JPH01254356A - Continuous casting method by belt caster - Google Patents
Continuous casting method by belt casterInfo
- Publication number
- JPH01254356A JPH01254356A JP32132188A JP32132188A JPH01254356A JP H01254356 A JPH01254356 A JP H01254356A JP 32132188 A JP32132188 A JP 32132188A JP 32132188 A JP32132188 A JP 32132188A JP H01254356 A JPH01254356 A JP H01254356A
- Authority
- JP
- Japan
- Prior art keywords
- belt
- slab
- heat transfer
- solidified shell
- continuous casting
- 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 21
- 238000009749 continuous casting Methods 0.000 title claims abstract description 16
- 239000011810 insulating material Substances 0.000 claims abstract description 7
- 238000005266 casting Methods 0.000 claims abstract description 5
- 229910052751 metal Inorganic materials 0.000 claims description 28
- 239000002184 metal Substances 0.000 claims description 28
- 238000001816 cooling Methods 0.000 claims description 15
- 238000007711 solidification Methods 0.000 claims description 15
- 230000008023 solidification Effects 0.000 claims description 15
- 229910000975 Carbon steel Inorganic materials 0.000 abstract description 8
- 239000010962 carbon steel Substances 0.000 abstract description 8
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 abstract description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract description 5
- 239000011248 coating agent Substances 0.000 abstract description 3
- 238000000576 coating method Methods 0.000 abstract description 2
- 230000001105 regulatory effect Effects 0.000 abstract 2
- 238000007751 thermal spraying Methods 0.000 abstract 2
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 230000008602 contraction Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 229910000831 Steel Inorganic materials 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000009413 insulation Methods 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 238000005336 cracking Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910052582 BN Inorganic materials 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- 229910000655 Killed steel Inorganic materials 0.000 description 1
- RQMIWLMVTCKXAQ-UHFFFAOYSA-N [AlH3].[C] Chemical compound [AlH3].[C] RQMIWLMVTCKXAQ-UHFFFAOYSA-N 0.000 description 1
- 238000013142 basic testing Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005524 ceramic coating Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 230000005499 meniscus Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0605—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two belts, e.g. Hazelett-process
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
この発明はＮ鋳片をベルトキャスターにより製造する方
法に係り、特に表面割れのない品質良好な薄鋳片を安定
して製造する方法に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for manufacturing N slabs using a belt caster, and more particularly to a method for stably manufacturing thin slabs of good quality without surface cracks.
従来の技術
従来の薄鋼板は固定のモールドを用いた縦型のいわゆる
連続鋳造機により製造された鋳片（スラブ）を熱間圧延
、冷間圧延を施して製造されてきた。しかるに近年、薄
板の製造において前記圧延工程を省略するために５０ｍ
ｍ以下の薄鋳片を連続的に鋳造する方法が検討され、上
下一対のベルトを用いたツインベルトキャスター方式の
連続鋳造装置が開発されている。BACKGROUND OF THE INVENTION Conventional thin steel sheets have been produced by hot rolling and cold rolling a slab produced by a so-called vertical continuous casting machine using a fixed mold. However, in recent years, in order to omit the rolling process in the production of thin plates,
A method of continuously casting thin slabs with a thickness of less than m has been studied, and a twin-belt caster type continuous casting device using a pair of upper and lower belts has been developed.
このツインベルトキャスター方式には、傾斜型と水平型
の２種類が代表的であり、溶融金属の給湯方式にもタン
デイツシュ密着方式と、オーバーフロ一方式等の非密着
方式の２種類がある。There are two typical types of this twin belt caster system, an inclined type and a horizontal type, and there are also two types of molten metal hot water supply methods: a tandem-dish contact method and a non-contact method such as an overflow one-way method.
第１図は一般的な傾斜型ツインベルトキャスター方式の
連続鋳造装置を示す概略図で、装置は上下各プーリ（２
Ｘ３）の回転により移動する無端ベルト（１）（１１）
と、上下ベルト間に挟まれ同調回転するダムブロック（
４）により構成され、このベルトキャスターの上下無端
ベルト（１）（１１）間にタンデイツシュ（５）よりオ
ーバーフロ一方式にて溶融金属（６）を注入し、無端ベ
ルト（１）（１１）の移動とともにその注入された溶融
金属（６）を順次冷却凝固させ、凝固した薄鋳片（力を
ピンチロール（図示せず）にて連続的に川辺く方式であ
る。Figure 1 is a schematic diagram showing a general continuous casting machine using inclined twin belt casters.
Endless belt (1) (11) that moves by the rotation of X3)
and a dam block that is sandwiched between the upper and lower belts and rotates synchronously (
4), molten metal (6) is injected between the upper and lower endless belts (1) (11) of this belt caster using an overflow method from the tundish (5), and the endless belts (1) (11) are As it moves, the injected molten metal (6) is sequentially cooled and solidified, and the solidified thin cast slab (force) is continuously passed through the river by pinch rolls (not shown).
なお、図は省略したが、水平型のツインベルトキャスタ
ー方式の連続鋳造装置についても、ベルトが水平に配置
されている点と給湯方式がタンデイツシュ密着方式であ
る点を除けば、傾斜型と同様である。Although the diagram is omitted, the horizontal twin-belt caster type continuous casting equipment is similar to the inclined type, except that the belts are placed horizontally and the hot water supply method is a tandem-touch type. be.
しかるに、ツインベルトキャスター方式の連続鋳造装置
の場合、鋳片の上面と下面の凝固開始位置が異なる鋳造
装置においては、上下の金属ベルトとして材質的に同一
のものを使用した場合、鋳片の凝固熱収縮に伴う上面側
凝固殻の収縮力と下面側凝固殻の収縮力とのアンバラン
スによって鋳片に表面割れが発生するという問題がある
。However, in the case of a twin-belt caster continuous casting machine, where the solidification start positions of the top and bottom surfaces of the slab are different, if the same material is used as the upper and lower metal belts, the solidification of the slab will be delayed. There is a problem in that surface cracks occur in the slab due to an imbalance between the contraction force of the upper solidified shell and the contraction force of the lower solidified shell due to thermal contraction.
第１図に示す傾斜型ツインベルトキャスター方式を例に
とり説明すると、タンデイツシュ（５）内の溶融金属（
６）をオーバーフロー型の樋（５−１）から注入しよう
とすると、上ベルト駆動プーリ（２）を下ベルト駆動プ
ーリ（３）より長ざＬ下げなければならない。Taking the inclined twin belt caster system shown in Fig. 1 as an example, the molten metal (
6) from the overflow type gutter (5-1), the upper belt drive pulley (2) must be lowered by a length L than the lower belt drive pulley (3).
このため、下面側凝固殻（７−１）は上面側凝固殻（７
−２）に比べてＬだけ早く凝固を開始し、上面側凝固殻
（７−２）が形成し始めるａ点では下面側凝固殻（７−
１）はかなり成長しており、下面側のベルト（１１）と
接する凝固殻（７−１）の温度は上面側の凝固初期膜温
度に比べ１５０〜２００’Ｃも低く、上面側凝固殻（７
−２）が収縮しようとする時、下面側凝固殻（７−１）
に拘束され、凝固殻の弱い部分に表面割れを生じること
となる。Therefore, the lower surface side solidified shell (7-1) is the upper surface side solidified shell (7-1).
-2), solidification starts earlier by L, and at point a, where the upper surface side solidified shell (7-2) begins to form, the lower surface side solidified shell (7-2) begins to solidify.
1) has grown considerably, and the temperature of the solidified shell (7-1) in contact with the belt (11) on the lower side is 150 to 200'C lower than the initial solidification film temperature on the upper side. 7
-2) is about to contract, the lower solidified shell (7-1)
This results in surface cracks occurring in weak areas of the solidified shell.
このような現象は、タンデイツシュ密着方式にて溶融金
属を給湯する水平型ツインベルトキャスター方式におい
ても同様である。This phenomenon is also the same in the horizontal twin belt caster system that supplies molten metal in a tandem dish contact system.
したがって、ツインベルトキャスター方式にて薄鋳片を
製造する場合は、下ベルト駆動プーリ（３）と上ベルト
駆動ブー１バ２）との距離（一般にオフセットと称して
いる）Ｌを可及的に小さくして鋳片の上面側と下面側の
凝固を同時進行させることが望ましいが、ベルトキャス
ターの場合は品質を考慮してキャスター内溶融金属プー
ル（６−１）の極力深い位置に溶融金属を注入する必要
があり、また給湯方式がタンデイツシュ密着方式の場合
タンデイツシュ設置スペース等が必要であるため、オフ
セットＬを小ざくするには限界がある。Therefore, when producing thin slabs using the twin belt caster method, the distance L (generally referred to as offset) between the lower belt drive pulley (3) and the upper belt drive pulley (1 bar 2) should be minimized. It is desirable to make the slab smaller so that the upper and lower sides of the cast slab solidify at the same time, but in the case of belt casters, the molten metal should be poured as deep as possible into the molten metal pool (6-1) inside the caster in consideration of quality. There is a limit to how small the offset L can be made.
このオフセットＬが存在する以上、上ベルト（１）およ
び下ベルト（１１）と接する溶融金属の湯境の長さに差
を生じ、前記したような表面割れが生じるのである。As long as this offset L exists, there will be a difference in the length of the molten metal boundary in contact with the upper belt (1) and the lower belt (11), and the above-mentioned surface cracks will occur.
発明が解決しようとする課題
この発明は前に述べた従来の傾斜型あるいは水平型のツ
インベルトキャスターに特有の問題、すなわち材質的に
同一の上下金属ベルトで構成されたツインベルトキャス
ターにおいて、鋳片の上面と下面の凝固開始位置が異な
る場合に、鋳片の凝固熱収縮に伴う上面側凝固殻の収縮
力と下面側凝固殻の収縮力とのアンバランスによって鋳
片に表面割れが発生し、鋳造される薄板の表面品質が不
良となるという問題を解決する連続鋳造方法を提案しよ
うとするものである。Problems to be Solved by the Invention This invention solves the problems specific to the conventional inclined or horizontal twin belt casters mentioned above, namely, in twin belt casters composed of upper and lower metal belts of the same material, cast slab When the solidification start positions of the upper and lower surfaces are different, surface cracks occur in the slab due to an imbalance between the contraction force of the upper solidified shell and the contraction force of the lower solidified shell due to thermal contraction of the slab. This paper attempts to propose a continuous casting method that solves the problem of poor surface quality of thin sheets being cast.
課題を解決するための手段
ツインベルトキャスターにより製造される鋳片の凝固収
縮に起因する表面割れを防止するためには、前記したと
おり鋳片の上面側および下面側の凝固収縮を可及的に同
時に進行させる必要があり、そのためには鋳片の上面側
と下面側の冷却速度に差をつける必要がある。Means for Solving the Problem In order to prevent surface cracks caused by solidification shrinkage of slabs produced by twin belt casters, as mentioned above, it is necessary to minimize solidification shrinkage on the upper and lower sides of the slab. It is necessary to allow the cooling to proceed at the same time, and for this purpose it is necessary to differentiate the cooling rates on the upper and lower surfaces of the slab.
つまり、鋳片下面のみの冷却速度を低下させれば、上ベ
ルト側の溶鋼メニスカス近傍での上下面の凝固殻厚さの
差が小さくなり、上ベルト側凝固殻の収縮時の下ベルト
側凝固殻の拘束による割れの発生を防止できるとの考え
方で種々検討し、テストした結果、上下の金属ベルトの
熱伝達率を変えることによって鋳片下面のみの冷却速度
を低下させることが可能となり、上ベルト側の薄い凝固
殻の割れを防止できることを見い出した。In other words, if the cooling rate of only the lower surface of the slab is reduced, the difference in the thickness of the solidified shell between the upper and lower surfaces near the molten steel meniscus on the upper belt side will become smaller, and the solidified shell on the lower belt side will solidify when the solidified shell on the upper belt side contracts. As a result of various studies and tests based on the idea that cracking due to shell restraint can be prevented, it was found that by changing the heat transfer coefficient of the upper and lower metal belts, it was possible to reduce the cooling rate of only the bottom surface of the slab. It has been discovered that cracking of the thin solidified shell on the belt side can be prevented.
