JPS5938065B2 - Electromagnetic stirring method for slabs in continuous casting - Google Patents
Electromagnetic stirring method for slabs in continuous castingInfo
- Publication number
- JPS5938065B2 JPS5938065B2 JP1273677A JP1273677A JPS5938065B2 JP S5938065 B2 JPS5938065 B2 JP S5938065B2 JP 1273677 A JP1273677 A JP 1273677A JP 1273677 A JP1273677 A JP 1273677A JP S5938065 B2 JPS5938065 B2 JP S5938065B2
- Authority
- JP
- Japan
- Prior art keywords
- slab
- continuous casting
- mold
- curved
- electromagnetic stirring
- 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.)
- Expired
Links
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- Continuous Casting (AREA)
- Mixers With Rotating Receptacles And Mixers With Vibration Mechanisms (AREA)
Description
【発明の詳細な説明】
この発明は、鋳型から単一彎曲半径で彎曲している装置
高さの低い連続鋳造設備により連続鋳造されるスラブの
鋳造組織を改善するための電磁攪拌方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic stirring method for improving the casting structure of a slab that is continuously cast by continuous casting equipment with a low height and curved from a mold with a single radius of curvature.
一般に鋳型から単一彎曲半径で彎曲している連続鋳造設
備は、設備高さが低いため設備費が安く、しかも2次冷
却帯長さを長くでき、鋳造速度を増すことができる等多
くの利点があるため近年多く採用されている。In general, continuous casting equipment that curves from the mold with a single radius of curvature has many advantages, such as low equipment costs due to the low equipment height, and the ability to increase the length of the secondary cooling zone and increase casting speed. Because of this, it has been widely adopted in recent years.
この彎曲型連続鋳造設備は、たとえば短辺が130〜3
00 mvt、長辺が900〜2600771帳度の大
型スラブを連続鋳造する場合には長辺の広巾の側面が単
一円弧の曲面を描きながら引抜かれる。This curved continuous casting equipment, for example, has a short side of 130 to 3
When continuously casting a large slab with a length of 00 mvt and a length of 900 to 2,600,771 on the long side, the wide side surface of the long side is drawn out while drawing a curved surface of a single arc.
この広巾の曲面は、一般にはロールで支持されているが
、これはスラブの末凝固部における溶鋼静圧に凝固殻が
耐えきれず、膨れようとするのを押えつけるのと、スラ
ブが設定された彎曲面に沿って円滑に移動させる案内装
置の役割りをもつものである。This wide curved surface is generally supported by rolls, but this is to suppress the solidified shell from expanding due to the static pressure of the molten steel in the final solidified part of the slab, and to prevent the slab from expanding. It functions as a guide device that allows smooth movement along curved surfaces.
このように広巾のスラブを連続鋳造すると、ロールと接
触していない部分でスラブは膨張し、ロールと接触して
いる部分でスラブは圧縮される。When a wide slab is continuously cast in this manner, the slab expands in the portion not in contact with the rolls, and is compressed in the portions in contact with the rolls.
このように膨張と圧縮が繰返されると、スラブ中心部に
炭素、いおう、りん等が大きく偏析し、成品の商品価値
を著しく低下させるとともに、機械的性質にも悪影響を
及ぼす。When expansion and compression are repeated in this way, carbon, sulfur, phosphorus, etc. are largely segregated in the center of the slab, which significantly reduces the commercial value of the finished product and also adversely affects the mechanical properties.
この中心偏析は鋳片中心部に等軸晶を多く生成させるこ
とによって軽減できることは、すでに知られており、こ
の等軸晶を多く生成させる方法の一つとして、スラブの
凝固途中において内部の末凝固部分を電磁攪拌する方法
が提案されている。It is already known that this center segregation can be reduced by producing a large number of equiaxed crystals in the center of the slab. A method has been proposed in which the solidified portion is electromagnetically stirred.
しかし、大型スラブの連続鋳造機、特に鋳型から単一彎
曲半径で1/4円周までスラブを支持案内する連続鋳造
機において、電磁石を使って電磁攪拌するには、ロール
を取外して電磁石を設置するため、ロールに代わるべき
支持案内装置が必要で設備費が高くなり、又彎曲面を維
持して電磁石を組込むには相当な無理が生ずる。However, in continuous casting machines for large slabs, especially in continuous casting machines that support and guide slabs from the mold to 1/4 of the circumference with a single radius of curvature, in order to perform electromagnetic stirring using electromagnets, the rolls must be removed and the electromagnets installed. Therefore, a supporting and guiding device is required to replace the roll, which increases the equipment cost, and it is also extremely difficult to incorporate the electromagnet while maintaining the curved surface.
