JPS62287009A - Method for preventing rephosphorization in production of extra-low phosphorus steel - Google Patents
Method for preventing rephosphorization in production of extra-low phosphorus steelInfo
- Publication number
- JPS62287009A JPS62287009A JP12942986A JP12942986A JPS62287009A JP S62287009 A JPS62287009 A JP S62287009A JP 12942986 A JP12942986 A JP 12942986A JP 12942986 A JP12942986 A JP 12942986A JP S62287009 A JPS62287009 A JP S62287009A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- dephosphorization
- molten
- slag
- converter
- 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 51
- 239000010959 steel Substances 0.000 title claims abstract description 51
- 229910052698 phosphorus Inorganic materials 0.000 title claims abstract description 39
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 title claims abstract description 37
- 239000011574 phosphorus Substances 0.000 title claims abstract description 37
- 238000000034 method Methods 0.000 title claims description 30
- 238000004519 manufacturing process Methods 0.000 title description 7
- 239000002893 slag Substances 0.000 claims abstract description 44
- 238000010079 rubber tapping Methods 0.000 claims abstract description 18
- 238000007670 refining Methods 0.000 claims abstract description 15
- 230000009467 reduction Effects 0.000 claims abstract description 12
- 238000007664 blowing Methods 0.000 claims abstract description 8
- 239000002184 metal Substances 0.000 claims description 20
- 229910052751 metal Inorganic materials 0.000 claims description 20
- 238000002844 melting Methods 0.000 claims description 4
- 230000008018 melting Effects 0.000 claims description 4
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 claims description 3
- 238000010309 melting process Methods 0.000 claims 1
- 238000011282 treatment Methods 0.000 abstract description 16
- 239000003795 chemical substances by application Substances 0.000 abstract description 8
- 239000010436 fluorite Substances 0.000 abstract description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 2
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 abstract description 2
- 238000006243 chemical reaction Methods 0.000 abstract description 2
- 229910052760 oxygen Inorganic materials 0.000 abstract description 2
- 239000001301 oxygen Substances 0.000 abstract description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract 6
- 229910052742 iron Inorganic materials 0.000 abstract 3
- 238000005261 decarburization Methods 0.000 abstract 1
- 238000009628 steelmaking Methods 0.000 abstract 1
- 238000007796 conventional method Methods 0.000 description 9
- 230000008569 process Effects 0.000 description 8
- 229910000805 Pig iron Inorganic materials 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000013256 coordination polymer Substances 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 239000007858 starting material Substances 0.000 description 2
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 235000012255 calcium oxide Nutrition 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
Description
【発明の詳細な説明】
3、発明の詳細な説明
(産業上の利用分野)
本発明は、極低燐鋼の溶製法、特に30 ppm以下の
燐を含有する極低燐鋼の溶製時に復燐を防止する方法に
関する。Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention provides a method for producing ultra-low phosphorus steel, particularly for producing ultra-low phosphorus steel containing 30 ppm or less of phosphorus. This invention relates to a method for preventing rephosphorization.
(従来の技術)
極低燐鋼を溶製する際、処理の多段化を含めた徹底脱燐
と、脱燐処理後の還元精錬時の復燐量を極少化すること
が重要であるが、成品CP)≦30ppm程度の極低燐
化を図る際には、技術的にかなり困難を伴い、コスト的
にも負荷が大きい。(Prior art) When melting ultra-low phosphorus steel, it is important to perform thorough dephosphorization, including multistage processing, and to minimize the amount of rephosphorus during reduction refining after dephosphorization treatment. Achieving extremely low phosphorus levels (CP)≦30 ppm in the finished product is technically quite difficult, and also imposes a large cost burden.
従来は、例えば第1図(a)に示すように、P≦0’、
025重量%にまで脱燐した予備脱燐銑を使用し、これ
を転炉に装入して吹錬を行い、出鋼脱燐後、取鍋に収容
し、その際取鍋脱燐を行って脱燐処理が終了してから、
還元精錬を行う。このような従来法にあっては出鋼脱燐
後、脱燐処理終了までに適宜段階で1回除滓を行う。Conventionally, as shown in FIG. 1(a), for example, P≦0',
Using pre-dephosphorized pig iron that has been dephosphorized to 0.025% by weight, it is charged into a converter and subjected to blowing, and after dephosphorization, it is stored in a ladle, and at that time, ladle dephosphorization is performed. After the dephosphorization process is completed,
Perform reduction refining. In such a conventional method, slag removal is performed once at an appropriate stage after the dephosphorization of the tapped steel and before the end of the dephosphorization process.
