JPS5967309A - Manufacture of high cr steel using dephosphorized molten iron - Google Patents
Manufacture of high cr steel using dephosphorized molten ironInfo
- Publication number
- JPS5967309A JPS5967309A JP57177854A JP17785482A JPS5967309A JP S5967309 A JPS5967309 A JP S5967309A JP 57177854 A JP57177854 A JP 57177854A JP 17785482 A JP17785482 A JP 17785482A JP S5967309 A JPS5967309 A JP S5967309A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- molten
- melted
- electric furnace
- low
- 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.)
- Pending
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
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は溶解炉で溶解した高Cr溶湯と脱P溶銑とを合
せ湯して高Cr鋼を溶製する方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing high Cr steel by combining high Cr molten metal melted in a melting furnace and dephosphorized hot metal.
従来、低P高Cr鋼の溶製方法としては、電気炉等の溶
解炉でスクラップおよびCr源を溶解し、これをAOD
転炉才たは上底吹き転炉で精錬する方法、または脱S溶
銑を転炉で脱P精錬しこれにCr源を装入して再度精錬
するいわゆる2回吹錬を行い、中炭城((C〕=0.5
〜0.6チ)で出鋼した後、減圧下で脱炭する方法が主
なものであった。Conventionally, the method for producing low P high Cr steel is to melt scrap and Cr source in a melting furnace such as an electric furnace, and then melt the scrap and Cr source using AOD.
A method of refining in a converter or top-bottom blowing converter, or a so-called double blowing method in which S-free hot metal is dephosphorized in a converter, a Cr source is charged into it, and refining is performed. ((C)=0.5
The main method was to tap the steel at ~0.6 inch) and then decarburize it under reduced pressure.
前者の方法では、電気炉からの目標溶製量の粗溶鋼をA
OD炉または上底吹き転炉で低炭域まで脱炭し、しかる
後、Fe−慣合金を投−人し不活性ガスを底吹きして攪
拌することにより、スラグ中に酸化除去されていたCr
酸化物を還元してCrを回収すると共に、脱Sすること
が可能である。In the former method, the target amount of crude molten steel from the electric furnace is
It was decarburized to a low carbon range in an OD furnace or a top-bottom blowing converter, and then oxidized and removed into the slag by pouring Fe-inertial alloy into the furnace and stirring with inert gas blowing from the bottom. Cr
It is possible to recover Cr and remove S by reducing the oxide.
この方法は、 Cr歩留りが高く、出鋼後の脱炭を要し
ないという利点を有する反面、電気炉におけるスクラッ
プやCr合金鉄の溶解コストが嵩み、また、上底吹き転
炉でCr粗溶鋼を脱炭還元処理する場合、上吹ランスの
効果により精錬時間が短くてすむlとも拘らず電気炉l
こおける溶解に長時間を要し、生産性が低いという問題
があった。Although this method has the advantage of high Cr yield and no need for decarburization after tapping, it increases the cost of melting scrap and Cr alloy iron in an electric furnace, and also melts Cr crude molten steel in a top-bottom blowing converter. When performing decarburization reduction treatment, the refining time is short due to the effect of the top blowing lance, but an electric furnace is required.
There was a problem in that it took a long time to dissolve in the oven, resulting in low productivity.
後者の方法では、安価な溶銑を使用できる反面、脱P吹
錬および本吹錬の金無母合計2回の吹錬を要し、しかも
Cr歩留りを高く保つために中炭出鋼後減圧下で低炭域
まで脱炭する必要があり、 Cr歩留りき能率面とが両
立しないという問題がある。Although the latter method allows the use of cheap hot metal, it requires two rounds of blowing, one for removing P and the other for main blowing.Moreover, in order to maintain a high Cr yield, hot metal is heated under reduced pressure after tapping the hot metal. There is a problem in that it is necessary to decarburize to the low coal range at low coal levels, which is incompatible with Cr yield efficiency.
本発明は、近年開発された溶銑脱P技術の進歩に着目し
、本来電気炉で溶解されるべき普通鋼スクラップを低P
溶銑で置換し、電気炉で溶解した高Cr溶湯と合ぜ湯し
、これを上底吹き転炉で精錬することにより、低コスト
高能率で低P高Cr鋼を製造する方法を折供するもので
ある。The present invention focuses on the progress of hot metal deP technology that has been developed in recent years, and aims to reduce the amount of P by reducing ordinary steel scrap that should originally be melted in an electric furnace.
Provides a method for producing low-P, high-Cr steel at low cost and high efficiency by substituting hot metal with high-Cr molten metal melted in an electric furnace and refining it in a top-bottom blowing converter. It is.
以下図面によって本発明方法を説明する。第1図は、本
発明方法の実施例の工程図である。The method of the present invention will be explained below with reference to the drawings. FIG. 1 is a process diagram of an embodiment of the method of the present invention.
高炉溶銑を例えばトーピードカー内で脱Pしておく。Blast furnace hot metal is dephosphorized, for example, in a torpedo car.
一方、電気炉等の溶解炉において、本来装入溶解される
べき高Cr釧と普通鋼スクラップのうち、普通鋼スクラ
ップの60〜80%を削減して、軽負荷溶解で高Cr溶
湯を溶製するー
この高Cr溶湯と、前記普通鋼スクラップ削減量相当量
の脱P溶銑とを合せ湯し、この混合溶湯を上底吹き転炉
で精錬することにより、低P高Cr鋼を溶製する。On the other hand, in melting furnaces such as electric furnaces, 60 to 80% of the ordinary steel scraps that should be charged and melted are reduced by 60 to 80%, and high Cr molten metal is melted with light load melting. - This high Cr molten metal is combined with the dephosphorized hot metal equivalent to the amount of reduced ordinary steel scrap, and this mixed molten metal is refined in a top-bottom blowing converter to produce low P high Cr steel. .
溶解炉は溶解量を削減して溶解するので、溶解時間を短
縮することができ、高Cr鋼溶製工程全体の生産能率が
向上することは明らかである。It is clear that since the melting furnace reduces the melting amount and melts, the melting time can be shortened and the production efficiency of the entire high Cr steel melting process is improved.
また、普通鋼スクラップ溶解量の削減量、すなわぢ、脱
P溶銑との置換量について、置換比率を種々変更し、こ
れを上底吹き転炉で精錬した場合の、鉄源、電気炉溶解
における市;力および原料、転炉における副原料および
吹錬ガス等、ならびに電気炉転炉を含む耐火物等につい
てコストを調査する試験を行ったうその結果をコスト指
数として第2図に示した。In addition, regarding the reduction in the amount of ordinary steel scrap melted, that is, the amount replaced with P-free hot metal, we changed the replacement ratio variously, and when refining this in a top-bottom blowing converter, the iron source, electric furnace melting Figure 2 shows the results of a test to investigate the cost of power and raw materials, auxiliary raw materials and blowing gas in converters, and refractories including electric furnace converters as a cost index. .
普通鋼スクラップと脱P溶銑との置換率が80チを超え
るさ、電気炉における溶解が合金鉄を主体さしたものさ
なり、炉内容積に比し装入材料容積が減少するので熱効
率が低下することと、合金鉄の大部分が高炭素I、TC
Cr、高炭素Fe’−Ni等の高融点であること等から
、溶は残りが発生17やすくなり、大電力を投入せざる
を得ないので、電力費の高騰、電極消耗量の増大、耐火
物損耗量の増加等を招来する、
また、普通銅スクラツプと脱P溶銑との置換率が60%
未満では、電気炉の溶解量や転炉操業費。When the replacement rate between ordinary steel scrap and dephosphorized hot metal exceeds 80 cm, the melting in the electric furnace is mainly made of ferroalloy, and the volume of charged material decreases compared to the volume inside the furnace, resulting in a decrease in thermal efficiency. and that most of the ferroalloys are high carbon I, TC.
Due to the high melting point of Cr, high carbon Fe'-Ni, etc., molten residue is likely to be generated17 and a large amount of power must be input, resulting in soaring power costs, increased electrode consumption, and fire resistance. In addition, the replacement rate between ordinary copper scrap and dephosphorized hot metal is 60%.
If it is less than the amount melted in an electric furnace or the operating cost of a converter.
耐火物損耗量などが低減しない。また、脱P溶銑の使用
量が余り少ない場合には、温度が低下し、溶銑鍋に付着
する問題が生ずる。The amount of loss of refractories is not reduced. Furthermore, if the amount of dephosphorized hot metal used is too small, the temperature will drop and there will be a problem that the hot metal will stick to the ladle.
従って、現状の普通鋼スクラップ、含Crスクラップ、
Cr合金鉄の市価に著しい不均衡な価格変動がない限り
、普通鋼スクラップと脱P溶銑との置換比率を60〜8
0%とするのが最も有利である。Therefore, the current ordinary steel scrap, Cr-containing scrap,
Unless there is a significant unbalanced price change in the market price of Cr alloy ferroalloy, the replacement ratio of ordinary steel scrap and dephosphorized hot metal should be set at 60 to 8.
A value of 0% is most advantageous.
次に1本発明方法では、上底吹き転炉を用いる。Next, in one method of the present invention, a top-bottom blowing converter is used.
本発明方法で合せ湯した粗溶湯は、第1表に示すように
、転炉精錬初期条件が低温高炭素となる。As shown in Table 1, the crude molten metal combined by the method of the present invention has a converter refining initial condition of low temperature and high carbon.
第1表
上底吹き転炉を用い、脱炭期に上吹きランスを底吹きと
併用することにより、従来と同等程度の精錬時間で精錬
することができ、高い熱効率および精錬効果を得ること
ができる。Table 1 By using a top-bottom blowing converter and using a top-blowing lance in conjunction with bottom blowing during the decarburization period, refining can be performed in the same refining time as conventional methods, and high thermal efficiency and refining effects can be obtained. can.
Crは低温で酸化され易いので、脱炭期になるべく迅速
に鋼浴温度を」二昇さぜれば、Cr酸化ロスが・低減し
、還元時に添加するli″e S+原単位を削減する
ことが可能である。Since Cr is easily oxidized at low temperatures, raising the steel bath temperature as quickly as possible during the decarburization stage will reduce Cr oxidation loss and reduce the S+ basic unit added during reduction. is possible.
第3図に転炉待時間と熱効率との関係を、精錬初期C含
有量の変化について示した21本発明法では、脱P溶銑
を普通鋼スクラップの60〜80%と置換するので、精
錬初期には高C含有量となり、第3図Aのように高熱効
率となる。すなわち、同一酸素吹精条件および転炉待時
間において、精錬初期C含有量が高ければ高い程、また
精錬初期C含有量、転炉待時間が同一の場合には土吹き
ランスを使用することにより高い熱効率が得られる。Figure 3 shows the relationship between converter waiting time and thermal efficiency with respect to changes in C content at the initial stage of refining. has a high C content, resulting in high thermal efficiency as shown in Figure 3A. In other words, under the same oxygen blowing conditions and converter waiting time, the higher the initial refining C content, and when the initial refining C content and converter waiting time are the same, the use of earth blowing lances increases. High thermal efficiency can be obtained.
第1表に示すように、本発明方法では上底吹き転炉にお
いて、精錬初期C含有量≧2.5%で精錬を開始するこ
ととなる。従って、脱炭期に上吹きを実施することによ
り従来を遥かに上層る熱効率を得ることが可能である。As shown in Table 1, in the method of the present invention, refining is started at an initial refining C content of 2.5% or more in a top-bottom blowing converter. Therefore, by performing top blowing during the decarburization period, it is possible to obtain a thermal efficiency far higher than that of the conventional method.
以上の結果、本発明法では従来法に比し、 Crロスを
減少することができた。第4図は8US430鋼につい
て吹止C%に対するCrロス量を示すグラフである。本
発明法は熱効率が高く、鋼浴温度が迅速に上昇するので
Crが酸化されに<<、また、鋼浴のC含有量が高いた
めスラグ中のCr酸化物が下式のスラグメタル反応によ
り還元されるためである。As a result, the method of the present invention was able to reduce Cr loss compared to the conventional method. FIG. 4 is a graph showing the amount of Cr loss versus blow-stop C% for 8US430 steel. The method of the present invention has high thermal efficiency, and the steel bath temperature rises quickly, so Cr is not oxidized. Also, since the steel bath has a high C content, Cr oxides in the slag are oxidized by the slag metal reaction as shown below. This is because it will be returned.
Cr2O3+ 3C−+ 2Cr + 3CO↑従って
、本発明法は、脱P溶銑を用いて、低コストで高能率に
高Cr鋼を溶製することができると共に、上底吹き転炉
を用いて、最も適切な吹錬のできる吹錬初期C含有量の
粗溶湯を最も効率的に好適に吹錬することができるもの
である。Cr2O3+ 3C-+ 2Cr + 3CO↑Therefore, the method of the present invention is capable of producing high-Cr steel at low cost and with high efficiency using dephosphorized hot metal, and at the same time, using a top-bottom blowing converter, Crude molten metal having an initial C content that can be appropriately blown can be blown most efficiently and suitably.
以上、高Cr鋼の溶製について説明したが、ステンレス
鋼の溶製についても、もちろん、本方法はそのまま適用
されるものである。さらに特殊高鳩鋼、KHC鋼等の溶
製においても本方法を適用して低コストの溶製を行うこ
とができる。Although the above description has been made regarding the melting of high Cr steel, the present method can of course be applied as is to the melting of stainless steel. Furthermore, this method can also be applied to the melting of special Takahato steel, KHC steel, etc. to achieve low-cost melting.
実施例 第1図に示す工程により8U8430鋼を溶製した。Example 8U8430 steel was produced by the process shown in FIG.
250トンのトビードカー内で脱P処理した150トン
の溶銑を50トンずつに3分割して用いた。150 tons of hot metal that had been dephosphorized in a 250-ton tobbed car was divided into three 50-ton portions and used.
一方100トン電気炉でクロム源のスクラップおよび合
金鉄35トンと普通鋼スクラップ15トン計50トンを
溶解した。Meanwhile, a total of 50 tons of chromium source scrap, 35 tons of alloyed iron, and 15 tons of ordinary steel scrap were melted in a 100-ton electric furnace.
電気炉溶湯50トンと脱P溶銑50トンとを装入鍋内で
合せ渇し、計100トンとした。このときの溶解すべき
普通鋼スクラップの脱P溶銑置換率は76.9チである
。50 tons of electric furnace molten metal and 50 tons of dephosphorized hot metal were combined in a charging pot to make a total of 100 tons. At this time, the dephosphorization hot metal replacement rate of the ordinary steel scrap to be melted was 76.9 inches.
上記合せ湯した粗溶湯100トンを上底吹き転炉に装入
し、脱炭期のみ(C=0.60%まで)、純酸素を上底
吹きし、C含有量O96チ以下とした後、酸素とアルゴ
ンの比率を変化させなからC含有量0.05%まで底吹
き精錬し、次いて引続き、アルゴンガスのみて還元処理
を行った。100 tons of the above combined crude molten metal was charged into a top-bottom blowing converter, and during the decarburization period only (up to C = 0.60%), pure oxygen was blown from the top and bottom to reduce the C content to 096 cm or less. Bottom blow refining was carried out to a C content of 0.05% without changing the ratio of oxygen and argon, and then reduction treatment was performed using only argon gas.
」二底吹転炉における脱炭期酸素吹精量は上吹き110
Nm3/min、下吹き60 Nm37m1nである
。” The amount of oxygen blown during decarburization in a double-bottom blown converter is top-blown 110
Nm3/min, downward blowing 60 Nm37m1n.
第2表にトピードカー内における脱P、脱S条件を示し
、第3表に第1図の製造工程の各段階における溶湯の成
分および温度を示し、第4表に本実施例と従来法との操
業成績を比較して示し、第5表に原単位の比較を示した
。Table 2 shows the P and S removal conditions in the torpedo car, Table 3 shows the components and temperatures of the molten metal at each stage of the manufacturing process shown in Figure 1, and Table 4 shows the differences between this example and the conventional method. The operational results are shown in comparison, and Table 5 shows a comparison of the basic unit.
第2表 トビード脱P脱S処理条件
第4表 操業成績比較(指数表示)
第5表 原単位比較(指数標示)
実施例では、電気炉溶解時間(出湯間隔)が短縮し製出
鋼量が増加し、歩留りが向上している。Table 2 Tobeed deP desulfurization treatment conditions Table 4 Comparison of operational results (index display) Table 5 Comparison of basic units (index display) In the example, the electric furnace melting time (tapping interval) was shortened and the amount of steel produced was and the yield is improving.
また、各原単位も低減し、Cr源を同一とした場合、綜
合的に約14%のコストダウンとなった。In addition, each unit consumption was reduced, resulting in a total cost reduction of about 14% when the Cr source was the same.
第1図は本発明方法の実施例の工程図、第2図は、普通
鋼スクラップと脱P溶銑との置換比率に対するコスト指
数のグラフ、第3図は精錬初期C含有量の変化による転
炉待時間と熱効率との関係を示すグラフ、第4図は吹止
C含有量とCrロス量との関係を示すグラフである。Figure 1 is a process diagram of an embodiment of the method of the present invention, Figure 2 is a graph of the cost index versus the replacement ratio of ordinary steel scrap and dephosphorized hot metal, and Figure 3 is a graph of the change in C content at the initial stage of refining in the converter. FIG. 4 is a graph showing the relationship between waiting time and thermal efficiency, and FIG. 4 is a graph showing the relationship between blowback C content and Cr loss amount.
Claims (1)
プの60〜80%を削減して溶解炉で溶解した高Cr溶
湯と、前記削減量相描量の脱P溶銑とを合ぜ湯し、この
合湯を上底吹き転炉に装入して精錬することを特徴とす
る脱P溶銑を使用した高Cr鋼の溶製方法。For the production of high Cr steel, high Cr molten metal melted in a melting furnace by reducing 60 to 80% of the ordinary steel scrap that should be added is combined with the dephosphorized hot metal of the same amount as the reduction amount. A method for producing high Cr steel using dephosphorized hot metal, characterized in that the combined metal is charged into a top-bottom blowing converter and refined.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57177854A JPS5967309A (en) | 1982-10-09 | 1982-10-09 | Manufacture of high cr steel using dephosphorized molten iron |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57177854A JPS5967309A (en) | 1982-10-09 | 1982-10-09 | Manufacture of high cr steel using dephosphorized molten iron |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS5967309A true JPS5967309A (en) | 1984-04-17 |
Family
ID=16038251
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP57177854A Pending JPS5967309A (en) | 1982-10-09 | 1982-10-09 | Manufacture of high cr steel using dephosphorized molten iron |
Country Status (1)
Country | Link |
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JP (1) | JPS5967309A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008531840A (en) * | 2005-12-02 | 2008-08-14 | エス・エム・エス・デマーク・アクチエンゲゼルシャフト | Method and melting apparatus for producing high manganese low carbon steel |
JP2010280942A (en) * | 2009-06-03 | 2010-12-16 | Nippon Yakin Kogyo Co Ltd | Method for manufacturing low-phosphorus stainless steel |
JP2011214125A (en) * | 2010-04-02 | 2011-10-27 | Nippon Steel Corp | Method for decarburizing chromium-containing steel by blowing oxygen |
JP2013209738A (en) * | 2011-04-27 | 2013-10-10 | Jfe Steel Corp | Method of manufacturing molten steel |
JP2014058719A (en) * | 2012-09-18 | 2014-04-03 | Nisshin Steel Co Ltd | Production method of molten iron |
-
1982
- 1982-10-09 JP JP57177854A patent/JPS5967309A/en active Pending
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008531840A (en) * | 2005-12-02 | 2008-08-14 | エス・エム・エス・デマーク・アクチエンゲゼルシャフト | Method and melting apparatus for producing high manganese low carbon steel |
KR101113717B1 (en) | 2005-12-02 | 2012-02-27 | 에스엠에스 지마크 악티엔게젤샤프트 | Method and melting system for manufacturing a steel containing high contents of manganese and low contents of carbon |
JP2010280942A (en) * | 2009-06-03 | 2010-12-16 | Nippon Yakin Kogyo Co Ltd | Method for manufacturing low-phosphorus stainless steel |
JP2011214125A (en) * | 2010-04-02 | 2011-10-27 | Nippon Steel Corp | Method for decarburizing chromium-containing steel by blowing oxygen |
JP2013209738A (en) * | 2011-04-27 | 2013-10-10 | Jfe Steel Corp | Method of manufacturing molten steel |
JP2014058719A (en) * | 2012-09-18 | 2014-04-03 | Nisshin Steel Co Ltd | Production method of molten iron |
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