JPH01156416A - Method for decarburizing high-chromium steel having excellent decarburizing characteristic under reduced pressure - Google Patents
Method for decarburizing high-chromium steel having excellent decarburizing characteristic under reduced pressureInfo
- Publication number
- JPH01156416A JPH01156416A JP31377287A JP31377287A JPH01156416A JP H01156416 A JPH01156416 A JP H01156416A JP 31377287 A JP31377287 A JP 31377287A JP 31377287 A JP31377287 A JP 31377287A JP H01156416 A JPH01156416 A JP H01156416A
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- ladle
- blown
- inert gas
- chromium
- 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
- 238000000034 method Methods 0.000 title claims abstract description 11
- 229910001220 stainless steel Inorganic materials 0.000 title claims abstract description 8
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 35
- 239000010959 steel Substances 0.000 claims abstract description 35
- 239000011651 chromium Substances 0.000 claims abstract description 22
- 238000005261 decarburization Methods 0.000 claims abstract description 19
- 238000007664 blowing Methods 0.000 claims abstract description 17
- 239000007789 gas Substances 0.000 claims abstract description 14
- 239000011261 inert gas Substances 0.000 claims abstract description 12
- 238000007670 refining Methods 0.000 claims abstract description 8
- 230000001590 oxidative effect Effects 0.000 claims abstract description 7
- 230000000630 rising effect Effects 0.000 claims abstract description 4
- 238000007654 immersion Methods 0.000 claims description 23
- 229910052804 chromium Inorganic materials 0.000 claims description 8
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 6
- 229910052760 oxygen Inorganic materials 0.000 abstract description 6
- 239000001301 oxygen Substances 0.000 abstract description 6
- 238000006243 chemical reaction Methods 0.000 description 11
- 238000003756 stirring Methods 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 238000013019 agitation Methods 0.000 description 3
- QEFDIAQGSDRHQW-UHFFFAOYSA-N [O-2].[Cr+3].[Fe+2] Chemical class [O-2].[Cr+3].[Fe+2] QEFDIAQGSDRHQW-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- 229910003430 FeCr2O4 Inorganic materials 0.000 description 1
- 229910000604 Ferrochrome Inorganic materials 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004060 metabolic process Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、高クロム溶鋼の精錬を効率的におこない、ス
テンレス鋼などを経済的に製造するための減圧脱炭方法
に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a vacuum decarburization method for efficiently refining high chromium molten steel and economically producing stainless steel or the like.
（従来の技術）
クロムを５％以上含有した高クロム鋼をＣが０、１％以
下の低次域までクロムの酸化を抑制しつつ脱炭する代表
的な方法として減圧下で酸素を溶鋼に吹付けるＶＯＤ法
が広く用いられている。（鉄鋼便覧■、第３版Ｐ７１８
以降）このＶＯＤ法は酸素を上吹ランスより供給するた
め底吹きに比較してスプラッシュ量自体は低い。しかし
、装置全体を真空に吸引するため、許容できるスプラッ
シュ高さ（フリーボード）に設備的な上限がある。また
、たとえ、このスプラッシュの問題が解決されたとして
も、鋼浴の撹拌力が弱いために酸素供給速度を過大にす
ると、Ｃｒの酸化損失が大きくなるばかりで、脱炭速度
の増大には結びつかない。(Prior technology) A typical method for decarburizing high chromium steel containing 5% or more chromium while suppressing oxidation of chromium to a low C content of 0.1% or less is to introduce oxygen into molten steel under reduced pressure. The VOD method of spraying is widely used. (Steel Handbook■, 3rd edition, p.718
Since this VOD method supplies oxygen from a top blowing lance, the amount of splash itself is lower than that of bottom blowing. However, since the entire device is vacuumed, there is an equipment-related upper limit to the allowable splash height (freeboard). Furthermore, even if this splash problem were solved, increasing the oxygen supply rate too much due to the weak stirring power of the steel bath would only increase the oxidation loss of Cr and would not lead to an increase in the decarburization rate. do not have.
一方、このフリーボードの問題を解決するために、ＲＨ
の真空槽内の溶鋼へ上吹ランスから０２ガスを供給する
ＲＨ−ＯＢ法がある（第４７回特殊鋼部会（１９７３）
− ５ ）。On the other hand, in order to solve this freeboard problem, RH
There is an RH-OB method in which 02 gas is supplied from a top blowing lance to molten steel in a vacuum chamber (47th Special Steel Committee (1973)).
-5).
しかし、ＲＨの場合、ガス撹拌された取鍋に比べて、か
なりの撹拌ガスを増量しても取鍋の撹拌が弱く、均一混
合時間も長い（第１００回百出記念技術講座ｐ６５以降
）。したがって、脱炭速度上昇を狙い、酸素供給速度を
増しても、真空槽内の溶鋼は脱炭されても、それが、取
鍋の溶鋼と十分に混合されない、いわゆる環流律速とな
るという欠点が生ずる。However, in the case of RH, compared to a gas-stirred ladle, even if the amount of stirring gas is increased considerably, the stirring of the ladle is weaker, and the uniform mixing time is longer (100th Hyakude Memorial Technology Lecture, p. 65 onwards). Therefore, even if the oxygen supply rate is increased with the aim of increasing the decarburization rate, even if the molten steel in the vacuum chamber is decarburized, it will not mix sufficiently with the molten steel in the ladle, resulting in what is called reflux rate limiting. arise.
（発明が解決しようとする問題点）
本発明は、取鍋内の溶鋼を浸漬管内減圧精錬するに際し
て鋼浴全体の撹拌を十分におこなわせ、かつ、火点での
Ｃｒ酸化物の生成を促進するとともに、このＣｒ酸化物
を有効に脱炭反応に寄与させることにより、Ｃｒロスの
少ない、効率的な脱炭を可能にした優れた高クロム鋼の
減圧脱炭法の提供にある。(Problems to be Solved by the Invention) The present invention provides sufficient stirring of the entire steel bath when refining molten steel in a ladle under reduced pressure in an immersion tube, and also promotes the formation of Cr oxides at the hot point. Another object of the present invention is to provide an excellent vacuum decarburization method for high chromium steel that enables efficient decarburization with little Cr loss by effectively contributing to the decarburization reaction by this Cr oxide.
（問題点を解決するための手段） 高クロム鋼の脱炭は吹酸火点においてＦｅＣｒｚＯ。(Means for solving problems) High chromium steel is decarburized by FeCrzO at the blown acid hot point.
の如き、鉄−クロム酸化物が形成される。この鉄−クロ
ム酸化物が溶鋼中の炭素と反応して脱炭が進行する。し
かも、この反応は溶鋼中の炭素が高い場合はＦｅＣｒｚ
Ｏ４の供給律速であり、逆に、炭素が低い場合は炭素の
移動律速となり、下記（１）式が重要となる。Iron-chromium oxides are formed, such as This iron-chromium oxide reacts with carbon in the molten steel, and decarburization progresses. Moreover, this reaction is difficult when the carbon content in the molten steel is high.
It is rate-determining the supply of O4, and conversely, when the carbon content is low, it is rate-determining the movement of carbon, and the following equation (1) is important.
ＦｅＣｒｚＯｎ−１−４Ｃ＝ Ｆｅ＋２Ｃｒ＋４ＣＯ−
（１）これより、この反応を効果的にするためには、Ｐ
ｃｏを低下させること、つまり、真空下にさらされる鋼
浴表面近くでの反応界面積を増やすことが極めて重要な
ポイントとなる。FeCrzOn-1-4C= Fe+2Cr+4CO-
(1) From this, in order to make this reaction effective, P
It is extremely important to lower the co, that is, to increase the reaction interfacial area near the surface of the steel bath exposed to vacuum.
このような基礎的認識に立脚し小型真空溶解炉にて、実
験をおこなった。実験はＣｒをあらかじめ約１５％含有
させた溶銑に上吹ランスより酸素を吹き付けＣが約０．
５％になるまで脱炭させ（約１６５０°Ｃ一定）、その
時のＣｒ４度の低下分を調べたもので、第１図に実験炉
を上方から見おろした場合の模式図を示す。結果を第２
図に示すが、底吹の不活性ガスが鋼浴表面に露出する上
昇気泡群成の面積（Ａ）と上吹の酸化性ガスの溶鋼表面
の衝突域（Ｓ）との重複域（０）が（０） ／ （Ｓ）
で０．８５以上でないとクロムロスが増加する。これは
、火点て生成された ＦｅＣｒｚＯａがＰｃｏの低い表
面近傍で反応することなく、反転流により浴内部へ引き
込まれるためと、未反応のＦｅＣｒｚ（ｈがたとえ表面
に存在しても底吹ガス吹込位置と反対側の炉壁に堆積す
るためと考えられる。即ち、この（０） ／ （Ｓ）が
０．８５より小さい場合には、表面撹拌が大きいＡｊｌ
域での反応に比べ、表面撹拌が小さい領域での反応が多
くなるため一旦生成したＦｅＣｒ２Ｏ４がＰｃｏの小さ
い表面近傍で反応することなく反転流により浴内部へ引
きこまれＦｅＣｒｚＯｎの還元がおこりにく（なる上に
、たとえ表面に存在したとしても領域Ａと反対側の炉壁
付近に堆積し反応速度が著しく低下することから、Ｃｒ
ロスが大きくなると考えられる。Based on this basic understanding, we conducted experiments in a small vacuum melting furnace. In the experiment, oxygen was blown from a top blowing lance onto hot metal that had previously contained about 15% Cr until the carbon content was about 0.
The decarburization was carried out until it reached 5% (approximately 1650°C constant), and the decrease in Cr of 4°C at that time was investigated. Figure 1 shows a schematic diagram of the experimental furnace looking down from above. Second result
As shown in the figure, the overlap area (0) between the area (A) of the rising bubble group where the bottom-blown inert gas is exposed on the steel bath surface and the collision area (S) of the top-blown oxidizing gas on the molten steel surface is (0) / (S)
If it is not 0.85 or more, chrome loss will increase. This is because the FeCrzOa generated at the flash point does not react near the low surface of Pco and is drawn into the bath by the reverse flow, and also because the unreacted FeCrz This is thought to be due to deposition on the furnace wall opposite to the blowing position.In other words, if (0)/(S) is smaller than 0.85, surface agitation is large.
Compared to the reaction in the bath, the reaction occurs more often in the area where the surface agitation is small, so the FeCr2O4 once generated does not react near the small surface of Pco and is drawn into the bath by the reverse flow, making it difficult for reduction of FeCrzOn to occur. (Moreover, even if Cr exists on the surface, it will accumulate near the furnace wall on the opposite side of region A and the reaction rate will drop significantly.
It is thought that the loss will be large.
このため、火点の大部分は表面撹拌が大きく、ＦｅＣｒ
ｚＯａがただちに還元される領域Ａにあることが必要で
ある。Therefore, most of the hot spots have large surface agitation, and FeCr
It is necessary that zOa be in region A where it is immediately reduced.
一方、上記の実験は、第３図に模式的に示した浸漬管内
減圧吹錬装置における浸漬管内の脱炭反応のみを注目し
たもので、この他に、脱炭された浸漬管内の溶鋼がその
他の部分の溶鋼と十分速く混合することが必要である。On the other hand, the above experiment focused only on the decarburization reaction inside the immersion tube in the immersion tube vacuum blowing device schematically shown in Figure 3. It is necessary to mix the molten steel with the molten steel part quickly enough.
