JPH024650B2 - - Google Patents
Info
- Publication number
- JPH024650B2 JPH024650B2 JP13429585A JP13429585A JPH024650B2 JP H024650 B2 JPH024650 B2 JP H024650B2 JP 13429585 A JP13429585 A JP 13429585A JP 13429585 A JP13429585 A JP 13429585A JP H024650 B2 JPH024650 B2 JP H024650B2
- Authority
- JP
- Japan
- Prior art keywords
- degassing
- molten steel
- gas
- ppm
- amount
- 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
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
- C21C7/072—Treatment with gases
-
- 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
- C21C7/10—Handling in a vacuum
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明はRH脱ガス装置を用いた強脱N2によ
る介在物浮上促進方法に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for promoting inclusion flotation by strong N 2 removal using an RH degassing device.
RH脱ガス法は酸素、窒素、水素等のガス成分
を除去する精錬法として広く行われているが、素
鋼のT.O値は精錬直後のT.O値だけではなく、精
錬後鋳造までの経過時間や鋳造温度によつても影
響されるため、従来の手法では素鋼のT.O値のバ
ラツキが大きく、素鋼T.O10ppmを安定して達
成することは困難であつた。
The RH degassing method is widely used as a refining method to remove gas components such as oxygen, nitrogen, and hydrogen, but the TO value of raw steel is determined not only by the TO value immediately after refining, but also by the elapsed time from refining to casting. Since it is also affected by the casting temperature, conventional methods have large variations in the TO value of raw steel, making it difficult to stably achieve a T.O of 10 ppm for raw steel.
したがつて、T.O10ppmを安定して得るため
には、精錬後の製造条件を整えてやれば良いが、
そのために大幅な設備の改変等が必要であり、コ
ストがかかる欠点がある。 Therefore, in order to stably obtain 10ppm of T.O, it is only necessary to adjust the manufacturing conditions after refining.
This requires major modifications to the equipment, which has the disadvantage of being costly.
本発明は、上記した点に鑑みてなされたもの
で、従来設備の持つ機能を最大限に有効利用する
ことにより、到達T.Oレベルを安定して低下させ
ることを目的とするものである。
The present invention has been made in view of the above-mentioned points, and aims to stably lower the achieved TO level by making maximum effective use of the functions of conventional equipment.
ところでRH脱ガス装置においては、単に直接
的に脱ガスを行うだけではなく、溶鋼の還流やパ
ウダ或はガスインジエクシヨン処理等によつて介
在物の浮上促進を図り、これにより間接的に脱
O2を行つている。したがつて介在物の浮上促進
を更に図ることができれば、精錬段階で極低O2
を実現でき、素鋼T.Oを安定して低下させること
ができる。 By the way, RH degassing equipment does not only directly degas, but also indirectly degass by promoting the floating of inclusions through molten steel reflux, powder or gas injection treatment, etc.
I'm doing O2 . Therefore, if it is possible to further promote the floating of inclusions, extremely low O 2 can be achieved at the refining stage.
can be realized, and the TO of raw steel can be stably lowered.
本発明は、このような知見に基づいてなされた
もので、RH脱ガス処理前に該脱ガス処理で容易
に抜くことができる気体を溶鋼中に所定量添加せ
しめ、次いでRH脱ガス装置により強脱ガス処理
することを基本的な特徴とするものである。 The present invention was made based on such findings, and involves adding a predetermined amount of gas that can be easily removed by the degassing process to molten steel before the RH degassing process, and then strengthening the molten steel with an RH degassing device. The basic feature is degassing treatment.
第１図は本発明法の説明図であり、１は転炉、
２はインジエクシヨン設備、３はRH脱ガス装置
である。本発明法では、RH脱ガス処理前に溶鋼
中にガス添加４を行う。この実施例ではN2ガス
を添加しているが、次工程の脱ガス処理において
容易に抜くことのできるガスであればどのような
ガスでも良い。ガスの添加量は、溶鋼中に50〜
400ppm、好ましくは200〜300ppm含有させる範
囲とする。転炉精錬後の溶鋼中には通常40ppm程
度のN2ガスが含まれているため、これより多い
50ppmを最下限とする。また溶鋼温度は通常1550
〜1650℃であり、この場合400ppmでガスは飽和
するため、これを最大値とする。但し、飽和点ま
でガス含有せしめるには、インジエクシヨンに際
しても、脱ガスに際しても時間がかかるため、脱
ガス時における介在物浮上効果も考え合せると
200〜300ppmが最も好ましい範囲である。 FIG. 1 is an explanatory diagram of the method of the present invention, where 1 is a converter;
2 is an injection equipment, and 3 is an RH degassing equipment. In the method of the present invention, gas addition 4 is performed in the molten steel before the RH degassing treatment. Although N 2 gas is added in this example, any gas may be used as long as it can be easily removed in the next degassing process. The amount of gas added to molten steel is 50~
The content is 400 ppm, preferably 200 to 300 ppm. Molten steel after converter refining usually contains about 40 ppm of N2 gas, so the amount is higher than this.
The minimum limit is 50ppm. Also, the molten steel temperature is usually 1550
The temperature is ~1650°C, and in this case, the gas is saturated at 400 ppm, so this is taken as the maximum value. However, it takes time to contain gas up to the saturation point, both during injection and degassing, and considering the floating effect of inclusions during degassing.
200-300 ppm is the most preferred range.
第２図にN2インジエクシヨンによる溶鋼中の
N2量の変化を示す。インジエクシヨン量に関係
なく400ppm程度で飽和していることがわかる。 Figure 2 shows the amount of water in molten steel produced by N2 injection.
Shows the change in the amount of N2 . It can be seen that it is saturated at around 400 ppm regardless of the amount of injection.
以上のようにN2を添加した後、既存のRH脱ガ
ス装置３により脱ガス処理を行えば、溶鋼中に含
有されたN2ガスが気泡となり溶鋼を撹拌し、介
在物の浮上を促進せしめる。この脱ガス処理にお
ける脱〔N〕量が200ppmとすると、脱ガス処理中
に発生するN2ガス気泡は溶鋼MTONに対して
（0.16×Ｍ）Ｎm3に達する。これは250TON溶鋼
で20分脱ガス処理の場合は、2000Nl／minのN2
ガス気泡発生速度に相当する。 After adding N 2 as described above, if degassing is performed using the existing RH degassing device 3, the N 2 gas contained in the molten steel becomes bubbles and stirs the molten steel, promoting the floating of inclusions. . Assuming that the amount of [N] removed in this degassing treatment is 200 ppm, the N 2 gas bubbles generated during the degassing treatment reach (0.16×M)Nm 3 relative to M TON of molten steel. This is 2000Nl/min of N 2 when degassing 250TON molten steel for 20 minutes.
Corresponds to the rate of gas bubble generation.
このような大量のN2ガス気泡により、介在物
浮上促進が図れ、溶鋼中のT.Oを安定して低減せ
しめることができる。 Such a large amount of N 2 gas bubbles can promote the floating of inclusions and can stably reduce TO in the molten steel.
〔実施例〕
Ｃ：0.10％、Mn：0.30％、Ｐ：0.013％、Ｓ：
0.010％、Al：0.035％を含有する溶鋼を転炉にて
250T精錬し、インジエクシヨン設備において溶
鋼中にN2を吹込ランスにより吹込み量夫々
1000l／min、1500l／min、2000l／minで吹込み、
初期〔N〕：240、250、270ppmとした。[Example] C: 0.10%, Mn: 0.30%, P: 0.013%, S:
Molten steel containing 0.010% and Al: 0.035% is processed in a converter.
After 250T refining, N2 was injected into the molten steel using an injector injection lance.
Blow at 1000l/min, 1500l/min, 2000l/min,
Initial [N]: 240, 250, 270ppm.
次いでRH脱ガス装置により脱ガス処理した。
還流不活性ガスはArを用い、流量は2000l／min
とした。脱ガス終了時、〔N〕：30〜40ppmであつ
た。 Next, degassing was performed using an RH degassing device.
Ar is used as the reflux inert gas, and the flow rate is 2000 l/min.
And so. At the end of degassing, [N] was 30 to 40 ppm.
この時の溶鋼中T.Oの時間的推移を第３図に示
す。本発明法の場合、処理時間20分を経過すると
T.O低減効果が表われ、斜線で示す従来法に比較
して低いT.O値を得られることがわかる。 Figure 3 shows the time course of TO in the molten steel at this time. In the case of the method of the present invention, after 20 minutes of processing time,
It can be seen that the TO reduction effect appears, and a lower TO value can be obtained compared to the conventional method indicated by the diagonal line.
第１図は本発明法の説明図、第２図は溶鋼に
N2をインジエクシヨンした場合の溶鋼中Ｎ量の
推移を示すグラフ、第３図は本発明法の実施例に
おけるT.O値の推移を示すグラフである。
１……転炉、２……インジエクシヨン設備、３
……RH脱ガス装置。
Figure 1 is an explanatory diagram of the method of the present invention, Figure 2 is for molten steel.
FIG. 3 is a graph showing the change in the amount of N in molten steel when N 2 is injected, and FIG. 3 is a graph showing the change in the TO value in an example of the method of the present invention. 1... Converter, 2... Injection equipment, 3
...RH degassing equipment.
Claims (1)
くことができる気体を溶鋼中に所定量添加せし
め、次いでRH脱ガス装置により強脱ガス処理す
ることを特徴とするRH脱ガス装置を用いた強脱
ガスによる介在物浮上促進方法。1 Using an RH degassing device characterized in that before the RH degassing treatment, a predetermined amount of gas that can be easily removed by the degassing treatment is added to molten steel, and then strong degassing treatment is performed by the RH degassing device. A method for promoting the levitation of inclusions by strong degassing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13429585A JPS61295314A (en) | 1985-06-21 | 1985-06-21 | Method for promoting inclusion floating through strong degassing using RH degassing equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13429585A JPS61295314A (en) | 1985-06-21 | 1985-06-21 | Method for promoting inclusion floating through strong degassing using RH degassing equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61295314A JPS61295314A (en) | 1986-12-26 |
| JPH024650B2 true JPH024650B2 (en) | 1990-01-30 |
Family
ID=15124943
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13429585A Granted JPS61295314A (en) | 1985-06-21 | 1985-06-21 | Method for promoting inclusion floating through strong degassing using RH degassing equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61295314A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0742524B2 (en) * | 1988-10-06 | 1995-05-10 | 日本鋼管株式会社 | Method for cleaning molten metal |
| JP2780342B2 (en) * | 1989-06-09 | 1998-07-30 | 日本鋼管株式会社 | Vacuum degassing method for molten metal |
-
1985
- 1985-06-21 JP JP13429585A patent/JPS61295314A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61295314A (en) | 1986-12-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |