of manufacturing austenite stainless steel | |
| KR100887860B1 (en) | Manufacturing method of ferritic stainless steel | |
| KR100423446B1 (en) | A method for manufacturing high chrome ferrite stainless steel | |
| CN113151744B (en) | Steel S48C for engineering machinery slewing bearing and production method thereof | |
| KR100361778B1 (en) | Manufacturing method of ultra low carbon stainless steel by slag control | |
| KR100992303B1 (en) | Refining method of ultra low sulfur stainless steel | |
| KR100325715B1 (en) | Refining method of low carbon stainless steel | |
| KR100361613B1 (en) | Absorption prevention method of ultra low carbon and low nitrogen steel during tapping | |
| JP3411220B2 (en) | Refining method of high nitrogen low oxygen chromium-containing molten steel | |
| JP4544126B2 (en) | Manufacturing method of low carbon sulfur free cutting steel | |
| KR101786931B1 (en) | Method for refining of molten stainless steel | |
| JP3626445B2 (en) | Fe-Ni alloy for low thermal expansion and high rigidity shadow mask excellent in surface property and etching processability and method for producing the same | |
| KR100516497B1 (en) | Method for Refining Stainless Molten Steel | |
| KR101676140B1 (en) | Method for refining austenite stainless steel | |
| KR100709009B1 (en) | Method of manufacturing titanium-added stainless steel | |
| KR100411264B1 (en) | METHOD FOR MANUFACTURING FERRITIC STAINLESS STEEL CONTAINING Ti FOR ELECTRONIC PART | |
| KR100340574B1 (en) | Method for refining non-oriented electrical steel containing phosphorus | |
| KR20020040022A (en) | A method for manufacturing high chromium stainless steel using molybdenium oxides | |
| CN121183242A (en) | A low-cost RE-based high-fatigue-resistant hydrogen pipeline steel with a yield strength ≥500MPa and its preparation method. | |
| KR20020051961A (en) | A method for refining high phosphurous steel in converter | |
| KR20010048854A (en) | Method of Manufacturing Ultra Low Carbon Steel for Supper Extra Deep Drawing Quality | |
| KR20040090208A (en) | Refining method of molten steel | |
| CN120311089A (en) | A method for improving product elongation based on all-iron smelting and continuous casting and rolling production line |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PA0109 | Patent application |
St.27 status event code: A-0-1-A10-A12-nap-PA0109 |
|
| PN2301 | Change of applicant |
St.27 status event code: A-3-3-R10-R13-asn-PN2301 St.27 status event code: A-3-3-R10-R11-asn-PN2301 |
|
| R18-X000 | Changes to party contact information recorded |
St.27 status event code: A-3-3-R10-R18-oth-X000 |
|
| PG1501 | Laying open of application |
St.27 status event code: A-1-1-Q10-Q12-nap-PG1501 |
|
| A201 | Request for examination | ||
| PA0201 | Request for examination |
St.27 status event code: A-1-2-D10-D11-exm-PA0201 |
|
| D13-X000 | Search requested |
St.27 status event code: A-1-2-D10-D13-srh-X000 |
|
| D14-X000 | Search report completed |
St.27 status event code: A-1-2-D10-D14-srh-X000 |
|
| E902 | Notification of reason for refusal | ||
| PE0902 | Notice of grounds for rejection |
St.27 status event code: A-1-2-D10-D21-exm-PE0902 |
|
| P11-X000 | Amendment of application requested |
St.27 status event code: A-2-2-P10-P11-nap-X000 |
|
| P13-X000 | Application amended |
St.27 status event code: A-2-2-P10-P13-nap-X000 |
|
| E701 | Decision to grant or registration of patent right | ||
| PE0701 | Decision of registration |
St.27 status event code: A-1-2-D10-D22-exm-PE0701 |
|
| PR1002 | Payment of registration fee |
