WO2006109739A1 - Process for the casting of molten alloy - Google Patents

Process for the casting of molten alloy Download PDF

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Publication number
WO2006109739A1
WO2006109739A1 PCT/JP2006/307484 JP2006307484W WO2006109739A1 WO 2006109739 A1 WO2006109739 A1 WO 2006109739A1 JP 2006307484 W JP2006307484 W JP 2006307484W WO 2006109739 A1 WO2006109739 A1 WO 2006109739A1
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WO
WIPO (PCT)
Prior art keywords
slag
molten alloy
water
forging
molten
Prior art date
Application number
PCT/JP2006/307484
Other languages
French (fr)
Japanese (ja)
Inventor
Setsuo Mishima
Yasushi Ishimoto
Takanori Aikawa
Original Assignee
Hitachi Metals, Ltd.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Metals, Ltd. filed Critical Hitachi Metals, Ltd.
Priority to JP2007512980A priority Critical patent/JP4548483B2/en
Priority to EP06731431.0A priority patent/EP1870182B1/en
Priority to CN2006800117610A priority patent/CN101155653B/en
Publication of WO2006109739A1 publication Critical patent/WO2006109739A1/en

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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
    • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
    • B22D11/059—Mould materials or platings
    • 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
    • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
    • B22D11/0401—Moulds provided with a feed head

Definitions

  • the present invention relates to a method for producing a molten alloy that can prevent segregation such as center segregation and reverse V segregation, and can form a microstructure.
  • VAR vacuum arc remelting method
  • ESR electroslag remelting method
  • This form of stacked solidification can alleviate the occurrence of segregation such as center segregation and reverse V segregation that occur in ingot fabrication due to the small solidification space.
  • the use of a water-cooled mold has the advantage that the cooling rate can be increased and the structure becomes fine and uniform.
  • Patent Document 1 discloses a technique for pulling out the lump with the layer bottom force.
  • Patent Document 1 Japanese Patent Laid-Open No. 62-4840
  • Patent Document 1 discloses a continuous forging method in which molten steel is held in a refinery tank and drawn from a water-cooled mold in which the molten steel is separately provided. In Patent Document 1, this is referred to as laminating solidification.
  • Technical fields in ESR and VAR methods As described above, the lamination and solidification in is solidified in a stacked manner, and is different from the method disclosed in Patent Document 1.
  • Patent Document 1 it is effective to exert the slag squeezing effect, which is one of the effects when ESR is applied, but only the surface layer must be pulled out in a solidified state. ⁇ Since applying the continuous forging method, there is a possibility that defects such as center segregation, especially in high alloys, may occur, and a solidification space that is an important effect of ESR is reduced to obtain a fine uniform structure However, there is a problem that the effect cannot be obtained.
  • the object of the present invention is to eliminate the adverse effects of solidified slag in the lump extraction operation, to prevent the praying of the solid steel ingot and to refine the structure, and to improve the steel ingot skin.
  • V to provide a method for producing molten alloy.
  • the present inventors have provided a molten pool with a small solidification space that approximates ESR even by supplying the molten metal to the solidification space in which the slag is arranged at a very low speed of 0.3 mZ or less at the forging speed.
  • a slag lump having a fine uniform structure can be obtained by the action of heat insulation on the surface of the molten metal pool and blocking of the outside air by slag.
  • the slag layer existing around the mass of the slag hinders the refinement of the structure, cracks occur in the slag layer and the solidified shell, and the molten steel oozes out.
  • the inventors of the present invention slurried the molten alloy toward a water-cooled mold made of metal such as copper or iron.
  • the direct cause of the roughening of the steel ingot surface that occurs when laminating and solidifying such as ESR is performed by supplying molten metal at extremely low speed through the joint is near the boundary between the solidified shell and slag.
  • the present invention injects molten alloy from a container for holding molten alloy into a solidified space surrounded by an inner wall of a water-cooled mold and provided with slag at a forging rate of 0.3 mZ or less.
  • the molten alloy is solidified while forming, and the molten metal is drawn vertically from the lower part of the water-cooled mold according to the injection rate of the molten alloy.
  • the upper part of the water-cooled mold is continuous with the inner wall of the water-cooled mold.
  • the upper surface position of the meniscus of the molten pool is within the arrangement range of the heat retaining member in the steady state of forging.
  • the heat retaining member in the present invention preferably has an inner wall shape that is substantially the same as the inner wall of the water-cooling mold on the downstream side in a cross section perpendicular to the pulling direction of the lump.
  • the heat retaining member is preferably a graphite material.
  • the forging speed of the molten alloy in the present invention is preferably 0.005-0.lmZ, more preferably 0.005-0.08 m / min, and still more preferably 0.01-0.05 m / min. Minutes.
  • the slag may be forged while being heated by a heating means.
  • the slag to be applied is preferably a low melting point slag having a melting point of 500 to 1400 ° C.
  • the slag thickness is preferably 20 to: LOOmm.
  • the molten alloy applied to the present invention includes tool steels such as cold die steel, hot die steel, and high-speed tool steel, which are difficult to reduce microstructure and component bias, and other high alloy metals. It can be applied to steel, etc., or ESR applied alloys.
  • molten metal containing Fe as a main component and containing 3.0% or less by mass% and 5% or more of a metal element other than Fe, more preferably% by mass.
  • Deji Applies to molten metal with a composition of 0.1 to 3.0%.
  • the present invention since a laminated solidified steel ingot can be obtained directly from the molten metal, low cost and high productivity can be secured. Further, the present invention is particularly effective when applied to the production of a high alloy that is prone to partial prayer and the skin is liable to deteriorate because the number of man-hours can be dramatically reduced.
  • an important feature of the present invention is a forging method in which molten metal is supplied to a solidification space in which slag is disposed at an extremely low speed. Forging while suppressing heat removal.
  • a molten alloy is poured from a container such as a tundish holding the molten alloy into a solidified space surrounded by the inner wall of the water-cooled mold and provided with slag.
  • molten alloy is injected at a very low casting speed of 0.3 mZ or less, and the molten metal supplied while forming a molten pool is quickly To solidify. Therefore, a solidified space surrounded by the inner wall of the water-cooled mold is used.
  • the lump is pulled out from the lower part of the water-cooled mold in the vertical direction according to the injection speed of the molten alloy (that is, the upper surface position of the meniscus is maintained at a substantially constant position). As a result, a meniscus having a fixed shape is formed, and a laminated solidified ingot having a fine uniform structure similar to ESR can be obtained.
  • the heat retaining member having the inner wall shape continuous with the inner wall of the water-cooled mold is provided at the upper part of the water-cooled mold to remove heat from the slag force. The method of forging while suppressing was adopted.
  • This heat retaining member can prevent the slag from solidifying excessively at the boundary with the solidified shell, and the simultaneous lowering of the solid slag and the solidified shell rupture caused by pulling out the lumps can be suppressed. If there is a crack in the slag, it is possible to prevent the molten steel from seeping out due to a crack in the undeveloped solidified shell and to improve the cooling of the ingot, as well as improving the skin surface of the ingot.
  • the inner wall shape continuous to the inner wall of the water-cooled mold is a discontinuous large step or gap. When the formed solidified shell slides on the mold wall surface, This is because extra stress acts to destroy the solidified shell and deteriorate the lump skin.
  • the shape of the heat insulation member is the lump of the lump I It is effective to make the inner wall shape substantially the same as the inner wall of the water-cooling mold on the downstream side in the cross section perpendicular to the direction.
  • the arrangement position of the heat retaining member is set in a range having an effect of suppressing heat removal from the slag.
  • the solidification of slag has the most adverse effect on the boundary between the slag and the meniscus of the molten metal pool near the mold, that is, the formation position of the solidified shell.
  • the present invention dynamically performs forging, and in the steady state of forging, it is effective to exhibit the effect of suppressing heat removal of the slag force by the heat retaining member particularly at the position where the solidified shell is formed.
  • the formation position of the solidified shell is close to the upper surface position of the meniscus of the molten pool, and the upper surface position of the meniscus is easy to detect as a control target.
  • the upper surface position of the meniscus of the molten pool is in the steady state of forging. It would be desirable to control the temperature keeping member within the range of arrangement.
  • the lower end position of the heat retaining member disposed in the vicinity of the boundary between the solidified shell and the slag deteriorates the original cooling function if the water cooling mold is covered too much by the heat retaining member. It is preferable to set the range from the control position (meniscus upper surface position) to 100 mm below, and considering the fluctuation of the hot water surface control position during the forging period, the lower end position of the heat retaining member is within 10 mm below the meniscus upper surface position. Is preferably avoided.
  • the upper end position of the heat retaining member beyond the upper surface of the slag. This is for easy handling in the installation of heat insulation members and for heat insulation throughout the slag.
  • the heat retaining member in the region corresponding to the slag layer portion is made thicker or a heat insulating layer is further provided on the outer peripheral portion of the heat retaining member. It is also possible to suppress the heat loss with a method as necessary.
  • the heat-retaining member in the present invention is preferably made of a material excellent in slag erosion resistance and slidability in addition to heat resistance. Ceramics or the like may be used. However, regarding the slidability, graphite-containing ceramics and the like are effective, and it is preferable to dispose a graphite material having excellent slag erosion resistance, formability, and slidability.
  • any container other than what is called a tundish may be used as a container for holding an alloy.
  • a container for holding an alloy may have a heating means if necessary.
  • the shape of the bowl formed by the water-cooled mold is preferably a round shape uniformity force, but may be an ellipse or a rectangle in consideration of the lump shape and manufacturability.
  • a material for the water-cooled mold it is desirable to use a metal water-cooled mold having excellent heat conduction characteristics such as iron or copper in order to reduce the solidification space.
  • slag is important for insulating the surface of the molten metal pool and blocking outside air, in addition to trapping inclusions, desulfurizing the molten metal, and!
  • the method for supplying the molten metal is not limited.
  • the molten alloy is injected so as to pass through the slag, it is possible to expect an improvement in the refining effect due to the slag reaction by the slag.
  • the slag is forced by the molten metal flow at the time of pouring and may be trapped in the lump and become inclusions.
  • the molten metal is supplied using an immersion nozzle that reaches the molten metal pool, the effect of slag reaction cannot be expected to be significant, but the generation of inclusions due to the slurry can be suppressed. Therefore, it is desirable that the molten metal supply method in the present invention is appropriately selected based on the required quality in consideration of the relationship with the slag.
  • slag has the effect of scouring, heat insulation on the surface of the molten pool, and shielding against outside air.
  • slag having a melting point exceeding 1400 ° C
  • slag is sufficiently liquefied only by heat transfer from the molten metal.
  • the solidified shell of the slag surrounding the molten metal pool develops too much, and abnormal tissue may form deeply in the outer layer of the lump.
  • slag 1400 ° C or less
  • solidification of the slag is suppressed, and abnormal tissue formation in the outer layer of the lump is remarkably suppressed.
  • such a low melting point slag has a low viscosity and has an effect that an unnecessarily thick slag skin is not formed on the lump surface.
  • the present invention uses a molten metal that is melted by the heat energy supplied by the Joule heat from the electrode, such as ESR, so a special heating means for the slag is always required. is not.
  • a separate heating means can be provided to control the slag temperature.
  • the use of Joule heat obtained by slag energization is simple and effective.
  • the slag temperature is preferably below the penetration temperature.
  • slag with a melting point of 500 ° C or lower, which is not practical, but a low melting point slag of 500 to 1400 ° C.
  • the thickness of the slag layer is preferably 20mm or more.
  • the optimum thickness range is 20mn! ⁇ 1 OOmm.
  • the forging rate of the molten alloy is set to 0.3 mZ or less because if it is too fast, it is difficult to obtain a homogeneous structure with less bias for the purpose of lamination and solidification. This is because slag may be caught inside. More preferably, it is less than or equal to 0.0 lmZ, and more preferably less than or equal to 0.05 mZ. In consideration of productivity, it is desirable that the content be 0.005 mZ or more, more preferably 0.005 mZZ or more.
  • FIG. 1 shows an example of a forging process of the present invention using an apparatus for carrying out the present invention.
  • FIG. 1 shows a cross section of the device, which is a device including a tundish 10 for holding a molten alloy 11, a water-cooled mold made of iron 2, and a lifting device 20 for pulling out a lump.
  • a graphite sleeve 3 is disposed as a heat retaining member on the upper part of the water cooling mold.
  • the shape of the water-cooled mold is 400mm in length, the inner diameter of the upper 200mm part where the graphite sleeve is placed is 47lmm and the lower inner diameter is 450mm.
  • a graphite sleeve with a length of 200 mm, an inner diameter of 450 mm, and an outer diameter of 470 mm is installed inside the water-cooled mold.
  • a secondary cooling zone 30 is located below the water cooling mold.
  • a shield 14 and a slag energizing electrode 15 that block molten alloy and outside air can be disposed as additional devices.
  • a molten metal flow 13 is injected from a nozzle 12 provided at the bottom of a tundish 10 holding a molten alloy 11 into a water-cooled mold 2 serving as a solidification space in which the slag 1 is disposed.
  • the slag is arranged by introducing the melted slag into the mold at the initial stage of fabrication.
  • the molten metal pool 4 having the meniscus upper surface position “A” is controlled to be formed 50 mm from the lower end “B” of the graphite sleeve 3 which is a heat retaining member built in the water cooling mold 2. Thereby, a solidified shell can be formed on the inner wall side of the heat retaining member.
  • the elevating device 20 is lowered and the lump 5 is pulled out, so that the lamination and solidification can be advanced while maintaining a constant meniscus position.
  • the lump that has escaped from the water-cooling mold force is mist cooled in the secondary cooling zone 30.
  • a forging experiment was conducted using the apparatus of FIG.
  • the molten metal was held in a tundish that did not use the slag energizing electrode 15, and slag having the composition and melting point shown in Table 1 was arranged in a thickness of 50 mm, and the water-cooled mold was fabricated.
  • Molten metal is mass. / oJIS SKD11, SKH 51 equivalent steel grade was used.
  • Table 2 shows the components of the molten metal.
  • the casting temperature was set to 1500 ° C and the casting speed was equivalent to 0.02 mZ (20 mmZ), and the casting was carried out to 3 m. Further, as a comparative example, the apparatus of FIG. 1 was manufactured without installing a graphite sleeve (heat insulating member).
  • Table 3 shows the thickness of the skin slag of the obtained lump.
  • Table 4 shows.
  • a slag energizing electrode 15 was added to the apparatus shown in Example 1, and a forging experiment was performed.
  • the slag energizing electrode 15 is immersed in the slag having the composition shown in Table 1, and the slag is energized to heat the slag. At the same time, the temperature is measured between the graphite electrode and the molten metal surface. Controlled to C.
  • the slag thickness is 50 mm, and the molten metal component is SKD11 shown in Table 2.
  • Example 2 The other conditions were the same as in Example 1, except that the molten metal temperature was 1500 ° C., and the forging speed was 0.02 mZ (20 mmZ) equivalent to 3 m.
  • slag temperature control by slag heating can suppress the growth of the solidified slag layer and promote homogenization of the texture of the lump surface.
  • Table 7 also shows that slag heating to 1400 ° C has almost no effect on the DASII value and maintains a fine structure. This is thought to be because heat removal in the water-cooled mold and heat removal in the secondary cooling zone are progressing because there is no skin slag even after slag heating.