この発明は、彎曲型連続鋳造機の電磁攪拌におけるかか
る欠点を解消するため、永久磁石を用いて、スラブの未
凝固溶融部分に静止磁場を作用させることを特徴とする
末凝固溶融金属の攪拌方法を提案するものである。In order to eliminate such drawbacks in the electromagnetic stirring of a curved continuous casting machine, this invention provides a method for stirring partially solidified molten metal, which is characterized by applying a static magnetic field to the unsolidified molten portion of a slab using a permanent magnet. This is what we propose.
次に、この発明の一実施例を図面について説明する。Next, an embodiment of the present invention will be described with reference to the drawings.
第1図はスラブを連続鋳造するための彎曲型連続鋳造機
の要部を示すもので、1は鋳型、2はスラブ、3は2次
冷却帯において単一彎曲半径で1/4円周までスラブを
支持案内するローラエプロンを形成するローラ群である
。Figure 1 shows the main parts of a curved continuous casting machine for continuous casting of slabs, where 1 is the mold, 2 is the slab, and 3 is the secondary cooling zone with a single curved radius up to 1/4 circumference. A group of rollers forming a roller apron that supports and guides the slab.
前記ローラ群の任意個所においてローラ3□、3□間に
永久磁石4,4′を設ける。Permanent magnets 4, 4' are provided between the rollers 3□, 3□ at arbitrary locations in the roller group.
この永久磁石は一つの磁極面が鋳片表面に対向し、かつ
近接して置かれ、さらにスラブ2を挟んで両面に対向す
る永久磁石4,4′の磁極が互に逆となるように設けら
れる。This permanent magnet is arranged so that one magnetic pole face faces the slab surface and is placed close to it, and the magnetic poles of permanent magnets 4 and 4', which face both sides with the slab 2 in between, are opposite to each other. It will be done.
又各永久磁石は鋳片の巾方向全長にわたるように複数の
永久磁石のN極とS極が交互に鋳片表面に対向するよう
にして継鉄にて接続し磁気回路を構成してもよい。Further, each permanent magnet may be connected with a yoke so as to form a magnetic circuit so that the N and S poles of the plurality of permanent magnets alternately face the surface of the slab so as to span the entire length in the width direction of the slab. .
前記永久磁石は残留磁束密度Brが5〜l0KG、保磁
力Hcが5〜10KOeで最大エネルギー積(BrHc
)maxが大きいものが適しており、YCo5CeCo
5tPrCo5.SmCo5tSmCo5tS等の成分
をもつ希土類コバルト磁石が最適である。The permanent magnet has a residual magnetic flux density Br of 5 to 10 KG, a coercive force Hc of 5 to 10 KOe, and a maximum energy product (BrHc
) max is suitable, YCo5CeCo
5tPrCo5. A rare earth cobalt magnet having components such as SmCo5tSmCo5tS is optimal.
そして、ローラ3、と3□にはそれぞれ通電用ブラシ5
,5を設け、各ブラシを直流電源回路に接続し、通電の
際電流が通電用ブラシ5、ローラ3□からスラブ内を通
りローラ32、通電用ブラシ5へ流れるように構成する
。Then, rollers 3 and 3□ are each equipped with energizing brushes 5.
.
この直流回路は電流が他のローラから漏洩するのを防止
するため、各ローラは軸受部分で連続鋳造機本体から絶
縁される。In order to prevent current from leaking from other rollers in this DC circuit, each roller is insulated from the continuous casting machine body at the bearing portion.
この装置により連続鋳造すれば、鋳型1より引抜かれ2
次冷却帯部分で凝固途中のスラブ2には、第2図に示す
ように相対向する永久磁石4,4′により主方向が引抜
き方向と直角の静止磁界6が作用する(図にはスラブの
両面にそれぞれ2個の永久磁石を継鉄に固着した場合を
示した)。If continuous casting is performed using this device, 2
As shown in Fig. 2, a stationary magnetic field 6 whose main direction is perpendicular to the drawing direction is applied to the slab 2, which is in the middle of solidification in the next cooling zone, by opposed permanent magnets 4 and 4'. The case where two permanent magnets are fixed to the yoke on each side is shown).
一方前記直流回路への通電により、スラブ内部には主方
向がスラブの引抜き方向と同じ方向に直流電流7が流れ
る。On the other hand, by energizing the DC circuit, a DC current 7 flows inside the slab in the same direction as the direction in which the slab is pulled out.
