JP2003112235A - CONTINUOUS CASTING METHOD FOR HIGH Cr- AND HIGH Al- CONTAINING STEEL - Google Patents
CONTINUOUS CASTING METHOD FOR HIGH Cr- AND HIGH Al- CONTAINING STEELInfo
- Publication number
- JP2003112235A JP2003112235A JP2002207805A JP2002207805A JP2003112235A JP 2003112235 A JP2003112235 A JP 2003112235A JP 2002207805 A JP2002207805 A JP 2002207805A JP 2002207805 A JP2002207805 A JP 2002207805A JP 2003112235 A JP2003112235 A JP 2003112235A
- Authority
- JP
- Japan
- Prior art keywords
- mass
- molten steel
- steel
- coordinate
- 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.)
- Granted
Links
Landscapes
- Continuous Casting (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、高Ｃｒ及び高Ａｌ
含有鋼の連続鋳造方法に関する。TECHNICAL FIELD The present invention relates to high Cr and high Al.
The present invention relates to a continuous casting method for containing steel.
【０００２】[0002]
【従来の技術】一般に、ステンレス鋼板等のＣｒ含有鋼
は、図３（ａ）及び（ｂ）に工程を示すが、精錬後の溶
鋼を鋳型に鋳造して一旦インゴットにした後、分塊圧延
して長方形で所定サイズの鋼鋳片（以下、スラブとい
う）とするか、あるいは溶鋼を連続鋳造して直接スラブ
とし、そのスラブに熱間圧延及び冷間圧延を順次施して
製造される。2. Description of the Related Art Generally, for a Cr-containing steel such as a stainless steel plate, the steps are shown in FIGS. 3 (a) and 3 (b). Molten steel after refining is cast in a mold and once made into an ingot, followed by slab rolling. Then, a rectangular steel slab having a predetermined size (hereinafter referred to as a slab) is formed, or molten steel is continuously cast to directly form a slab, and the slab is sequentially subjected to hot rolling and cold rolling.
【０００３】ところで、Ｃｒ及びＡｌ含有量の多い溶鋼
は、これまで前記造塊法にてスラブを製造している。し
かしながら、造塊法は、工程が多くて時間がかかるの
で、生産性が低いばかりでなく、分塊工程でスラブに形
成する前の鋼鋳片から形状不良部分を切り捨てる必要が
あり、溶鋼歩留まりが低いという問題がある。また、ス
ラブに非金属介在物が多く含まれ、それに起因して表面
疵が多くなるという問題もある。By the way, slabs of molten steel containing a large amount of Cr and Al have been manufactured by the above-mentioned ingot making method. However, since the ingot-making method has many steps and takes a long time, not only the productivity is low, but also it is necessary to cut off the defective shape portion from the steel slab before forming into the slab in the slab-making step, which results in a molten steel yield. There is a problem of being low. There is also a problem that the slab contains a lot of non-metallic inclusions, which causes a large number of surface defects.
【０００４】従って、経済的な見地から判断すると、手
間がかからず且つ迅速にスラブが得られる連続鋳造法の
採用が望ましい。しかしながら、Ｃｒ及びＡｌ含有量の
多い溶鋼の連続鋳造法にも、現在のところ、以下に述べ
るような問題がある。Therefore, from an economical point of view, it is desirable to adopt a continuous casting method that can obtain a slab quickly and with little effort. However, the continuous casting method for molten steel containing a large amount of Cr and Al has the following problems at present.
【０００５】それは、溶鋼を鋳型に鋳込む初期に、溶鋼
を覆うモールド・パウダーが溶融不足で溶鋼中に巻き込
まれたり、凝固した殻（シェルと称する）の鋳型への付
着に起因して、ブレーク・アウト（凝固開始した鋼鋳片
の殻を破って溶鋼が溢れ出る現象）を多発することであ
る。また、鋳込みが定常的になった時期でも、鋼鋳片の
表面に縦割れやコーナ部に小ブレークアウトが多量に生
じたり、その後の熱間圧延の初期にスラブが破断したり
する。加えて、熱間圧延や冷間圧延後にコイル状に巻き
取られた鋼帯の表面に疵が多発し、製品として使用出来
ないため溶鋼歩留まりが低いという問題がある。これ
は、一般の炭素鋼やＳＵＳ４３０，ＳＵＳ３０４等のス
テンレス鋼を鋳造する場合と同様に、連続鋳造で使用し
たモールド・パウダーの組成選択の不適正が一因になっ
ている。しかしながら、本願が対象としている鋼種は、
上記のような鋼種に比べてＡｌ含有量が多いため、鋳造
中にモールド・パウダーのＡｌ2Ｏ3濃度が大きく変化
し、その粘度や溶融温度等が変化してしまうことにも原
因があると考えられる。In the early stage of casting the molten steel into the mold, a breakage occurs due to the mold powder covering the molten steel being caught in the molten steel due to insufficient melting, or the solidified shell (referred to as shell) adhering to the mold.・ Out is a frequent occurrence (a phenomenon in which molten steel overflows by breaking the shell of a steel slab that has started to solidify). Further, even when the casting becomes steady, vertical cracks occur on the surface of the steel slab, a large amount of small breakouts occur at the corners, and the slab ruptures in the initial stage of hot rolling thereafter. In addition, there is a problem that the yield of molten steel is low because many defects occur on the surface of the steel strip wound into a coil after hot rolling or cold rolling, and the steel strip cannot be used as a product. This is partly due to the improper selection of the composition of the mold powder used in continuous casting, as in the case of casting general carbon steel or stainless steel such as SUS430 and SUS304. However, the steel types targeted by this application are:
Since the Al content is higher than that of the above steel grades, the Al 2 O 3 concentration of the mold powder changes greatly during casting, which may cause the viscosity and melting temperature to change. Conceivable.
