JPH01129925A - Method for adding calcium to molten steel - Google Patents
Method for adding calcium to molten steelInfo
- Publication number
- JPH01129925A JPH01129925A JP28777787A JP28777787A JPH01129925A JP H01129925 A JPH01129925 A JP H01129925A JP 28777787 A JP28777787 A JP 28777787A JP 28777787 A JP28777787 A JP 28777787A JP H01129925 A JPH01129925 A JP H01129925A
- Authority
- JP
- Japan
- Prior art keywords
- calcium
- alloy
- molten steel
- additive
- refractory
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 32
- 239000010959 steel Substances 0.000 title claims abstract description 32
- 229910052791 calcium Inorganic materials 0.000 title claims abstract description 31
- 239000011575 calcium Substances 0.000 title claims description 60
- 238000000034 method Methods 0.000 title claims description 34
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 title claims description 29
- 239000000654 additive Substances 0.000 claims abstract description 23
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 20
- 238000007872 degassing Methods 0.000 claims abstract description 19
- 229910000882 Ca alloy Inorganic materials 0.000 claims abstract description 18
- 230000000996 additive effect Effects 0.000 claims abstract description 18
- 239000002184 metal Substances 0.000 claims abstract description 12
- 229910052751 metal Inorganic materials 0.000 claims abstract description 12
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 6
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 6
- 229910045601 alloy Inorganic materials 0.000 claims description 13
- 239000000956 alloy Substances 0.000 claims description 12
- 239000011819 refractory material Substances 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 239000004484 Briquette Substances 0.000 claims description 3
- 229910018107 Ni—Ca Inorganic materials 0.000 claims description 2
- 238000000748 compression moulding Methods 0.000 claims description 2
- 229910014458 Ca-Si Inorganic materials 0.000 claims 1
- 229910000691 Re alloy Inorganic materials 0.000 claims 1
- 239000000463 material Substances 0.000 claims 1
- 229910021484 silicon-nickel alloy Inorganic materials 0.000 claims 1
- 238000006243 chemical reaction Methods 0.000 abstract description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 8
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 abstract description 7
- 239000011248 coating agent Substances 0.000 abstract description 6
- 238000000576 coating method Methods 0.000 abstract description 6
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 abstract description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract description 4
- 239000010436 fluorite Substances 0.000 abstract description 4
- 239000000377 silicon dioxide Substances 0.000 abstract description 4
- 239000000779 smoke Substances 0.000 abstract description 4
- 230000001965 increasing effect Effects 0.000 abstract description 3
- 229910052681 coesite Inorganic materials 0.000 abstract 1
- 229910052593 corundum Inorganic materials 0.000 abstract 1
- 229910052906 cristobalite Inorganic materials 0.000 abstract 1
- 235000012239 silicon dioxide Nutrition 0.000 abstract 1
- 229910052682 stishovite Inorganic materials 0.000 abstract 1
- 229910052905 tridymite Inorganic materials 0.000 abstract 1
- 229910001845 yogo sapphire Inorganic materials 0.000 abstract 1
- 238000006477 desulfuration reaction Methods 0.000 description 9
- 230000023556 desulfurization Effects 0.000 description 9
- 238000011282 treatment Methods 0.000 description 9
- 238000010992 reflux Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 239000012159 carrier gas Substances 0.000 description 3
- 230000003111 delayed effect Effects 0.000 description 3
- 239000000395 magnesium oxide Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000009991 scouring Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910008455 Si—Ca Inorganic materials 0.000 description 2
- 229910021346 calcium silicide Inorganic materials 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 229910001020 Au alloy Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 229910017116 Fe—Mo Inorganic materials 0.000 description 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 238000011276 addition treatment Methods 0.000 description 1
- 229910001634 calcium fluoride Inorganic materials 0.000 description 1
- JEZHBSJTXKKFMV-UHFFFAOYSA-N calcium nickel Chemical compound [Ca].[Ni] JEZHBSJTXKKFMV-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 239000003353 gold alloy Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000009849 vacuum degassing Methods 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)
本発明は熔鋼にカルシウムを歩留まり良く添加する方法
に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for adding calcium to molten steel with good yield.