すると前記静止磁界5との相互作用によりスラブ2の末
凝固溶融金属にはスラブ巾方向の電磁力Fが作用し、末
凝固溶融金属は撹拌され、スラブ中心部の偏析は解消す
る。Then, due to the interaction with the static magnetic field 5, an electromagnetic force F in the width direction of the slab acts on the unsolidified molten metal of the slab 2, the unsolidified molten metal is stirred, and the segregation at the center of the slab is eliminated.
前記はスラブの両面のそれぞれ1個所に永久磁石4,4
′を設けた場合について説明したが、第3図に示すよう
に複数個の永久磁石41,4□、43゜44 t 41
’ ? 42’ t 43’ 544/を対設し、最上
部の永久磁石4□、4□′に相対する上側のローラ3□
。In the above, permanent magnets 4, 4 are placed at one location on each side of the slab.
′ was explained, but as shown in FIG. 3, a plurality of permanent magnets 41, 4
' ? 42' t 43' 544/ are arranged oppositely, and the upper roller 3□ faces the uppermost permanent magnets 4□, 4□'.
.
3、′と最下部の永久磁石44 t 44’に相対する
下側のローラ3□、32′にそれぞれ通電用ブラシ5,
5を設け、各ブラシを直流電源回路に接続し、スラブの
末凝固溶融金属に上下複数個所でスラブ巾方向の電磁力
Fを作用させ、複数個所で同時に攪拌することもできる
。3,' and the lower rollers 3□, 32' facing the lowermost permanent magnet 44t44' are respectively provided with energizing brushes 5,
5, each brush is connected to a DC power supply circuit, and electromagnetic force F is applied in the width direction of the slab at multiple locations above and below the solidified molten metal of the slab to simultaneously stir the metal at multiple locations.
なお、この発明において2次冷却帯における攪拌位置を
スラブ表面温度が800℃以上にある彎曲部分に限定し
たのは、末凝固溶融金属の電磁攪拌が十分に行われ、す
ぐれた偏析解消効果を得るために必要である。In addition, in this invention, the stirring position in the secondary cooling zone is limited to the curved part where the slab surface temperature is 800°C or higher, so that sufficient electromagnetic stirring of the final solidified molten metal can be achieved and an excellent segregation elimination effect can be obtained. It is necessary for
実施例
160を転炉で連続して溶製した3チヤージの低炭素ア
ルミ−けい素キルド鋼(成分:炭素0.16%、けい素
0.3%、マンガン1.45%、り肋、018%、いお
う0.013%、残り鉄)を2ストランドの彎曲半径1
0mの彎曲型スラブ連続鋳造機にて連続して、鋳込温度
1540℃、引抜き速度0.8 m /minの条件で
鋳込み、断面寸法が190 miX1600mmのスラ
ブを各ストランド240を製造した。3-charge low carbon aluminum-silicon killed steel manufactured by continuously melting Example 160 in a converter (components: 0.16% carbon, 0.3% silicon, 1.45% manganese, ribs, 018 %, sulfur 0.013%, remaining iron), the radius of curvature of 2 strands is 1
Each strand 240 was manufactured into a slab having a cross-sectional dimension of 190 mi x 1600 mm by continuously casting in a 0 m curved slab continuous casting machine at a casting temperature of 1540° C. and a drawing speed of 0.8 m /min.
この際第1ストランドのスラブは、この発明の実施によ
り、スラブの厚さ方向中央相当位置での磁束密度がIK
Gの永久磁石を鋳型上面より450ぼ、475cm及び
530cm、560CrrL離れた4個所に、第3図に
示した状態で配設し、又ローラエプロンの上から10番
目と15番目のローラに通電用ブラシを設置し、引抜き
方向に電圧20V、電流5500Aの直流電流を流して
未凝固部を攪拌しながら凝固させた。At this time, by implementing the present invention, the first strand slab has a magnetic flux density of IK at a position corresponding to the center in the thickness direction of the slab.
G permanent magnets were placed at four locations 450 cm, 475 cm, 530 cm, and 560 CrrL away from the top of the mold as shown in Figure 3, and the 10th and 15th rollers from the top of the roller apron were energized. A brush was installed, and a DC current of 20 V and 5500 A was applied in the drawing direction to solidify the unsolidified portion while stirring.
他方の第2ストランドのスラブは電磁攪拌を行わずに通
常の方法で凝固させた。The other second strand slab was solidified in the usual manner without electromagnetic stirring.
そして、鋳込開始後10mの個所より試験片を切り出し
、横断面のサルファプリント及びスラブ厚み方向の成分
分布を調ベスラブ中心部の偏析状況を調査した。Then, a test piece was cut out from a point 10 m after the start of casting, and the sulfur print on the cross section and the component distribution in the thickness direction of the slab were examined, and the segregation situation at the center of the slab was investigated.
その結果を第4図に示す。この第4図はスラブ厚み方向
のりんの分布状況を示したものであるが、線Aはこの発
明の実施による第1ストランドスラブの試料、線Bは電
磁攪拌を行なわない第2ストランドスラブの試料のりん
分布である。The results are shown in FIG. This Figure 4 shows the distribution of phosphorus in the thickness direction of the slab, where line A is a sample of the first strand slab according to the present invention, and line B is a sample of the second strand slab without electromagnetic stirring. This is the phosphorus distribution.
この図から明らかなように、電磁攪拌を行なわなかった
ものは中心部に太きなりん偏析が存在しているに対し、
この発明の実施により電磁攪拌したものは全体的にほと
んど偏析がないことがわかる。As is clear from this figure, in the case where electromagnetic stirring was not performed, there was a thick phosphorus segregation in the center.
It can be seen that there is almost no segregation overall in the electromagnetically stirred product according to the present invention.
【図面の簡単な説明】
第1図はこの発明の実施による彎曲型連続鋳造機の要部
を示す斜視図、第2図は同上永久磁石設置部の横断面図
、第3図はこの発明の他の実施による彎曲型連続鋳造機
の要部を示す斜視図、第4図はスラブのりん偏析状況を
示す図表である。
図中、1・・・・・・鋳型、2・・・・・・スラブ、3
・・・・・・ローラ、4・・・・・・永久磁石、5・・
・・・・通電用ブラシ、6・・・・・・静止磁界、7・
・・・・・直流電流、F・・・・・・電磁力、線A・・
・・・・この発明の実施による試料、線B・・・・・・
比較例の試料。[Brief Description of the Drawings] Fig. 1 is a perspective view showing the main parts of a curved continuous casting machine according to the present invention, Fig. 2 is a cross-sectional view of the permanent magnet installation part of the same, and Fig. 3 is a perspective view showing the main parts of a curved continuous casting machine according to the present invention. FIG. 4 is a perspective view showing the main parts of a curved continuous casting machine according to another embodiment, and a chart showing the phosphorus segregation situation in the slab. In the diagram, 1...Mold, 2...Slab, 3
...Roller, 4...Permanent magnet, 5...
...Electrifying brush, 6...Static magnetic field, 7.
...DC current, F...electromagnetic force, line A...
...Sample according to the implementation of this invention, line B...
Comparative sample.
Claims (1)
された状態で鋳型から引出して単一彎曲半径で連続鋳造
する際、鋳型から引出されたスラブの表面が800℃以
上の高温状態にある彎曲部分の、彎曲部の上面及び下面
のそれぞれのスラブ案内支持用ローラ間にスラブ表面に
近接し、かつ互に逆極性の磁極面を対向した永久磁石を
対設して主方向がスラブ厚さ方向の静止磁場を作用させ
、前記永久磁石の上流側と下流側に位置するローラ間に
直流電流を流し、前記静止磁場と直流電流とにより鋳片
の巾方向に電磁力を作用させてスラブ内部の末凝固部分
を電磁攪拌することを特徴とする連続鋳造におけるスラ
ブの電磁攪拌方法。1. When pouring molten steel into a curved mold and pulling it out from the mold with a solidified shell formed on its outer surface for continuous casting with a single radius of curvature, the surface of the slab pulled out of the mold is at a high temperature of 800°C or higher. Permanent magnets are placed close to the slab surface between the slab guiding and supporting rollers on the upper and lower surfaces of the curved part, and have magnetic pole faces of opposite polarity facing each other, so that the main direction is the thickness of the slab. A static magnetic field is applied in the direction, a direct current is passed between the rollers located upstream and downstream of the permanent magnet, and the static magnetic field and the direct current cause an electromagnetic force to act in the width direction of the slab, and the inside of the slab is A method for electromagnetically stirring a slab in continuous casting, characterized by electromagnetically stirring the final solidified portion of the slab.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1273677A JPS5938065B2 (en) | 1977-02-07 | 1977-02-07 | Electromagnetic stirring method for slabs in continuous casting |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1273677A JPS5938065B2 (en) | 1977-02-07 | 1977-02-07 | Electromagnetic stirring method for slabs in continuous casting |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5397933A JPS5397933A (en) | 1978-08-26 |
JPS5938065B2 true JPS5938065B2 (en) | 1984-09-13 |
Family
ID=11813710
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1273677A Expired JPS5938065B2 (en) | 1977-02-07 | 1977-02-07 | Electromagnetic stirring method for slabs in continuous casting |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5938065B2 (en) |
-
1977
- 1977-02-07 JP JP1273677A patent/JPS5938065B2/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
JPS5397933A (en) | 1978-08-26 |
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