【０００６】[0006]
【発明が解決しようとする課題】本発明は、かかる事情
に鑑み、Ｃｒ及びＡｌの含有量が多くても、鋳造時に操
業トラブルの発生が低減でき、また得られたスラブに縦
割れやヘゲ状欠陥の発生が従来に比べて少ない高Ｃｒ及
び高Ａｌ含有鋼の連続鋳造方法を提供することを目的と
している。In view of the above circumstances, the present invention can reduce the occurrence of operational troubles during casting even if the contents of Cr and Al are large, and the obtained slab has vertical cracks and shavings. It is an object of the present invention to provide a continuous casting method for high-Cr and high-Al-containing steel, in which the occurrence of shape defects is less than in the conventional case.
【０００７】[0007]
【課題を解決するための手段】発明者は、上記目的を達
成するため、高Ｃｒ及び高Ａｌ含有鋼を連続鋳造する場
合の問題点を鋭意検討し、その対策を本発明に具現化し
た。In order to achieve the above object, the inventor diligently studied the problems in the case of continuously casting high Cr and high Al content steels, and realized the measures in the present invention.
【０００８】すなわち、本発明は、Ｃ≦０．０２質量
％，Ｎ≦０．０２質量％，Ｓｉ≦１．０質量％，Ｍｎ≦
１．０質量％，Ｎｉ≦０．５質量％，Ｃｕ≦０．５質量
％，Ｃｒ：１０〜３０質量％，Ａｌ：１．０〜１０．０
質量％，Ｔｉ≦０．０５質量％，Ｃａ≦０．０５質量
％，Ｍｇ≦０．０５質量％を含み，残部が不可避不純物
及びＦｅからなる溶鋼を、タンディッシュを介して鋳型
に注ぎ、凝固した鋼鋳片を連続的に鋳型より引き抜く高
Ｃｒ及び高Ａｌ含有鋼の連続鋳造方法において、溶鋼の
過熱度（Ｘ；℃）と鋳造速度（Ｙ；ｍ／ｍｉｎ）とを、
下記の６座標で囲む領域内及び外郭線上で、前記溶鋼を
鋳造することを特徴とする高Ｃｒ及び高Ａｌ含有鋼の連
続鋳造方法である。That is, according to the present invention, C ≦ 0.02% by mass, N ≦ 0.02% by mass, Si ≦ 1.0% by mass, Mn ≦
1.0 mass%, Ni ≦ 0.5 mass%, Cu ≦ 0.5 mass%, Cr: 10 to 30 mass%, Al: 1.0 to 10.0
Mass steel, Ti ≤ 0.05 mass%, Ca ≤ 0.05 mass%, Mg ≤ 0.05 mass%, molten steel consisting of inevitable impurities and Fe as the balance is poured into a mold through a tundish and solidified. In a continuous casting method for high Cr and high Al content steel in which the formed steel slab is continuously drawn from the mold, the superheat degree (X; ° C) of the molten steel and the casting speed (Y; m / min) are
It is a continuous casting method for high Cr and high Al content steel, characterized in that the molten steel is cast in a region surrounded by the following 6 coordinates and on an outer line.
【０００９】座標Ａ（Ｘ＝０．３、Ｙ＝１００）、座標
Ｂ（Ｘ＝０．８、Ｙ＝１００）、座標Ｃ（Ｘ＝１．２、
Ｙ＝６０），座標Ｄ（Ｘ＝１．２，Ｙ＝３０），座標Ｅ
（Ｘ＝０．５，Ｙ＝３０），座標Ｆ（Ｘ＝０．３，Ｙ＝
５０）
この場合、前記溶鋼は、Ｌａ，Ｈｆ，Ｙ，Ｐｒ，Ｎｄ，
Ｚｒ，Ｃｅ，Ｓｍ及びＢから選ばれた１種又は２種以上
の元素を合計でさらに０．００５〜０．２００質量％含
有するのが好ましい。Coordinate A (X = 0.3, Y = 100), Coordinate B (X = 0.8, Y = 100), Coordinate C (X = 1.2,
Y = 60), coordinate D (X = 1.2, Y = 30), coordinate E
(X = 0.5, Y = 30), coordinate F (X = 0.3, Y =
50) In this case, the molten steel is La, Hf, Y, Pr, Nd,
It is preferable to further contain one or more elements selected from Zr, Ce, Sm and B in a total amount of 0.005 to 0.200 mass%.
【００１０】なお、ここで、溶鋼の過熱度（Ｘ）は、タ
ンディッシュ内の溶鋼温度―溶鋼の液相線温度とする。
このタンディッシュ内の溶鋼温度は、一般に溶鋼への浸
漬型熱伝対にて測定する。また、液相線温度は、２点以
上の溶鋼サンプルについて、示差熱分析法（ｄｉｆｆｅ
ｒｅｎｔｉａｌ ｔｈｅｒｍａｌ ａｎａｌｙｓｉｓ）
により求めた実際の液相線温度ＡＭＰ値と下記の平井の
式から求めたＭＰ値との差ΔＭＰ（ＡＭＰ−ＭＰ）の平
均ΔＭＰ値を求め、これを平井の式にプラスすることに
より求めた。すなわち、液相線温度＝ＭＰ＋平均ΔＭＰ
である（平井の式中の成分％の単位は、質量％）：
ＭＰ＝１５３８−｛ｆ（Ｃ）＋１３．０×Ｓｉ＋４．８
×Ｍｎ＋１．５×Ｃｒ＋３．１×Ｎｉ＋４．７×Ｃｕ＋
３．６×Ａｌ＋３．０×Ｍｏ｝
ここで、Ｃ＜＝０．５０％の時、ｆ（Ｃ）＝５５×Ｃ＋
８０×Ｃ2
Ｃ＞０．５０％の時、ｆ（Ｃ）＝４４−２１×Ｃ＋５２
×Ｃ2
本発明によれば、連続鋳造時の溶鋼温度及び鋳造速度を
適切にでき、Ａｌ及びＣｒの含有量が多くても、連続鋳
造時に操業トラブルの発生がなく、且つ得られたスラブ
に縦割れやヘゲ状欠陥の発生が従来に比べて少なくな
る。Here, the degree of superheat (X) of the molten steel is defined as the temperature of the molten steel in the tundish minus the liquidus temperature of the molten steel.
The temperature of the molten steel in the tundish is generally measured by an immersion thermocouple in the molten steel. The liquidus temperature of the molten steel sample at two or more points is measured by a differential thermal analysis method (diffe
rental thermal analysis)
The average .DELTA.MP value of the difference .DELTA.MP (AMP-MP) between the actual liquidus temperature AMP value obtained by the above equation and the MP value obtained by the following Hirai equation was obtained, and this was added to the Hirai equation. . That is, liquidus temperature = MP + average ΔMP
(The unit of the component% in the formula of Hirai is mass%): MP = 1538- {f (C) + 13.0 × Si + 4.8
X Mn + 1.5 x Cr + 3.1 x Ni + 4.7 x Cu +
3.6 × Al + 3.0 × Mo} Here, when C <= 0.50%, f (C) = 55 × C +
When 80 × C 2 C> 0.50%, f (C) = 44-21 × C + 52
According to × C 2 present invention, can the molten steel temperature and casting speed of the continuous casting appropriately, at most a content of Al and Cr, there is no occurrence of operation troubles in continuous casting, and the resulting slab The occurrence of vertical cracks and whisker-like defects is less than in the conventional case.
【００１１】[0011]
【発明の実施の形態】以下、発明をなすに至った経緯を
交え、本発明の実施形態について説明する。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below together with the background to the invention.
【００１２】まず、本発明に係る鋳造方法の対象とする
溶鋼は、成分を下記のように定めた高Ｃｒ及び高Ａｌ含
有溶鋼に限る。下記の成分範囲を外れる溶鋼では、連続
鋳造において操業のトラブルやスラブに縦割れやヘゲ状
欠陥の発生が大きな問題にならないからである。
Ｃ≦０．０２質量％
Ｃは、耐食性に対して低い程良く、常温での靭性を考慮
して０．０２質量％を上限とする。下限値は、特に規定
しないが、不可避的不純物レベルまで含むものとする。
Ｎ≦０．０２質量％
Ｎは、耐食性に対して低ければ低いほど良く、常温での
靭性を考慮して０．０２質量％を上限とする。下限値
は、特に規定しないが、不可避的不純物レベルまで含む
ものとする。
Ｓｉ≦１．０質量％
Ｓｉは、溶鋼の脱酸には効果があるが、あまり多いとス
ラブが脆化するので、１.０質量％を上限とする。下限
値は、特に規定しないが、不可避的不純物レベルまで含
むものとする。
Ｍｎ≦１．０質量％
Ｍｎは、鋼の強度を高める作用を有するが、含有量が多
過ぎると鋼の耐酸化性を劣化させるので、その含有量は
１．０質量％を上限とする。下限値は、特に規定しない
が、不可避的不純物レベルまで含むものとする。
Ｎｉ≦０．５質量％
Ｎｉは、含有量が多過ぎると鋼の靭性を劣化させるの
で、含有量の上限を０．５質量％とした。下限値は、特
に規定しないが、不可避的不純物レベルまで含むものと
する。
Ｃｕ≦０．５質量％
Ｃｕは、耐酸化性に有効な元素であるが、含有量が多い
と表面疵が増加したり、靭性を劣化させるので、０．５
質量％を上限とする。下限値は、特に規定しないが、不
可避的不純物レベルまで含むものとする。
Ｃｒ：１０〜３０質量％
Ｃｒは、Ｃｒ含有鋼の耐食性の点から少なくとも１０質
量％以上は必要であるが、加工性を配慮して３０質量％
を上限とする。
Ａｌ：１．０〜１０．０質量％
Ａｌは、鋼の耐高温酸化性を向上させる元素であり、こ
の効果を持たせるためには、１．０質量％以上含有させ
る必要がある。一方、含有量が多過ぎると、スラブや熱
延後の鋼板の靭性を劣化させるので、その上限を１０.
０質量％とした。
Ｔｉ≦０．０５質量％
Ｔｉは、含有量が多いと、連続鋳造時にノズル詰まりの
原因となるので、上限を０．０５質量％とした。下限値
は、特に規定しないが、不可避的不純物レベルまで含む
ものとする。
Ｃａ≦０．０５質量％
Ｃａは、連続鋳造時にノズル詰まりを防止する効果があ
るが、含有量が多過ぎると、鋼中に介在物が増加し、こ
れが製品の表面欠陥に繋がるので、上限値を０．０５質
量％とした。下限値は、特に規定しないが、不可避的不
純物レベルまで含むものとする。
Ｍｇ≦０．０５質量％
Ｍｇは、酸化スケールの耐剥離性を向上させる作用を有
する元素であるが、含有量が多過ぎると、スラブの靭性
を劣化させるので、上限を０．０５質量％とした。下限
値は、特に規定しないが、不可避的不純物レベルまで含
むものとする。First, the molten steel which is the object of the casting method according to the present invention is limited to the molten steel containing high Cr and high Al whose components are defined as follows. This is because in the case of molten steel that deviates from the following composition ranges, problems in operation and the occurrence of vertical cracks and whisker-like defects in the slab do not pose a serious problem in continuous casting. C ≦ 0.02% by mass The lower the C, the better the corrosion resistance, and the upper limit is 0.02% by mass in consideration of the toughness at room temperature. The lower limit is not particularly specified, but it shall include the unavoidable impurity level. N ≦ 0.02 mass% N is better as it is lower than the corrosion resistance, and considering the toughness at room temperature, the upper limit is 0.02 mass%. The lower limit is not particularly specified, but it shall include the unavoidable impurity level. Si ≦ 1.0 mass% Si is effective in deoxidizing molten steel, but if it is too much, the slab becomes brittle, so 1.0 mass% is the upper limit. The lower limit is not particularly specified, but it shall include the unavoidable impurity level. Mn ≦ 1.0 mass% Mn has an action of increasing the strength of steel, but if the content is too large, it deteriorates the oxidation resistance of the steel, so the content is made 1.0 mass% as the upper limit. The lower limit is not particularly specified, but it shall include the unavoidable impurity level. Ni ≦ 0.5% by mass Since Ni deteriorates the toughness of steel when the content is too large, the upper limit of the content was made 0.5% by mass. The lower limit is not particularly specified, but it shall include the unavoidable impurity level. Cu ≦ 0.5 mass% Cu is an element effective for oxidation resistance, but if the content is large, surface defects increase and toughness deteriorates, so 0.5
The upper limit is mass%. The lower limit is not particularly specified, but it shall include the unavoidable impurity level. Cr: 10 to 30% by mass Cr is required to be at least 10% by mass or more from the viewpoint of the corrosion resistance of Cr-containing steel, but 30% by mass in consideration of workability.
Is the upper limit. Al: 1.0 to 10.0 mass% Al is an element that improves the high temperature oxidation resistance of steel, and in order to have this effect, it is necessary to contain 1.0 mass% or more. On the other hand, if the content is too large, the toughness of the slab and the steel sheet after hot rolling is deteriorated, so the upper limit is 10.
It was set to 0 mass%. Ti ≦ 0.05 mass% If the content of Ti is large, it causes nozzle clogging during continuous casting, so the upper limit was made 0.05 mass%. The lower limit is not particularly specified, but it shall include the unavoidable impurity level. Ca ≦ 0.05% by mass Ca has the effect of preventing nozzle clogging during continuous casting, but if the content is too large, inclusions increase in the steel, which leads to surface defects of the product. Was set to 0.05% by mass. The lower limit is not particularly specified, but it shall include the unavoidable impurity level. Mg ≦ 0.05 mass% Mg is an element having an action of improving the peel resistance of the oxide scale, but if the content is too large, the toughness of the slab is deteriorated, so the upper limit is made 0.05 mass%. did. The lower limit is not particularly specified, but it shall include the unavoidable impurity level.
【００１３】さらに，上記溶鋼に、Ｌａ，Ｈｆ，Ｙ，Ｐ
ｒ，Ｎｄ，Ｚｒ，Ｃｅ，Ｓｍ及びＢから選ばれた１種又
は２種以上の元素をさらに添加する。これらの成分は、
合計で、０．００５〜０．２００質量％程度添加するだ
けで、いずれもスラブの高温耐酸化性を向上させるから
である。なお、合計で、０．００５〜０．２００質量％
としたのは、０．００５質量％未満では、耐酸化性を向
上させる効果が小さいためであり、０．２００質量％超
えでは，スラブや熱延後の鋼板の靭性を劣化させるため
である。Furthermore, La, Hf, Y, P is added to the molten steel.
One or more elements selected from r, Nd, Zr, Ce, Sm and B are further added. These ingredients are
This is because the addition of 0.005 to 0.200 mass% in total improves the high temperature oxidation resistance of the slab. In addition, 0.005 to 0.200 mass% in total
The reason is that if it is less than 0.005% by mass, the effect of improving the oxidation resistance is small, and if it exceeds 0.200% by mass, the toughness of the slab or the steel sheet after hot rolling is deteriorated.
【００１４】次に、発明者は、上記で規定した組成を有
する溶鋼の連続鋳造が従来難しいと言われる理由を見直
した。そして、以下のように整理した。
１）Ａｌ含有量が高いので、モールド・パウダーは、そ
れを考慮し、Ａｌ2Ｏ3を低めに調整した成分系である。
そのため、鋳造初期に該パウダーの溶融速度が遅く、未
溶解パウダーが凝固殻に噛み込み、前記ブレーク・アウ
ト等の操業トラブルや製品劣化を招く。
２）このモールド・パウダーの溶融を促進させるために
溶鋼の鋳造温度を通常より高めると、製造されたスラブ
の表面に縦割れが発生し、この割れが大きい場合、スク
ラップにせざるを得ない。
３）高Ｃｒ及び高Ａｌ含有のスラブは、ある温度以下に
なると応力割れが生じ易いため、温間（２００〜３００
℃程度）でスラブ表面の手入れをし、直ちに加熱炉に装
入して圧延加工を待つ。このため、スラブを詳細に観察
できず、微小な縦割れの発見が難しい。このスラブをそ
のまま圧延すると、破断したり、ヘゲ状欠陥が多くな
り、製品にできない鋼板になる。Next, the inventor has reviewed the reason why continuous casting of molten steel having the composition defined above is conventionally difficult. And arranged as follows. 1) Since the Al content is high, the mold powder is a component system in which Al 2 O 3 is adjusted to be low in consideration of it.