この点に関しては、耐火物コストの面や、上記の浸漬管
内溶鋼表面の大部分を底吹ガス気泡露出面で占めさせる
といった要因から考えて取鍋の内直径（Ｄ）と浸漬管の
内直径（Ｒ）を（Ｒ） ／ （Ｄ） −０，３５以上が
必要で、且つ取鍋底部に設けた不活性ガス吸込孔と浸漬
投影面中心との距離（ｘ）を（ｘ）／（Ｒ）で（０，３
３（Ｒ）／（０） −０，０７）〜（０，３３（Ｒ）／
（Ｄ））とすることにより脱炭の停滞と異常クロム酸の
形成を抑止した精錬が可能となる。Regarding this point, considering the factors such as the cost of refractories and the fact that most of the surface of the molten steel inside the immersion tube should be occupied by the exposed surface of the bottom blown gas bubbles, the inner diameter of the ladle (D) and the inner diameter of the immersion tube should be considered. (R) must be (R) / (D) -0.35 or more, and the distance (x) between the inert gas suction hole provided at the bottom of the ladle and the center of the immersion projection surface must be (x) / (R ) in (0,3
3(R)/(0) -0,07)~(0,33(R)/
(D)) enables refining that suppresses stagnation of decarburization and the formation of abnormal chromic acid.
この理由として（Ｒ） ／ （Ｄ）が０．３５より小さ
いと溶鋼の撹拌力の低下と底吹き不活性ガスが浸漬管の
端部に当り耐火物の損耗を招くとともに、浸漬管外に逸
流した不活性ガスにより精錬阻害を招く。The reason for this is that if (R) / (D) is smaller than 0.35, the stirring power of the molten steel will decrease and the bottom-blown inert gas will hit the end of the immersion pipe, causing damage to the refractory, and will also leak out of the immersion pipe. The flow of inert gas causes refining inhibition.
また、（ｘ）／（Ｒ）が前記値より小さいと同様に溶鋼
の撹拌力の低下と反応表界面の代謝促進（横流れ方向性
を持った撹拌）が阻害され脱炭の停滞とクロム酸の過剰
形成により耐火物への付着及びクロムロスを生じる。さ
らにまた、（ｘ） ／ （Ｒ）があまりにも大きすぎる
と浸漬管外への逸流となり前述同様の障害を招く。In addition, if (x)/(R) is smaller than the above value, the stirring power of molten steel will decrease and the promotion of metabolism at the reaction surface interface (stirring with lateral flow direction) will be inhibited, resulting in stagnation of decarburization and the production of chromic acid. Excessive formation causes adhesion to refractories and chromium loss. Furthermore, if (x)/(R) is too large, the flow will flow out of the immersion tube, causing the same trouble as described above.
このように本発明は前述の構成に（０） ／ （Ｓ）
＝０．８５以上で酸化性ガスを吹酸して脱炭精錬するこ
とにより、減圧下による反応表界面の底Ｐｃｏ雰囲気を
有効に活用し、且つＦｅＣｒ２Ｏ，の形成促進とこれに
よる脱炭反応の促進が実現できた。In this way, the present invention has the above configuration (0) / (S)
By decarburizing and refining by blowing oxidizing gas at =0.85 or higher, the bottom Pco atmosphere at the reaction surface interface under reduced pressure is effectively utilized, and the formation of FeCr2O is promoted and the decarburization reaction is thereby accelerated. The promotion was achieved.
（実施例）
以下、工業規模でおこなった実験の結果について述べる
。ここで、溶鋼は転炉で溶製された約１６％Ｃｒ、０．
８％Ｃのステンレス粗溶鋼約１６０ｔｏｎを用い、上吹
送酸速度は５０００ Ｎｍ’／Ｈｒ、底吹Ａｒは６０Ｏ
Ｎｎ／分とし、真空度は約５０Ｔｏｒｒでおこない、処
理後温度は約１７００″Ｃであった。又、用いた取鍋の
直径（Ｄ）は３１００ｍｍとし、取鍋内網浴面と浸漬管
先端の距離いわゆる浸漬深さは約３００ ｍｍとした。(Example) The results of experiments conducted on an industrial scale will be described below. Here, the molten steel is about 16% Cr, 0.
Approximately 160 tons of 8% C stainless crude molten steel was used, the top blowing acid rate was 5000 Nm'/Hr, and the bottom blowing Ar was 60O.