(従来の技術)
一般に、鋼の精練過程において脱酸、脱硫作用は、必須
の精練工程として行われている。その内でも脱酸につい
ては、近時は種々の公知の脱酸剤により、比較的簡単に
脱酸操作が行われ又さらには真空脱ガス処理技術や、D
H法、RH法、vOD法、AOD法等各種の精練方法の
発達により比較的容易に脱酸処理が行われるようになっ
た。(Prior Art) In general, deoxidation and desulfurization are performed as essential scouring steps in the steel scouring process. Among them, deoxidizing has recently been relatively easily performed using various known deoxidizing agents, and vacuum degassing technology and D
With the development of various scouring methods such as the H method, RH method, vOD method, and AOD method, deoxidation treatment can now be performed relatively easily.
他方、脱硫に関しては造滓による脱硫、特にカーバイド
滓を造る化学反応により脱硫する方法が主流であり、こ
れに類するものとして、CaOによるものや、CaOと
CaF2やNal COsによる物、等造滓による方法
があっI;。しかし、これらの造滓による方法はある程
度の反応時間が必要であり、炭素濃度が上昇したり、硫
黄の含有率の極めて低い、例えば、S含有量がo、oo
s%以下のような場合には効率が悪く時間がかかりすぎ
る欠点があった。On the other hand, with regard to desulfurization, the mainstream is desulfurization using slag, especially desulfurization by a chemical reaction that creates carbide slag, and similar methods include those using CaO, those using CaO and CaF2, Nal COs, etc. There is a way. However, these slag-making methods require a certain amount of reaction time, and the carbon concentration may increase or the sulfur content may be extremely low, such as when the S content is o or oo.
If it is less than s%, there is a drawback that the efficiency is poor and it takes too much time.
これらの欠点を是正する為に脱硫元素を直接に熔鋼中に
添加する方法が、例えば、特開昭52−139623号
公報、特開昭53−12411号公報、あるいは特公昭
57−15170号公報にて種々提案されている。これ
らの方法では、添加効率を高めるために脱硫元素を充分
に脱酸された熔鋼中に添加するのが殆どであった。その
理由は強力な脱硫元素は、概ね、酸素との親和力が強い
ため、脱硫効率を高めるためには最も酸素値の低い時、
即ち、鋳造直前に行う必要があるからである。また、鋳
造直前に脱硫を行うと、発生する非金属介在物が浮上除
去される時間的余裕がない為、発生する介在物が有害な
形態でないことが重要となるので、この観点より有害な
非金属介在物をつくりにくいCaが通常用いられてきた
。又、Caは非金属介在物の形能制御のためにも近年は
盛んに用いられてきている。In order to correct these defects, a method of directly adding desulfurization elements to molten steel is disclosed, for example, in JP-A-52-139623, JP-A-53-12411, or JP-B-Sho 57-15170. Various proposals have been made. In most of these methods, desulfurization elements are added to molten steel that has been sufficiently deoxidized in order to increase the addition efficiency. The reason is that strong desulfurization elements generally have a strong affinity for oxygen, so in order to increase desulfurization efficiency, it is necessary to
That is, this is because it needs to be performed immediately before casting. Furthermore, if desulfurization is performed immediately before casting, there will not be enough time for the generated non-metallic inclusions to float away, so it is important that the generated inclusions are not in a harmful form. Ca, which does not easily form metal inclusions, has been commonly used. In addition, Ca has been widely used in recent years to control the shape of nonmetallic inclusions.