Therefore, the melting speed of the powder is slow at the initial stage of casting, and the undissolved powder is caught in the solidified shell, which causes operational troubles such as breakout and product deterioration. 2) When the casting temperature of molten steel is raised above the normal temperature to accelerate the melting of the mold powder, vertical cracks occur on the surface of the manufactured slab, and if this crack is large, it must be scrapped. 3) Since slabs containing high Cr and high Al are susceptible to stress cracking at a certain temperature or lower, warm (200 to 300)
Care the surface of the slab at (° C) and immediately put it in a heating furnace and wait for rolling. Therefore, the slab cannot be observed in detail, and it is difficult to find minute vertical cracks. If this slab is rolled as it is, it becomes a steel plate that cannot be made into a product, because it breaks or there are a lot of hairy defects.
【００１５】発明者は、これらの知見から、操業トラブ
ルや製品欠陥に対しては鋳造時の温度を今までよりもっ
と適正にする必要があると感じ、上記成分範囲に該当す
る溶鋼（質量％で、Ｃ：０．００４，Ｓｉ：０．５６，
Ｍｎ：０．１５、Ｐ：０．０１９、Ｓ：０．００２，Ｎ
ｉ：０．３１，Ｃｕ：０．２５，Ｃｒ：２２．１，Ａ
ｌ：８．９６，Ｎ：０．００８２，Ｔｉ：０．００１
２，Ｃａ：０．００４３，Ｍｇ：０．００４２，Ｙ：
０．００４８，Ｌａ：０．００４４）で、鋳造時の温度
及び鋳造速度を種々変更する試験操業を多数チャージ行
った。なお、鋳造温度は、前記したように、タンディッ
シュ内における溶鋼の温度と溶鋼の液相線温度との差を
過熱度と定義して表すようにした。From these findings, the inventor feels that it is necessary to make the temperature during casting more appropriate for operation troubles and product defects, and it is considered that molten steel (in mass% by mass%) corresponding to the above-mentioned composition range is used. , C: 0.004, Si: 0.56
Mn: 0.15, P: 0.019, S: 0.002, N
i: 0.31, Cu: 0.25, Cr: 22.1, A
l: 8.96, N: 0.0082, Ti: 0.001
2, Ca: 0.0043, Mg: 0.0042, Y:
0.0048, La: 0.0044), a number of test operations were performed in which the casting temperature and casting speed were variously changed. The casting temperature was defined as the degree of superheat by defining the difference between the temperature of the molten steel and the liquidus temperature of the molten steel in the tundish as described above.
【００１６】その結果を図１に集約して示す。図１によ
れば、Ａ，Ｂ，Ｃ，Ｄ，Ｅ及びＦで示す各座標点を結ぶ
直線で囲む領域内から外れた過熱度と鋳造速度の組合せ
で鋳造すると、操業トラブル及び製品の欠陥のいずれか
が生じることが明らかである。つまり、高Ｃｒ及び高Ａ
ｌを含有していても、溶鋼の過熱度と鋳造速度との一定
な関係を維持して鋳造すれば、円滑で安定な連続鋳造が
できることを知った。そこで、その関係を維持して鋳造
することを要件に本発明を完成させたのである。ちなみ
に、溶鋼の過熱度をＹ（℃）及び鋳造速度をＸ（ｍ／ｍ
ｉｎ）とすると、その関係は、下記６つの式の線分上、
あるいは線分で囲まれた領域内である。The results are summarized in FIG. According to FIG. 1, when casting is performed with a combination of the superheat degree and the casting speed that deviates from the area surrounded by the straight line connecting the coordinate points indicated by A, B, C, D, E, and F, operation troubles and product defects may occur. It is clear that either will occur. That is, high Cr and high A
It has been found that smooth and stable continuous casting can be performed if casting is performed while maintaining a constant relationship between the degree of superheat of molten steel and the casting speed, even if the alloy contains l. Therefore, the present invention has been completed on the condition that casting is performed while maintaining the relationship. By the way, the superheat of molten steel is Y (° C) and the casting speed is X (m / m).
in), the relationship is as follows on the line segment of the following six equations:
Alternatively, it is within the area surrounded by the line segment.
【００１７】
線分Ａ−Ｂ： Ｙ＝１００ （１）
線分Ｂ−Ｃ： Ｙ＝−１００Ｘ＋１８０ （２）
線分Ｃ−Ｄ： Ｘ＝１．２ （３）
線分Ｄ−Ｅ： Ｙ＝３０ （４）
線分Ｅ−Ｆ： Ｙ＝−１００Ｘ＋８０ （５）
線分Ｆ−Ａ： Ｘ＝０．３ （６）
なお、本願発明が適用されるスラブ寸法は、通常、厚み
１５０〜２７０ｍｍ、幅６００〜１６００ｍｍだが、特
に、モールドサイズによる制限は無い。Line segment AB: Y = 100 (1) Line segment BC: Y = -100X + 180 (2) Line segment CD: X = 1.2 (3) Line segment DE: Y = 30 (4) Line segment EF: Y = -100X + 80 (5) Line segment F-A: X = 0.3 (6) The slab dimension to which the present invention is applied is usually 150 to 270 mm in thickness, The width is 600 to 1600 mm, but there is no particular limitation due to the mold size.
【００１８】以下、実施例において、各成分量が異なる
多くの高Ｃｒ，高Ａｌ含有溶鋼で本発明の要件が成立す
ることを確認する。In the following examples, it is confirmed that the requirements of the present invention are satisfied with many high Cr and high Al content molten steels having different amounts of each component.
【００１９】[0019]
【実施例】使用した高Ｃｒ，高Ａｌ溶鋼の組成を一括し
て表１に示す。実際に湾曲型連続鋳造機を用い、これら
の溶鋼の過熱度と鋳造速度を種々変化させて鋳造した結
果を図２に示す。図２において、○印及び×印の下に記
した括弧内のａ〜ｊまでの数字は、表１の鋼Ｎｏ．に対
応し、ＩＩ〜ＶＩＩまでのローマ数字は、操業トラブル
や製品欠陥の内容を表す。なお、各鋼Ｎｏ．ａ〜Ｎｏ．
ｊのタンディッシュ内の溶鋼温度は、溶鋼への浸漬型熱
伝対にて測定した。また、液相線温度は、２点の溶鋼サ
ンプル（Ｃｒ：２０質量％， Ａｌ：５質量％， Ｃ：
０．００５質量％， Ｓｉ：０．１質量％， Ｍｎ：
０．１質量％， Ｎ：０．００５質量％）について、示
差熱分析法（試験装置に真空理工製示差熱重量分析装置
を用い，測定雰囲気をＡｒ，標準試料をα−Ａｌ2Ｏ3に
して、昇温速度を５℃／ｍｉｎとした）により求めた実
際の液相線温度ＡＭＰ値と、下記の平井の式から求めた
ＭＰ値との差ΔＭＰ値（ＡＭＰ−ＭＰ）の平均ΔＭＰ値
を求め、これを前記した平井の式にプラスすることによ
り求めた。この実施例では、平均ΔＭＰ値＝３５℃であ
った。すなわち、各鋼Ｎｏ．ａ〜Ｎｏ．ｊの液相線温度
＝ＭＰ＋３５℃で求めて、表１に記載した。EXAMPLES The compositions of the high Cr and high Al molten steels used are shown in Table 1 collectively. FIG. 2 shows the results of actual casting using a curved continuous casting machine while varying the degree of superheat and casting speed of these molten steels. In FIG. 2, the numbers from a to j in parentheses below the circles and the circles are steel Nos. In Table 1. Corresponding to, the Roman numerals from II to VII represent the contents of operational troubles and product defects. In addition, each steel No. a-No.
The molten steel temperature in the tundish of j was measured by the immersion type thermocouple to molten steel. Further, the liquidus temperature is two points of molten steel samples (Cr: 20 mass%, Al: 5 mass%, C:
0.005% by mass, Si: 0.1% by mass, Mn:
0.1% by mass, N: 0.005% by mass, using a differential thermal analysis method (using a differential thermogravimetric analyzer manufactured by Vacuum Riko Co., Ltd. as a test apparatus, the measurement atmosphere was Ar, and the standard sample was α-Al 2 O 3) . Then, the average ΔMP value of the difference ΔMP value (AMP-MP) between the actual liquidus temperature AMP value obtained by (the heating rate was 5 ° C./min) and the MP value obtained by the following Hirai equation. Was calculated by adding it to the above-mentioned Hirai's formula. In this example, the average ΔMP value was 35 ° C. That is, each steel No. a-No. The liquidus temperature of j = MP + 35 ° C. was calculated and listed in Table 1.
【００２０】なお、鋳造したスラブは、厚み１９７ｍ
ｍ，幅１０８０ｍｍ，長さ７０５０ｍｍであり、縦割れ
の発生状況は、目視で調査した。また、それらスラブ
は、引き続き熱間圧延、冷間圧延により、厚み２．５ｍ
ｍ，幅１０４０ｍｍの鋼帯にされた。その際、必要に応
じてスラブの手入れを加えたものもある。The cast slab has a thickness of 197 m.
m, width 1080 mm, length 7050 mm, and the occurrence of vertical cracks was visually inspected. The slabs are continuously hot-rolled and cold-rolled to a thickness of 2.5 m.
m, width 1040 mm steel strip. At that time, some slabs have been added if necessary.
【００２１】[0021]
【表１】 [Table 1]
【００２２】図２より、本発明によれば、操業トラブル
や製品欠陥を起こさずに連続鋳造が可能なことが明らか
である。また、鋳造で得た各溶鋼の歩留まり及び熱間圧
延後のコイル精整歩留まりを表２に一括して示す。From FIG. 2, it is clear that according to the present invention, continuous casting can be performed without causing operational troubles and product defects. Table 2 collectively shows the yield of each molten steel obtained by casting and the coil refinement yield after hot rolling.
【００２３】[0023]
【表２】 [Table 2]
【００２４】表２より、スラブ歩留まり、コイル精整歩
留まりも本発明法領域で鋳造した方が良好であることが
明らかで、本発明が非常に優れていることがわかる。From Table 2, it is clear that the slab yield and the coil refinement yield are also better when cast in the method area of the present invention, and the present invention is very excellent.
【００２５】[0025]
【発明の効果】以上述べたように、本発明により、連続
鋳造を採用しても、操業トラブルの発生がなく、且つ得
られたスラブに縦割れやヘゲ状欠陥の発生が従来に比べ
て少ない高Ｃｒ，高Ａｌ含有鋼板が入手できるようにな
る。As described above, according to the present invention, even if continuous casting is adopted, no operational trouble occurs, and the obtained slab has vertical cracks or whiskers-like defects as compared with the conventional case. Steel sheets containing a small amount of high Cr and high Al will be available.
【図１】本発明をなす基礎となった試験操業の結果を、
溶鋼の過熱度及び鋳造速度との関係で示す図である。FIG. 1 shows the results of a test operation, which is the basis of the present invention,
It is a figure shown in relation with a superheat degree of molten steel, and a casting speed.
【図２】多種の高Ｃｒ，高Ａｌ含有溶鋼での試験操業の
結果を、溶鋼の過熱度及び鋳造速度との関係で示す図で
ある。FIG. 2 is a diagram showing the results of test operations with various types of molten steel containing high Cr and high Al in relation to the degree of superheat of molten steel and the casting speed.
【図３】一般的な鋼板の製造工程を示す流れ図であり、
（ａ）は、スラブを造塊法で、（ｂ）は連続鋳造法で製
造する場合である。FIG. 3 is a flow chart showing a general steel plate manufacturing process,
(A) is a case where a slab is manufactured by the ingot making method, and (b) is a case where it is manufactured by a continuous casting method.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｃ２２Ｃ 38/54 Ｃ２２Ｃ 38/54 (72)発明者 萩原 俊哉 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 錦織 正規 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 柏 孝幸 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 吉田 孝行 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 Ｆターム(参考） 4E004 MC05 MC11 NB01 NC02 TB01─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) C22C 38/54 C22C 38/54 (72) Inventor Toshiya Hagiwara 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Made by Kawasaki Iron Co., Ltd. Chiba Works (72) Inventor Nishikori Regular 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Prefecture Kawasaki Works Chiba Works (72) Inventor Takayuki Kashiwa 1 Kawasaki-cho, Chuo-ku, Chiba Chiba Iron Co., Ltd. Chiba Steel Works (72) Inventor Takayuki Yoshida 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Co., Ltd. Chiba Works F-term (reference) 4E004 MC05 MC11 NB01 NC02 TB01
Claims (2)
％，Ｓｉ≦１．０質量％，Ｍｎ≦１．０質量％，Ｎｉ≦
０．５質量％，Ｃｕ≦０．５質量％，Ｃｒ：１０〜３０
質量％，Ａｌ：１．０〜１０．０質量％，Ｔｉ≦０．０
５質量％，Ｃａ≦０．０５質量％，Ｍｇ≦０．０５質量
％を含み，残部が不可避不純物及びＦｅからなる溶鋼
を、タンディッシュを介して鋳型に注ぎ、凝固した鋼鋳
片を連続的に鋳型より引き抜く高Ｃｒ及び高Ａｌ含有鋼
の連続鋳造方法において、 溶鋼の過熱度（Ｘ；℃）と鋳造速度（Ｙ；ｍ／ｍｉｎ）
とを、下記の６座標で囲む領域内及び外郭線上で、前記
溶鋼を鋳造することを特徴とする高Ｃｒ及び高Ａｌ含有
鋼の連続鋳造方法。 座標Ａ（Ｘ＝０．３、Ｙ＝１００）、座標Ｂ（Ｘ＝０．
８、Ｙ＝１００）、 座標Ｃ（Ｘ＝１．２、Ｙ＝６０），座標Ｄ（Ｘ＝１．
２，Ｙ＝３０）， 座標Ｅ（Ｘ＝０．５，Ｙ＝３０），座標Ｆ（Ｘ＝０．
３，Ｙ＝５０） ここで、Ｘ＝タンディッシュ内の溶鋼温度−溶鋼の液相
線温度（℃）1. C ≦ 0.02% by mass, N ≦ 0.02% by mass, Si ≦ 1.0% by mass, Mn ≦ 1.0% by mass, Ni ≦
0.5% by mass, Cu ≦ 0.5% by mass, Cr: 10-30
Mass%, Al: 1.0 to 10.0 mass%, Ti ≦ 0.0
Molten steel containing 5% by mass, Ca ≦ 0.05% by mass, Mg ≦ 0.05% by mass and the balance being inevitable impurities and Fe was poured into a mold through a tundish to continuously solidify a solidified steel slab. In the continuous casting method of steel containing high Cr and high Al, which is drawn out from the mold, the degree of superheat of molten steel (X; ° C) and casting speed (Y; m / min)
In the area surrounded by the following 6 coordinates and on the outline, the molten steel is cast, and a continuous casting method for high Cr and high Al-containing steel is provided. Coordinate A (X = 0.3, Y = 100), Coordinate B (X = 0.
8, Y = 100), coordinates C (X = 1.2, Y = 60), coordinates D (X = 1.
2, Y = 30), coordinates E (X = 0.5, Y = 30), coordinates F (X = 0.
3, Y = 50) where X = molten steel temperature in tundish-liquidus temperature of molten steel (° C)
ｒ，Ｎｄ，Ｚｒ，Ｃｅ，Ｓｍ及びＢから選ばれた１種又
は２種以上の元素を合計で、０．００５〜０．２００質
量％含有することを特徴とする請求項１記載の高Ｃｒ及
び高Ａｌ含有鋼の連続鋳造方法。2. The molten steel further comprises La, Hf, Y, P
The high Cr according to claim 1, characterized in that it contains 0.005 to 0.200 mass% in total of one or more elements selected from r, Nd, Zr, Ce, Sm and B. And a method for continuously casting high Al content steel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002207805A JP3873832B2 (en) | 2001-07-27 | 2002-07-17 | Continuous casting method of high Cr and high Al content steel |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001-227463 | 2001-07-27 | ||
| JP2001227463 | 2001-07-27 | ||
| JP2002207805A JP3873832B2 (en) | 2001-07-27 | 2002-07-17 | Continuous casting method of high Cr and high Al content steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003112235A true JP2003112235A (en) | 2003-04-15 |
| JP3873832B2 JP3873832B2 (en) | 2007-01-31 |
Family
ID=26619413
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002207805A Expired - Lifetime JP3873832B2 (en) | 2001-07-27 | 2002-07-17 | Continuous casting method of high Cr and high Al content steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3873832B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005138175A (en) * | 2003-11-10 | 2005-06-02 | Sumitomo Metal Ind Ltd | CONTINUOUS CASTING METHOD FOR HIGH Al STEEL SLAB HAVING EXCELLENT SURFACE PROPERTY |
| JP2011230182A (en) * | 2010-04-30 | 2011-11-17 | Sumitomo Metal Ind Ltd | Method for manufacturing high manganese-steel |
| WO2018074405A1 (en) * | 2016-10-17 | 2018-04-26 | Ｊｆｅスチール株式会社 | Stainless steel sheet and stainless steel foil |
| KR20200066046A (en) * | 2018-11-30 | 2020-06-09 | 주식회사 포스코 | Casting method of light weight steel |
-
2002
- 2002-07-17 JP JP2002207805A patent/JP3873832B2/en not_active Expired - Lifetime
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005138175A (en) * | 2003-11-10 | 2005-06-02 | Sumitomo Metal Ind Ltd | CONTINUOUS CASTING METHOD FOR HIGH Al STEEL SLAB HAVING EXCELLENT SURFACE PROPERTY |
| JP2011230182A (en) * | 2010-04-30 | 2011-11-17 | Sumitomo Metal Ind Ltd | Method for manufacturing high manganese-steel |
| WO2018074405A1 (en) * | 2016-10-17 | 2018-04-26 | Ｊｆｅスチール株式会社 | Stainless steel sheet and stainless steel foil |
| JP6319537B1 (en) * | 2016-10-17 | 2018-05-09 | Ｊｆｅスチール株式会社 | Stainless steel plate and stainless steel foil |
| CN109844157A (en) * | 2016-10-17 | 2019-06-04 | 杰富意钢铁株式会社 | Stainless steel plate and stainless steel foil |
| US11008636B2 (en) | 2016-10-17 | 2021-05-18 | Jfe Steel Corporation | Stainless steel sheet and stainless steel foil |
| KR20200066046A (en) * | 2018-11-30 | 2020-06-09 | 주식회사 포스코 | Casting method of light weight steel |
| KR102228310B1 (en) * | 2018-11-30 | 2021-03-15 | 주식회사 포스코 | Casting method of light weight steel |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3873832B2 (en) | 2007-01-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1326143C (en) | Ferritic stainless steel and processing therefore | |
| WO2010008019A1 (en) | Continuously cast slab and process for production of same | |
| JP7408347B2 (en) | High Ni alloy and method for producing high Ni alloy | |
| JP5285895B2 (en) | Stainless steel refining method | |
| JP3852396B2 (en) | Method for deoxidizing thin steel sheet and molten steel for thin steel sheet | |
| JP2003112235A (en) | CONTINUOUS CASTING METHOD FOR HIGH Cr- AND HIGH Al- CONTAINING STEEL | |
| JP3241114B2 (en) | Method for producing ferritic stainless steel sheet excellent in ridging property and workability | |
| EP2738281A1 (en) | Method for producing high si-content austenitic stainless steel | |
| JP5223720B2 (en) | Continuous casting slab of steel for B-containing high-strength thick steel plate and method for producing the same | |
| CN116529396A (en) | High Ni alloy excellent in weld high temperature cracking resistance | |
| JP2000319730A (en) | Production of hot rolled steel sheet excellent in surface property and formability | |
| JP3294846B2 (en) | Fe-Cr-Al alloy steel sheet and method for producing the same | |
| JP2003147492A (en) | Ti-CONTAINING Fe-Cr-Ni STEEL HAVING EXCELLENT SURFACE PROPERTY, AND CASTING METHOD THEREFOR | |
| JP2001303197A (en) | Steel with fine solidification structure | |
| JP2004307931A (en) | Continuously cast piece, and casting method therefor | |
| JPH07268455A (en) | Production of cr-ni stainless alloy free from microracking in hot rolling | |
| JP3079756B2 (en) | Manufacturing method of S free cutting austenitic stainless steel | |
| JP7158618B1 (en) | Austenitic Fe-Ni-Cr alloy with excellent oxidation resistance and method for producing the same | |
| JP3606199B2 (en) | Manufacturing method of thin steel sheet | |
| WO2023286338A1 (en) | Ni-cr-mo-based alloy for welded pipe having excellent workability and corrosion resistance | |
| JP3923485B2 (en) | Manufacturing method of ferritic single-phase stainless steel with excellent deep drawability | |
| JP3660811B2 (en) | Steel wire rod and manufacturing method thereof | |
| JP3714190B2 (en) | Method of deoxidizing thin steel sheet and molten steel for thin steel sheet | |
| JP2001288542A (en) | Cr-CONTAINING THIN STEEL SHEET EXCELLENT IN RIDGING RESISTANCE AND ITS PRODUCING METHOD | |
| JP3423815B2 (en) | Method for producing ferritic stainless steel to prevent surface flaws from occurring during hot rolling |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20041027 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20060925 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20061003 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20061016 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 3873832 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101102 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111102 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111102 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121102 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131102 Year of fee payment: 7 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |