JPH0413053B2 - - Google Patents
Info
- Publication number
- JPH0413053B2 JPH0413053B2 JP62240479A JP24047987A JPH0413053B2 JP H0413053 B2 JPH0413053 B2 JP H0413053B2 JP 62240479 A JP62240479 A JP 62240479A JP 24047987 A JP24047987 A JP 24047987A JP H0413053 B2 JPH0413053 B2 JP H0413053B2
- Authority
- JP
- Japan
- Prior art keywords
- cooling drum
- drum
- cooling
- depressions
- slab
- 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 - Lifetime
Links
- 238000001816 cooling Methods 0.000 claims description 59
- 238000009749 continuous casting Methods 0.000 claims description 6
- 238000000034 method Methods 0.000 description 12
- 230000000694 effects Effects 0.000 description 9
- 239000002184 metal Substances 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 8
- 238000007711 solidification Methods 0.000 description 7
- 230000008023 solidification Effects 0.000 description 7
- 238000005266 casting Methods 0.000 description 6
- 238000005336 cracking Methods 0.000 description 4
- 238000003754 machining Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000010583 slow cooling Methods 0.000 description 4
- 230000008602 contraction Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 230000035882 stress Effects 0.000 description 2
- 230000008646 thermal stress Effects 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 206010067482 No adverse event Diseases 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000005058 metal casting Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229910052845 zircon Inorganic materials 0.000 description 1
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 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
- B22D11/0637—Accessories therefor
- B22D11/0648—Casting surfaces
- B22D11/0651—Casting wheels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B27/00—Rolls, roll alloys or roll fabrication; Lubricating, cooling or heating rolls while in use
- B21B27/005—Rolls with a roughened or textured surface; Methods for making same
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、ツインドラム方式、単ドラム方式、
ドアム−ベルド方式等の連続鋳造装置に使用され
る冷却ドラムに関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to a twin drum system, a single drum system,
The present invention relates to a cooling drum used in a continuous casting apparatus such as a door-am-beld method.
近年、金属の連続鋳造の分野では、製造コスト
の切り下げ、新材質の創出などを目的として、最
終形状に近い薄肉鋳片の鋳造技術の開発が強く望
まれている。この要求に対して各種の方法が提案
され、その一部は工業生産のレベルにまで達して
いる。しかし、これまでの方法は、生産性、鋳片
品質確保等の点で未だ充分なものとはいえない。
In recent years, in the field of continuous metal casting, there has been a strong desire to develop casting technology for thin-walled slabs that closely resemble the final shape, with the aim of reducing manufacturing costs and creating new materials. Various methods have been proposed to meet this requirement, some of which have reached the level of industrial production. However, the conventional methods are still not sufficient in terms of productivity, ensuring quality of slabs, etc.
これらの薄肉鋳片の連続鋳造方法の中で構造が
比較的簡単なものとして、鋳造の主構成要素に内
部水冷機構を備えた一対のドラムを使用するツイ
ンドラム方式、一本の冷却ドラムを使用する単ド
ラム方式、冷却ドラムとベルトとの間に湯溜り部
を形成するドラム−ベルト方式等がある。これ等
の鋳造方法においては、鋳片の表面性状を安定し
て高水準に維持することが重要な課題である。す
なわち、これらの連続鋳造方法は、従来の連続鋳
造設備によつて製造されるスラブの場合と異な
り、以後の工程で圧延される度合を小さくするこ
とができる薄肉鋳片を得ることを狙つて、開発さ
れたものである。そのため、薄肉鋳片の表面に肉
厚変動等があると、これが製品表面の欠陥とな
り、商品価値を著しく損なう危険性が大きい。 Among these continuous casting methods for thin-walled slabs, the twin-drum method uses a pair of drums with an internal water-cooling mechanism as the main casting components, and the twin-drum method uses a single cooling drum. There is a single-drum method, which uses a cooling drum, and a drum-belt method, which forms a pool between the cooling drum and the belt. In these casting methods, it is an important issue to stably maintain the surface quality of the slab at a high level. That is, unlike the case of slabs manufactured by conventional continuous casting equipment, these continuous casting methods aim to obtain thin slabs that can reduce the degree of rolling in subsequent steps. It was developed. Therefore, if there is a thickness variation on the surface of a thin slab, this will cause a defect on the surface of the product, and there is a great risk that the product value will be significantly impaired.
そこで、良好な表面品質が鋳片を安定して得る
手段として、種々の方法が検討されている。その
一つとして、冷却ドラムと凝固シエルとの間に断
熱層となるエアギヤツプを形成するように、冷却
ドラムの表面に凹凸を設けることが特開昭60−
184449号公報で提案されている。このエアギヤツ
プによつて、冷却ドラムの抜熱能力が小さくな
り、溶融金属の緩慢な冷却が行われる。その結
果、凝固厚みが板幅方向に均一化され、形状特性
の優れた薄肉鋳片の製造が可能になるとされてい
る。 Therefore, various methods have been studied as means for stably obtaining slabs with good surface quality. One of the methods is to provide unevenness on the surface of the cooling drum so as to form an air gap between the cooling drum and the solidification shell, which serves as a heat insulating layer.
This is proposed in Publication No. 184449. This air gap reduces the heat extraction capacity of the cooling drum, and slow cooling of the molten metal is achieved. As a result, the solidified thickness is made uniform in the plate width direction, making it possible to manufacture thin slabs with excellent shape characteristics.
しかし、本発明者等の実験によれば、冷却ドラ
ムの表面に特定深さの凹凸を均一に付け、それを
初期の常態に維持するようにしただけでは、充分
な効果が安定して得られないことが判つた。たと
えば、冷却ドラムの表面に大きな凹凸を互いに連
続して設けるとき、得られた薄肉鋳片の表面に凹
凸が生成することは勿論、連続している凹凸の部
分において熱応力の集中が促進され、かえつて割
れの発生が助長される。また、冷却ドラムの表面
に線状、角状の凹凸を形状すると、これら凹化の
角の部分が割れの起点となり、薄肉鋳片に多数の
割れが発生する。
However, according to experiments conducted by the present inventors, sufficient effects cannot be stably obtained simply by uniformly forming irregularities of a certain depth on the surface of the cooling drum and maintaining it in the initial normal state. It turns out there isn't. For example, when large irregularities are provided in succession on the surface of a cooling drum, not only irregularities are generated on the surface of the obtained thin slab, but also the concentration of thermal stress is promoted in the continuous irregularities. On the contrary, the occurrence of cracks is promoted. Furthermore, if linear or angular irregularities are formed on the surface of the cooling drum, the corners of these concave portions become starting points for cracks, and many cracks occur in the thin slab.
このようなことから、冷却ドラムの表面に設け
る凹凸の分布の均一性を確保し、凹凸の深さを特
定することはもちろん、凹凸の形状や凹部（窪
み）の大きさが薄肉鋳片の表面性状に大きな影響
を与えることが判つた。 For this reason, it is necessary to ensure the uniformity of the distribution of the unevenness provided on the surface of the cooling drum and to specify the depth of the unevenness, as well as the shape of the unevenness and the size of the recesses (dents) on the surface of the thin slab. It was found that this had a great influence on the properties.
本発明は、この知見に基づき完成されたもので
あり、特定された形状の窪みを冷却ドラムの表面
に設けることによつて、割れ、肉厚変動等のない
優れた表面性状及び形状特性をもつ薄肉鋳片を製
造することを目的とする。 The present invention was completed based on this knowledge, and by providing depressions with a specified shape on the surface of the cooling drum, it has excellent surface properties and shape characteristics without cracks, wall thickness fluctuations, etc. The purpose is to manufacture thin-walled slabs.
本発明の冷却ドラムは、その目的を達成するた
め、直径が0.1〜1.2mmの円形又は長円形の開口部
をもち、深さが５〜100μｍの窪みを、互いに接
することなく均一に鋳型の一部を構成するドラム
表面に形成したことを特徴とする。
In order to achieve this purpose, the cooling drum of the present invention has a circular or oval opening with a diameter of 0.1 to 1.2 mm, and the depressions with a depth of 5 to 100 μm are uniformly aligned with the mold without touching each other. It is characterized by being formed on the surface of the drum that constitutes the section.
ここで重要なことは、本発明における窪みは、
凹凸ではなく、凹部を形成することを意味する点
である。 What is important here is that the depression in the present invention is
This means forming concave portions rather than concave and convex portions.
〔作用〕
本発明の冷却ドラムには、その表面に多数の円
形又は長円形の窪みが形成されている。この冷却
ドラムの表面で凝固シエルが形成されたとき、こ
の窪みは、互いに連続しない独立したエアギヤツ
プを形成する。そのため、このエアギヤツプによ
つて緩冷却された未だ剛性の低い状態にある高温
部分は、凝固シエルの表面上に連続することな
く、互いに分断された分布となつている。そし
て、この周囲を、冷却ドラムに直接接触すること
によつて充分に冷却された剛性の大きな部分が取
り囲む。その結果、剛性の低い部分に集中する熱
応力が小さなものとなり、またその部分が互いに
独立した状態にあるため、凝固シエルの収縮に伴
う割れが複数の剛性の低い部分にまたがつて発生
することがなくなることは勿論、各々の剛性の低
い部分においても割れの発生が抑制される。[Function] The cooling drum of the present invention has a large number of circular or oval depressions formed on its surface. When a solidified shell is formed on the surface of the cooling drum, the depressions form independent air gaps that are not continuous with each other. Therefore, the high-temperature parts, which have been slowly cooled by the air gap and are still in a low rigidity state, are not continuous on the surface of the solidified shell, but are distributed in a separated manner from each other. This is surrounded by a highly rigid portion that is sufficiently cooled by direct contact with the cooling drum. As a result, the thermal stress concentrated in the low-rigidity parts becomes small, and since the parts are independent from each other, cracks due to the contraction of the solidified shell can occur across multiple low-rigidity parts. Not only is this eliminated, but the occurrence of cracks is also suppressed in each portion of low rigidity.
このようにして、互いに連続することのない窪
みを冷却ドラム表面に形成することによつて凝固
シエルの冷却条件を緩和すると共に、局部的に剛
性が低い状態にある部分の応力が集中することに
よる悪影響を抑制している。 In this way, by forming depressions on the surface of the cooling drum that are not continuous with each other, the cooling conditions for the solidified shell are relaxed, and the stress is concentrated in areas where the rigidity is locally low. Controls negative effects.
以下、図面を参照しながら、実施例により本発
明の特徴を具体的に説明する。
Hereinafter, the features of the present invention will be specifically explained using examples with reference to the drawings.
第５図は、本発明が適用されたツインドラム方
式の連続鋳造装置を示す。 FIG. 5 shows a twin-drum continuous casting apparatus to which the present invention is applied.
溶融金属は、タンデイツシユ１等の中間容器か
ら、一対の冷却ドラム２及びサイド堰（図示せ
ず）で仕切られた湯溜り部３に注入される。注入
された溶融金属は、冷却ドラム２の抜熱によつ
て、その表面で冷却・凝固する。このようにし
て、それぞれの冷却ドラム２の表面に形成された
凝固シエルは、冷却ドラム２の回転に伴つて下方
に移動し、キツシングポイント４で圧接、一体化
されて、一枚の薄肉鋳片５として冷却ドラム２の
間から送り出される。この薄肉鋳片５は、ループ
を描きながらピンチロール６に向けて搬送され
る。 Molten metal is poured from an intermediate container such as a tundish 1 into a sump 3 partitioned by a pair of cooling drums 2 and a side weir (not shown). The injected molten metal is cooled and solidified on the surface of the cooling drum 2 by removing heat. In this way, the solidified shells formed on the surface of each cooling drum 2 move downward as the cooling drum 2 rotates, are pressed together at the kissing point 4, and are integrated into a single thin-walled casting. It is sent out from between the cooling drums 2 as a piece 5. This thin slab 5 is conveyed toward the pinch rolls 6 while drawing a loop.
このとき、湯溜り部３の溶融金属と接触する冷
却ドラム２の表面には、第１図に拡大して示すよ
うに、直径が0.1〜1.2mmの円形状開口部をもち、
深さが５〜100μｍの窪み１１が、互いに接する
ことなく、均一に且つ稠密に配置されている。こ
の円形状開口部をもつ窪み１１は、線状、矩形
状、偏平状の開口部をもつ窪みと異なり、割れ発
生の起点となる角の部分がない。また、窪み１１
の開口部としては、円形状の他に、長円形状のも
のも使用される。開口部を長円形とする場合、短
径と長径との比を0.6以上とすることが好ましい。
この場合、短径及び長径のいずれも、0.1〜1.2mm
の範囲に維持する。この意味で、本願明細書にお
ける開口部の直径とは、これら短径及び長径を包
含する意味で使用している。 At this time, the surface of the cooling drum 2 that comes into contact with the molten metal in the sump 3 has a circular opening with a diameter of 0.1 to 1.2 mm, as shown in an enlarged view in FIG.