Nn/min, the degree of vacuum was approximately 50 Torr, and the temperature after treatment was approximately 1700''C.The diameter (D) of the ladle used was 3100 mm, and the net bath surface inside the ladle and the tip of the immersion tube were The distance, so-called immersion depth, was approximately 300 mm.
表１は浸漬管径は一定とし、底吹の位置を変化させた場
合であるが、Ｎｏ、 ２のように偏心しすぎると精錬特
性は良いが、浸漬管先端の溶損が大きく、逆にＮｏ、
３のように偏心が不足すると混合が悪くなるため、Ｃｒ
ロスが大きくなっている。Table 1 shows the case where the diameter of the immersion pipe is constant and the position of the bottom blow is changed.If the bottom blow is too eccentric as in No. 2, the refining properties are good, but the tip of the immersion pipe suffers large melting damage, and vice versa. No,
If the eccentricity is insufficient as shown in 3, the mixing will be poor, so Cr
Loss is getting bigger.
一方、表２は浸漬管径を変化させた場合であるが、Ｎｏ
、 ４のように小さくしすぎると偏心しない場合でさえ
も、底吹ガスが浸漬管先端を洗い、溶損が大きい上に、
混合が悪いため、Ｃｒロスも大きい。On the other hand, Table 2 shows the case where the immersion pipe diameter was changed, but No.
If it is made too small as in 4, even if it is not eccentric, the bottom blowing gas will wash the tip of the immersion tube, causing large erosion and damage.
Due to poor mixing, Cr loss is also large.
またＮｏ、 ５のように上吹ランスを上げ、偏心量を大
きくすることで、Ｏ／Ｓが小さくなると浸漬管溶損の問
題も、混合の悪化という問題もないがＣｒロスがやや大
きくなっている。Also, as shown in No. 5, by raising the top blow lance and increasing the amount of eccentricity, when the O/S becomes smaller, there is no problem of immersion tube melting or worsening of mixing, but the Cr loss becomes slightly larger. There is.
これらに対して、Ｎｏ、 １のように第２図、第４図の
ベスト領域で吹錬をおこなえば、浸漬管の溶損やＣｒロ
スを抑制した脱炭が可能となる。On the other hand, if blowing is carried out in the best region shown in FIGS. 2 and 4 as shown in No. 1, decarburization can be performed while suppressing melting loss of the immersion pipe and Cr loss.
（発明の効果）
以上述べた如く、本発明によればＣｒ損失が少なく、し
かも脱炭効率が良好であり、歩留、品質、生産性ともに
優れた高Ｃｒ鋼の溶製を実現しうるので産業上の効果は
極めて顕著である。(Effects of the Invention) As described above, according to the present invention, it is possible to produce high Cr steel with low Cr loss, good decarburization efficiency, and excellent yield, quality, and productivity. The industrial effects are quite significant.
第１図は小型試験時の実験装置を上方より見おろした場
合の模式図であり、第２図は鋼浴表面で底吹気泡が露出
している領域と上吹ガス火点領域とが重なり合っている
領域（０）と上吹ガス火点領域（Ｓ）との相対面積比と
Ｃｒロスの関係を示している。第３図は本性の模式図で
あり、第４図は水モデルによる浸漬管径と底吹位置の偏
心量により決まる、浸漬管下端を気泡が洗うことなく混
合が良好となる領域を示している。
第１図
シー
第２図
ωざ Ｘ／θ０（％）
χ／Ｒ
も ＼ 〜Figure 1 is a schematic view of the experimental equipment during a small-scale test, looking down from above, and Figure 2 shows the area where the bottom-blown bubbles are exposed on the steel bath surface and the top-blown gas ignition area overlap. The relationship between the relative area ratio of the region (0) where the gas is present and the top-blown gas flash point region (S) and Cr loss is shown. Figure 3 is a schematic diagram of the true nature, and Figure 4 shows the area where mixing is good without air bubbles washing the lower end of the immersion tube, which is determined by the diameter of the immersion tube and the eccentricity of the bottom blowing position based on the water model. . Figure 1 Sea Figure 2 ωza X/θ0 (%) χ/R too ＼ ~
Claims (1)
を減圧して上吹ランスにより酸化性ガスを吹付けるとと
もに、取鍋底部より不活性ガスを供給して該溶鋼を撹拌
する高クロム鋼の脱炭精錬法において、取鍋の内直径（
Ｄ）と浸漬管の内直径（Ｒ）を（Ｒ）／（Ｄ）＝０．３
５以上とし、取鍋底部に設けた不活性ガス吹込孔と浸漬
管の投影面中心との距離（ｘ）を（ｘ）／（Ｒ）＝（０
．３３（Ｒ）／（Ｄ）−０．０７）〜（０．３３（Ｒ）
／（Ｄ））にするとともに、上吹の酸化性ガスの溶鋼表
面衝突域（Ｓ）と底吹き不活性ガスの上昇気泡群域（Ａ
）との重複域（Ｏ）を溶鋼表面衝突域（Ｓ）の８５％以
上とすることを特徴とする脱炭特性の優れた高クロム鋼
の減圧脱炭法。A high-chromium immersion tube is immersed in chromium-containing molten steel in a ladle, the pressure inside the immersion tube is reduced, and oxidizing gas is blown with a top blowing lance, while the molten steel is stirred by supplying inert gas from the bottom of the ladle. In the steel decarburization refining method, the inner diameter of the ladle (
D) and the inner diameter (R) of the immersion tube as (R)/(D)=0.3
5 or more, and the distance (x) between the inert gas blowing hole provided at the bottom of the ladle and the center of the projection plane of the immersion tube is (x)/(R) = (0
．． 33(R)/(D)-0.07)~(0.33(R)
/(D)), and the collision area (S) of top-blown oxidizing gas on the molten steel surface and the rising bubble group area (A) of bottom-blown inert gas.
) A vacuum decarburization method for high chromium steel having excellent decarburization properties, characterized in that the overlapping area (O) with the molten steel surface collision area (S) is 85% or more of the molten steel surface collision area (S).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31377287A JPH01156416A (en) | 1987-12-11 | 1987-12-11 | Method for decarburizing high-chromium steel having excellent decarburizing characteristic under reduced pressure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31377287A JPH01156416A (en) | 1987-12-11 | 1987-12-11 | Method for decarburizing high-chromium steel having excellent decarburizing characteristic under reduced pressure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01156416A true JPH01156416A (en) | 1989-06-20 |
Family
ID=18045339
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31377287A Pending JPH01156416A (en) | 1987-12-11 | 1987-12-11 | Method for decarburizing high-chromium steel having excellent decarburizing characteristic under reduced pressure |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01156416A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04235213A (en) * | 1991-01-10 | 1992-08-24 | Sumitomo Metal Ind Ltd | Method for heating molten steel in ladle |
| JPH05105936A (en) * | 1991-10-14 | 1993-04-27 | Nippon Steel Corp | Method for decarbonizing extremely low carbon chromium-containing molten steel |
| US5902374A (en) * | 1995-08-01 | 1999-05-11 | Nippon Steel Corporation | Vacuum refining method for molten steel |
| WO2000077264A1 (en) * | 1999-06-16 | 2000-12-21 | Nippon Steel Corporation | Refining method and refining apparatus of molten steel |
-
1987
- 1987-12-11 JP JP31377287A patent/JPH01156416A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04235213A (en) * | 1991-01-10 | 1992-08-24 | Sumitomo Metal Ind Ltd | Method for heating molten steel in ladle |
| JPH05105936A (en) * | 1991-10-14 | 1993-04-27 | Nippon Steel Corp | Method for decarbonizing extremely low carbon chromium-containing molten steel |
| US5902374A (en) * | 1995-08-01 | 1999-05-11 | Nippon Steel Corporation | Vacuum refining method for molten steel |
| WO2000077264A1 (en) * | 1999-06-16 | 2000-12-21 | Nippon Steel Corporation | Refining method and refining apparatus of molten steel |
| US6432164B1 (en) | 1999-06-16 | 2002-08-13 | Nippon Steel Corporation | Method for refining molten steel and apparatus therefor |
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