JP3103121B2 - RH reflux vacuum degassing method - Google Patents
RH reflux vacuum degassing methodInfo
- Publication number
- JP3103121B2 JP3103121B2 JP03001320A JP132091A JP3103121B2 JP 3103121 B2 JP3103121 B2 JP 3103121B2 JP 03001320 A JP03001320 A JP 03001320A JP 132091 A JP132091 A JP 132091A JP 3103121 B2 JP3103121 B2 JP 3103121B2
- Authority
- JP
- Japan
- Prior art keywords
- argon gas
- tuyere
- tuyeres
- vacuum degassing
- reflux
- 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.)
- Expired - Lifetime
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ＲＨ環流式真空脱ガス
法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an RH reflux vacuum degassing method.
【０００２】[0002]
【従来の技術】ＲＨ環流式真空脱ガス法に於いて、溶鋼
の環流を効率よく達成する方法として種々の方法が提案
されている。例えば、特開昭60-28467号公報には、浸漬
管内の羽口の吐出方向を従来の90°から上向きとして環
流速度を増加させる方法が提唱されている。また、特開
昭62-8937号公報では、上下２段のアルゴンガス吹き込
み羽口をずらす方法が提唱されている。2. Description of the Related Art In the RH recirculating vacuum degassing method, various methods have been proposed as a method for efficiently achieving the recirculation of molten steel. For example, Japanese Patent Application Laid-Open No. 60-28467 proposes a method in which the discharge direction of the tuyere in the immersion tube is increased from 90 ° in the past to increase the reflux speed. Japanese Patent Application Laid-Open No. 62-8937 proposes a method in which the upper and lower two-stage argon gas injection tuyeres are shifted.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、以上に
述べたような従来の方法は、以下のような問題点を有し
ている。 1) 特開昭60-28467号公報においては、アルゴンガス吹
き込み羽口を上向きにセットするため、その施工方法が
困難であり、また浸漬管用耐火物にも斜めに穴を空けな
ければならず耐火物の施工方法もかなりの技術が必要で
ある。However, the above-mentioned conventional method has the following problems. 1) In Japanese Unexamined Patent Publication No. 60-28467, it is difficult to apply argon gas injection tuyere with the tuyere set upward. A considerable skill is required for the construction method of the object.
【０００４】2) また特開昭 62-8937号公報では、上下
２段の羽口が互い違いとなるため、かならずしもその効
果が十分に現れない。 そこで本発明はこのような複雑な手段をとることなく、
ＲＨ環流式真空脱ガス法において、より効率的な環流速
度の増加方法を提案することを目的とするものである。[0004] 2) In Japanese Patent Application Laid-Open No. 62-8937, the tuyeres of the upper and lower stages are staggered, so that the effect is not always sufficiently exhibited. Therefore, the present invention does not take such complicated means,
It is an object of the present invention to propose a more efficient method of increasing the reflux velocity in the RH reflux vacuum degassing method.
【０００５】[0005]
【課題を解決するための手段】そこで、発明者は、上記
問題点を解決する方法として羽口一本当たりのガス流量
の溶鋼の環流に及ぼす影響について明らかにしその関係
により浸漬管径に応じた最適な羽口本数を見出したもの
であり、すなわち、本発明はＲＨ環流式真空脱ガス法に
おいて、浸漬管の上昇管に配置する円周方向のアルゴン
ガス吹き込み羽口数Ｎを次式１を満足するようにし、か
つアルゴンガス吹き込み方向が浸漬管の中心に向くよう
に各羽口を設けることを特徴としたＲＨ環流式真空脱ガ
ス法である。In order to solve the above-mentioned problems, the inventor has clarified the effect of the gas flow per tuyere on the reflux of molten steel, and determined the relationship between the diameter of the submerged pipe and the relationship. The present invention has found the optimum number of tuyeres. That is, in the present invention, in the RH reflux vacuum degassing method, the number N of circumferential tuyeres for blowing argon gas arranged in the riser of the immersion tube satisfies the following formula 1. To do
The argon gas injection direction to the center of the dip tube
RH recirculation type vacuum degassing method, wherein each tuyere is provided.
【０００６】 Ｎ≧（４π3 ×Ａ2 ×ａ2 ）／（ｋ2 ×Ｌ）・・・（式１） である。N ≧ (4π 3 × A 2 × a 2 ) / (k 2 × L) (Equation 1) It is.
【０００７】[0007]
【作用】以下にこの発明についてさらに詳細に説明す
る。図１(a),(b) に水モデル実験で求めた羽口一本当た
りのガス吐出流速と吐出ガスが溶鋼を水平方向に動かす
距離との関係を示す。なお、１は羽口より吹き込まれた
アルゴンガスが水平方向の溶鋼の動きに影響を及ぼす範
囲であり、２は浸漬管の中心にアルゴンガス吹き込み方
向が向いたアルゴン吹き込み用羽口であり、３は浸漬管
内周である。この実験より、発明者はガス吐出流速と吐
出ガスが溶鋼を水平方向に動かす距離との関係は、以下
の式２で示されることを見出した。The present invention will be described below in more detail. FIGS. 1 (a) and 1 (b) show the relationship between the gas discharge velocity per tuyere and the distance that the discharged gas moves the molten steel in the horizontal direction, as determined by a water model experiment. Incidentally, 1 is the movement affecting the scope of the tuyere by Ri blown argon gas horizontally molten steel, 2 centered on how blowing argon gas dip tube
The tuyere is a tuyere for injecting argon, and 3 is the inner circumference of the dip tube. From this experiment, the inventor has found that the relationship between the gas discharge flow rate and the distance that the discharged gas moves the molten steel in the horizontal direction is expressed by the following equation (2).
【０００８】 である。[0008] It is.
【０００９】またガス吐出速度は、以下の式３で示され
る。 Ｂ＝Ｌ／（πａ2 ×ｎ）・・・（式３） ここで、ｎ：アルゴンガス吹き込み羽口個数（−) ａ：アルゴンガス吹き込み羽口内径（ｍ) Ｌ：アルゴンガス流量（ｍ3/min) である。The gas discharge speed is expressed by the following equation (3). B = L / (πa 2 × n) (Equation 3) where, n: number of tuyere of argon gas blowing tuyere (-) a: inner diameter of tuyere of argon gas blowing tuyere (m) L: flow rate of argon gas (m 3) / min).
【００１０】水モデル実験で、図２の(a) に示すように
適切な羽口本数の場合は、吐出ガスの溶鋼を水平方向に
動かす距離の範囲が、環流管の全内周を網羅しており、
図２の(b) のように不適切な羽口本数の場合は、一部吐
出ガスの影響の及ばない範囲が存在することが分かっ
た。これにより本発明者は、効率良く環流を行わせる為
には、吐出ガスが溶鋼を水平方向に動かす距離が、浸漬
管円周方向全域に行きわたることが必要であることを知
見した。In the water model experiment, as shown in FIG. 2 (a), when the number of tuyeres is appropriate, the range of the distance in which the molten steel of the discharge gas is moved in the horizontal direction covers the entire inner circumference of the reflux tube. And
In the case of an inappropriate number of tuyeres as shown in FIG. 2 (b), it was found that there was a range that was partially unaffected by the discharge gas. Accordingly, the present inventor has found that in order to perform the reflux efficiently, the distance that the discharged gas moves the molten steel in the horizontal direction needs to reach the entire circumferential direction of the immersion tube.
【００１１】そのためには、次式４の成立が必要であ
る。 Ｎ×Ｘ≧２πＡ・・・（式４） ここで、Ａ：浸漬管内径（ｍ） である。式４に式２と式３を代入することにより式１が
求まる。For this purpose, the following equation 4 must be satisfied. N × X ≧ 2πA (Equation 4) where A is the inner diameter of the immersion tube (m). Expression 1 is obtained by substituting Expression 2 and Expression 3 into Expression 4.
【００１２】即ち式１が成立する。 Ｎ≧（４π3 ×Ａ2 ×ａ2 ）／（ｋ2 ×Ｌ）・・・（式１） ここでアルゴンガス吹き込み用羽口本数は、Ｎよりも大
きすぎるとガスが環流に影響を及ぼす範囲が重なりあっ
て互いに干渉するためにかえって逆効果となるため式１
の左辺よりも大きい最小の整数が好ましい。したがっ
て、ある一定流量のアルゴンガスを流す場合は、その適
正羽口本数は、浸漬管内径およびアルゴンガス吹き込み
用羽口内径の２乗に比例することがわかる。That is, equation 1 is established. N ≧ (4π 3 × A 2 × a 2 ) / (k 2 × L) (Equation 1) Here, if the number of tuyeres for blowing argon gas is too large than N, the gas affects the reflux. Since the ranges are overlapped and interfere with each other, the opposite effect is obtained.
The smallest integer larger than the left side of is preferred. Therefore, when flowing argon gas at a certain constant flow rate, it is understood that the appropriate number of tuyeres is proportional to the square of the inner diameter of the immersion tube and the inner diameter of the tuyeres for blowing argon gas.
【００１３】次に本発明の実施例について本発明をより
詳細に説明する。Next, the present invention will be described in more detail with reference to embodiments of the present invention.
【００１４】[0014]
【実施例】実施例１ 浸漬管内径 600mm, アルゴンガス吹き込み用羽口の内径
が６mmで羽口数が18本（実施例）および12本（従来例）
の２種の浸漬管を用いて環流式脱ガス処理を実施した。
またこの時のアルゴンガス流量は、2500ｌ/minである。
処理鋼種の目標成分を表１に示す。この鋼種は、高清浄
度が要求されるDI (Draw and Ironing)管用素材であ
る。それぞれ18本と12本羽口で処理を実施した場合の処
理後成分の平均値を表２に示す。脱ガス処理後酸素値
は、12本羽口は、 22ppmであったが18本羽口の酸素値
は、 18ppmまで低下した。尚この時の処理前溶存酸素
は、それぞれ 35ppmおよび 34ppmで処理時間は20分であ
った。Example 1 Immersion tube inner diameter 600 mm, inner diameter of argon gas injection tuyere 6 mm, number of tuyeres 18 (Example) and 12 (conventional example)
Reflux degassing treatment was performed using the two types of dip tubes.
At this time, the flow rate of the argon gas is 2500 l / min.
Table 1 shows the target components of the treated steel types. This steel grade is a material for DI (Draw and Ironing) pipes that require high cleanliness. Table 2 shows the average values of the components after treatment when the treatment was carried out with 18 and 12 tuyeres, respectively. After degassing, the oxygen value of the 12 tuyeres was 22 ppm, but the oxygen value of the 18 tuyeres dropped to 18 ppm. At this time, the dissolved oxygen before the treatment was 35 ppm and 34 ppm, respectively, and the treatment time was 20 minutes.
【００１５】因みにこの実施例の式１の値は 17.95であ
る。 実施例２ 浸漬管内径 600mm, アルゴンガス吹き込み用羽口の内径
が６mmで羽口数が18本（実施例）および12本（従来例）
の２種の浸漬管を用いて環流式脱ガス処理を実施した。
またこの時のアルゴンガス流量は、2500ｌ/minである。
処理鋼種の目標成分を表３に示す。この鋼種は、真空脱
炭処理を要する極低炭素鋼である。それぞれ18本と12本
羽口で処理を実施した場合の処理後成分の平均値を表４
に示す。真空脱炭処理時間が、15分であるが、処理後炭
酸濃度値は、12本羽口は、 20ppmであったが18本羽口は
15ppmまで低下した。尚この時の処理前フリー酸素は、
それぞれ350ppmおよび346ppmであった。Incidentally, the value of equation 1 in this embodiment is 17.95. Example 2 Immersion tube inner diameter 600 mm, inner diameter of argon gas injection tuyere 6 mm, number of tuyeres 18 (Example) and 12 (conventional example)
Reflux degassing treatment was performed using the two types of dip tubes.
At this time, the flow rate of the argon gas is 2500 l / min.
Table 3 shows the target components of the treated steel types. This steel type is an ultra-low carbon steel requiring vacuum decarburization treatment. Table 4 shows the average values of the components after treatment when the treatment was performed with 18 and 12 tuyeres, respectively.
Shown in Vacuum decarburization treatment time was 15 minutes, but the carbonic acid concentration after treatment was 20 ppm for 12 tuyeres, but 18 ppm for tuyeres.
It dropped to 15 ppm. The free oxygen before treatment at this time is
350 ppm and 346 ppm, respectively.