The depressions 11 having a depth of 5 to 100 μm are arranged uniformly and densely without touching each other. This depression 11 having a circular opening is different from a depression having a linear, rectangular, or flat opening, in that it does not have a corner portion that can be a starting point for cracking. Also, depression 11
In addition to circular openings, oval openings are also used. When the opening is oval, the ratio of the short axis to the long axis is preferably 0.6 or more.
In this case, both the short axis and long axis are 0.1 to 1.2 mm.
Maintain within the range. In this sense, the diameter of the opening in this specification is used to include the short axis and long axis.
本発明者等の実験によると、窪み１１の直径が
0.1mm未満では緩冷却効果が少ないばかりか、ク
リーニングが難しく、ドラム表面の打疵や汚れの
影響を受け易くて、加工も難しい。他方、窪み１
１の直径が1.2mmをこえると、窪み１１自体が微
小割れの起点になり易くなり、かつ、窪み１１に
溶融金属が侵入して、得られた薄肉鋳片の表面に
多数の微細な突起が生成される。また、窪み１１
が5μｍ未満の浅いものであると、そこに形成さ
れるエアギヤツプの断熱効果が著しく低下する。
加えて、窪みに溶湯が侵入して鋳片の表面に多数
の微細な突起が生成され、製品の品質上も好まし
く無い。他方、100μｍを越える深さをもつ窪み
１１にあつては、開口直径1.2mm以下に窪みに関
する限り、効果の増大は認められず、また冷却ド
ラムの表面強度が低下して摩擦量が増加した。 According to experiments conducted by the present inventors, the diameter of the depression 11 is
If it is less than 0.1 mm, not only will it have little slow cooling effect, but it will also be difficult to clean, susceptible to scratches and dirt on the drum surface, and difficult to process. On the other hand, depression 1
If the diameter of 1 exceeds 1.2 mm, the recess 11 itself tends to become a starting point for micro-cracks, and molten metal will penetrate into the recess 11, resulting in many fine protrusions on the surface of the resulting thin slab. generated. Also, depression 11
If the gap is shallow, less than 5 μm, the insulation effect of the air gap formed there will be significantly reduced.
In addition, the molten metal enters into the depressions and many fine protrusions are generated on the surface of the slab, which is unfavorable in terms of product quality. On the other hand, in the case of the recesses 11 having a depth exceeding 100 μm, no increase in the effect was observed as far as the recesses had an opening diameter of 1.2 mm or less, and the surface strength of the cooling drum decreased and the amount of friction increased.
第２図は、窪み１１の開口部の直径及び深さが
鋳片の表面性状に与える影響を表したグラフであ
る。 FIG. 2 is a graph showing the influence of the diameter and depth of the opening of the recess 11 on the surface quality of the slab.
領域Ａの窪みを設けた冷却ドラムを使用して、
薄肉鋳片を鋳造したとき、得られた鋳片は比較的
平滑な表面をもち、ドラム表面に設けた窪みの悪
影響も見られなかつた。ところが、領域Ｂ及びＣ
の窪みを設けた冷却ドラムを使用した場合にあつ
ては、充分なエアギヤツプが確保されないため、
緩冷却の効果がみられず、得られた鋳片には、強
冷却鋳片に顕著に現れる凹み及び連続した割れが
検出された。また、領域Ｄの窪みをもつ冷却ドラ
ムの場合には、冷却ドラムの表面に設けた窪みに
溶融金属が侵入し、ドラム表面の模様が鋳片に転
写され、後続する圧延工程で表面欠陥として残つ
た。更に、領域Ｅの窪みをもつ冷却ドラムでは、
得られた鋳片の表面性状に関する限り領域Ａの場
合と大差なかつたが、使用中に冷却ドラム表面の
窪み形状に変化があり、長時間の鋳造には適さな
かつた。 Using a cooling drum with a depression in area A,
When thin-walled slabs were cast, the slabs obtained had relatively smooth surfaces, and no adverse effects of the depressions formed on the drum surface were observed. However, areas B and C
When using a cooling drum with a recess, a sufficient air gap cannot be secured.