すなわち、この発明は下側ベルトと鋳片間の熱伝達率（
ＨＬ ）と、上側ベルトと鋳片間の熱伝達率（ＨＵ ）
との比（ＨＬ ／Ｈｕ ）が０．１５〜０．８の範囲で
あるベルトを用いることを特徴とし、また下側ベルト表
面に耐火断熱材をコーティングし、鋳片下面側の冷却速
度を鋳片上面側より低下させて鋳片の上面側と下面側の
凝固を可及的に同時進行させることによって、鋳片の上
面側および下面側の凝固殻の厚み差と凝固殻温度差を減
少させることを特徴とするものである。In other words, this invention improves the heat transfer coefficient between the lower belt and the slab (
HL) and the heat transfer coefficient between the upper belt and the slab (HU)
It is characterized by using a belt having a ratio (HL/Hu) in the range of 0.15 to 0.8, and the lower belt surface is coated with a refractory heat insulating material to control the cooling rate of the lower surface of the slab. By lowering the temperature from the top side of the slab to allow solidification of the top and bottom sides of the slab to proceed simultaneously as much as possible, the difference in thickness and temperature of the solidified shell between the top and bottom sides of the slab is reduced. It is characterized by this.
作 用
この発明において、下側ベルトと鋳片間の熱伝達率（Ｈ
Ｌ ＞と、上側ベルトと鋳片間の熱伝達率（ＨＵ ＞と
の比（ＨＬ ／ＨＬＪ ）が０．１５〜０，６０の範囲
のベルトを用いることとしたのは、次に記載する理由に
よる。Function In this invention, the heat transfer coefficient (H
The reason why we decided to use a belt with a ratio (HL/HLJ) between L> and the heat transfer coefficient (HU>) between the upper belt and the slab in the range of 0.15 to 0.60 is as follows. by.
ＨＬ／ＨＬＪが０．１５より小さい場合、下面側の冷却
速度が低下しすぎて下面に割れが生じる。他方Ｈし／Ｈ
ｕが０．６より大きい場合には、鋳片下面側の冷却速度
を上面側の冷却速度に比べて十分に低下させることがで
きず、鋳片上面の割れを防止し得ない。When HL/HLJ is smaller than 0.15, the cooling rate on the lower surface side decreases too much and cracks occur on the lower surface. On the other hand H/H
When u is larger than 0.6, the cooling rate on the lower surface side of the slab cannot be sufficiently lowered compared to the cooling rate on the upper surface side, and cracking on the upper surface of the slab cannot be prevented.
上側の金属ベル１〜は、背面の水冷により鋳型内の溶湯
を下側の金属ベルトより大きい速度で冷却する必要があ
り、材質としては炭素鋼が、また厚みは１〜３ｍが望ま
しい。しかし、下側の金属ベルトより冷却速度が大きけ
れば、材質、厚みとも特に限定しない。The upper metal bell 1~ needs to cool the molten metal in the mold at a higher rate than the lower metal belt by water cooling on the back side, and is preferably made of carbon steel and has a thickness of 1 to 3 m. However, the material and thickness are not particularly limited as long as the cooling rate is higher than that of the lower metal belt.
なお、上側の金属ベルトの材質として炭素鋼が好適な理
由は、経済性、加工性に優れ、かつ断熱効果が小さいた
めである。また、厚みが３ＩｎＩｒ１を超えると剛性が
高く、断熱効果が低下し、経済的にも好ましくなく、他
方、厚みが１ｍＭ未満であると鋳造時の熱負荷により金
属ベルトが破損する危険があるため、上側ベルトの厚み
は１〜３＃が好ましい。Note that carbon steel is suitable as the material for the upper metal belt because it is economical, has excellent workability, and has a small heat insulating effect. In addition, if the thickness exceeds 3InIr1, the rigidity will be high and the insulation effect will decrease, which is economically unfavorable. On the other hand, if the thickness is less than 1 mm, there is a risk that the metal belt will be damaged by the heat load during casting. The thickness of the upper belt is preferably 1 to 3 #.
次に、下側の金属ベルトは、背面の水冷により鋳型内の
溶湯を上側のベルトより小さい冷却速度で冷却する必要
がおり、ベルトの構成として炭素鋼母材の表面に耐火性
断熱材層を被覆したものを用いる。Next, the lower metal belt needs to cool the molten metal in the mold at a lower cooling rate than the upper belt by water cooling on the back side, and the belt has a refractory insulation layer on the surface of the carbon steel base material. Use a coated one.
この下側のベルトに被覆する断熱材層は、下側ベルトの
熱伝達率を小さくして下側ベルト側の凝固殻の成長を抑
制する作用を有するものであり、その材質としては特に
限定するものではないが、断熱効果が大きいアルミナ、
ジルコニア等のセラミックス溶射膜、あるいはカロライ
ズ処理被膜が好ましい。その理由は、これらの被膜が熱
的安定性、耐剥離性に優れるとともに被覆加工が容易な
ためである。The heat insulating layer covering the lower belt has the effect of reducing the heat transfer coefficient of the lower belt and suppressing the growth of solidified shells on the lower belt side, and its material is particularly limited. Alumina has a great heat insulating effect, although it is not a
A sprayed ceramic coating such as zirconia or a colorized coating is preferred. The reason for this is that these films have excellent thermal stability and peeling resistance, and are easy to process.
また、上記断熱層の膜厚としては５０〜３００μｍが望
ましい。その理由は、５０μｍ未満では下ベルト側凝固
殻の成長を抑制するのに十分な断熱効果が得られず、他
方、厚みが３００μｍを超えると金属ベルトの周回部、
すなわちプーリ一部での曲げ応力や溶湯と接触する際の
熱応力で断熱層の一部が剥離する可能性が高くなるため
である。Further, the thickness of the heat insulating layer is preferably 50 to 300 μm. The reason for this is that if the thickness is less than 50 μm, sufficient heat insulation effect cannot be obtained to suppress the growth of the solidified shell on the lower belt side, while if the thickness exceeds 300 μm, the
In other words, there is a high possibility that part of the heat insulating layer will peel off due to bending stress in a part of the pulley or thermal stress when it comes into contact with molten metal.
ところで、上記の上下金属ベルトは鋳片の凝固収縮およ
び熱収縮を円滑に進行させる必要があるので、必要に応
じて黒鉛粉、窒化はう素等の潤滑塗型剤を表面に被覆し
てもよい。By the way, since it is necessary for the above-mentioned upper and lower metal belts to smoothly progress solidification and thermal contraction of the slab, the surface may be coated with a lubricating coating agent such as graphite powder or boron nitride, if necessary. good.
第２図は下ベルト表面に耐火性断熱材としてアルミナを
溶射した場合の鋳片上下面の凝固殻外面温度差を、基礎
テストの結果に基づき計算により求めた結果を示す。こ
の図より、下ベルト表面に断熱材層を設けることにより
鋳片上下面の温度差が減少することがわかる。また、耐
火性断熱材により下面側ベルトに接する溶融金属の冷却
速度が遅くなることにより、下面側凝固殻と上面側凝固
殻の凝固速度差が減少し、その結果上下の凝固殻厚みの
差が減少する。Figure 2 shows the difference in temperature between the outer surface of the solidified shell between the upper and lower surfaces of the slab when alumina is thermally sprayed as a refractory heat insulating material on the surface of the lower belt, calculated based on the results of basic tests. This figure shows that by providing a heat insulating layer on the surface of the lower belt, the temperature difference between the upper and lower surfaces of the slab is reduced. In addition, the refractory insulation slows down the cooling rate of the molten metal in contact with the lower belt, which reduces the solidification rate difference between the lower solidified shell and the upper solidified shell, and as a result, the difference in the thickness of the upper and lower solidified shells decreases. Decrease.
したがって、上面側凝固殻と下面側凝固殻の収縮力はほ
ぼ平衡することになり、上面側凝固殻が収縮しようとす
る時下面側凝固殻に拘束されることがなくなるので、鋳
片表面に割れが発生することがなくなるのである。Therefore, the contraction forces of the upper solidified shell and the lower solidified shell are almost balanced, and when the upper solidified shell tries to contract, it is no longer restrained by the lower solidified shell, so cracks appear on the surface of the slab. will no longer occur.
実 施 例
この発明におけるベルトと鋳片間の熱伝達率（Ｈし＞（
ＨＵ）の算出方法としては、例えば第３図に示す実験装
置を使って求めることができる。Example Heat transfer coefficient between belt and slab in this invention (H>(
HU) can be calculated using, for example, the experimental apparatus shown in FIG.
第３図に示す実験装置は、背面が水冷された薄鋼板製ベ
ルト（２０）上にＭｃｔＯ製の側壁を設けて鋳型（２１
）となし、中に溶１１１］（２２）を注入した時のベル
ト背面および鋳片内部の温度変化をそれぞれ熱電対△、
Ｂにより測定できるｉ造となっている。The experimental apparatus shown in FIG.
) and temperature changes inside the belt and inside the slab when melt 111] (22) was injected into the inside were measured using thermocouples △ and △, respectively.
It has an i structure that can be measured by B.
図中、（２３）はバックアップロール、（２４Ｎ、；冷
却水供給ノズルである。In the figure, (23) is a backup roll, and (24N) is a cooling water supply nozzle.
すなわち、上記実験装置により測定した溶鋼およびベル
ト背面（冷却面側）の温度変化に基づいて、公知の一次
元非定常伝熱計算よりベルトと鋳片間の熱伝達率を求め
るのである。That is, the heat transfer coefficient between the belt and the slab is determined by a known one-dimensional unsteady heat transfer calculation based on the temperature changes of the molten steel and the back surface (cooling surface side) of the belt measured by the above-mentioned experimental device.
次に、第１図に示すような一般的な傾斜型ツインベルト
キャスター方式の連続鋳造装置の上側ベルトを炭素鋼製
と被覆炭素！ｒＡ製とし、下側ベルトをアルミナ溶射層
、ジルコニア溶射層等の断熱材を被覆した炭素鋼製とし
、上下台ベルトと鋳片間の熱伝達率を前記方法により求
め、ＨＬ／ＨＵが０．１５〜０．６０となるように組合
わせて、低炭素アルミキルド鋼の薄鋳片（厚さ５０Ｍ、
幅１３２０ｍ。Next, the upper belt of a typical inclined twin-belt caster type continuous casting machine as shown in Figure 1 was made of carbon steel and coated with carbon! The lower belt is made of carbon steel coated with a heat insulating material such as an alumina sprayed layer and a zirconia sprayed layer.The heat transfer coefficient between the upper and lower stand belts and the slab is determined by the method described above, and HL/HU is 0. 15 to 0.60, and thin slabs of low carbon aluminum killed steel (thickness 50M,
Width: 1320m.
長さ１００ｍ、）を製造し、１ｑられた各鋳片の表面性
状（縦割れ）を調査した結果を、熱伝達率が本発明の範
囲より外れたベルトを用いた場合と、上下ベルト共に炭
素鋼製のベルトを用いた場合と比較して第１表に示す。A belt with a heat transfer coefficient outside the range of the present invention was used, and a belt with a heat transfer coefficient outside the range of the present invention was used. Table 1 shows a comparison with the case where a steel belt is used.
第１表より明らかなごとく、熱伝達率が本発明の範囲を
外れたベルトを用いて製造したもの、および上下ベルト
共に炭素鋼製ベルトを用いて製造したものは、いずれも
鋳片表面に好ましくない縦割れが発生したのに対し、本
発明では溶射層厚が５０μｍの試験陽１と黒鉛層厚が２
０μｍの試験陽７および上ベルトも被覆した試験Ｎｏ、
８に品質的にはほとんど問題とならない縦割れが生じた
のみで、他の薄鋳片には全く縦割れは確認されず、表面
性状の優れたものが得られた。As is clear from Table 1, belts manufactured using belts with heat transfer coefficients outside the range of the present invention, and belts manufactured using carbon steel belts for both the upper and lower belts have favorable effects on the surface of the slab. In contrast, in the present invention, test positive 1 with a sprayed layer thickness of 50 μm and test positive 2 with a graphite layer thickness
Test No. 7 with 0 μm and test No. 7 in which the upper belt was also covered,
No. 8 had only vertical cracks, which were of no problem in terms of quality, and no vertical cracks were observed in the other thin slabs, resulting in excellent surface properties.
以下余白
なお、本実施例は傾斜型のツインベルキャスタ一方式に
対する適用例であるが、鋳片の上面と下面の凝固開始位
置が異なるツインベルト式連続鋳造装置であれば、傾斜
型に限らず水平型や特開昭５８−９０３５６＠公報に開
示されたベルト背面から金属ブロックによるバックアッ
プを行なうもの、おるいは実公昭６１−６９８３号公報
に開示された水平型に似た湾曲型のもの等にも適用でき
ることはいうまでもない。Note: This example is an example of application to a tilted twin-belt caster, but any twin-belt continuous casting machine in which the solidification start positions of the top and bottom surfaces of the slab are different, is applicable not only to the tilted type but also to horizontal Types such as those disclosed in Japanese Unexamined Patent Publication No. 58-90356@ that provide backup with a metal block from the back of the belt, or curved types similar to the horizontal type disclosed in Japanese Utility Model Publication No. 61-6983. Needless to say, it can also be applied.
発明の詳細
な説明したごとく、この発明方法によれば、鋳片の上面
と下面の凝固開始位置が異なるツインベルトキャスター
方式の連続鋳造装置のベルト下面側と上面側の鋳片凝固
殻厚みの差および凝固殻温度の差を減少さけることがで
きるので、鋳片の凝固収縮に起因する表面υｊれを防止
することができ、薄鋳片品質の向上に大なる効果を秦す
るものである。As described in detail, according to the method of the present invention, the difference in the thickness of the solidified slab shell between the belt lower side and the upper side of a twin belt caster type continuous casting machine, in which the solidification start positions of the upper and lower surfaces of the slab are different, can be reduced. Since the difference in the solidified shell temperature can be avoided, surface warping caused by solidification shrinkage of the slab can be prevented, and this has a great effect on improving the quality of the thin slab.
第１図はこの発明の対象とするベルトキャスタ一方式の
連続鋳８設備を示す概略図である。
第２図は同上ベルトキャスターの下ベルト表面に耐火断
熱材としてアルミナを溶射した場合の鋳片上下面の凝固
殻外面温度差をｈ４算により求めた結果を示す図でおる
。
第３図はこの発明における上下金属ベルＩ〜と鋳片間の
熱伝達率を算出するのに用いる実験装置例を示す概略図
である。
１．１１・・・無端ベルｌへ２．３・・・プーリ４・・
・ダムブロック ５・・・タンデイツシュ６・・・
溶融金属 ７・・・薄鋳片出願人 住友金属
工業株式会社
代理人 弁理士 押田良久：”゛２円１・−し１．Ｑ
、’FIG. 1 is a schematic diagram showing eight belt caster one-type continuous casting facilities to which the present invention is applied. FIG. 2 is a diagram showing the results obtained by h4 calculation of the temperature difference between the outer surfaces of the solidified shell between the upper and lower surfaces of the slab when alumina is thermally sprayed as a refractory heat insulating material on the lower belt surface of the same belt caster. FIG. 3 is a schematic diagram showing an example of an experimental apparatus used to calculate the heat transfer coefficient between the upper and lower metal bells I and the slab in this invention. 1.11...To endless bell l2.3...Pulley 4...
・Dam block 5...Tandice 6...
Molten metal 7... Thin slab Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Yoshihisa Oshida: "゛2 yen 1.-shi 1.Q
,'
Claims (1)
鋳片を連続鋳造する方法において、鋳片の上面と下面の
凝固開始位置が異なるツインベルトキャスター方式の連
続鋳造装置の下側ベルトと鋳片間の熱伝達率（Ｈ＿Ｌ）
と、上側ベルトと鋳片間の熱伝達率（Ｈ＿Ｕ）との比（
Ｈ＿Ｌ／Ｈ＿Ｕ）が０．１５〜０．６０の範囲であるベ
ルトを用いることを特徴とするベルトキャスターによる
連続鋳造方法。 ２ 上下一対の回転移動するベルト問に溶融金属を注入し薄
鋳片を連続鋳造する方法において、鋳片の上面と下面の
凝固開始位置が異なるツインベルトキヤスター方式の連
続鋳造装置の下側ベルト表面に耐火断熱材をコーティン
グし、鋳片下面側の冷却速度を鋳片上面側より低下させ
ることを特徴とするベルトキャスターによる連続鋳造方
法。[Scope of Claims] 1. In a method of continuously casting thin slabs by injecting molten metal between a pair of upper and lower rotating belts, continuous casting using a twin-belt caster method in which the solidification start positions of the upper and lower surfaces of the slab are different. Heat transfer coefficient between the lower belt of the equipment and the slab (H_L)
and the heat transfer coefficient (H_U) between the upper belt and the slab (
A continuous casting method using a belt caster, characterized in that a belt having H_L/H_U) in a range of 0.15 to 0.60 is used. 2. In a method of continuously casting thin slabs by injecting molten metal between a pair of upper and lower rotating belts, the lower belt of a twin-belt caster type continuous casting device in which the solidification start positions of the upper and lower surfaces of the slab are different. A continuous casting method using belt casters, characterized in that the surface is coated with a refractory heat insulating material, and the cooling rate of the lower surface of the slab is lower than that of the upper surface of the slab.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32132188A JPH01254356A (en) | 1987-12-23 | 1988-12-19 | Continuous casting method by belt caster |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62-327678 | 1987-12-23 | ||
| JP32767887 | 1987-12-23 | ||
| JP32132188A JPH01254356A (en) | 1987-12-23 | 1988-12-19 | Continuous casting method by belt caster |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01254356A true JPH01254356A (en) | 1989-10-11 |
Family
ID=26570431
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32132188A Pending JPH01254356A (en) | 1987-12-23 | 1988-12-19 | Continuous casting method by belt caster |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01254356A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004037466A1 (en) * | 2002-10-24 | 2004-05-06 | Heinrich Tanner | Method and roll-type continuous casting machine for the production of a metal strip |
| CN107755652A (en) * | 2017-09-01 | 2018-03-06 | 燕山大学 | A kind of non-crystaline amorphous metal twin-belt caster and its continuous casing |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01118346A (en) * | 1987-10-29 | 1989-05-10 | Sumitomo Heavy Ind Ltd | Casting method and device by twin belt caster of steel |
-
1988
- 1988-12-19 JP JP32132188A patent/JPH01254356A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01118346A (en) * | 1987-10-29 | 1989-05-10 | Sumitomo Heavy Ind Ltd | Casting method and device by twin belt caster of steel |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004037466A1 (en) * | 2002-10-24 | 2004-05-06 | Heinrich Tanner | Method and roll-type continuous casting machine for the production of a metal strip |
| CN107755652A (en) * | 2017-09-01 | 2018-03-06 | 燕山大学 | A kind of non-crystaline amorphous metal twin-belt caster and its continuous casing |
| CN107755652B (en) * | 2017-09-01 | 2019-09-10 | 燕山大学 | A kind of amorphous alloy twin-belt caster and its continuous casing |
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