  • FIG. 1 is a conceptual diagram showing an example of an apparatus to which the present invention is applied.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Continuous Casting (AREA)
  • Forging (AREA)

Abstract

A novel process for the casting of molten alloy which is freed from the adverse effects brought about by the solidification of slag in drawing an ingot and can attain the inhibition of a solidified steel ingot from segregation and grain refinement and which can give a steel ingot improved in surface texture. Namely, a process for the casting of molten alloy which comprises pouring a molten alloy at a casting rate of 0.3m/min or below into a solidification space enclosed by the inside wall of a water-cooled mold (2) and holding slag (1) therein from a container (10) holding a molten alloy (11) therein to solidify the molten alloy while forming a molten metal pool (4), and drawing an ingot (5) vertically from the bottom of the water-cooled mold depending on the pouring rate of the molten alloy, wherein a heat insulator (3) for inhibiting the extraction of heat from slag which insulator has such an inside wall shape as to form an inside wall continuous with the inside wall of the water-cooled mold is placed in the upper section of the mold.

Description

明 細 書  Specification
合金溶湯の铸造方法  Method of forging molten alloy
技術分野  Technical field
[0001] 本発明は、中心偏析、逆 V偏析等の偏析を防止し、微細組織を形成することができ る合金溶湯の铸造方法に関するものである。  [0001] The present invention relates to a method for producing a molten alloy that can prevent segregation such as center segregation and reverse V segregation, and can form a microstructure.
背景技術  Background art
[0002] 従来、偏祈が少なく、微細組織が得られる合金溶湯の铸造方法として、真空アーク 再溶解法 (VAR)やエレクトロスラグ再溶解法 (ESR)が良く用いられている。これらの 方法は、水冷モールド壁で囲まれた凝固空間において、溶湯プールを形成させつつ 、凝固させるものであり、凝固空間が小さぐ積み上げるように凝固させる一般に積層 凝固と呼ばれる凝固形態となる。  Conventionally, the vacuum arc remelting method (VAR) and the electroslag remelting method (ESR) are often used as methods for producing a molten alloy with a small number of prayers and a fine structure. In these methods, a solidified space surrounded by a water-cooled mold wall is solidified while forming a molten metal pool, and a solidified form generally called laminated solidification is obtained in which the solidified space is solidified so as to be piled up.
この積層凝固の形態は、凝固空間が小さいことに起因して、インゴット铸造で発生 する中心偏析や、逆 V偏析といった偏祈の発生を緩和することができる。また、水冷 モールドの使用により、冷却速度を高めることができるため、組織が微細均一になる という利点もある。  This form of stacked solidification can alleviate the occurrence of segregation such as center segregation and reverse V segregation that occur in ingot fabrication due to the small solidification space. In addition, the use of a water-cooled mold has the advantage that the cooling rate can be increased and the structure becomes fine and uniform.
[0003] このように、有効な特徴をもつ再溶解法であるが、 VAR, ESRともに、再溶解用電 極を製造する必要があり、多くの工数と、再溶解のためのエネルギーを必要とするも のであった。  [0003] As described above, this is a remelting method having an effective feature, but it is necessary to manufacture a remelting electrode for both VAR and ESR, which requires many man-hours and energy for remelting. It was to do.
この様な問題を解決しょうとする方法として、スラグ反応により精鍊効果が期待でき る ESR法を起源として、電極を使わず細滴化した溶湯を、加熱溶融したスラグ層を追 カロして、精鍊層底部力も铸塊を引き抜く技術が、特許文献 1に示されている。  As a method to solve such problems, the ESR method, which can be expected to have a slag effect by the slag reaction, originates from the slag layer that has been heated and melted from the slag layer that has been made into fine droplets without the use of electrodes. Patent Document 1 discloses a technique for pulling out the lump with the layer bottom force.
特許文献 1：特開昭 62— 4840号公報  Patent Document 1: Japanese Patent Laid-Open No. 62-4840
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0004] 上述した特許文献 1に記載される具体的な方法は、溶鋼を精鍊槽中に保持し、溶 鋼を別に設けた水冷モールドから引き出すという連続铸造法を開示するものである。 特許文献 1では、これを積層凝固と称している力 ESRや VAR法における技術分野 における積層凝固は、上述した通り、積み上げるように凝固させるものであって、特許 文献 1に開示される方法とは異なるものである。 [0004] The specific method described in Patent Document 1 described above discloses a continuous forging method in which molten steel is held in a refinery tank and drawn from a water-cooled mold in which the molten steel is separately provided. In Patent Document 1, this is referred to as laminating solidification. Technical fields in ESR and VAR methods As described above, the lamination and solidification in is solidified in a stacked manner, and is different from the method disclosed in Patent Document 1.
そのため、特許文献 1においては、 ESRを適用する場合の効果の一つであるスラグ の精鍊効果を発揮させるのには有効であるが、表層部のみが凝固した状態で引き抜 かれざるを得な ヽ連続铸造法を適用して ヽるため、特に高合金における中心偏析ゃ センターポロシティという欠陥の発生する可能性があるとともに、 ESRの重要な効果 である凝固空間を小さくして微細均一組織を得ると 、う効果を得ることができな 、と ヽ う問題がある。  Therefore, in Patent Document 1, it is effective to exert the slag squeezing effect, which is one of the effects when ESR is applied, but only the surface layer must be pulled out in a solidified state.ヽ Since applying the continuous forging method, there is a possibility that defects such as center segregation, especially in high alloys, may occur, and a solidification space that is an important effect of ESR is reduced to obtain a fine uniform structure However, there is a problem that the effect cannot be obtained.
[0005] 本発明の目的は、铸塊引き抜き動作における凝固したスラグの悪影響を排除し、凝 固鋼塊の偏祈の防止と組織の微細化を達成するとともに、鋼塊肌を改善できる新し V、合金溶湯の铸造方法を提供することである。  [0005] The object of the present invention is to eliminate the adverse effects of solidified slag in the lump extraction operation, to prevent the praying of the solid steel ingot and to refine the structure, and to improve the steel ingot skin. V, to provide a method for producing molten alloy.
課題を解決するための手段  Means for solving the problem
[0006] 本発明者等は、溶湯を、スラグを配置した凝固空間へ铸造速度にて 0. 3mZ分以 下という極低速の条件で供給することでも、 ESRに近似する凝固空間の小さな溶湯 プールが形成できることを見出し、さらに、スラグによる、溶湯プール表面の断熱及び 外気遮断の作用によって、微細均一組織をもった铸塊を得ることができることを見出 した。しかし、この方法によっても、铸塊外周に存在するスラグ層により、組織微細化 が阻害されたり、スラグ層や凝固シェルにクラックが発生し溶鋼が滲み出したり、ひど Vヽ場合にはブレークアウトすると 、う ESRにはない問題に直面し、その原因の追求を 行った。そして、铸塊の引き抜き時に、水冷モールド内面のメニスカス部に形成した スラグ固化部の一部または全体が偶発的に铸塊と同時に降下すること、または、初期 凝固シェルが固ィ匕スラグ部カゝら離れる際の抵抗で破断することによることを突き止め た。 [0006] The present inventors have provided a molten pool with a small solidification space that approximates ESR even by supplying the molten metal to the solidification space in which the slag is arranged at a very low speed of 0.3 mZ or less at the forging speed. In addition, it was found that a slag lump having a fine uniform structure can be obtained by the action of heat insulation on the surface of the molten metal pool and blocking of the outside air by slag. However, even with this method, the slag layer existing around the mass of the slag hinders the refinement of the structure, cracks occur in the slag layer and the solidified shell, and the molten steel oozes out. I faced a problem that ESR did not have and pursued its cause. At the time of pulling out the lump, part or all of the solidified slag formed on the meniscus portion on the inner surface of the water-cooled mold may accidentally descend simultaneously with the lump, or the initial solidified shell may be I found out that it was due to the breakage caused by the resistance when leaving the car.
そのため、安定操業を実現するためには、铸塊引き抜き動作における凝固したスラ グの悪影響を排除する必要がある。これは、極低速で動的に接触するモールド壁と 凝固シェルならびにスラグの挙動における問題であり、スラグの存在と極低速の溶湯 供給速度を組み合わせた場合の特有の課題と考えられる。  Therefore, in order to realize stable operation, it is necessary to eliminate the adverse effects of solidified slag in the lump extraction operation. This is a problem in the behavior of the mold wall, solidified shell, and slag that are in dynamic contact at extremely low speed, and is considered to be a particular problem when combining the presence of slag and the supply speed of molten metal at very low speed.
本発明者らは、合金溶湯を、銅製、鉄製等の金属製の水冷モールドに向けてスラ グを介して極低速で溶湯を供給して、 ESRのごとき積層凝固を行わせようとする場合 に発生する鋼塊肌の荒れの直接的な原因は、凝固シェルとスラグとの境界近傍、つ まり溶湯プールのメニスカス位置近傍の抜熱が大きすぎ、スラグが広 、範囲で固化し てしまい、断熱層を形成しつつ引き抜かれること、または、初期凝固シェルの破断に あることを突き止め、上記境界付近に保温部材を配置することで、冷却を阻害するこ となく鋼塊肌が著しく改善できることを見出し本発明に到達した。 The inventors of the present invention slurried the molten alloy toward a water-cooled mold made of metal such as copper or iron. The direct cause of the roughening of the steel ingot surface that occurs when laminating and solidifying such as ESR is performed by supplying molten metal at extremely low speed through the joint is near the boundary between the solidified shell and slag. Ascertained that the heat removal near the meniscus position of the molten metal pool was too large, the slag was widened and solidified in a range, pulled out while forming a heat insulation layer, or that the initial solidified shell was ruptured. It has been found that by placing a heat retaining member in the vicinity, the steel ingot skin can be remarkably improved without impeding cooling, and the present invention has been achieved.
[0007] すなわち、本発明は、合金溶湯を保持する容器より、水冷モールド内壁で囲まれ、 かつスラグを配置した凝固空間へ合金溶湯を、 0. 3mZ分以下の铸造速度で注入し 、溶湯プールを形成させつつ凝固させるとともに、合金溶湯の注入速度に応じて、水 冷モールド下部より垂直方向に铸塊を引き抜く合金溶湯の铸造方法であって、水冷 モールド上部には、水冷モールド内壁に連続した内壁形状を有する、スラグからの抜 熱を抑制する保温部材を配置した合金溶湯の铸造方法である。  That is, the present invention injects molten alloy from a container for holding molten alloy into a solidified space surrounded by an inner wall of a water-cooled mold and provided with slag at a forging rate of 0.3 mZ or less. The molten alloy is solidified while forming, and the molten metal is drawn vertically from the lower part of the water-cooled mold according to the injection rate of the molten alloy. The upper part of the water-cooled mold is continuous with the inner wall of the water-cooled mold. This is a method for forging a molten alloy in which a heat retaining member having an inner wall shape and suppressing heat removal from slag is arranged.
本発明においては、铸造の定常状態において、溶湯プールのメニスカス上面位置 が保温部材の配置範囲内になるように制御することが好ま 、。  In the present invention, it is preferable to control so that the upper surface position of the meniscus of the molten pool is within the arrangement range of the heat retaining member in the steady state of forging.
[0008] 本発明における保温部材は、铸塊の引き抜き方向に垂直な断面において下流側 の水冷モールド内壁と実質的に同じ内壁形状を有することが好ましい。  [0008] The heat retaining member in the present invention preferably has an inner wall shape that is substantially the same as the inner wall of the water-cooling mold on the downstream side in a cross section perpendicular to the pulling direction of the lump.
また、保温部材は、黒鉛材料とすることが好ましい。  The heat retaining member is preferably a graphite material.
また、本発明における合金溶湯の铸造速度は、 0. 005-0. lmZ分が好ましぐよ り好ましくは、 0. 005〜0. 08m/分、さらに好ましくは 0. 01〜0. 05m/分である。  Further, the forging speed of the molten alloy in the present invention is preferably 0.005-0.lmZ, more preferably 0.005-0.08 m / min, and still more preferably 0.01-0.05 m / min. Minutes.
[0009] 本発明においては、スラグを、加熱手段により、加熱しつつ、铸造を行なっても良い 。また、本発明において、適用するスラグは融点 500〜1400°Cの低融点スラグを使 用することが望ましい。 [0009] In the present invention, the slag may be forged while being heated by a heating means. In the present invention, the slag to be applied is preferably a low melting point slag having a melting point of 500 to 1400 ° C.
また、スラグの厚さとしては、 20〜： LOOmmとすることが望ましい。  The slag thickness is preferably 20 to: LOOmm.
また、本発明に適用する合金溶湯としては、特に微細組織化と成分偏祈の低減が 困難とされる冷間ダイス鋼、熱間ダイス鋼、高速度工具鋼等の工具鋼、その他高合 金鋼等、または ESR適用の合金に適用することができる。  In addition, the molten alloy applied to the present invention includes tool steels such as cold die steel, hot die steel, and high-speed tool steel, which are difficult to reduce microstructure and component bias, and other high alloy metals. It can be applied to steel, etc., or ESR applied alloys.
具体的には、 Feを主成分として、質量％でじを 3. 0%以下、 Fe以外の金属元素を 5%以上含有する溶湯の铸造に適用することが望ましぐより望ましくは、質量％でじ は 0. 1〜3. 0%の組成の溶湯に適用する。 Specifically, it is more desirable to apply to the fabrication of molten metal containing Fe as a main component and containing 3.0% or less by mass% and 5% or more of a metal element other than Fe, more preferably% by mass. Deji Applies to molten metal with a composition of 0.1 to 3.0%.
発明の効果  The invention's effect
[0010] 本発明によれば、溶湯カゝら直接に、積層凝固鋼塊を得ることができるため、低コスト かつ高い生産性を確保できる。また、本発明は、偏祈の発生、铸肌の劣化しやすい 高合金の製造に適用すれば、工数を飛躍的に低減できるため、特に有効なものとな る。  [0010] According to the present invention, since a laminated solidified steel ingot can be obtained directly from the molten metal, low cost and high productivity can be secured. Further, the present invention is particularly effective when applied to the production of a high alloy that is prone to partial prayer and the skin is liable to deteriorate because the number of man-hours can be dramatically reduced.
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0011] 上述したように、本発明の重要な特徴は、スラグを配置した凝固空間へ溶湯を、極 低速で供給する铸造方法であって、水冷モールド上部に配置した保温部材により、 スラグ力もの抜熱を抑制しつつ铸造することである。  [0011] As described above, an important feature of the present invention is a forging method in which molten metal is supplied to a solidification space in which slag is disposed at an extremely low speed. Forging while suppressing heat removal.
本発明において、具体的には合金溶湯を保持するタンディッシュ等の容器より、水 冷モールド内壁で囲まれ、かつスラグを配置した凝固空間へ合金溶湯を注入するも のとする。  In the present invention, specifically, a molten alloy is poured from a container such as a tundish holding the molten alloy into a solidified space surrounded by the inner wall of the water-cooled mold and provided with slag.
再溶解法のような電極を使わず、積層凝固するためには、合金溶湯を、 0. 3mZ分 以下と ヽぅ極低速の铸造速度で注入し、溶湯プールを形成させつつ供給した溶湯を 速やかに凝固させる。そのために水冷モールド内壁で囲まれた凝固空間とする。 そして、本発明では合金溶湯の注入速度に応じて (すなわち、メニスカス上面位置 を概ね一定の位置に保つように）、水冷モールド下部より垂直方向に铸塊を引き抜く 。これにより、一定形状のメニスカスを形成し、 ESRと類似する微細均一組織の積層 凝固铸塊を得ることができるものである。  In order to stack and solidify without using an electrode as in the remelting method, molten alloy is injected at a very low casting speed of 0.3 mZ or less, and the molten metal supplied while forming a molten pool is quickly To solidify. Therefore, a solidified space surrounded by the inner wall of the water-cooled mold is used. In the present invention, the lump is pulled out from the lower part of the water-cooled mold in the vertical direction according to the injection speed of the molten alloy (that is, the upper surface position of the meniscus is maintained at a substantially constant position). As a result, a meniscus having a fixed shape is formed, and a laminated solidified ingot having a fine uniform structure similar to ESR can be obtained.
