JPS6112812A - Method for decarburizing stainless steel - Google Patents
Method for decarburizing stainless steelInfo
- Publication number
- JPS6112812A JPS6112812A JP13278484A JP13278484A JPS6112812A JP S6112812 A JPS6112812 A JP S6112812A JP 13278484 A JP13278484 A JP 13278484A JP 13278484 A JP13278484 A JP 13278484A JP S6112812 A JPS6112812 A JP S6112812A
- Authority
- JP
- Japan
- Prior art keywords
- gas
- blowing
- inert gas
- steel
- molten steel
- 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
- 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
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)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
この発明は、ＡＯＤ炉、転炉等によりステンレス鋼の精
錬（脱炭）を行なう方法に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for refining (decarburizing) stainless steel using an AOD furnace, a converter, or the like.
従来技術とその問題点
Ａ Ｏ、Ｄ炉、転炉等によるステンレス鋼の精錬は、酸
素ガスとアルゴン等の不活性ガスを大気圧下で鋼浴中に
吹き込んで行なわれるが、底吹きＡＯＤ法の場合、底吹
き羽口を介して０１．Ａｒガスを吹き込むため吹き込み
流量に限界があり、精錬時間が長くかかる。また、底吹
き羽目と上吹きランスによる上下吹きＡＯＤ法の場合、
純酸素上吹き、アルゴン、酸素ガス底吹きでは、精錬時
間は短かいが、Ｃｒの酸化損失が大きい、また、アルゴ
ン、酸素の混合ガス上吹き、アルゴン、酸素の混合ガス
底吹きでは、Ｃｒ酸化損失の問題は解消されるが、上吹
き混合ガスの酸素ガスとアルゴンガスの混合比制御範囲
が狭く、高価なアルゴンガスを大量に使用する必要があ
る。さらに、酸素ガスと不活性ガスを一定割合で吹き込
む精錬においては、大量のガスを強く吹き込むと溶鋼中
のＣｒが酸化されて歩留りが悪化し、Ｃｒの酸化を防止
するために少ない量で弱く吹き込むと精錬に長時間かか
るという問題があった。Prior art and its problems A Stainless steel refining using O, D furnaces, converters, etc. is carried out by blowing oxygen gas and inert gas such as argon into the steel bath under atmospheric pressure, but the bottom blowing AOD method 01 through the bottom blowing tuyere. Since Ar gas is injected, there is a limit to the blowing flow rate, and the refining time takes a long time. In addition, in the case of the top-bottom blowing AOD method using bottom-blowing slats and top-blowing lances,
With pure oxygen top blowing, argon, and oxygen gas bottom blowing, the refining time is short, but the oxidation loss of Cr is large. Although the problem of loss is solved, the control range of the mixture ratio of oxygen gas and argon gas in the top-blown mixed gas is narrow, and it is necessary to use a large amount of expensive argon gas. Furthermore, in refining where oxygen gas and inert gas are injected at a fixed ratio, if a large amount of gas is injected strongly, the Cr in the molten steel will be oxidized and the yield will deteriorate, so to prevent oxidation of Cr, a small amount of gas is injected weakly. There was a problem that refining took a long time.
発明の目的
この発明は、従来の前記問題点ＶＣ鑑みなされたもので
、Ｃｒの酸化を防止して鋼への酸化歩留りを上げるとと
もに、脱炭時間の短縮がはかられるステンレス鋼の脱炭
方法を提案するととを目的とするものである。Purpose of the Invention The present invention was made in view of the above-mentioned problems in the conventional VC, and provides a method for decarburizing stainless steel that prevents oxidation of Cr, increases the oxidation yield of steel, and shortens decarburization time. The purpose of this proposal is to
発明の構成
この発明に係るステンレス鋼の脱炭方法は、ＡＯＤ炬、
転炉等により酸素ガスと不活性ガスを吹き込んで脱炭す
る際、上吹きランスをダブルフロ鋼中の炭素（Ｃ）含有
量に応じて〔０，ガス量／不活性ガヌ虐〕の１′直を下
記第１表の範囲に調整して吹き込むことを特徴とするも
のである。Structure of the Invention The method for decarburizing stainless steel according to the present invention includes an AOD kow,
When decarburizing by blowing oxygen gas and inert gas in a converter etc., the top blowing lance is set at 1' of [0, gas amount/inert gas] depending on the carbon (C) content in the double flow steel. It is characterized by adjusting the direct pressure to the range shown in Table 1 below.