No effect of slow cooling was observed, and in the obtained slab, dents and continuous cracks, which are noticeable in strongly cooled slabs, were detected. In addition, in the case of a cooling drum with depressions in area D, molten metal enters the depressions provided on the surface of the cooling drum, and the pattern on the drum surface is transferred to the slab, which remains as surface defects in the subsequent rolling process. Ivy. Furthermore, in a cooling drum with a depression in area E,
As far as the surface properties of the obtained slab were concerned, it was not much different from that in Area A, but the shape of the depressions on the surface of the cooling drum changed during use, making it unsuitable for long-term casting.
本発明における窪み１１の形状や分布の仕方
は、好適なエアギヤツプを形成する上で大きな影
響をもつ。すなわち、窪み１１の成形には高度な
精度が求められるので、普通の工作機械によるよ
りも、エツチング、放電加工、プラズマ加工、電
子ビーム加工、レーザ加工等によつて窪み１１を
形成することが好ましい。 The shape and distribution of the depressions 11 in the present invention have a great influence on forming a suitable air gap. That is, since a high degree of precision is required for forming the depressions 11, it is preferable to form the depressions 11 by etching, electric discharge machining, plasma machining, electron beam machining, laser machining, etc. rather than by using ordinary machine tools. .
第３図（第１図の−線断面図）は、このよ
うな手段によつて窪みが形成された冷却ドラムの
表面部分を示す。すなわち、冷却ドラム２は、合
金鋼製のスリーブ１２の表面にニツケルメツキ層
１３が形成されており、このニツケルメツキ層１
３に窪み１１が前述した適宜の手段によつて形成
される。尚、窪み１１とは反対側にあるスリーブ
１２の裏面は、水冷面１４とされている。 FIG. 3 (a sectional view taken along the line -- in FIG. 1) shows a surface portion of the cooling drum in which depressions have been formed by such means. That is, in the cooling drum 2, a nickel plating layer 13 is formed on the surface of a sleeve 12 made of alloy steel.
A recess 11 is formed in 3 by the appropriate means described above. Note that the back surface of the sleeve 12 on the opposite side from the recess 11 is a water-cooled surface 14.
この窪み１１を形成することにより、冷却ドラ
ム２の表面で形成された凝固シエルイ１５は、窪
み１１のない部分で冷却ドラム２の表面に直接接
触し、窪み１１のある部分ではエアギヤツプを介
して冷却ドラム２に対向する。このエアギヤツプ
が前述した緩冷却効果をもたらす原因となる。そ
こで、冷却ドラム２の全表面に対するエアギヤツ
プ、換言すれば冷却ドラム２の表面に対する凝固
シエル１５の接触面積率を調整することにより、
冷却ドラム２の冷却能を調整することが可能とな
る。 By forming the depressions 11, the solidified shell 15 formed on the surface of the cooling drum 2 comes into direct contact with the surface of the cooling drum 2 in the areas where the depressions 11 are not present, and is cooled through the air gap in the areas where the depressions 11 are present. It faces drum 2. This air gap causes the slow cooling effect mentioned above. Therefore, by adjusting the air gap with respect to the entire surface of the cooling drum 2, in other words, the contact area ratio of the solidification shell 15 with respect to the surface of the cooling drum 2,
It becomes possible to adjust the cooling capacity of the cooling drum 2.
第４図は、この冷却ドラム２の表面に対する凝
固シエル１５の接触率を、溶融金属が冷却ドラム
に触れて鋳片となり冷却ドラムから離れるまでの
時間、すなわち凝固時間との関係において調べた
ものである。この凝固時間が長くなると、冷却ド
ラムから離れるときの鋳片の厚みが大きくなる。 FIG. 4 shows the contact ratio of the solidified shell 15 with the surface of the cooling drum 2, investigated in relation to the time it takes for molten metal to touch the cooling drum and turn into slabs and leave the cooling drum, that is, the solidification time. be. As this solidification time increases, the thickness of the slab increases when it leaves the cooling drum.
そこで、この凝固時間に対応して、第４図のハ
ツチング領域にある接触面積率をもつ窪み１１付
き冷却ドラム２を使用することにより、所定の肉
厚を確保して、且つ健全な表面性状をもつ薄肉鋳
片が製造される。すなわち、厚肉の鋳片を製造す
るためには凝固時間を長くする必要がある。しか
し、冷却ドラム２と接触している間に鋳片の表面
温度が低下するため、領域Ａで示すように、温度
低下に伴つた熱収縮によつて、鋳片の表面に引張
り応力が加わる結果、脆弱部に割れが発生する。
そこで、領域Ｂに示すように、冷却時間が長い場
合には、接触面積率を小さくすることにより、鋳
片から冷却ドラムに伝わる熱量を少なくし、鋳片
を緩冷却する。その結果、鋳片の表面温度が大き
く下降することがなく、鋳片表面の熱収縮量が低
減され、割れが防止される。しかし、領域Ｃに示
すように、接触面積率を小さくし過ぎると、この
段階にある鋳片の表面層全部が未だ充分な強度を
もつていないため、冷却ドラムを離れた鋳片は、
その形状を維持することができずに、破断するこ
ととなる。 Therefore, by using a cooling drum 2 with recesses 11 having a contact area ratio in the hatched area shown in FIG. 4 in accordance with this solidification time, a predetermined wall thickness can be secured and a healthy surface quality can be achieved. Thin-walled cast slabs are produced. That is, in order to produce thick slabs, it is necessary to increase the solidification time. However, since the surface temperature of the slab decreases while in contact with the cooling drum 2, as shown in area A, tensile stress is applied to the surface of the slab due to thermal contraction accompanying the temperature drop. , cracks occur in the weak parts.
Therefore, as shown in region B, when the cooling time is long, by reducing the contact area ratio, the amount of heat transmitted from the slab to the cooling drum is reduced, and the slab is slowly cooled. As a result, the surface temperature of the slab does not drop significantly, the amount of thermal contraction of the slab surface is reduced, and cracking is prevented. However, as shown in region C, if the contact area ratio is made too small, the entire surface layer of the slab at this stage does not yet have sufficient strength, so the slab leaves the cooling drum.
It will not be able to maintain its shape and will break.
一方、このようにして窪み１１を表面に形成し
た冷却ドラム２を使用して薄肉鋳片を製造すると
き、その窪み１１には酸化物、不純物等が堆積・
付着し易い。このような堆積・付着があると、窪
み１１を設けた効果が低減する。そこで、第５図
に示すように、冷却ドラム２の表面に対向してク
リーニングブラシ７を配置することが好ましい。
このクリーニングブラシ７によつて、冷却ドラム
２の表面、特に窪み１１に堆積している付着物が
除去される。 On the other hand, when manufacturing thin slabs using the cooling drum 2 with the depressions 11 formed on the surface in this way, oxides, impurities, etc. accumulate in the depressions 11.
Easy to adhere. Such deposition/adhesion reduces the effect of providing the depressions 11. Therefore, as shown in FIG. 5, it is preferable to arrange the cleaning brush 7 so as to face the surface of the cooling drum 2.
The cleaning brush 7 removes deposits accumulated on the surface of the cooling drum 2, particularly in the recesses 11.
こうして清浄化された冷却ドラム２の表面に対
し、更にドラムコーター８によつて、ジルコン又
はアルミナ等を主成分とするドラム塗布材を塗布
することもできる。これにより、鋳片の一層と品
質向上とドラム寿命の延長が図られる。 The surface of the cooling drum 2 thus cleaned can be further coated with a drum coating material containing zircon, alumina, or the like as a main component using the drum coater 8. This will further improve the quality of the slab and extend the life of the drum.
以上に説明したように、本発明においては、冷
却ドラムの表面に、それぞれが独立した円形又は
長円形の開口部をもつ窪みを不連続に形成するこ
とによつて、冷却条件を緩和し、平滑な表面をも
つ薄肉鋳片が製造される。また、この窪みは、不
連続であつて、角の部分のない円形又は長円形の
開口部を持つているので、亀裂発生の起点となる
ことがない。したがつて、得られた薄肉鋳片は割
れのない表面性状をもつものとなり、これを後続
する工程で圧延した場合にあつても、割れ、破断
等の問題を生じることがない。
As explained above, in the present invention, by discontinuously forming depressions each having an independent circular or oval opening on the surface of the cooling drum, the cooling conditions are eased and the surface becomes smooth. Thin-walled slabs with a smooth surface are produced. Furthermore, since the depression is discontinuous and has a circular or oval opening with no corners, it does not become a starting point for cracking. Therefore, the obtained thin slab has a crack-free surface quality, and even when it is rolled in a subsequent step, problems such as cracking and breakage do not occur.
第１図は本発明の冷却ドラムの表面に設けた窪
みを示す平面図であり、第２図はその窪みの大き
さが薄肉鋳片の表面性状に与える影響を示し、第
３図は第１図の−線断面図、第４図は凝固時
間及び冷却ドラムの接触面積率が薄肉鋳片の欠陥
発生に与える影響を表し、第５図は本発明の冷却
ドラムを組み込んだツインドラム方式の連続鋳造
機を示す全体図を示している。
FIG. 1 is a plan view showing the depressions provided on the surface of the cooling drum of the present invention, FIG. 2 shows the influence of the size of the depressions on the surface quality of the thin slab, and FIG. Figure 4 shows the influence of solidification time and contact area ratio of the cooling drum on the occurrence of defects in thin slabs, and Figure 5 shows the continuous flow of the twin drum system incorporating the cooling drum of the present invention. 1 shows an overall view of the casting machine.
Claims (1)
をもち、深さが５〜100μｍの窪みを、互いに接
することなく均一に鋳型の一部を構成するドラム
表面に形成したことを特徴とする薄肉鋳片の連続
鋳造装置用冷却ドラム。1. A mold having a circular or oval opening with a diameter of 0.1 to 1.2 mm and a depth of 5 to 100 μm is uniformly formed on the surface of the drum constituting a part of the mold without touching each other. Cooling drum for continuous casting equipment for thin-walled slabs.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62240479A JPS6483340A (en) | 1987-09-24 | 1987-09-24 | Cooling drum for continuous casting apparatus for cast thin slab |
| EP88308808A EP0309247B1 (en) | 1987-09-24 | 1988-09-22 | Cooling drum for continuous-casting machines for manufacturing thin metallic strip |
| ES198888308808T ES2037232T3 (en) | 1987-09-24 | 1988-09-22 | REFRIGERATION DRUM FOR CONTINUOUS CAST MACHINES TO MANUFACTURE THIN METALLIC STRAP. |
| AU22498/88A AU588742B2 (en) | 1987-09-24 | 1988-09-22 | Cooling drum for continuous-casting machines for manufacturing thin metallic strip |
| US07/247,691 US4887662A (en) | 1987-09-24 | 1988-09-22 | Cooling drum for continuous-casting machines for manufacturing thin metallic strip |
| DE8888308808T DE3877675T2 (en) | 1987-09-24 | 1988-09-22 | COOLING DRUM FOR CONTINUOUS CASTING MACHINES FOR THE PRODUCTION OF THIN METAL STRIPS. |
| CA000578351A CA1320333C (en) | 1987-09-24 | 1988-09-23 | Cooling drum for continuous-casting machines for manufacturing thin metallic strip |
| KR1019880012408A KR920000513B1 (en) | 1987-09-24 | 1988-09-24 | Cooling drum for coninuous casting apparatus for cast thin slab |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62240479A JPS6483340A (en) | 1987-09-24 | 1987-09-24 | Cooling drum for continuous casting apparatus for cast thin slab |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6483340A JPS6483340A (en) | 1989-03-29 |
| JPH0413053B2 true JPH0413053B2 (en) | 1992-03-06 |
Family
ID=17060125
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62240479A Granted JPS6483340A (en) | 1987-09-24 | 1987-09-24 | Cooling drum for continuous casting apparatus for cast thin slab |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6483340A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5103895A (en) * | 1989-07-20 | 1992-04-14 | Nippon Steel Corporation | Method and apparatus of continuously casting a metal sheet |
| JP2574471B2 (en) * | 1989-08-03 | 1997-01-22 | 新日本製鐵株式会社 | Cooling drum for continuous casting of thin cast slabs |
| JPH03128149A (en) * | 1989-10-13 | 1991-05-31 | Ishikawajima Harima Heavy Ind Co Ltd | Twin roll type continuous casting machine |
| JP3058185B2 (en) * | 1990-01-12 | 2000-07-04 | 新日本製鐵株式会社 | Austenitic stainless steel continuous cast slab |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62254953A (en) * | 1986-04-30 | 1987-11-06 | Hitachi Ltd | Twin roll type continuous caster |
-
1987
- 1987-09-24 JP JP62240479A patent/JPS6483340A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62254953A (en) * | 1986-04-30 | 1987-11-06 | Hitachi Ltd | Twin roll type continuous caster |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6483340A (en) | 1989-03-29 |
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