従来、カルシウムを鋼中に効率よく添加する方法として
は、
■ カルシウムシリサイドに代表されるように硅化カル
シウムやニッケルカルシウムを出鋼時の流れに捲き込む
ように投入する方法、
■ 特開昭52−139623号公報に示されるように
金属カルシウムを細長い軟鋼板で包み電線状となし、鋼
中に連続的に押し込む方法、■ 金属カルシウムやCa
合金、鉄−力ルシウムブリケットなどを置注ぎプランジ
ャーその他の方法で鋼中に添加する方法、
■ CaやCa合金粉末を不活性ガスにて熔鋼中に噴射
するインジェクション法、
■ Ca含有物の固形棒状品を取鍋熔鋼中に差し込む方
法、
■ タンプッシュにて粒状品を連続的に添加していく方
法、
などが知られている。Conventionally, methods for efficiently adding calcium to steel include: ■ Injecting calcium silicide or nickel calcium, as represented by calcium silicide, into the flow during tapping; ■ JP-A-52- As shown in Publication No. 139623, a method of wrapping metallic calcium in a long and thin mild steel plate to form an electric wire shape and continuously pushing it into steel, ■ Metallic calcium or Ca
A method in which alloys, iron-lucium briquettes, etc. are added to steel using a pouring plunger or other methods; ■ An injection method in which Ca or Ca alloy powder is injected into molten steel using an inert gas; Methods such as inserting a solid bar into molten steel in a ladle, and ■continuously adding granular products using a tongue push are known.
(発明が解決しようとする問題点)
しかしながら、これらの方法に共通している問題は、カ
ルシウムが非常に活性な金属であるため、添加時に発生
する白煙や、猛烈な反応の制御が困難であること、並び
に非常に複雑な添加操作を必要とするなどの作業工程上
の問題である。例えば現在、最も多く用いられている■
の方法では、キャリアガスに捲き込まれて入る窒素濃度
の上昇や、温度の低下をもたらし、また、吹き込み不活
性キャリアガスやランスパイプの費用とそれに要する時
間のロスが大きな問題であった。(Problems to be Solved by the Invention) However, problems common to these methods are that calcium is a very active metal, so it is difficult to control the white smoke generated during addition and the violent reaction. There are problems with the work process, such as the fact that there is a large amount of oxidation, and that a very complicated addition operation is required. For example, currently the most commonly used ■
This method causes an increase in the concentration of nitrogen introduced into the carrier gas and a decrease in temperature, and the cost and time required for the inert carrier gas and lance pipe to be blown into the carrier gas are major problems.
また、一般にCafi理を必要とする高級鋼は、RH脱
ガス装置で脱ガス処理が行われることに着目し、脱ガス
処理後、RH脱ガス槽内の減圧度を少し軽減してCa添
加剤を添加することが考えられるが、RH脱ガス檀は2
00 Torr以下に減圧しないと熔鋼が還流せず、し
かも、Ca添加剤は極めて活性度が高<、1483℃で
沸騰、蒸発するため、熔鋼と接触した瞬間にCaの燃焼
と蒸発が起り、蒸発したCaのガスが吸引フードにて逸
散してしまうため、極めて歩留りが低く著しく実用性を
欠くものであった。In addition, we focused on the fact that high-grade steel, which generally requires Cafi treatment, is degassed in an RH degassing device, and after the degassing treatment, the degree of vacuum in the RH degassing tank is slightly reduced to remove Ca additives. It is possible to add 2
Molten steel will not reflux unless the pressure is reduced to 0.00 Torr or less, and Ca additive has extremely high activity and boils and evaporates at 1483°C, so the moment it comes into contact with molten steel, Ca burns and evaporates. However, since the evaporated Ca gas was dissipated in the suction hood, the yield was extremely low and it was extremely impractical.
現在、製鋼精練において、Ca添加による非金属介在物
の形能制御は、高級鋼の必須の条件であり、又、ノズル
閉塞の防止などにも、ますますその必要性は増加してい
るが、前記にあげた各種方法の中には、適切で満足のい
く方法がないのが現状である。Currently, in steel refining, controlling the shape of nonmetallic inclusions by adding Ca is an essential condition for producing high-grade steel, and the need for this is increasing to prevent nozzle clogging. At present, there is no suitable and satisfactory method among the various methods listed above.
(問題点を解決するための手段)
本発明は、極めて簡単で、しかも、全く発煙を生じない
無公害の添加方法の開発を目的としてなされたもので、
前記問題点を解決する手段として、表面を耐火物材料お
よび/または鉄粉で被覆され、カルシウムを3〜35%
含有する粒状もしくは塊状のカルシウム合金および/ま
たはカルシウム含有金属添加剤をRH脱ガス槽内の熔鋼
に添加することを特徴とする熔鋼へのカルシウム添加方
法を提供するものである。(Means for Solving the Problems) The present invention was made for the purpose of developing an extremely simple and non-polluting addition method that does not generate smoke at all.
As a means to solve the above problems, the surface is coated with a refractory material and/or iron powder, and the calcium content is 3 to 35%.
The present invention provides a method for adding calcium to molten steel, which comprises adding a granular or lumpy calcium alloy and/or a calcium-containing metal additive to molten steel in an RH degassing tank.
即ち、本発明は、RH脱ガス槽内では熔鋼の還流が順次
行われているが、この流れに従って取鍋内に熔鋼が戻っ
た時にCaの添加が実質的になされれば、蒸発すべき減
圧時間がないためカルシウムの蒸発が起こらないという
点に着目して、Ca合金及びCa添加剤のそれぞれの粒
子又は塊表面を熔鋼に有害でない耐火物もしくは鉄粉に
で被覆し、又は鉄粉及び耐火物の交互の層被覆又は両者
の混合被覆などの方法で被覆を行い、反応を遅延させる
ようにしたものである。That is, in the present invention, although the reflux of molten steel is performed sequentially in the RH degassing tank, if Ca is substantially added when the molten steel returns to the ladle according to this flow, evaporation will occur. Focusing on the fact that calcium evaporation does not occur because there is no decompression time, the surfaces of each particle or lump of Ca alloy and Ca additive are coated with refractory or iron powder that is not harmful to molten steel, or The reaction is delayed by coating with alternating layers of powder and refractory, or a mixture of both.
前記カルシウム合金としては、Fe−Ca−3i合金、
Fe−Ca−Si−RE金合金Fe−Ca−Ni−3i
合金、Ni−Ca合金、Ni−Fe−Ca合金、および
Cu−Ca合金など任意のものを採用でき、これらの合
金は単独であるいは2種以上を併用することができ、ま
た粒径も任意に選択できる。As the calcium alloy, Fe-Ca-3i alloy,
Fe-Ca-Si-RE gold alloy Fe-Ca-Ni-3i
Any alloy such as Ni-Ca alloy, Ni-Fe-Ca alloy, and Cu-Ca alloy can be used, and these alloys can be used alone or in combination of two or more, and the particle size can also be set arbitrarily. You can choose.
また、前記カルシウム含有金属添加剤としては、金属カ
ルシウム3〜35%、残部実質的に鉄粉からなる混合物
を圧縮成形してなるFe−Caブリケットが代表的なも
のとして挙げられるが、これに限定されるものではない
。In addition, a representative example of the calcium-containing metal additive is an Fe-Ca briquette obtained by compression molding a mixture consisting of 3 to 35% metallic calcium and the remainder substantially iron powder, but is not limited thereto. It is not something that will be done.
前記粒状もしくは塊状カルシウム合金またはカルシウム
含有金属添加剤は、その粒子もしくは塊の表面が耐火物
材料や微細鉄粉で被覆されるが、耐火物材料としては、
マグネシア、アルミナ、シリカ、蛍石その他の金属酸化
物が好適である。これらの金属酸化物は単独または2種
以上を併用しても良く、また、鉄と併用して金属酸化物
と鉄とで交互に被覆するようにしても良い。The surface of the particles or lumps of the granular or lumpy calcium alloy or calcium-containing metal additive is coated with a refractory material or fine iron powder, but as a refractory material,
Magnesia, alumina, silica, fluorite and other metal oxides are preferred. These metal oxides may be used alone or in combination of two or more, or may be used in combination with iron so that the metal oxide and iron are alternately coated.
また、前記被覆によって添加ホッパーより切り出された
Ca添加物は取鍋より吸い上げられて還流中の熔鋼に接
触するが、従来の様なCa添加物と異なり瞬時の反応が
なく被覆の厚みによって数秒乃至数十秒の後に反応する
、即ち、還流中の熔鋼がそれらの添加物を捲き込んで取
鍋に返流してきた時に、減圧下でない取鍋の中で反応す
るように被覆の厚みを調整するの好適である。In addition, the Ca additive cut out from the addition hopper by the coating is sucked up from the ladle and comes into contact with the refluxing molten steel, but unlike conventional Ca additives, there is no instantaneous reaction and it takes several seconds depending on the thickness of the coating. The thickness of the coating is adjusted so that the reaction occurs after several tens of seconds, that is, when the molten steel during reflux incorporates these additives and returns to the ladle, the reaction occurs in the ladle that is not under reduced pressure. It is suitable for adjustment.