【００１６】因みにこの実施例の式１の値は実施例１と
同じ 17.95である。表１ 表２ 表３ 表４ Incidentally, the value of equation 1 in this embodiment is 17.95, which is the same as in the first embodiment. Table 1 Table 2 Table 3 Table 4
【００１７】[0017]
【発明の効果】本発明により、溶鋼のトータル酸素が 2
5ppm以下又は処理後溶鋼中炭素が 20ppm以下の極低炭素
の溶鋼を安定的に溶製することが可能となった。According to the present invention, the total oxygen of molten steel is 2
It has become possible to stably produce ultra-low carbon molten steel with a carbon content of 5 ppm or less or carbon in the molten steel after treatment of 20 ppm or less.
【図１】羽口一本当たりのガス吐出流速と吐出ガスが水
平方向に溶鋼を動かす距離との関係を示すグラフであ
る。FIG. 1 is a graph showing the relationship between the gas discharge flow rate per tuyere and the distance over which the discharged gas moves molten steel in a horizontal direction.
【図２】環流管内の吐出ガスの水平方向の溶鋼の動きに
及ぼす影響を示した概念図である。FIG. 2 is a conceptual diagram showing an effect of a discharge gas in a reflux pipe on a movement of molten steel in a horizontal direction.
１ アルゴンガスが水平方向の溶鋼の動きに影響を及ぼ
す範囲 ２ アルゴンガス吹き込み用羽口 ３ 浸漬管内周1 Range in which argon gas affects the movement of molten steel in the horizontal direction 2 Tuyere for injecting argon gas 3 Inner circumference of immersion tube
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) C21C 5/48,7/00 C21C 7/072,7/10 F27B 17/00 F27D 7/06 ＪＩＣＳＴファイル（ＪＯＩＳ)──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. 7 , DB name) C21C 5/48, 7/00 C21C 7/072, 7/10 F27B 17/00 F27D 7/06 JICST file ( JOIS)
Claims (1)
管の上昇管に配置する円周方向のアルゴンガス吹き込み
羽口数Ｎを、次式１を満足するようにし、かつアルゴン
ガス吹き込み方向が浸漬管の中心に向くように各羽口を
設けることを特徴としたＲＨ環流式真空脱ガス法。 Ｎ≧（４π3 ×Ａ2 ×ａ2 ）／（ｋ2 ×Ｌ）・・・（式１） 但し、Ａ：浸漬管内径（ｍ） Ｌ：アルゴンガス流量（ｍ3/min) ｋ：比例定数＝5.98×10-3（ｍ1/2 ・min1/2） ａ：アルゴンガス吹き込み羽口内径（ｍ）In the RH reflux type vacuum degassing method, the number N of circumferentially arranged argon gas blowing wings arranged on the riser of the immersion tube is set so as to satisfy the following expression (1) , and
An RH recirculating vacuum degassing method , wherein each tuyere is provided such that a gas blowing direction is directed to the center of the immersion tube . N ≧ (4π 3 × A 2 × a 2 ) / (k 2 × L) (Equation 1) where A: inner diameter of immersion tube (m) L: flow rate of argon gas (m 3 / min) k: proportional Constant = 5.98 × 10 -3 (m 1/2 · min 1/2 ) a: Argon gas injection tuyere inner diameter (m)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03001320A JP3103121B2 (en) | 1991-01-10 | 1991-01-10 | RH reflux vacuum degassing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03001320A JP3103121B2 (en) | 1991-01-10 | 1991-01-10 | RH reflux vacuum degassing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04235212A JPH04235212A (en) | 1992-08-24 |
| JP3103121B2 true JP3103121B2 (en) | 2000-10-23 |
Family
ID=11498202
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03001320A Expired - Lifetime JP3103121B2 (en) | 1991-01-10 | 1991-01-10 | RH reflux vacuum degassing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3103121B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4806863B2 (en) * | 2001-06-13 | 2011-11-02 | Ｊｆｅスチール株式会社 | Method for refining molten steel in RH vacuum degassing equipment |
| JP6268963B2 (en) * | 2013-11-15 | 2018-01-31 | 新日鐵住金株式会社 | Method for refining molten steel |
| CN105256106A (en) * | 2015-11-20 | 2016-01-20 | 山东钢铁股份有限公司 | RH refining device |
-
1991
- 1991-01-10 JP JP03001320A patent/JP3103121B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04235212A (en) | 1992-08-24 |
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