[0012] しかし、この方法だけでは、鋼塊の肌荒れ性は改善できず、本発明では、水冷モー ルド上部に、水冷モールド内壁に連続した内壁形状を有する保温部材により、スラグ 力 の抜熱を抑制しつつ铸造する手法を採用した。 [0012] However, this method alone cannot improve the roughness of the steel ingot. In the present invention, the heat retaining member having the inner wall shape continuous with the inner wall of the water-cooled mold is provided at the upper part of the water-cooled mold to remove heat from the slag force. The method of forging while suppressing was adopted.
この保温部材により、凝固シェルとの境界においてスラグが過度に凝固するのを抑 制することができ、铸塊の引き抜きによる固ィ匕スラグの同時降下や凝固シェル破断が 抑制されるため、偶発的なスラグのクラックある 、は未発達の凝固シェルのクラックに よる溶鋼の滲み出しの防止ができ、鋼塊肌を改善することができるだけでなぐ铸塊 の冷却を向上することができる。 [0013] なお、本発明において水冷モールド内壁に連続した内壁形状としているのは、不 連続の大きな段差あるいは間隙になって 、ると、形成された凝固シェルがモールド壁 面を摺動する際に余計な応力が作用して、凝固シェルが破壊されてしまい铸塊肌が 劣化するためである。 This heat retaining member can prevent the slag from solidifying excessively at the boundary with the solidified shell, and the simultaneous lowering of the solid slag and the solidified shell rupture caused by pulling out the lumps can be suppressed. If there is a crack in the slag, it is possible to prevent the molten steel from seeping out due to a crack in the undeveloped solidified shell and to improve the cooling of the ingot, as well as improving the skin surface of the ingot. In the present invention, the inner wall shape continuous to the inner wall of the water-cooled mold is a discontinuous large step or gap. When the formed solidified shell slides on the mold wall surface, This is because extra stress acts to destroy the solidified shell and deteriorate the lump skin.
また、保温部材の内壁に生成した不安定な凝固シェルを、余分な応力を与えない で下流側の水冷モールド内壁に誘導するためには、保温部材の形状としては、铸塊 の弓 Iき抜き方向に垂直な断面にお 、て下流側の水冷モールド内壁と実質的に同じ 内壁形状とすることが有効である。  In addition, in order to guide the unstable solidified shell generated on the inner wall of the heat insulation member to the inner wall of the water-cooled mold on the downstream side without applying extra stress, the shape of the heat insulation member is the lump of the lump I It is effective to make the inner wall shape substantially the same as the inner wall of the water-cooling mold on the downstream side in the cross section perpendicular to the direction.
[0014] 本発明における保温部材の配置位置は、スラグからの抜熱を抑制する効果のある 範囲にする。  [0014] In the present invention, the arrangement position of the heat retaining member is set in a range having an effect of suppressing heat removal from the slag.
また、スラグの凝固がもっとも悪影響を与えるのは、モールド近傍におけるスラグと 溶湯プールのメニスカスとの境界、即ち凝固シェルの形成位置である。  Moreover, the solidification of slag has the most adverse effect on the boundary between the slag and the meniscus of the molten metal pool near the mold, that is, the formation position of the solidified shell.
そして、本発明は動的に铸造を行うものであり、铸造の定常状態において、特に凝 固シェルの形成位置に保温部材によるスラグ力 の抜熱抑制効果を発揮させること が有効である。  The present invention dynamically performs forging, and in the steady state of forging, it is effective to exhibit the effect of suppressing heat removal of the slag force by the heat retaining member particularly at the position where the solidified shell is formed.
凝固シェルの形成位置は、溶湯プールのメニスカス上面位置に近接し、メニスカス 上面位置は、制御対象として検出しやすいので、上記目的のためには、铸造の定常 状態において、溶湯プールのメニスカス上面位置が保温部材の配置範囲内になるよ うに制御することが望ま 、ものとなる。  The formation position of the solidified shell is close to the upper surface position of the meniscus of the molten pool, and the upper surface position of the meniscus is easy to detect as a control target.For this purpose, the upper surface position of the meniscus of the molten pool is in the steady state of forging. It would be desirable to control the temperature keeping member within the range of arrangement.
[0015] 本発明にお ヽて、凝固シェルとスラグとの境界近傍に配置した保温部材の下端位 置は、保温部材により水冷モールドを覆いすぎると、本来の冷却機能を劣化するため 、湯面制御位置 (メニスカス上面位置)から下方 100mmまでの範囲とすることが好ま しぐまた铸造期間中の湯面制御位置の変動を考慮すると、保温部材の下端位置は 、メニスカス上面位置から下方 10mmの範囲は避けることが好ましい。 [0015] In the present invention, the lower end position of the heat retaining member disposed in the vicinity of the boundary between the solidified shell and the slag deteriorates the original cooling function if the water cooling mold is covered too much by the heat retaining member. It is preferable to set the range from the control position (meniscus upper surface position) to 100 mm below, and considering the fluctuation of the hot water surface control position during the forging period, the lower end position of the heat retaining member is within 10 mm below the meniscus upper surface position. Is preferably avoided.
一方、保温部材の上端位置は、スラグ上面を超えて配置させることが好ましい。保 温部材の設置におけるハンドリング性とスラグ全域の保温のためである。  On the other hand, it is preferable to arrange the upper end position of the heat retaining member beyond the upper surface of the slag. This is for easy handling in the installation of heat insulation members and for heat insulation throughout the slag.
さらに、保温部材内面でのスラグ固化の成長を抑制するために、スラグ層部に相当 する領域の保温部材を厚くすることや、保温部材外周部にさらに断熱層を設けること 等で熱の損失を抑制することも、必要に応じて適用することができる。 Furthermore, in order to suppress the growth of slag solidification on the inner surface of the heat retaining member, the heat retaining member in the region corresponding to the slag layer portion is made thicker or a heat insulating layer is further provided on the outer peripheral portion of the heat retaining member. It is also possible to suppress the heat loss with a method as necessary.
[0016] 本発明における保温部材としては、耐熱性に加えて、耐スラグ侵食性に優れ、且つ 摺動性に優れた材料とすることが好ましい。セラミックス等でも良いが、摺動性に関し ては黒鉛含有のセラミックス等が有効であり、さらに耐スラグ侵食性、成形性および摺 動性に優れた黒鉛材料を配置することが好ましい。  [0016] The heat-retaining member in the present invention is preferably made of a material excellent in slag erosion resistance and slidability in addition to heat resistance. Ceramics or the like may be used. However, regarding the slidability, graphite-containing ceramics and the like are effective, and it is preferable to dispose a graphite material having excellent slag erosion resistance, formability, and slidability.
[0017] なお、本発明にお 、て合金を保持する容器としては、タンディッシュと呼ばれるもの の他、どのようなものであっても構わない。たとえば必要に応じて加熱手段を持つもの でも良い。  [0017] In the present invention, any container other than what is called a tundish may be used as a container for holding an alloy. For example, it may have a heating means if necessary.
また、水冷モールドによって形成される铸型の形状は、凝固形態の均一性力 は円 形が好ましいが、铸塊形状と製造性等を考慮し、楕円や矩形としても良い。また、水 冷モールドの材質として、凝固空間を小さくするために、鉄製や銅製等の熱伝導特 性に優れた金属製の水冷モールドとすることが望ましい。  In addition, the shape of the bowl formed by the water-cooled mold is preferably a round shape uniformity force, but may be an ellipse or a rectangle in consideration of the lump shape and manufacturability. As a material for the water-cooled mold, it is desirable to use a metal water-cooled mold having excellent heat conduction characteristics such as iron or copper in order to reduce the solidification space.
[0018] 本発明にお ヽて、スラグは、介在物の捕獲や溶湯の脱硫と!/ヽつた精練作用に加え て、溶湯プール表面の断熱及び外気遮断にとって重要である。 [0018] In the present invention, slag is important for insulating the surface of the molten metal pool and blocking outside air, in addition to trapping inclusions, desulfurizing the molten metal, and!
また、本発明においては、溶湯の供給方法を限定する物ではないが、合金溶湯を スラグを通過する如ぐ注入すると、スラグによるスラグ反応による精鍊効果の向上を期 待できる。しかし、この場合は注入時の溶湯流によってスラグが力べはんされ、铸塊に 捕獲され介在物となる恐れもある。一方、溶湯プールにまで達する浸漬ノズルを使用 して溶湯を供給すると、スラグ反応による精鍊効果は大きくは期待出来ないが、スラ ダカべはんによる介在物の発生は抑制できる。従って、本発明における溶湯の供給 方法は、スラグとの関係を考慮し、要求される品質に基づいて適宜選択することが望 ましい。  In the present invention, the method for supplying the molten metal is not limited. However, when the molten alloy is injected so as to pass through the slag, it is possible to expect an improvement in the refining effect due to the slag reaction by the slag. However, in this case, the slag is forced by the molten metal flow at the time of pouring and may be trapped in the lump and become inclusions. On the other hand, if the molten metal is supplied using an immersion nozzle that reaches the molten metal pool, the effect of slag reaction cannot be expected to be significant, but the generation of inclusions due to the slurry can be suppressed. Therefore, it is desirable that the molten metal supply method in the present invention is appropriately selected based on the required quality in consideration of the relationship with the slag.
また、本発明者等の実験によれば、スラグの特性を調整することで、 ESRには無い 以下の新 、効果を得ることができる。  In addition, according to experiments by the present inventors, the following new effects not found in ESR can be obtained by adjusting the slag characteristics.
[0019] まず、スラグには精鍊効果と、溶湯プール表面の断熱と外気との遮蔽の作用がある 力 1400°Cを超える融点を有するスラグでは、溶湯からの伝熱だけでは、十分に液 化できない場合があり、溶湯プールを囲むスラグ固化層シェルが発達しすぎて、铸塊 外層に異常組織が深く形成する場合がある。これに対して、 1400°C以下のスラグで は、溶湯力ゝらの熱を受けてスラグの固化が抑制され铸塊外層の異常組織形成が著し く抑制される。また、このような低融点スラグは、粘性も低く铸塊表面に不必要に厚い スラグスキンが形成されな 、と 、う効果もある。 [0019] First, slag has the effect of scouring, heat insulation on the surface of the molten pool, and shielding against outside air. For slag having a melting point exceeding 1400 ° C, slag is sufficiently liquefied only by heat transfer from the molten metal. In some cases, the solidified shell of the slag surrounding the molten metal pool develops too much, and abnormal tissue may form deeply in the outer layer of the lump. In contrast, with slag of 1400 ° C or less In response to heat from the molten metal, solidification of the slag is suppressed, and abnormal tissue formation in the outer layer of the lump is remarkably suppressed. In addition, such a low melting point slag has a low viscosity and has an effect that an unnecessarily thick slag skin is not formed on the lump surface.
[0020] また、本発明は、 ESRのような電極からのジュール熱による熱エネルギーの供給で はなぐあら力じめ溶けた溶湯を使用するため、スラグへの特別な加熱手段は必ずし も必要ではない。しかし、スラグの温度コントロールのために、別途加熱手段を設ける こともできる。加熱手段としてはスラグ通電で得られるジュール熱の利用が簡便で有 効な手段である。スラグ全体の温度を上げず、保温部材内面でのスラグ固化成長を 抑えるには、スラグ外周部に集中して電気が流れるように通電用電極を設置すること が好ましい。スラグを加熱することで、表層異常組織の生成を抑制することができ、融 点の高 、スラグの有害性を緩和することができる。過度に高温までスラグを加熱する と、スラグ力も溶湯への熱移動がおこるため、冷却速度が遅くなる。スラグ温度として は铸込み温度以下が好ま U、。  [0020] In addition, the present invention uses a molten metal that is melted by the heat energy supplied by the Joule heat from the electrode, such as ESR, so a special heating means for the slag is always required. is not. However, a separate heating means can be provided to control the slag temperature. As a heating means, the use of Joule heat obtained by slag energization is simple and effective. In order to suppress slag solidification growth on the inner surface of the heat retaining member without increasing the temperature of the entire slag, it is preferable to install a current-carrying electrode so that electricity flows in a concentrated manner on the outer periphery of the slag. By heating the slag, it is possible to suppress the formation of an abnormal structure of the surface layer, and to reduce the harmfulness of the slag with a high melting point. If the slag is heated to an excessively high temperature, the slag force is also transferred to the molten metal, resulting in a slow cooling rate. The slag temperature is preferably below the penetration temperature.
[0021] さらに、このような低融点スラグの適用は、保温部材の効果と合わさって、適度なス ラグ固化層が保温部材側に形成され、铸塊と水冷モールドの間に殆どスラグが侵入 せず、かつ凝固シェルにクラックの発生を抑制できる。これにより、溶湯と水冷モール ドとの直接接触が回避され、良好な铸肌のまま水冷モールドに沿って引き抜くことが できるため、好ましいものとなる。  Furthermore, the application of such a low-melting-point slag is combined with the effect of the heat retaining member, so that an appropriate slag solidified layer is formed on the heat retaining member side, and almost no slag penetrates between the lump and the water-cooled mold. And the occurrence of cracks in the solidified shell can be suppressed. As a result, direct contact between the molten metal and the water-cooled mold is avoided, and the molten metal can be pulled out along the water-cooled mold while maintaining a good skin surface, which is preferable.
なお、スラグとして融点 500°C以下のものは、現実的ではなぐ 500〜1400°Cの低 融点スラグを使用するのが望ましい。  In addition, it is desirable to use slag with a melting point of 500 ° C or lower, which is not practical, but a low melting point slag of 500 to 1400 ° C.
このようなスラグの効果を得るためには、スラグ層の厚さは 20mm以上が好ましぐ 最適な厚さ範囲は 20mn！〜 1 OOmmである。  In order to obtain this slag effect, the thickness of the slag layer is preferably 20mm or more. The optimum thickness range is 20mn! ~ 1 OOmm.
[0022] また、本発明において、合金溶湯の铸造速度を、 0. 3mZ分以下としたのは、速す ぎると、積層凝固の目的とする偏祈の少ない均質な組織が得にくくなること、溶湯中 へのスラグ巻き込みのおそれがあるためである。より好ましくは 0. lmZ分以下、さら に望ましくは 0. 05mZ分以下である。生産性を考慮すれば、 0. 005mZ分以上、よ り好ましくは 0. OlmZ分以上とすることが望ましい。  [0022] In the present invention, the forging rate of the molten alloy is set to 0.3 mZ or less because if it is too fast, it is difficult to obtain a homogeneous structure with less bias for the purpose of lamination and solidification. This is because slag may be caught inside. More preferably, it is less than or equal to 0.0 lmZ, and more preferably less than or equal to 0.05 mZ. In consideration of productivity, it is desirable that the content be 0.005 mZ or more, more preferably 0.005 mZZ or more.