(作用)
本発明方法によれば、取鍋熔鋼の上に導管を差し入れて
減圧されたRH脱ガス槽内に熔鋼を還流して脱ガスを行
うと共に、上部に設けられた合金添加ホッパーより、F
e−Ti、Fo−Cr、Fe−Mo。(Function) According to the method of the present invention, the molten steel is degassed by being refluxed into the depressurized RH degassing tank by inserting a conduit above the molten steel in the ladle, and the alloy addition hopper provided at the upper part From, F
e-Ti, Fo-Cr, Fe-Mo.
Fa−Siなどの合金添加元素を切り出して添加するR
H脱ガス槽を用い、脱酸、脱ガス処理が行われた直後の
一香酸素濃度の低いところでCa添加処理を行い、しか
もカルシウム合金もしくはカルシウム含有金属添加剤を
粒状もしくは塊状とし、その表面が耐火物材料および/
または鉄粉で被覆されているため、Ca合金および/ま
たはCa添加剤の反応が遅延され、歩留まりを向上させ
る効果をもたらす。R to cut out and add alloy additive elements such as Fa-Si
Immediately after the deoxidation and degassing treatment, Ca addition treatment is carried out using a H degassing tank at a place where the concentration of oxygen is low.Moreover, the calcium alloy or calcium-containing metal additive is made into granules or lumps, and the surface is Refractory materials and/or
Alternatively, since it is coated with iron powder, the reaction of the Ca alloy and/or Ca additive is delayed, resulting in an effect of improving the yield.
Caの反応の遅延は、Ca含有量を少なくすることによ
ってもできるが、Caの濃度を3%以下にすると、添加
する量が多くなりすぎるために絶対量の増加や、温度低
下および処理時間の増大を招き好ましくないので、本発
明では、カルシウム合金およびカルシウム含有金属添加
剤におけるカルシウムの含有量の下限を3%以上と定め
ている。The Ca reaction can be delayed by reducing the Ca content, but if the Ca concentration is 3% or less, the amount added becomes too large, resulting in an increase in the absolute amount, a decrease in temperature, and a reduction in processing time. Since this is undesirable, the lower limit of the calcium content in calcium alloys and calcium-containing metal additives is set at 3% or more.
また、カルシウムの含有量が35%を越えると、いくら
反応抑制の方法を用いても歩留りが悪くなるので、その
上限を35%とした。Furthermore, if the calcium content exceeds 35%, the yield will be poor no matter how many reaction suppression methods are used, so the upper limit was set at 35%.
即ち、本発明方法においては、減圧下のRH脱ガス処理
槽の中で添加されたCa添加剤はその表面が被覆されて
いるため、RH脱ガス層内でなく、実質的に還流された
取鍋内にて反応するため、従来極めて困難であったCa
添加歩留りを著しく向上させることができ、極めて工業
的量産に於いての利用価値が高い。That is, in the method of the present invention, since the surface of the Ca additive added in the RH degassing treatment tank under reduced pressure is coated, the Ca additive is not contained in the RH degassing layer but is substantially refluxed. Since Ca reacts in a pot, it was previously extremely difficult to remove Ca.
It can significantly improve the addition yield and has extremely high utility value in industrial mass production.
次に実施例につき述べる。Next, examples will be described.
実施例(1)
■ Cal 0%、Si45%残実質的に鉄よりなるF
e−3i−Ca合金を用い、250トンRH脱ガス槽に
て一般鋼を次のようにして処理した。すなわち、常圧よ
り0.3〜Q 、 4 Torrまで減圧して脱ガス後
、120 Torrに戻した後、上記Fe−Si−Ca
合金500kgを連続にて添加した後、約1還流程度で
常圧に戻した。Example (1) ■ Cal 0%, Si 45% remaining F consisting essentially of iron
Using the e-3i-Ca alloy, general steel was treated in a 250 ton RH degassing tank as follows. That is, after degassing by reducing the pressure from normal pressure to 0.3 to 4 Torr and returning it to 120 Torr, the Fe-Si-Ca
After continuously adding 500 kg of the alloy, the pressure was returned to normal pressure by about 1 reflux.
■ 上記と全く同じ成分組成のFe−Si−Ca合金粒
子の表面をマグネシアとアルミナとシリカと蛍石の混合
耐火物にて、1〜3m/m厚にて被覆した。合金の正味
重量500kgを■と同条件にて添加した。(2) The surface of Fe-Si-Ca alloy particles having exactly the same composition as above was coated with a mixed refractory of magnesia, alumina, silica, and fluorite to a thickness of 1 to 3 m/m. A net weight of 500 kg of the alloy was added under the same conditions as in (2).
前記それぞれの一般鋼について、カルシウムの歩留まり
を調べたところ第1表に示す通りであっtこ。The calcium yield of each of the above-mentioned general steels was investigated and was as shown in Table 1.
第1表
実施例(2)
■ 金属CaパウダーlO%残部実質的に鉄粉りなる高
圧造粒した鉄−Caブリケットを用い、50トンRH脱
ガス槽にて一般鋼を次のようにて処理した。始め常圧よ
り0.3〜Q、4Torrまで減圧して脱ガス処理を行
ったるのち、130T orrまで槽内圧力を高めた状
態で前記鉄−Caブリケットを500kg連続的に添加
したるのち約1還流程度で常圧に戻した。Table 1 Example (2) ■ Metallic Ca powder 1O% Using high-pressure granulated iron-Ca briquettes, the remainder of which is essentially iron powder, general steel was treated in a 50-ton RH degassing tank as follows. did. Initially, the pressure was reduced from normal pressure to 0.3 to 4 Torr for degassing treatment, and then 500 kg of the above-mentioned iron-Ca briquettes were continuously added while increasing the pressure in the tank to 130 Torr. The pressure was returned to normal pressure at around reflux.
■ 上記と全く同じ成分組成の鉄−Caブリケットの表
面を実施例(1)にて使用したのと同じマグネシア+ア
ルミナ+シリカ+蛍石系の耐火物で厚み1〜2m/mに
被覆を行い、さらにその上を微細鉄粉にて厚さ約1m/
m程度に二重被覆した鉄−Caブリケットの正味重量5
00kgを■と同条件にて添加した。■ The surface of an iron-Ca briquette with the same composition as above was coated with the same magnesia + alumina + silica + fluorite refractory used in Example (1) to a thickness of 1 to 2 m/m. , and then coat the top with fine iron powder to a thickness of about 1m/
Net weight of double-coated iron-Ca briquettes of about 5 m
00 kg was added under the same conditions as ().
このようにして得た鋼におけるカルシウムの歩留まりを
調べたところ第2表に示す結果が得られた。When the yield of calcium in the steel thus obtained was investigated, the results shown in Table 2 were obtained.
第2表
(発明の効果)
以上の説明から明らかなように、本発明によれば、 ■
RH脱ガス槽内で脱酸、脱ガス処理が行われた直後の一
香酸素濃度の低いところでCa処理が可能である、
■日常的に使用しているRH脱ガス槽装置で行えるため
、特別の装置、器具が不用で、通常の作業の流れの中で
円滑にCa処理ができる、■反応時間を要せず時間のロ
スを解消できる、■温度低下が■■の理由で最小にでき
る、■RH脱ガス槽装置には、通常排煙集塵装置がある
ので、自動的にこれが利用できるために、特別の猛烈な
Ca処理ガス用の集塵装置が不要である、
■従来不可能であった減圧下でのカルシウム添加を実現
でき、しかも高歩留まりで行える、即ち、只でさえ熔鋼
温度では蒸発し易いカルシウムを真・空に近い減圧槽内
で添加することと、Ca添加の高歩留りを得るという非
常に矛盾した要求を満足させることができる、
など優れた効果を奏する。Table 2 (Effects of the Invention) As is clear from the above explanation, according to the present invention, ■
Immediately after deoxidation and degassing treatment has been performed in the RH degassing tank, Ca treatment is possible at a place where the concentration of oxygen is low. No equipment or equipment is required, and Ca treatment can be carried out smoothly in the normal work flow; ■ Reaction time is not required, eliminating time loss; ■ Temperature drop can be minimized due to ■■ reasons. ■The RH degassing tank equipment usually has a flue gas dust collector, so this can be used automatically, so there is no need for a special dust collector for intense Ca processing gas. Calcium addition can be achieved under reduced pressure and at a high yield. In other words, it is possible to add calcium, which easily evaporates even at molten steel temperature, in a near-vacuum/vacuum pressure tank, and to add calcium at a high yield. It has excellent effects such as being able to satisfy the extremely contradictory demands of obtaining yield.
特許出願人 大阪特殊合金株式会社Patent applicant: Osaka Special Alloy Co., Ltd.
Claims (6)
、カルシウムを3〜35%含有する粒状もしくは塊状の
カルシウム合金および/またはカルシウム含有金属添加
剤をRH脱ガス槽内の熔鋼に添加することを特徴とする
熔鋼へのカルシウム添加方法。(1) Granular or lumpy calcium alloys and/or calcium-containing metal additives whose surfaces are coated with refractory materials and/or iron powder and which contain 3 to 35% calcium are added to molten steel in the RH degassing tank. A method for adding calcium to molten steel.
e−Ca−Si−RE合金、Fe−Ca−Ni−Si合
金、Ni−Ca合金、Ni−Fe−Ca合金、およびC
u−Ca合金からなる群から選ばれた少なくとも一種で
あることを特徴とする特許請求の範囲第1項記載の方法
。(2) The calcium alloy is a Fe-Ca-Si alloy, F
e-Ca-Si-RE alloy, Fe-Ca-Ni-Si alloy, Ni-Ca alloy, Ni-Fe-Ca alloy, and C
2. The method according to claim 1, wherein the material is at least one selected from the group consisting of u-Ca alloys.
ム3〜35%、残部実質的に鉄粉からなる混合物を圧縮
成形してなるFe−Caブリケットであることを特徴と
する特許請求の範囲第1項記載の方法。(3) The calcium-containing metal additive is an Fe-Ca briquette obtained by compression molding a mixture consisting of 3 to 35% metallic calcium and the remainder substantially iron powder. The method described in section.
シウム含有金属添加剤の表面が微細鉄粉で被覆されてい
ることを特徴とする特許請求の範囲第1項〜第3項のい
づれか一項記載の方法。(4) The method according to any one of claims 1 to 3, wherein the surface of the granular or lumpy calcium alloy or calcium-containing metal additive is coated with fine iron powder.
ルシウム含有金属添加剤の表面が耐火物材料と鉄とで交
互に被覆されていることを特徴とする特許請求の範囲第
1項〜第3項のいづれか一項記載の方法。(5) Any one of claims 1 to 3, characterized in that the surface of the granular or lumpy calcium alloy or calcium-containing metal additive is alternately coated with a refractory material and iron. The method described in paragraph 1.
する特許請求の範囲第1項〜第4項および第5項のいづ
れか一項記載の方法。(6) The method according to any one of claims 1 to 4 and 5, wherein the refractory material is a metal oxide.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28777787A JPH01129925A (en) | 1987-11-13 | 1987-11-13 | Method for adding calcium to molten steel |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28777787A JPH01129925A (en) | 1987-11-13 | 1987-11-13 | Method for adding calcium to molten steel |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH01129925A true JPH01129925A (en) | 1989-05-23 |
Family
ID=17721614
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP28777787A Pending JPH01129925A (en) | 1987-11-13 | 1987-11-13 | Method for adding calcium to molten steel |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH01129925A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5228902A (en) * | 1992-09-03 | 1993-07-20 | Usx Corporation | Method of desulfurization in vacuum processing of steel |
EP1428894A1 (en) * | 2002-12-13 | 2004-06-16 | SMS Mevac GmbH | A method of degassing molten steel |
-
1987
- 1987-11-13 JP JP28777787A patent/JPH01129925A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5228902A (en) * | 1992-09-03 | 1993-07-20 | Usx Corporation | Method of desulfurization in vacuum processing of steel |
EP1428894A1 (en) * | 2002-12-13 | 2004-06-16 | SMS Mevac GmbH | A method of degassing molten steel |
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