JPH06306441A - Method for refining steel - Google Patents
Method for refining steelInfo
- Publication number
- JPH06306441A JPH06306441A JP12090093A JP12090093A JPH06306441A JP H06306441 A JPH06306441 A JP H06306441A JP 12090093 A JP12090093 A JP 12090093A JP 12090093 A JP12090093 A JP 12090093A JP H06306441 A JPH06306441 A JP H06306441A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- deoxidation
- molten steel
- gaseous hydrogen
- blowing
- 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.)
- Withdrawn
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は鋼中の酸素を除去するた
めの鋼の精錬方法に関するものであり、更に詳しくは鋼
中にＡl2Ｏ3 等の介在物を残留させない清浄鋼の精錬方
法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for refining steel for removing oxygen in steel, and more particularly to a method for refining clean steel in which inclusions such as Al 2 O 3 do not remain in the steel. It is about.
【０００２】[0002]
【従来の技術】従来の鋼の脱酸方法は主としてＳi ，Ｍ
n により予備脱酸を行ない仕上脱酸はＡl を使用してい
た。上記Ａl による仕上脱酸は、４Ａl ＋３Ｏ2 →２Ａ
l2Ｏ3 により進行し、生成したＡl2Ｏ3 は溶鋼との密度
差による浮力によって浮上分離される。しかし微細なＡ
l2Ｏ3 の一部は浮上しきれず、溶鋼中に非金属介在物と
して残留することはまぬがれ得ない。鋼中に介在物を残
さない脱酸方法としてＣによる脱酸が考えられるが、こ
れを真空中で行なっても到達し得る酸素レベルに限度が
あり、仕上脱酸にはＡl を使用せざるを得ない。2. Description of the Related Art Conventional deoxidizing methods for steel are mainly Si, M
Pre-deoxidation was carried out depending on n, and Al was used for final deoxidation. Finishing deoxidation with Al is 4Al + 3O 2 → 2A
The Al 2 O 3 produced by advancing with l 2 O 3 is floated and separated by the buoyancy due to the density difference with the molten steel. But fine A
A part of l 2 O 3 cannot be completely floated up, and it is inevitable that it will remain as non-metallic inclusions in the molten steel. Although deoxidation by C can be considered as a deoxidation method that does not leave inclusions in the steel, even if this is performed in vacuum, the oxygen level that can be reached is limited, and Al must be used for finish deoxidation. I don't get it.
【０００３】[0003]
【発明が解決しようとする課題】Ａl2Ｏ3 として鋼中に
残留した場合には、Ａl2Ｏ3 が破壊の起点となり、部材
の寿命に重大な影響を及ぼすことは少なくない。従って
鋼中にＡl2Ｏ3 のような非金属介在物を残留させない脱
酸方法が望まれることは言うまでもない。If Al 2 O 3 remains in the steel as Al 2 O 3 , Al 2 O 3 often becomes the starting point of fracture, and often has a serious effect on the life of the member. Therefore, it goes without saying that a deoxidation method that does not leave nonmetallic inclusions such as Al 2 O 3 in steel is desired.
【０００４】[0004]
【課題を解決するための手段】Ａl2Ｏ3 等の非金属介在
物を鋼中に残留させない脱酸方法として、本発明者等は
水素による脱酸を検討し本発明を完成した。即ち、本発
明によれば、Ｈ2 ＋Ｏ2 →２Ｈ2 Ｏ として溶鋼中の酸
素を除去し、したがって鋼中にはＡl 等の添加が原因で
ある非金属介在物（酸化物）が残留しない。As a deoxidizing method in which non-metallic inclusions such as Al 2 O 3 do not remain in steel, the present inventors have studied deoxidation with hydrogen and completed the present invention. That is, according to the present invention, oxygen in the molten steel is removed as H 2 + O 2 → 2H 2 O, so that nonmetallic inclusions (oxides) caused by the addition of Al or the like do not remain in the steel.
【０００５】[0005]
【作用】本発明では、前記したように溶鋼中の酸素を介
在物を残さない形で除去するものであるが、この原理を
示せば下記の通りである。図１に溶鋼中の〔Ｈ〕，
〔Ｏ〕，〔２Ｈ2 Ｏ〕の平衡図を示した。図１によれば
アーク炉溶解後のＨ2 Ｏの濃度は夫々Ｈ＝１０ppm ，Ｏ
＝１００〜３００ppm であり、Ｔ＝１８７３°Ｋとして
次式からＰH2O を求めるとおよそ０．０１となる。 ２log Ｈ＋log Ｏ＝log ＰH2O −８８００／Ｔ−１．０
８６ また取鍋精錬（ＬＦ）において、取鍋底に設けたポーラ
スプラグからアルゴンガスを送給し精錬を行なうとＨは
約５ppm ，Ｏは４０〜５０ppm （Ａ点）であるからＰ
H2O ＝０．０００７となる。このＰH2O ＝０．０００７
下で溶鋼中のＨを２５ppm まで高めることが出来れば、
Ｏレベルが数ppm （Ｂ点）と言う低酸素含有の溶鋼が得
られることになる。In the present invention, oxygen in molten steel is removed without leaving inclusions as described above. The principle of this is as follows. Fig. 1 shows [H] in molten steel,
The equilibrium diagrams of [O] and [2H 2 O] are shown. According to FIG. 1, the concentrations of H 2 O after melting in the arc furnace are H = 10 ppm and O, respectively.
= 100 to 300 ppm, and when T = 1873 ° K, P H2O is approximately 0.01 when calculated from the following equation. 2log H + log O = log PH2O- 8800 / T-1.0
86 In the ladle refining (LF), when argon gas is fed from the porous plug provided at the bottom of the ladle for refining, H is about 5 ppm and O is 40 to 50 ppm (point A).
H2O = 0.0007. This P H2O = 0.0007
If H in molten steel can be increased to 25 ppm below,
Oxygen level of several ppm (point B) means that a low oxygen content molten steel can be obtained.
【０００６】図２にＯ−〔Ｃ〕平衡図を示したが、ＰCO
＝１は大気圧下での平衡であり、ＰCO＝０．２は真空下
の平衡である。この場合にはＣ１％でようやく１０ppm
を切る程度の酸素を含有する溶鋼が得られるにすぎな
い。しかし溶鋼中のＣはその用途、性能により異なり、
浸炭用鋼や強靱鋼はＣが０．２〜０．５％であるから真
空下でＣ脱酸のみではＯが数十ppm 存在し、公知の手法
に従えばＡl による脱酸が必要となる。軸受鋼において
はＣは０．９％前後であるが、このときのＯは７〜１０
ppm であるからＡl による仕上脱酸が必要である。Ａl
を使用した場合Ａl2Ｏ3 として鋼中に非金属介在物とし
て残留することは前記した通りである。また水素による
脱酸はアーク炉等通常の溶解炉で行なっても構わない
が、必要に応じて脱硫や成分調整と同時に進行させても
構わないから、取鍋精錬炉（ＬＦ）で行なうと好都合で
ある。水素による脱酸後は水素が飽和点２５ppm 程度と
なるので、脱酸終了後ＲＨ，ＤＨ，流摘脱ガス等による
真空脱ガスを行なうと数ppm 以下まで低下させることが
出来る。[0006] O 2 - showed [C] equilibrium diagram, P CO
= 1 is equilibrium under atmospheric pressure, and P CO = 0.2 is equilibrium under vacuum. In this case, C1% finally gives 10ppm
Only molten steel containing oxygen to the extent of cutting is obtained. However, C in molten steel differs depending on its application and performance,
Since carburizing steel and tough steel have C of 0.2 to 0.5%, deoxidation with Al is necessary according to the known method, if only C deoxidation under vacuum causes O of several tens of ppm. . In bearing steel, C is around 0.9%, but O at this time is 7 to 10
Since it is ppm, finishing deoxidation with Al is necessary. Al
When Al is used, Al 2 O 3 remains as non-metallic inclusions in the steel as described above. Also, deoxidation with hydrogen may be performed in an ordinary melting furnace such as an arc furnace, but it may be carried out simultaneously with desulfurization and component adjustment if necessary, so it is convenient to perform it in a ladle refining furnace (LF). Is. Since hydrogen reaches a saturation point of about 25 ppm after deoxidation with hydrogen, vacuum degassing such as RH, DH and flow degassing after completion of deoxidation can reduce it to several ppm or less.
【０００７】[0007]
【実施例】図３に示す取鍋(1) に炭素を０．０３％含有
する軸受鋼の溶鋼(5) ７０ｔを充填し、デカンテーショ
ンによる脱スラグの後、アーク電極(3) を取付けた蓋
(2)を装着しＣａＯ，ＣａＦ2 を造滓材として投入した
後、溶鋼(5) を１６００℃に加熱保持するとともに該取
鍋(1) 底部に取付けたポーラスプラグ(4) を介して水素
ガス吹込みをおこなう。水素ガスの吹込み速度は２００
０ｌ／分とし、吹込み時間は７０分行なった。上記水素
ガス吹込みによる脱酸効果を表１に示す。[Example] The ladle (1) shown in FIG. 3 was filled with 70 tons of molten steel (5) of bearing steel containing 0.03% of carbon, and the arc electrode (3) was attached after deslagging by decantation. lid
After mounting (2) and introducing CaO and CaF 2 as slag material, the molten steel (5) was heated and held at 1600 ° C and hydrogen was passed through the porous plug (4) attached to the bottom of the ladle (1). Blow gas. The blowing rate of hydrogen gas is 200
The blowing time was 70 minutes. Table 1 shows the deoxidizing effect by the hydrogen gas injection.
【表１】 [Table 1]
【０００８】表１によれば水素ガス吹込みのみで溶鋼中
のＯ濃度が１〜４ppm に低下し、効率的に脱酸が行なわ
れることが認められる。この後Ｃを投入し、Ｃ濃度を軸
受鋼（ＳＵＪ２）として所定のレベルに調整し、その後
ＲＨ脱ガスを４０分行なったところ水素が１．２ppm と
なり、鋼として問題のないレベルまで低下した。According to Table 1, it is recognized that the O concentration in the molten steel is reduced to 1 to 4 ppm only by blowing hydrogen gas, and the deoxidation is efficiently performed. After that, C was charged to adjust the C concentration to a predetermined level as the bearing steel (SUJ2), and then RH degassing was carried out for 40 minutes, and then hydrogen became 1.2 ppm, which decreased to a level at which there was no problem as steel.
【０００９】[0009]
【発明の効果】したがって本発明においてはＡl2Ｏ3 の
生成が防止され、かつ溶鋼中の脱酸が効率的に行なわれ
る。Therefore, in the present invention, the formation of Al 2 O 3 is prevented, and deoxidation in molten steel is efficiently performed.
【図１】Ｏ−Ｈ平衡線図[1] O - H equilibrium diagram
【図２】Ｏ−〔Ｃ〕平衡線図FIG. 2 is an O- [C] equilibrium diagram.
【図３】本実施例に用いた取鍋の模式断面図FIG. 3 is a schematic cross-sectional view of a ladle used in this example.
1 取鍋 2 蓋 3 アーク電極 4 ポーラスプラグ 5 溶鋼 1 Ladle 2 Lid 3 Arc electrode 4 Porous plug 5 Molten steel
Claims (3)
とを特徴とする鋼の精錬方法1. A method for refining steel, which comprises degassing by injecting hydrogen gas into molten steel.
溶鋼中に水素ガスを吹込み脱酸を行なうことを特徴とす
る鋼の精錬方法2. A method for refining steel, characterized in that molten steel is filled in a container separate from the melting furnace, and hydrogen gas is blown into the molten steel for deoxidation.
た後、真空脱ガスを行なうことを特徴とする請求項１ま
たは請求項２に記載の鋼の精錬方法3. The method for refining steel according to claim 1, wherein hydrogen gas is blown into the molten steel to perform deoxidation, and then vacuum degassing is performed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12090093A JPH06306441A (en) | 1993-04-23 | 1993-04-23 | Method for refining steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12090093A JPH06306441A (en) | 1993-04-23 | 1993-04-23 | Method for refining steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06306441A true JPH06306441A (en) | 1994-11-01 |
Family
ID=14797782
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12090093A Withdrawn JPH06306441A (en) | 1993-04-23 | 1993-04-23 | Method for refining steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06306441A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109628705A (en) * | 2019-02-26 | 2019-04-16 | 太原科技大学 | A kind of RH method of refining of low carbon stainless steel |
| CN113337669A (en) * | 2021-05-18 | 2021-09-03 | 北京科技大学 | Method for strengthening electric furnace smelting by bottom blowing hydrogen |
-
1993
- 1993-04-23 JP JP12090093A patent/JPH06306441A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109628705A (en) * | 2019-02-26 | 2019-04-16 | 太原科技大学 | A kind of RH method of refining of low carbon stainless steel |
| CN113337669A (en) * | 2021-05-18 | 2021-09-03 | 北京科技大学 | Method for strengthening electric furnace smelting by bottom blowing hydrogen |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20000704 |