JPS6184316A - Method for refining molten steel in ladle - Google Patents
Method for refining molten steel in ladleInfo
- Publication number
- JPS6184316A JPS6184316A JP20364084A JP20364084A JPS6184316A JP S6184316 A JPS6184316 A JP S6184316A JP 20364084 A JP20364084 A JP 20364084A JP 20364084 A JP20364084 A JP 20364084A JP S6184316 A JPS6184316 A JP S6184316A
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- calcium
- ladle
- addition
- yield
- 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
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
- C21C7/0075—Treating in a ladle furnace, e.g. up-/reheating of molten steel within the ladle
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)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、硫化物を球状化して形態制御するために溶
鋼中にカルシウム（Ｃａ ）を添加して精錬する溶鋼の
取鍋精錬方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for refining molten steel in a ladle by adding calcium (Ca) to the molten steel in order to control the shape of sulfides by spheroidizing them.
鋼材中にＭｎＳ系介在物が存在すると、この介在物が鋼
材の圧延によって延伸し、鋼中水素のトラップ場所とな
って鋼材の水素誘起割れを発生しやすい。このため、特
に寒冷地で使用されるラインノｆイブ用鋼材等はＭｎ８
の析出を極力防止する必要があシ、溶鋼にＣａを添加し
てＭｎ８の替シにＣａ８を析出させる硫化物系介在物の
形態制御が実施されている。これは、ＣａＳの場合は、
鋼材を圧延しても球状の形態を維持するので、水素誘起
割れが発生しにくいからである。When MnS-based inclusions are present in a steel material, these inclusions are elongated during rolling of the steel material, become a trap site for hydrogen in the steel, and are likely to cause hydrogen-induced cracking in the steel material. For this reason, steel materials for line nozzles used especially in cold regions are Mn8
It is necessary to prevent the precipitation of sulfide-based inclusions as much as possible, and the form control of sulfide-based inclusions is carried out by adding Ca to molten steel to precipitate Ca8 instead of Mn8. In the case of CaS, this is
This is because even when the steel material is rolled, it maintains its spherical shape, so hydrogen-induced cracking is less likely to occur.
ところで、溶鋼中にＣａを添加する方法として、Ｃａ−
８１合金等のＣａ合金の粉末をガスにキャリアさせてラ
ンスを介して溶鋼に吹き込むインジェクション法、粒状
のＣａ合金を溶鋼中に打ち込む弾丸打込み法及び鉄で被
覆された線状のＣａ合金を溶鋼に供給するＣｍワイヤー
法等がある。しかし、Ｃａは鋼の融点よシ低い沸点（１
４８３℃）を有し、蒸気圧が極めて高いため、前述のい
ずれの方法でも、Ｃｍの添加歩留が約１０％程度と極め
て低く、またその歩留のバラツキが大きいという欠点を
有する。このため、高価なＣａ合金が無駄に消費される
と共に、ＣＩＬの添加処理のために溶鋼の水素及び窒素
ピックアップ並びに温度降下が、生ずるという問題点が
ある。By the way, as a method of adding Ca to molten steel, Ca-
Injection method in which Ca alloy powder such as 81 alloy is carried in gas and injected into molten steel through a lance, bullet driving method in which granular Ca alloy is driven into molten steel, and linear Ca alloy coated with iron is injected into molten steel. There is a Cm wire method for supplying. However, Ca has a boiling point lower than the melting point of steel (1
483° C.) and has an extremely high vapor pressure, all of the above-mentioned methods have the disadvantage that the Cm addition yield is extremely low at about 10% and the yield varies widely. Therefore, there are problems in that expensive Ca alloy is wasted, and hydrogen and nitrogen pickup in the molten steel and temperature drop occur due to the CIL addition process.
この発明は、Ｃａの添加歩留を向上させると共に、添加
処理時間を短縮して溶鋼の温度降下環を防止した溶鋼の
取鍋精錬方法を提供することを目的とする。An object of the present invention is to provide a ladle refining method for molten steel that improves the Ca addition yield, shortens the addition treatment time, and prevents a temperature drop ring in the molten steel.
この発明に係る溶鋼の取鍋精錬方法は、溶鋼を転炉から
取鍋に出鋼し、取鍋内の溶鋼にカルシウムを添加してこ
の溶鋼が凝固して得られる鋼材中の硫化物系介在物をカ
ルシウムを含有するものに調整する溶鋼の取鍋精錬方法
において、カルシウムを溶鋼中に３０に９７分以上の速
度で添加することを特徴とする。The method for refining molten steel in a ladle according to the present invention includes tapping molten steel from a converter into a ladle, adding calcium to the molten steel in the ladle, and solidifying the molten steel to prevent sulfide-based inclusions in the steel material obtained. A ladle refining method for molten steel for adjusting a substance to contain calcium, characterized in that calcium is added to molten steel at a rate of 30 to 97 minutes or more.
第１図は溶鋼へのＣａの添加速度とＣａの歩留との関係
を示す。Ｃａの添加は（：ａ −８ｉ合金の粉末をＡｒ
ガス又はＮ２ガスにキャリアさせて、浸漬ランスを介し
て、溶鋼中に吹き込むインジェクション法により行った
。添加終了時の溶鋼温度は１５７５乃至１５８５℃の範
囲にｓｂ、略々一定である。各プロットは２０チヤージ
の平均値であシ、図中の棒線は各プロットにおけるバラ
ツキの範囲を示している。この第１図かられかるように
、Ｃａの添加速度が高くなるにつれてＣａの歩留が上昇
し、しかもその歩留のバラツキが少々い。FIG. 1 shows the relationship between the Ca addition rate to molten steel and the Ca yield. Addition of Ca (:a-8i alloy powder to Ar
An injection method was used in which a carrier gas or N2 gas was injected into molten steel through an immersion lance. The temperature of the molten steel at the end of addition is approximately constant, sb, in the range of 1575 to 1585°C. Each plot is an average value of 20 charges, and the bar line in the figure indicates the range of variation in each plot. As can be seen from FIG. 1, as the Ca addition rate increases, the Ca yield increases, and the yield varies slightly.
この現象は以下の如く説明される。Ｃａの添加量が一定
である場合は、添加速度が遅い程、添加時間が長くなる
。ところで、特にインジェクション法によりＣａを添加
する場合は、溶鋼中に吹き込まれているキャリアガスに
よって、添加処理の期間中、溶鋼が攪拌されている。ま
た、他の弾丸打込み法及びＣａワイヤー法においても、
添加されたＣａ合金を溶鋼に均一に分布させるために、
通常溶鋼を攪拌する。そうすると、Ｃａ合金の添加時間
が長いと、添加初期に溶鋼に添加されたＣａ合金は長時
間に亘って溶鋼の攪拌の影響を受けていることになシ、
低沸点で且つ蒸気圧が高いＣａが溶鋼から離散しやすく
なる。このような理由で添加時間が長いと、溶鋼中のＣ
ａ成分として止まらずに離散してしまうＣａの損失量が
多くなシ、Ｃａの歩留が低くなる。This phenomenon is explained as follows. When the amount of Ca added is constant, the slower the addition rate, the longer the addition time. By the way, especially when adding Ca by the injection method, the molten steel is stirred by the carrier gas blown into the molten steel during the addition process. Also, in other bullet driving methods and Ca wire methods,
In order to uniformly distribute the added Ca alloy in the molten steel,
Usually stirs molten steel. Therefore, if the Ca alloy addition time is long, the Ca alloy added to the molten steel at the initial stage of addition will be affected by the stirring of the molten steel for a long time.
Ca, which has a low boiling point and high vapor pressure, is easily dispersed from the molten steel. For these reasons, if the addition time is long, C in the molten steel will increase.
The amount of loss of Ca, which does not remain as the a component but becomes discrete, is large, and the yield of Ca is low.
第１図から、Ｃａの添加速度が１０に９７分である場合
は、従来と同様に、Ｃａ添加歩留は約１０チであるがＣ
ａの添加速度が３０ｋｇ／分を超えると、Ｃａの歩留は
約２０％以上に著しく上昇する。From FIG. 1, when the Ca addition rate is 10 to 97 minutes, the Ca addition yield is about 10 minutes, but C
When the addition rate of a exceeds 30 kg/min, the yield of Ca significantly increases to about 20% or more.
しかし、Ｃａの添加速度を更に速くした場合は、Ｃａ歩
留が上昇する割合が少なくなる。このため、Ｃａを３０
ｋｇ／分以上の速度で溶鋼に添加するのが得策であると
考えられる。However, when the Ca addition rate is further increased, the rate at which the Ca yield increases becomes smaller. For this reason, Ca is 30
It is considered to be a good idea to add it to molten steel at a rate of at least kg/min.
なお、Ｃａの添加方法は、インジェクション法、弾丸打
込み法又はＣａワイヤー法のいずれでもよい。Note that the Ca addition method may be an injection method, a bullet driving method, or a Ca wire method.
この発明によれば、Ｃａの添加歩留を従来の約２倍以上
にすることができ、しかもそのバラツキが少ないので、
必要なＣａ合金の添加量が少なくて済み、精錬コストを
低減することができる。According to this invention, the Ca addition yield can be more than doubled compared to the conventional method, and there is little variation in the Ca addition yield.