予備脱燐処理は、初期のP濃度が高いなどの理由から、
50 ppm程度までの徹底した脱燐は行われないなど
、高価である割には十分な脱燐は行われない。現在のと
ころ、転炉操業の負荷の軽減という意義を有するにすぎ
ない。Preliminary dephosphorization treatment is performed due to the high initial P concentration, etc.
Thorough dephosphorization to about 50 ppm is not performed, and sufficient dephosphorization is not performed despite the high cost. At present, it only has the significance of reducing the load on converter operation.
従来法にあって、除滓が1回に制限されているが、これ
は、予備脱燐銑を使用した」−にさらに2回以上の除滓
を実施することはコスト的に極めて負荷が大きくなるた
めである。In the conventional method, slag removal is limited to one time, but carrying out slag removal two or more times after using preliminary dephosphorization pig iron is extremely costly in terms of cost. To become.
その他、極低燐鋼の製法には多数回出鋼法と言われてい
る方法がある。Another method for manufacturing ultra-low phosphorus steel is called the multiple recycle steel method.
例えば、特公昭56−48562号は2回出鋼法を開示
するものであり、それには転炉からの出鋼に際して、ス
ライデングゲートを利用することにより、滓を排出しな
いように出鋼することが開示されている。For example, Japanese Patent Publication No. 56-48562 discloses a double tapping method, which involves tapping steel without discharging slag by using a sliding gate when tapping steel from a converter. is disclosed.
特開昭56−41313号には(P)50.010%の
極低燐鋼を溶製する2回出鋼法として、転炉において1
次精錬終了後、炉を傾けて50〜60%の滓を除去し、
再び2次精錬を行い、出鋼後完全除滓してからAOD炉
などに装入することが開示されている。JP-A No. 56-41313 discloses a two-step steel tapping method for melting (P) 50.010% ultra-low phosphorus steel.
After the next refining, tilt the furnace and remove 50-60% of the slag.
It is disclosed that the steel is subjected to secondary refining again, completely removed from the slag after being tapped, and then charged into an AOD furnace or the like.
しかし、これらの方法では転炉2次精錬に先立って除滓
を行う必要があり、作業に時間を要し、結局コスト高の
処理方法となってしまう。また、完全に滓を除いた状態
で出鋼されるため、過剰量の表面酸化は避けられず、結
局、高価な処理方法となってしまう。However, in these methods, it is necessary to remove the slag prior to the secondary refining in the converter, which takes time and results in a high cost treatment method. Furthermore, since the steel is tapped with the slag completely removed, excessive surface oxidation is unavoidable, resulting in an expensive treatment method.
(発明が解決しようとする問題点)
このように、極低燐鋼を溶製する際、脱燐処理の多段化
による極低燐化が一般的に採用される手法であるが、多
段処理に伴うコストアンプ、工程の複雑化等の欠点があ
る。(Problems to be Solved by the Invention) As described above, when producing ultra-low phosphorus steel, the method of achieving ultra-low phosphorus through multi-stage dephosphorization is generally adopted. There are disadvantages such as increased cost and complexity of the process.
また、従来法が、極低燐鋼の溶製に際しては通常の溶銑
ではなく、予備脱燐処理を施した溶銑を使用する必要が
あるとともに、取鍋脱燐時に極低燐化を実現するため、
スラグ−メタル間の燐分配比を上げるための精密なスラ
グ組成のコントロール、あるいは大量の脱燐側を必要と
するなど、処理コストの高騰はさけられない。In addition, when the conventional method melts ultra-low phosphorus steel, it is necessary to use hot metal that has been pre-dephosphorized instead of regular hot metal, and it is necessary to use hot metal that has undergone preliminary dephosphorization treatment, and to achieve extremely low phosphorus during ladle dephosphorization. ,
A rise in processing costs is unavoidable as it requires precise control of the slag composition to increase the phosphorus distribution ratio between slag and metal, or requires a large amount of phosphorization.