（以下糸′白） 第１表 以下、この発明方法について詳細に説明する。(hereinafter referred to as thread'white) Table 1 The method of this invention will be explained in detail below.
ここでは、この発明方法を実施する設備としてＡＯＤ炉
を例にとり説明する。Here, an AOD furnace will be explained as an example of equipment for implementing the method of the present invention.
第１図はＡ ＯＤ炉による脱炭方法を、第２図はＡＯＤ
炉の精錬に使用するダブルフロー型上吹きランスをそれ
ぞれ示す。Figure 1 shows the decarburization method using an AOD furnace, and Figure 2 shows the method of decarburization using an AOD furnace.
Each figure shows a double flow type top blowing lance used for furnace refining.
ＡＯＤ坦（１）は・尾部の側壁に、炉内１で貯えられた
溶鋼（２）に０１ガスと不活性ガス（以下「Ｍガス」で
代表する）を吹込むための羽目（３）が設けられ、上部
には精錬用上吹きランス（４）が昇降可能に設置されて
いる。そして、精錬中は前記上吹きランス（４）を炉内
まで降下させて０！ガス（５）、または０．ガスとＡｒ
ガスの混合ガス（６）を吹き込むとともに羽口（３）か
らもＯ！ガスと舒ガスの混合ガス（６）を吹き込み、Ａ
ＯＤ炉（１）の上方を覆う排ガス吸引カバー（７）にて
排ガスを吸引しながら精錬を行なっている。The AOD flat (1) is equipped with a lining (3) on the side wall of the tail section for injecting 01 gas and inert gas (hereinafter referred to as "M gas") into the molten steel (2) stored in the furnace 1. A refining top blowing lance (4) is installed at the top so that it can be moved up and down. During refining, the top blowing lance (4) is lowered into the furnace and zero! Gas (5), or 0. gas and argon
At the same time as blowing in the gas mixture (6), O! Blow in the mixed gas (6) of gas and soy gas, and
Refining is performed while sucking exhaust gas with an exhaust gas suction cover (7) that covers the upper part of the OD furnace (1).
この発明では、前記の精錬用上吹きランス（４）を、第
２図に示すダブルフロー型のランス（１４に替えて精錬
することを特徴とする。このダブルフロー型上吹きラン
ス０４）は、中心孔（１４−１）とその周囲に多孔・（
１４−２）が配設されたもので、中心孔（１４−１）か
ら０２ガスとＡｒガスの混合ガス（６）を流し、その外
側の多孔（１４−２）より Ｏ，ガス（５）のみを流す
ようＫしている。このように、ランスの一系統を０２ガ
ス用とし、他の系統を０２ガスとＭガスの混合ガス用と
することにより、溶鋼（２）の炭素量に応じてＯ，ガス
量、Ｍガス量および〔０２ガス量／ Ａｒガス量〕値が
調整可能となり、脱炭精錬の効率化がはかられる。This invention is characterized in that the above-mentioned refining top blowing lance (4) is replaced with a double flow type lance (14) shown in FIG. 2 for refining. This double flow type top blowing lance 04) The central hole (14-1) and its surroundings are porous (
14-2) is arranged, a mixed gas (6) of 02 gas and Ar gas flows from the center hole (14-1), and O, gas (5) flows from the outer porous hole (14-2). I'm telling you to only let it flow. In this way, by using one system of the lance for 02 gas and the other system for a mixed gas of 02 gas and M gas, the amount of O, gas, and M gas can be adjusted according to the carbon content of the molten steel (2). and [02 gas amount/Ar gas amount] values can be adjusted, and the efficiency of decarburization refining can be improved.
第３図は横軸に溶鋼中の炭素含有量（ｗｔ％）を、縦軸
に精錬中におけるＣｒ酸化損失量（Ｋｐ／Ｔ−ｓｔ）を
とり、溶鋼中に吹き込む０２ガスとにガスの割合〔０２
ガス量／Ａ１′ガス量＝α〕の値を変化させて溶鋼中の
炭素含有量とＣｒ酸化損失量の関係を示、したものであ
る。なお、この結果は５ＵＳ４３０の場合である。Figure 3 shows the carbon content (wt%) in molten steel on the horizontal axis and the Cr oxidation loss (Kp/T-st) during refining on the vertical axis, and the ratio of gas to 02 gas injected into the molten steel. [02
The relationship between the carbon content in molten steel and the amount of Cr oxidation loss is shown by changing the value of gas amount/A1' gas amount = α]. Note that this result is for 5US430.
すなわち、炭素含有量の多い溶鋼では酸素ガス吹き込み
量が多くてもＣｒ酸化損失量は少ないが、炭素含有量が
少なくなるにつれてＣｒ酸化損失量が増加する傾向にあ
るため、炭素含有量の少ない溶鋼の場合はＯ，ガス量の
割合を少なくしなければならない。従って゛、０２ガス
吹き込みによる脱炭反応は周知の通り、
２ Ｃ＋ Ｏｘ→２ｃ。In other words, in molten steel with a high carbon content, the amount of oxidation loss of Cr is small even if the amount of oxygen gas blown is large, but as the carbon content decreases, the amount of oxidation loss of Cr tends to increase. In this case, the proportion of O and gas must be reduced. Therefore, as is well known, the decarburization reaction by 02 gas injection is 2 C+ Ox→2c.
であるから、溶鋼中に炭素含有量の多い精錬初期におい
ては、０２ガス吹き込み量を多くし、溶鋼中でのＣｏ分
圧（Ｐｃｏ）を下げ、０８分圧を高める程脱炭反応が急
速に進行し、脱炭精錬時間が短縮することになる。Therefore, in the early stage of refining when the molten steel has a high carbon content, the amount of 02 gas blown into the molten steel is increased to lower the Co partial pressure (Pco) in the molten steel, and the higher the 08 partial pressure is, the more rapidly the decarburization reaction occurs. As the process progresses, the decarburization refining time will be shortened.
この発明はかかる知見より、ステンレス鋼の脱炭に際し
、溶鋼中の炭素含有量が多い場合は０２ガス吹き込み量
を極力多くして脱炭時間を短縮し、溶鋼中の炭素含有量
が低下するにしたがって０２ガス吹き込み量を低下させ
るとともにＡｒガス吹き込み量を増加して溶鋼の攪拌を
十分に行ないながらＣｒ酸化損失量の低減をはかる方法
である。Based on this knowledge, when decarburizing stainless steel, if the carbon content in the molten steel is high, the present invention increases the amount of 02 gas blown as much as possible to shorten the decarburization time and reduce the carbon content in the molten steel. Therefore, this method aims to reduce the amount of Cr oxidation loss while sufficiently stirring the molten steel by decreasing the amount of 02 gas blown and increasing the amount of Ar gas blown.
すなわち、この発明は第３図の結果より、溶鋼中の炭素
量に応じて〔０２ガス量／Ａｒガス量〕値を前記、１１
表に示す範囲（第３図斜線部）で調整して脱炭する方法
であり、そのガス量調整を容品にするために第２図に示
すダブルフロー型の北吹きランスを使用し、該ランスの
中心孔（１４−１）から０２ガスとＡｒガスの混合ガス
（６）を、その外側の多孔（１４−２）より０２ガス（
５）をそれぞれ吹き込むこととしたのである。また、こ
のダブルフロー型ランスによれば、〔０２ガス流量／
Ａｒガス流量〕の値の広い調整範囲を得ることができる
。That is, based on the results shown in FIG. 3, this invention changes the value of [02 gas amount/Ar gas amount] to
This is a method of decarburizing by adjusting the gas amount within the range shown in the table (shaded area in Figure 3).In order to adjust the gas amount in a container, a double flow type north blowing lance shown in Figure 2 is used. A mixed gas (6) of 02 gas and Ar gas is introduced from the center hole (14-1) of the lance, and 02 gas (6) is introduced from the outer hole (14-2).
5) respectively. Moreover, according to this double flow type lance, [02 gas flow rate/
Ar gas flow rate] can be adjusted over a wide range.
この発明において、溶鋼中の炭素含有量に応じて〔Ｏ２
ガス流景／ Ａｒガス流量〕を前記第１表の範囲にＳ整
する理由は、各範囲の上限値以上ではｏ２ガス流量を上
昇させても脱炭速度はほとんど上昇しないだけでなく溶
鋼中のＣｒが酸化し損失量が増加するためであり、また
下限値以下では溶鋼中のＣｒの酸化は低下するが、脱炭
反応が遅く、脱炭処理時間が延長して処理能率の悪化を
招くからである。In this invention, [O2
The reason why the gas flow rate/Ar gas flow rate is adjusted to the ranges shown in Table 1 is that above the upper limit of each range, even if the O2 gas flow rate is increased, the decarburization rate not only hardly increases, but also the decarburization rate in the molten steel increases. This is because Cr oxidizes and the amount of loss increases.Also, below the lower limit, the oxidation of Cr in molten steel decreases, but the decarburization reaction is slow, prolonging the decarburization treatment time and causing deterioration of processing efficiency. It is.