実施例 1 [0023] 本発明を実施する装置を使用した本発明の铸造工程の一例を図 1に示す。図 1は 装置断面を示すものであり、合金溶湯 11を保持するタンディッシュ 10,鉄製の水冷 モールド 2,铸塊の引き抜きを行う昇降装置 20を具備する装置である。そして、水冷 モールド上部には、保温部材として黒鉛スリーブ 3を配置している。水冷モールドの 形状は、長さ 400mmであり、黒鉛スリーブを配置する上部 200mm部分の内径は 47 lmmで下部内径は 450mmである。長さ 200mmで内径 450mm、外径 470mmの 黒鉛スリーブが水冷モールド上部に内装されている。水冷モールド下方には 2次冷 却帯 30を配置している。 Example 1 [0023] Fig. 1 shows an example of a forging process of the present invention using an apparatus for carrying out the present invention. FIG. 1 shows a cross section of the device, which is a device including a tundish 10 for holding a molten alloy 11, a water-cooled mold made of iron 2, and a lifting device 20 for pulling out a lump. A graphite sleeve 3 is disposed as a heat retaining member on the upper part of the water cooling mold. The shape of the water-cooled mold is 400mm in length, the inner diameter of the upper 200mm part where the graphite sleeve is placed is 47lmm and the lower inner diameter is 450mm. A graphite sleeve with a length of 200 mm, an inner diameter of 450 mm, and an outer diameter of 470 mm is installed inside the water-cooled mold. A secondary cooling zone 30 is located below the water cooling mold.
また、付加装置として、合金溶湯と外気を遮断するシールド 14およびスラグ通電電 極 15を配置可能としている。  In addition, a shield 14 and a slag energizing electrode 15 that block molten alloy and outside air can be disposed as additional devices.
[0024] 図 1に示す装置において、合金溶湯 11を保持したタンディッシュ 10の底部に設け たノズル 12から溶湯流 13として、スラグ 1を配置した凝固空間となる水冷モールド 2に 注入する。なお、スラグは、あらカゝじめ溶解したものを铸造初期にモールドに導入す ることで配置したものである。 In the apparatus shown in FIG. 1, a molten metal flow 13 is injected from a nozzle 12 provided at the bottom of a tundish 10 holding a molten alloy 11 into a water-cooled mold 2 serving as a solidification space in which the slag 1 is disposed. In addition, the slag is arranged by introducing the melted slag into the mold at the initial stage of fabrication.
そして、水冷モールド 2に内装した保温部材である黒鉛スリーブ 3の下端「B」より 50 mmにメニスカス上面位置「A」を有する溶湯プール 4を形成するように制御する。こ れにより、保温部材内壁側に凝固シェルを形成することができる。  Then, the molten metal pool 4 having the meniscus upper surface position “A” is controlled to be formed 50 mm from the lower end “B” of the graphite sleeve 3 which is a heat retaining member built in the water cooling mold 2. Thereby, a solidified shell can be formed on the inner wall side of the heat retaining member.
具体的には合金溶湯 11の注入量に合わせて、昇降装置 20を降下して铸塊 5を引 き抜くことで、一定のメニスカス位置を保ちつつ、積層凝固を進行させることができる 。また、水冷モールド力 抜け出た铸塊は 2次冷却帯 30でミスト冷却されるようにして いる。  Specifically, in accordance with the injection amount of the molten alloy 11, the elevating device 20 is lowered and the lump 5 is pulled out, so that the lamination and solidification can be advanced while maintaining a constant meniscus position. In addition, the lump that has escaped from the water-cooling mold force is mist cooled in the secondary cooling zone 30.
[0025] 図 1の装置を用いて、铸造実験を行った。なお、スラグ通電電極 15は用いていない タンディッシュに溶湯を保持し、表 1に示す組成及び融点を有するスラグを 50mm の厚さで配置して水冷モールドに铸造を行った。溶湯は質量。/ oJIS SKD11、 SKH 51相当の 2鋼種を用いた。溶湯の成分を表 2に示す。  [0025] A forging experiment was conducted using the apparatus of FIG. The molten metal was held in a tundish that did not use the slag energizing electrode 15, and slag having the composition and melting point shown in Table 1 was arranged in a thickness of 50 mm, and the water-cooled mold was fabricated. Molten metal is mass. / oJIS SKD11, SKH 51 equivalent steel grade was used. Table 2 shows the components of the molten metal.
溶湯温度を 1500°Cとし、铸造速度は、 0. 02mZ分（20mmZ分)相当として 3mま で铸造を行った。 また、比較例として、図 1の装置において黒鉛スリーブ (保温部材)を設置しないで铸 造を行った。 The casting temperature was set to 1500 ° C and the casting speed was equivalent to 0.02 mZ (20 mmZ), and the casting was carried out to 3 m. Further, as a comparative example, the apparatus of FIG. 1 was manufactured without installing a graphite sleeve (heat insulating member).
[0026] 得られた铸塊のスキンスラグの厚さを表 3に示す。また铸塊長さの 2分の 1の位置の 横断面試料の表面から DZ8、 DZ4および DZ2の位置（Dは铸塊の直径)で 2次デ ンドライトアーム間隔 DASIIの値を測定した結果を表 4に示す。  [0026] Table 3 shows the thickness of the skin slag of the obtained lump. The measurement result of the secondary dendrite arm spacing DASII at the positions of DZ8, DZ4, and DZ2 (D is the diameter of the clot) from the surface of the cross-section sample at a half of the clot length. Table 4 shows.
表 3より本発明では保温部材の効果で、平滑な表面の铸塊が得られ、スキンスラグ の実質的にない铸塊が得られることがわかる。比較例ではスラグ固化層が铸塊と同 時に引抜かれるため数 mm厚と ヽぅ極めて厚 ヽスラグスキンが形成されて ヽることが ゎカゝる。  From Table 3, it can be seen that in the present invention, a smooth surface koji is obtained by the effect of the heat retaining member, and a koji lump substantially free of skin slag is obtained. In the comparative example, since the slag solidified layer is pulled out at the same time as the lump, a very thick slag skin is formed.
表 2に示すように、スキンスラグの形成が実質的にない本発明では、冷却速度の指 標である DASIIの値が小さぐ微細な組織が得られていることがわ力る。  As shown in Table 2, in the present invention in which skin slag is not substantially formed, it can be understood that a fine structure having a small value of DASII which is an index of cooling rate is obtained.
[0027] 次に得られた铸塊を 1100°Cで 115mm角までに熱間鍛造を行なった。 115角铸片 表面を 2mm研削した後、ダイマークを行ない疵の有無を調査した。その結果を表 5 に示す。 [0027] Next, the obtained ingot was hot forged at 1100 ° C to 115mm square. The surface of the 115 square pieces was ground by 2mm, and then a die mark was made to investigate the presence of wrinkles. The results are shown in Table 5.
本発明ではスラグスキンがなく平滑表面铸塊のため、熱間鍛造時の疵発生がな 、 ことがわかる。一方、比較例では厚いスラグスキンが形成し、铸塊表面に不規則な溶 湯浸出しがあり、熱間鍛造時に疵が発生し、 2mmの研削で取れきれない疵が存在 することが確認された。  In the present invention, since there is no slag skin and smooth surface lumps, it is understood that no creases are generated during hot forging. On the other hand, in the comparative example, it was confirmed that thick slag skin was formed, irregular melt leaching occurred on the surface of the ingot mass, soot was generated during hot forging, and there were soot that could not be removed by 2 mm grinding. It was.