The amount of Ca alloy required to be added is small, and refining costs can be reduced.
また、Ｃａ合金の添加処理時間が短縮されるので、溶鋼
の温度降下が少なく、更に、溶鋼の水素及び窒素ピック
アップが少々いと共に、インジェクションランスを使用
してＣ＆金合金添加する場合はランスの寿命が延長され
る。更にまた、Ｃａ合金の添加量が少ないので、Ｃａ合
金の添加によシネ要表成分が溶鋼中に増加するというこ
とが少なく、溶鋼の汚れを回避することができる。In addition, since the addition processing time for Ca alloy is shortened, there is less temperature drop in the molten steel.Furthermore, the hydrogen and nitrogen pickup of the molten steel is a little slow, and when adding C and gold alloy using an injection lance, the lance life is longer. will be extended. Furthermore, since the amount of the Ca alloy added is small, the addition of the Ca alloy hardly causes an increase in cinene surface components in the molten steel, making it possible to avoid contamination of the molten steel.
第１図はＣａ添加速度とＣａ歩留との関係を示すグラフ
図である。FIG. 1 is a graph showing the relationship between Ca addition rate and Ca yield.
Claims (1)
ムを添加してこの溶鋼が凝固して得られる鋼材中の硫化
物系介在物をカルシウムを含有するものに調整する溶鋼
の取鍋精錬方法において、カルシウムを溶鋼中に３０ｋ
ｇ／分以上の速度で添加することを特徴とする溶鋼の取
鍋精錬方法。Molten steel is tapped from a converter into a ladle, calcium is added to the molten steel in the ladle, and the molten steel is solidified to adjust the sulfide-based inclusions in the steel material to contain calcium. In the ladle refining method, 30k of calcium is added to the molten steel.
A method for refining molten steel in a ladle, characterized by adding the steel at a rate of at least g/min.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20364084A JPS6184316A (en) | 1984-09-28 | 1984-09-28 | Method for refining molten steel in ladle |
| US06/675,947 US4551173A (en) | 1984-07-12 | 1984-11-28 | Method for adjusting composition of molten steel in arc process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20364084A JPS6184316A (en) | 1984-09-28 | 1984-09-28 | Method for refining molten steel in ladle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6184316A true JPS6184316A (en) | 1986-04-28 |
Family
ID=16477392
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20364084A Pending JPS6184316A (en) | 1984-07-12 | 1984-09-28 | Method for refining molten steel in ladle |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6184316A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02166217A (en) * | 1988-12-20 | 1990-06-26 | Metal Res Corp:Kk | Manufacture of low carbon iron-chromium alloy |
-
1984
- 1984-09-28 JP JP20364084A patent/JPS6184316A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02166217A (en) * | 1988-12-20 | 1990-06-26 | Metal Res Corp:Kk | Manufacture of low carbon iron-chromium alloy |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4139369A (en) | Desulphurization of an iron melt | |
| US4268305A (en) | Process for treating liquid steel intended in particular for manufacturing machine wire | |
| GB2043696A (en) | Adjusting carbon contents of steel melts | |
| US5043028A (en) | High silicon, low carbon austemperable cast iron | |
| JPS6184316A (en) | Method for refining molten steel in ladle | |
| JP2000109924A (en) | Method for melting extra-low sulfur steel | |
| DD259001A5 (en) | METHOD FOR PRODUCING PERLITIC CAST SISTERS | |
| JP4180972B2 (en) | Method of adding Bi to molten steel | |
| JPS627814A (en) | Slag coating method | |
| JPS61179811A (en) | Production of clean steel having excellent sulfide corrosion cracking resistance | |
| JPS6184315A (en) | Method for refining molten steel in ladle | |
| RU2179586C1 (en) | Method for making steel in oxygen converter | |
| SU1587070A1 (en) | Method of producing silicomanganese | |
| RU1777609C (en) | Method for production of steel in converter | |
| RU2049115C1 (en) | Method of cast iron desulfurization before converter melting | |
| RU2061761C1 (en) | Method of treating steel in ladle | |
| JPS61199011A (en) | Method for dephosphorizing molten steel | |
| JPH1088216A (en) | Method for desulfurizing molten iron | |
| JP2001098314A (en) | Treating method of molten iron | |
| JPH0480088B2 (en) | ||
| JP2003064409A (en) | Hot metal pretreatment method | |
| SU1726532A1 (en) | Method of steelmaking in converter using phosphoric iron | |
| SU616329A1 (en) | Inoculant | |
| JP2024516544A (en) | Gas atomization of molten steel | |
| JPS5833292B2 (en) | Method of producing different types of molten steel from one molten steel |