実 施 例
５ＵＳ４３０糸ステンレス鋼の脱炭を９０トンＡＯＤ炉
で行なう際、第２表に示す初期成分（高炭素フェロクロ
ム添加前浴鋼成分）の溶鋼６０トンをＡＯＤ炬に貯え、
炉底部の羽口からＯ，ガスとＡｒガスの混合ガスを吹き
込みながら、第２図に示す上吹きランスを使用して０２
ガスとＡｒガスを吹き込んだ。Example 5 When decarburizing US430 yarn stainless steel in a 90-ton AOD furnace, 60 tons of molten steel with the initial composition shown in Table 2 (bath steel composition before high-carbon ferrochrome addition) was stored in the AOD furnace.
While blowing a mixed gas of O gas and Ar gas from the tuyere at the bottom of the furnace, use the top blowing lance shown in Figure 2 to
Gas and Ar gas were blown into it.
その際、推定される含有炭素量に応じて前記０２ガスと
Ａｒガスの吹き込み割合〔０２ガス流量／Ａｒガス流量
〕を調整した。その時の溶鋼中灰素含有量と［０２ガス
流量／ Ａｒガス流量］の関係を第３表に示す。なお、
高炭素フェロクロムの投入は、炉上ホッパーより吹錬を
行ないながら吹錬初期に投入した。At that time, the blowing ratio of the 02 gas and Ar gas [02 gas flow rate/Ar gas flow rate] was adjusted according to the estimated carbon content. Table 3 shows the relationship between the ash content in the molten steel and [02 gas flow rate/Ar gas flow rate] at that time. In addition,
High carbon ferrochrome was introduced from the hopper above the furnace at the beginning of the blowing process.
本実施例における脱炭後浴鋼成分等結果を第４表に、脱
炭の経緯を第４図に示す。なお、第４表には第３表に示
す従来法で脱炭した場合の結果を併せて示した。The results of the bath steel composition after decarburization in this example are shown in Table 4, and the history of decarburization is shown in FIG. Table 4 also shows the results of decarburization using the conventional method shown in Table 3.
第４表の結果より、従来法に比べてＣｒ酸化損失が少な
くなることにより還元用フェロシリコンも少なくてすみ
、また脱炭時間も大巾に短縮されることがわかる。From the results in Table 4, it can be seen that compared to the conventional method, the oxidation loss of Cr is reduced, so less ferrosilicon is needed for reduction, and the decarburization time is also greatly shortened.
第２表
（以下余白）
第４表
発明の詳細
な説明したごとく、この発明方法によれば、Ｃｒ酸化損
失を増加させることなく送酸速度を上昇させることがで
きるので、脱炭時間の短縮がはかられ、かつ巾広い不活
性ガス比の選択が可能であるためＣｒｅ化損失を最少限
に抑えることができ、ステンレス鋼の精錬に多大な効果
を奏するものである。Table 2 (blank below) Table 4 As detailed in the invention, according to the method of this invention, the oxygen delivery rate can be increased without increasing Cr oxidation loss, so the decarburization time can be shortened. Since the inert gas ratio can be selected from a wide range, the Cre loss can be minimized, and this is highly effective in refining stainless steel.
第１図はＡＯＤ炉による脱炭方法を示す説明図、第２図
はこの発明方法を実施するための上吹きランスの構造を
示す縦断面図、第３図は同上ランスを用い〔０，ガス量
／Ａｒガス量〕の値を変化させて脱炭したときの溶鋼中
炭素含有量とＣｒ酸化損失量の関係を示す図表、第４図
はこの発明の実施例における脱炭の経緯を示す図表であ
る。
１・・・・ＡＯＤ炉、２・・・・溶鋼、３・・・・羽口
、４・・・・ランス、５・・・・０□ガス、６・・・・
混合ガス、１４・・・・ダブルフロー型フンス。
出願人 住友金属工業株式会社
第１図
第２図
孔孔孔
第３図
溶鋼中の炭素含有１ｉ（ｗｔ％）
第４図
０ １０ ２０ ．３０
４０ ５０ ６０脱炭時間（分）Fig. 1 is an explanatory diagram showing a decarburization method using an AOD furnace, Fig. 2 is a longitudinal cross-sectional view showing the structure of a top blowing lance for carrying out the method of this invention, and Fig. 3 is a diagram showing the structure of a top blowing lance for carrying out the method of this invention. Figure 4 is a chart showing the relationship between the carbon content in molten steel and the amount of Cr oxidation loss when decarburizing is performed by changing the value of [Ar amount/Ar gas amount]. It is. 1...AOD furnace, 2...molten steel, 3...tuyere, 4...lance, 5...0□ gas, 6...
Mixed gas, 14...Double flow type funnel. Applicant: Sumitomo Metal Industries, Ltd. Figure 1 Figure 2 Holes Figure 3 Carbon content in molten steel 1i (wt%) Figure 4 0 10 20 . 30
40 50 60 Decarburization time (min)
Claims (1)
込んでステンレス鋼の脱炭を行なう方法において、上吹
きランスをダブルフロー型とし、その一系統を酸素ガス
用とし、他の系統を酸素と不活性ガスの混合ガス用とし
、溶鋼中の炭素〔Ｃ〕含有量に応じて〔Ｏ＿２ガス量／
不活性ガス量〕の値を下記表の範囲に調整して吹き込む
ことを特徴とするステンレス鋼の脱炭方法。 ▲数式、化学式、表等があります▼[Claims] In a method for decarburizing stainless steel by blowing an inert gas together with oxygen gas into a steel bath under atmospheric pressure, the top blowing lance is of a double flow type, and one system is used for oxygen gas. , the other system is for a mixed gas of oxygen and inert gas, and the [O_2 gas amount/
A method for decarburizing stainless steel, which is characterized by adjusting the amount of inert gas and injecting it within the range shown in the table below. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13278484A JPS6112812A (en) | 1984-06-27 | 1984-06-27 | Method for decarburizing stainless steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13278484A JPS6112812A (en) | 1984-06-27 | 1984-06-27 | Method for decarburizing stainless steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6112812A true JPS6112812A (en) | 1986-01-21 |
| JPH0456083B2 JPH0456083B2 (en) | 1992-09-07 |
Family
ID=15089461
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13278484A Granted JPS6112812A (en) | 1984-06-27 | 1984-06-27 | Method for decarburizing stainless steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6112812A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01172505A (en) * | 1987-12-26 | 1989-07-07 | Nkk Corp | Method for decarburizing pig iron containing cr |
| JPH04362115A (en) * | 1991-06-06 | 1992-12-15 | Nippon Steel Corp | Decarburizing method for molten steel |
| JP2010511100A (en) * | 2006-11-30 | 2010-04-08 | エス・エム・エス・ジーマーク・アクチエンゲゼルシャフト | Method and apparatus for producing stainless steel based on pig iron without using electrical energy supply |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2674186C1 (en) * | 2017-11-13 | 2018-12-05 | Публичное акционерное общество "Северсталь" (ПАО "Северсталь") | Procedure for melting steel in converter |
| RU2764455C1 (en) * | 2021-05-06 | 2022-01-17 | Публичное акционерное общество «Северсталь» (ПАО «Северсталь») | Method for steel smelting in a converter |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60230931A (en) * | 1984-04-26 | 1985-11-16 | アレゲニ− ルドラム スチ−ル コ−ポレ−シヨン | Steeling process in oxygen blast vessel |
-
1984
- 1984-06-27 JP JP13278484A patent/JPS6112812A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60230931A (en) * | 1984-04-26 | 1985-11-16 | アレゲニ− ルドラム スチ−ル コ−ポレ−シヨン | Steeling process in oxygen blast vessel |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01172505A (en) * | 1987-12-26 | 1989-07-07 | Nkk Corp | Method for decarburizing pig iron containing cr |
| JPH04362115A (en) * | 1991-06-06 | 1992-12-15 | Nippon Steel Corp | Decarburizing method for molten steel |
| JP2010511100A (en) * | 2006-11-30 | 2010-04-08 | エス・エム・エス・ジーマーク・アクチエンゲゼルシャフト | Method and apparatus for producing stainless steel based on pig iron without using electrical energy supply |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0456083B2 (en) | 1992-09-07 |
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