St.27 status event code: A-2-2-U10-U11-oth-PR1002 Fee payment year number: 1 |
|
| GRNT | Written decision to grant | ||
| PR0701 | Registration of establishment |
St.27 status event code: A-2-4-F10-F11-exm-PR0701 |
|
| PG1601 | Publication of registration |
St.27 status event code: A-4-4-Q10-Q13-nap-PG1601 |
|
| PR1001 | Payment of annual fee |
St.27 status event code: A-4-4-U10-U11-oth-PR1001 Fee payment year number: 4 |
|
| R17-X000 | Change to representative recorded |
St.27 status event code: A-5-5-R10-R17-oth-X000 |
|
| PR1001 | Payment of annual fee |
St.27 status event code: A-4-4-U10-U11-oth-PR1001 Fee payment year number: 5 |
|
| PR1001 | Payment of annual fee |
St.27 status event code: A-4-4-U10-U11-oth-PR1001 Fee payment year number: 6 |
|
| PR1001 | Payment of annual fee |
St.27 status event code: A-4-4-U10-U11-oth-PR1001 Fee payment year number: 7 |
|
| FPAY | Annual fee payment |
Payment date: 20120928 Year of fee payment: 8 |
|
| PR1001 | Payment of annual fee |
St.27 status event code: A-4-4-U10-U11-oth-PR1001 Fee payment year number: 8 |
|
| FPAY | Annual fee payment |
Payment date: 20130927 Year of fee payment: 9 |
|
| PR1001 | Payment of annual fee |
St.27 status event code: A-4-4-U10-U11-oth-PR1001 Fee payment year number: 9 |
|
| R17-X000 | Change to representative recorded |
St.27 status event code: A-5-5-R10-R17-oth-X000 |
|
| FPAY | Annual fee payment |
Payment date: 20141007 Year of fee payment: 10 |
|
| PR1001 | Payment of annual fee |
St.27 status event code: A-4-4-U10-U11-oth-PR1001 Fee payment year number: 10 |
|
| FPAY | Annual fee payment |
Payment date: 20151008 Year of fee payment: 11 |
|
| PR1001 | Payment of annual fee |
St.27 status event code: A-4-4-U10-U11-oth-PR1001 Fee payment year number: 11 |
|
| FPAY | Annual fee payment |
Payment date: 20161007 Year of fee payment: 12 |
|
| PR1001 | Payment of annual fee |
St.27 status event code: A-4-4-U10-U11-oth-PR1001 Fee payment year number: 12 |
|
| P22-X000 | Classification modified |
St.27 status event code: A-4-4-P10-P22-nap-X000 |
|
| PR1001 | Payment of annual fee |
St.27 status event code: A-4-4-U10-U11-oth-PR1001 Fee payment year number: 13 |
|
| R18-X000 | Changes to party contact information recorded |
St.27 status event code: A-5-5-R10-R18-oth-X000 |
|
| LAPS | Lapse due to unpaid annual fee | ||
| PC1903 | Unpaid annual fee |
St.27 status event code: A-4-4-U10-U13-oth-PC1903 Not in force date: 20181014 Payment event data comment text: Termination Category : DEFAULT_OF_REGISTRATION_FEE |
|
| PC1903 | Unpaid annual fee |
St.27 status event code: N-4-6-H10-H13-oth-PC1903 Ip right cessation event data comment text: Termination Category : DEFAULT_OF_REGISTRATION_FEE Not in force date: 20181014 |
|
| R18-X000 | Changes to party contact information recorded |
St.27 status event code: A-5-5-R10-R18-oth-X000 |
|
| R18-X000 | Changes to party contact information recorded |
St.27 status event code: A-5-5-R10-R18-oth-X000 |
|
| R18-X000 | Changes to party contact information recorded |
St.27 status event code: A-5-5-R10-R18-oth-X000 |
|
| R18-X000 | Changes to party contact information recorded |
St.27 status event code: A-5-5-R10-R18-oth-X000 |
|
| R18-X000 | Changes to party contact information recorded |
St.27 status event code: A-5-5-R10-R18-oth-X000 |
|
| R18 | Changes to party contact information recorded |
Free format text: ST27 STATUS EVENT CODE: A-5-5-R10-R18-OTH-X000 (AS PROVIDED BY THE NATIONAL OFFICE) |
|
| R18-X000 | Changes to party contact information recorded |
St.27 status event code: A-5-5-R10-R18-oth-X000 |