よって、本発明の目的は、上述のような従来技術の欠点
を解消した極低燐鋼の溶製法、特に極低燐鋼熔製時にお
ける復燐防止法を提供することである。SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for producing ultra-low phosphorus steel that eliminates the drawbacks of the prior art as described above, and in particular, a method for preventing rephosphorization during the production of ultra-low phosphorus steel.
本発明の別の目的は、通常の溶銑を出発原料とし、スラ
グコントロールに特に意を用いる必要のない極低tB鋼
の溶製方法、特に極低燐鋼の溶製時における復燐防止法
を提供することである。Another object of the present invention is to provide a method for producing ultra-low tB steel that uses ordinary hot metal as a starting material and does not require special attention to slag control, and in particular a method for preventing rephosphorization during melting of ultra-low phosphorus steel. It is to provide.
脱燐処理に際しては、従来のように脱燐反応促進を最優
先させると、予備脱燐溶銑を使い、低燐銑をさらに転炉
を経て出鋼時に脱燐処理を行い、そしてさらに取鍋脱燐
をするというように、絶えず脱燐のためスラグの組成の
コントロール、特に溶銑−スラグ間の燐の分配比を変え
るためにスラグ組成のコントロールを必要とした。その
ような操作の煩雑さを回避するために、従来法にあって
も出鋼脱燐後に除滓してから、取鍋脱燐に際して新たに
造滓することも考えられるが、かえって操作が複雑にな
るばかりか、すでに予備脱燐処理を行っているとともに
、そのうえ温度補償のため高価な処理となってしまう。During dephosphorization, if the top priority is given to promoting the dephosphorization reaction as in the past, pre-dephosphorized hot metal is used, low-phosphorus pig iron is further passed through a converter, dephosphorized at the time of tapping, and then ladle dephosphorized. In order to constantly dephosphorize the slag, it was necessary to control the composition of the slag, especially to change the distribution ratio of phosphorus between the hot metal and the slag. In order to avoid such complicated operations, it is conceivable in the conventional method to remove the slag after dephosphorizing the steel and then create new slag during ladle dephosphorization, but this would make the operation more complicated. Not only that, but preliminary dephosphorization treatment has already been carried out, and in addition, temperature compensation becomes an expensive treatment.
(問題点を解決するための手段)
本発明者らは、かかる目的達成のため種々検討を重ねた
ところ、成品の極低燐化を目指す上で、最も重要となる
のは、転炉での脱燐処理完了時から鋳造に至る間での、
滓あるいは耐火物からの復燐量を極少に抑えることであ
り、通常の溶銑を出発原料としても取鍋脱燐を適用し、
この後2回目の除滓をして復燐防止を図ることにより、
(P)≦50 ppm、好ましくはCP)≦30ppm
の極低燐鋼の製造が可能であることを知り、本発明を完
成した。(Means for Solving the Problems) The present inventors have conducted various studies to achieve this objective, and have found that the most important point in aiming for extremely low phosphorus products is the From the completion of the dephosphorization process to casting,
The aim is to minimize the amount of rephosphorization from slag or refractories, and ladle dephosphorization is applied using ordinary hot metal as the starting material.
After this, by removing slag a second time to prevent rephosphorization,
(P)≦50 ppm, preferably CP)≦30 ppm
After learning that it was possible to produce ultra-low phosphorous steel, the present invention was completed.
すなわち、本発明者らの知見によれば、燐含有量50p
pm程度までは復燐は問題とならず、むしろ積極的な脱
燐が進み、したがって、予備脱燐処理は、極低燐化にと
っては余分な工程であり、それよりも燐含有量が50p
pm以下となる時点において除滓することによって復燐
を効果的に防止するとともに、出鋼脱燐、取鍋脱燐を組
み合わせることにより、5Qppn+以下、好ましくは
30ppm以下の燐含有量の極低燐鋼を溶製できるので
ある。もちろん、P =50ppm以下では復燐が顕著
となるので、上述の出鋼脱燐、取鍋脱燐処理後はそれぞ
れ除滓するのである。なお、ここに、「除滓」とは、脱
燐情理を除去するとともにあらたに滓を更新することを
いうのである。単に滓を切りながら行う溶鋼注入は「除
滓」には包含されない。That is, according to the findings of the present inventors, the phosphorus content is 50p.
Rephosphorization is not a problem up to about 100 pm, and active dephosphorization progresses.Therefore, preliminary dephosphorization is an extra step for extremely low phosphorus, and if the phosphorus content is 50p
By removing the sludge at the point where it becomes below pm, rephosphorization can be effectively prevented, and by combining tapping dephosphorization and ladle dephosphorization, extremely low phosphorus content of below 5Qppn+, preferably below 30 ppm can be achieved. It is possible to melt steel. Of course, if P = 50 ppm or less, rephosphorization becomes noticeable, so slag is removed after the above-mentioned tapping and ladle dephosphorization treatments. Note that "removal of slag" as used herein refers to removing the phosphor removal process and renewing the slag. Injection of molten steel by simply cutting slag is not included in "slag removal."
よって、本発明の要旨とするところは、転炉吹錬、出鋼
脱燐、取鍋脱燐、次いで還元精錬を行うことから成る極
低燐鋼の溶製法にあって、転炉装入溶銑として予備脱燐
を行わない溶銑、例えばP2O,1重量%の溶銑を使用
するとともに転炉出鋼後から還元精錬を開始するまでの
間に少なくとも2回、除滓を行うことを特徴とする、極
低燐鋼熔製時における復燐防止法である。Therefore, the gist of the present invention is a method for producing ultra-low phosphorous steel, which comprises converter blowing, tapping dephosphorization, ladle dephosphorization, and then reduction refining. It is characterized by using hot metal that does not undergo preliminary dephosphorization, for example, hot metal containing 1% by weight of P2O, and performing slag removal at least twice between the time of tapping the steel in the converter and the start of reduction refining. This is a method to prevent rephosphorus when producing ultra-low phosphorus steel.
このように、本発明によれば、転炉出鋼後、2回除滓す
ることにより2回の滓更新ができるので、出鋼後からl
it 18処理終了までのトータルの脱燐率が向上する
ので、予備脱燐銑を使用せずとも、P≦0.003%程
度までの極低燐化が可能となる。さらに、復燐量も極少
に抑制でき、脱燐終了後から成品となる間での復燐量を
5ppm以下に抑えることができる。As described above, according to the present invention, the slag can be renewed twice by removing the slag twice after tapping the steel in the converter.
Since the total dephosphorization rate up to the end of the IT 18 treatment is improved, extremely low phosphorus reduction to about P≦0.003% can be achieved without using preliminary dephosphorization pig iron. Furthermore, the amount of rephosphorization can be suppressed to an extremely small amount, and the amount of rephosphorization can be suppressed to 5 ppm or less from the end of dephosphorization to the time when the finished product is produced.
さらに、本発明の好適態様にあっては、還元精錬に先立
って、取鍋において脱燐処理を行い、除滓後、還元処理
を行うために例えばAOn炉に取鍋より溶鋼を装入する
のである。これによれば、燐含有量を0.003重量%
以下にするとともに脱燐後の復燐を実質上ゼロとするこ
とができる。Furthermore, in a preferred embodiment of the present invention, dephosphorization treatment is performed in a ladle prior to reduction refining, and after slag removal, molten steel is charged from the ladle into an AOn furnace, for example, for reduction treatment. be. According to this, the phosphorus content is 0.003% by weight.
In addition to the following, rephosphorization after dephosphorization can be made substantially zero.
(作用)
第1図(b)には、1本発明法」として本発明にかかる
処理工程が開示されているが、これは予備脱燐しない通
常の溶銑(一般にp=0.10%以上、好ましくはP=
0.10〜0.15%)を使い、これを転炉で吹錬し、
吹錬終了後、出鋼に際して、出鋼流にスケール、ホタル
石等の脱燐剤を投入する出鋼脱燐を行う。このようにし
て行う出鋼脱燐後、P2O5が濃化したスラグを一度排
出し、再度脱燐スラグを造滓するので、1回除滓法(従
来法)に比べ、同一鋼中CP)を得るための取鍋脱燐ス
ラグ量が少なくてもよく、またスラグ−メタル間の燐分
配化を最大値にするためのスラグコントロールもさほど
精密に行う必要がない。(Function) In FIG. 1(b), the treatment process according to the present invention is disclosed as 1 Invention Method, but this is a process using ordinary hot metal (generally p = 0.10% or more, p = 0.10% or more, Preferably P=
0.10~0.15%), blow it in a converter,
After blowing, dephosphorization is performed by adding dephosphorizing agents such as scale and fluorspar to the tapping process. After dephosphorizing steel tapping in this way, the slag enriched with P2O5 is once discharged and the dephosphorized slag is made into slag again, so compared to the one-time slag removal method (conventional method), the CP in the same steel is reduced. The amount of ladle dephosphorized slag to be obtained may be small, and slag control to maximize phosphorus distribution between slag and metal does not need to be performed very precisely.
取鍋脱燐も出鋼脱燐と同様に脱燐剤を取鍋内温鋼に投入
するだけで良く、この際に得られた滓もAOD炉などで
の還元精錬に先立って除去し、復燐を防止する。Ladle dephosphorization, like tapping steel dephosphorization, only requires adding the dephosphorizing agent to the hot steel in the ladle, and the slag obtained at this time is also removed prior to reduction refining in an AOD furnace etc. Prevents phosphorus.
次に、本発明の詳細な説明する。Next, the present invention will be explained in detail.
夫施炎
第1図の本発明方法にしたがって280トンの通常の溶
銑を処理した。転炉吹錬条件その他は第1表に示すよう
に従来法のそれに同じであった。除滓は出鋼脱燐後およ
び取鍋脱燐後の計2回行った。280 tons of conventional hot metal were treated according to the method of the invention shown in FIG. The converter blowing conditions and other conditions were the same as those of the conventional method, as shown in Table 1. Slag removal was carried out twice: after dephosphorization of the tapped steel and after dephosphorization in the ladle.
燐含有量の変化を第2表にまとめて示す。Changes in phosphorus content are summarized in Table 2.
還元処理は慣用のAOD炉により行った。The reduction treatment was carried out using a conventional AOD furnace.
部1表
溶銑組成 : C:4.5%、Si:0.20%、M
n:0.30%、P:0.110%、S:0.003%
転炉吹錬
時間(min): 18
送酸量(Nm’/m1n): 800出鋼脱燐
脱燐剤: スケール50%−ホタル石50%投入量=
5〜6 kg/T
投入法二 上から出鋼流をねらって投入取鍋脱燐
脱燐剤: スケール40%−ホタル石20%−生石灰4
0%
投入量:20〜30 kg/T
投入法: 上置
第2表 (重¥%)
実施例2
次に、第3表に示す条件で脱燐剤としてスケール、ホタ
ル石を使用した本発明法と従来法による鋼中(P)推移
を比較した。結果411第2図に示す。Part 1 Table Hot metal composition: C: 4.5%, Si: 0.20%, M
n: 0.30%, P: 0.110%, S: 0.003% Converter blowing time (min): 18 Oxygen supply amount (Nm'/m1n): 800 Dephosphorization Dephosphorization agent: Scale 50% - fluorite 50% input amount =
5-6 kg/T Feeding method 2 Aiming at the tapping flow from above, pouring into the ladle Dephosphorization Dephosphorizing agent: Scale 40% - Fluorite 20% - Quicklime 4
0% Input amount: 20 to 30 kg/T Input method: Table 2 above (wt%) Example 2 Next, the present invention using scale and fluorite as a dephosphorizing agent under the conditions shown in Table 3 The changes in steel (P) between the conventional method and the conventional method were compared. The results 411 are shown in FIG.
本発明方法により、転炉吹錬終点からの脱燐率が大幅に
向4−シ、脱燐溶銑を用いずとも極低燐化が可能である
ことが分かる。また取鍋脱燐4%了から成品間の復燐量
も、取鍋脱燐を行うとともに除滓を行うことからほぼゼ
ロに抑制できる。It can be seen that the method of the present invention significantly increases the dephosphorization rate from the end point of converter blowing, and that it is possible to achieve extremely low phosphorus without using dephosphorizing hot metal. Furthermore, the amount of rephosphorus between finished products after 4% ladle dephosphorization is completed can be suppressed to almost zero by performing ladle dephosphorization and removing slag.
第3表 (発明の効果) 本発明によれば、次のような利点が得られる。Table 3 (Effect of the invention) According to the present invention, the following advantages can be obtained.
通常溶銑、つまり予備脱燐を行なわない溶銑を利用して
極低燐鋼の溶製が可能となる。It is possible to produce ultra-low phosphorus steel using normal hot metal, that is, hot metal that is not subjected to preliminary dephosphorization.
予備脱燐を行わないにもかかわらず、転炉出鋼後の所要
脱燐剤は30%はど節約される。Even without pre-dephosphorization, the required dephosphorization agent after tapping the converter is saved by 30%.
滓組成を調節する操作は全く不用となる。There is no need for any operation to adjust the slag composition.
燐含有量0.005%以下、好ましくは0.003%以
下の極低燐鋼が予備処理なしで容易に溶製できる。Ultra-low phosphorus steel with a phosphorus content of 0.005% or less, preferably 0.003% or less can be easily produced without pretreatment.
第1図は、従来法とともに、本発明方法の工程を比較し
て説明する図;および
第2図は、実施例の結果を示すグラフである。
第1図
第2図
kt准FIG. 1 is a diagram comparing and explaining the steps of the method of the present invention with the conventional method; and FIG. 2 is a graph showing the results of the example. Figure 1 Figure 2 kt standard
Claims (2)
を行うことから成る極低燐鋼の溶製法にあって、転炉装
入溶銑として予備脱燐を行わない溶銑を使用するととも
に転炉出鋼後から還元精錬を開始するまでの間に少なく
とも2回、除滓を行うことを特徴とする、極低燐鋼溶製
時における復燐防止法。(1) Hot metal that does not undergo preliminary dephosphorization as hot metal charged to the converter in the melting process for ultra-low phosphorous steel, which consists of converter blowing, tapping dephosphorization, ladle dephosphorization, and then reduction refining. A method for preventing rephosphorization during melting of ultra-low phosphorus steel, which is characterized by using a converter and removing slag at least twice from the time the steel is tapped in a converter until the start of reduction refining.
.1重量%以上である、特許請求の範囲の第1項記載の
方法。(2) The phosphorus content of the hot metal that was not subjected to preliminary dephosphorization is 0.
.. 1. The method according to claim 1, wherein the amount is 1% by weight or more.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP12942986A JPS62287009A (en) | 1986-06-04 | 1986-06-04 | Method for preventing rephosphorization in production of extra-low phosphorus steel |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP12942986A JPS62287009A (en) | 1986-06-04 | 1986-06-04 | Method for preventing rephosphorization in production of extra-low phosphorus steel |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS62287009A true JPS62287009A (en) | 1987-12-12 |
Family
ID=15009270
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP12942986A Pending JPS62287009A (en) | 1986-06-04 | 1986-06-04 | Method for preventing rephosphorization in production of extra-low phosphorus steel |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS62287009A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103014230A (en) * | 2012-06-01 | 2013-04-03 | 新疆八一钢铁股份有限公司 | Method for producing low-phosphorus high-carbon steel by duplex hot-adding slag washing for electric furnace |
CN103031401A (en) * | 2012-09-26 | 2013-04-10 | 新疆八一钢铁股份有限公司 | Method for converter steelmaking by LF (Ladle Furnace) refining furnace reducing slag |
CN103031405A (en) * | 2011-11-29 | 2013-04-10 | 新疆八一钢铁股份有限公司 | Steel making technology for hot addition and transit of liquid steel slag in electric furnace |
-
1986
- 1986-06-04 JP JP12942986A patent/JPS62287009A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103031405A (en) * | 2011-11-29 | 2013-04-10 | 新疆八一钢铁股份有限公司 | Steel making technology for hot addition and transit of liquid steel slag in electric furnace |
CN103014230A (en) * | 2012-06-01 | 2013-04-03 | 新疆八一钢铁股份有限公司 | Method for producing low-phosphorus high-carbon steel by duplex hot-adding slag washing for electric furnace |
CN103031401A (en) * | 2012-09-26 | 2013-04-10 | 新疆八一钢铁股份有限公司 | Method for converter steelmaking by LF (Ladle Furnace) refining furnace reducing slag |
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