[0028] [表 1] スラグ組成 (massQ/o)
Figure imgf000011_0001
[0028] [Table 1] Slag composition (massQ / o)
Figure imgf000011_0001
[0029] [表 2] 溶湯組成 (mass%)[0029] [Table 2] Molten metal composition (mass%)
Figure imgf000012_0001
Figure imgf000012_0001
[0030] [表 3]  [0030] [Table 3]
スキンスラグ厚さ Skin slag thickness
Figure imgf000012_0002
Figure imgf000012_0002
[0031] [表 4]  [0031] [Table 4]
DASII測定結果 DASII measurement results
Figure imgf000012_0003
Figure imgf000012_0003
[0032] [表 5] 研削後の残疵状況  [0032] [Table 5] Residue after grinding
保温部材 銅種 残疵 有り SKD11 無し 本発明  Insulation material Copper type Residue Yes SKD11 No This invention
有り SKH51 無し 無し SKD11 有り 比較例  Yes SKH51 No No SKD11 Yes Comparative example
無し SKH51 有り 実施例 2 None SKH51 Available Example 2
[0033] 実施例 1に示す装置にスラグ通電電極 15を付加して、铸造実験を行った。スラグ通 電電極 15としては、円筒状黒鉛電極を用いた。スラグ通電電極 15を表 1に示す組成 のスラグに浸漬し、スラグに通電してスラグ加熱を行い、同時に黒鉛電極と湯面の中 間位置で温度を測定し、電流値によりスラグ温度を 1400°Cに制御した。スラグの厚さ は、 50mmであり、溶湯成分は、表 2に示す SKD11である。  A slag energizing electrode 15 was added to the apparatus shown in Example 1, and a forging experiment was performed. As the slag conducting electrode 15, a cylindrical graphite electrode was used. The slag energizing electrode 15 is immersed in the slag having the composition shown in Table 1, and the slag is energized to heat the slag. At the same time, the temperature is measured between the graphite electrode and the molten metal surface. Controlled to C. The slag thickness is 50 mm, and the molten metal component is SKD11 shown in Table 2.
また、その他の条件は、実施例 1と同様に溶湯温度を 1500°Cとし、铸造速度は、 0 . 02mZ分（20mmZ分)相当として 3mまで铸造を行った。  The other conditions were the same as in Example 1, except that the molten metal temperature was 1500 ° C., and the forging speed was 0.02 mZ (20 mmZ) equivalent to 3 m.
[0034] その結果、スラグ通電による加熱を実施しても、铸塊は平滑でスキンスラグの形成 は実質的に無 、ことを確認した。  [0034] As a result, it was confirmed that even when heating by slag energization was performed, the lump was smooth and skin slag was not substantially formed.
また、得られた铸塊の長手方向の 2分の 1の位置の横断面試料の表面近傍の組織 を観察し表層異常組織深さを表 6に表面力も DZ8, DZ4および DZ2の位置 (Dは 铸塊の直径)での DASIIの測定値を表 7に示す。  In addition, the structure in the vicinity of the surface of the cross-sectional specimen at a half position in the longitudinal direction of the obtained lumps was observed, and the surface abnormal tissue depth is shown in Table 6 and the surface forces are also in the positions of DZ8, DZ4 and DZ2 (D is Table 7 shows the measured values of DASII in the diameter of the lump.
表 6より、スラグ加熱によるスラグ温度制御により、スラグ固化層の成長を抑制でき、 铸塊表面の組織の均一化が促進されていることがわかる。また、表 7より、 1400°Cへ のスラグ加熱は DASIIの値にほとんど影響がなく微細組織が維持されていることがわ かる。これは、スラグ加熱を行なってもスキンスラグがないために、水冷モールドでの 抜熱および 2次冷却帯での抜熱が進行しているためと考えられる。  From Table 6, it can be seen that slag temperature control by slag heating can suppress the growth of the solidified slag layer and promote homogenization of the texture of the lump surface. Table 7 also shows that slag heating to 1400 ° C has almost no effect on the DASII value and maintains a fine structure. This is thought to be because heat removal in the water-cooled mold and heat removal in the secondary cooling zone are progressing because there is no skin slag even after slag heating.
[0035] このように、スラグ加熱を行なっても平滑铸塊が得られるため、その後、 115角への 熱間鍛造後、 2mm研削でのダイマークで残疵の確認をおこなった力 実施例 1の保 温部材使用の铸塊同様に、残疵は皆無であった。  [0035] In this way, a smooth lump can be obtained even if slag heating is performed. After that, after hot forging to 115 squares, the force used to confirm the residue with a die mark in 2mm grinding Example 1 There was no residue, as was the case with the heat insulation material.
[0036] [表 6] 表面異常組織深さ (SKD11)  [0036] [Table 6] Surface abnormal tissue depth (SKD11)
保温部材 スラグ加熱 表面異常組織深  Thermal insulation material Slag heating Surface abnormal texture depth
さ  The
(mm)  (mm)
本発明 有り 有り 3 本発明 有り 無し 1 1 [0037] [表 7] Present invention Present Available 3 Present invention Present None 1 1 [0037] [Table 7]
DAS Π測定結果 DAS Π measurement results
Figure imgf000014_0001
産業上の利用可能性
Figure imgf000014_0001
Industrial applicability
[0038] 本発明によれば、このような急冷凝固を行うことで金属組織の微細化が図られ低コ ストで鋼材性能に優れる鉄鋼材料を供給することでき、省資源'省エネルギーという 観点でも広く需要が見込まれる。  [0038] According to the present invention, by performing such rapid solidification, it is possible to supply a steel material that is refined in metal structure and is excellent in steel material performance at low cost, and is also widely used from the viewpoint of resource saving and energy saving. Demand is expected.
図面の簡単な説明  Brief Description of Drawings
[0039] [図 1]本発明を適用する装置の一例を示す概念図である。 FIG. 1 is a conceptual diagram showing an example of an apparatus to which the present invention is applied.

Claims

請求の範囲 The scope of the claims
[1] 合金溶湯を保持する容器より、水冷モールド内壁で囲まれ、かつスラグを配置した 凝固空間へ合金溶湯を 0. 3mZ分以下の铸造速度で注入し、溶湯プールを形成さ せつつ凝固させるとともに、合金溶湯の注入速度に応じて、水冷モールド下部より垂 直方向に铸塊を引き抜く合金溶湯の铸造方法であって、水冷モールド上部には、水 冷モールド内壁に連続した内壁形状を有する、スラグからの抜熱を抑制する保温部 材を配置する、合金溶湯の铸造方法。  [1] From the container holding the molten alloy, the molten alloy is poured at a forging speed of 0.3 mZ or less into the solidification space surrounded by the inner wall of the water-cooled mold and slag, and solidified while forming a molten pool. In addition, according to the injection speed of the molten alloy, the molten alloy is forged from the lower part of the water-cooled mold in the vertical direction, and the upper part of the water-cooled mold has an inner wall shape continuous with the inner wall of the water-cooled mold. A method for forging molten alloy, in which a heat insulating material that suppresses heat removal from the slag is disposed.
[2] 铸造の定常状態において、溶湯プールのメニスカス上面位置が保温部材の配置範 囲内になるように制御される請求項 1に記載の合金溶湯の铸造方法。  [2] The method for forging a molten alloy according to claim 1, wherein, in a steady state of forging, the upper surface position of the meniscus of the molten pool is controlled to be within an arrangement range of the heat retaining member.
[3] 保温部材は、铸塊の引き抜き方向に垂直な断面において下流側の水冷モールド 内壁と実質的に同じ内壁形状を有する請求項 1または請求項 2に記載の合金溶湯の 铸造方法。  [3] The method for producing molten alloy according to claim 1 or 2, wherein the heat retaining member has an inner wall shape substantially the same as the inner wall of the water-cooling mold on the downstream side in a cross section perpendicular to the drawing direction of the lump.
[4] 保温部材は、黒鉛材料である請求項 1から請求項 3までのいずれか 1項に記載の 合金溶湯の製造方法。  [4] The method for producing molten alloy according to any one of claims 1 to 3, wherein the heat retaining member is a graphite material.
[5] 合金溶湯の铸造速度が、 0. 01〜0. 05mZ分である請求項 1から請求項 4までの いずれか 1項に記載の合金溶湯の铸造方法。  [5] The method for forging a molten alloy according to any one of claims 1 to 4, wherein the forging speed of the molten alloy is 0.01 to 0.05 mZ.
[6] スラグを、加熱手段により、加熱しつつ、铸造を行う請求項 1から請求項 5までのい ずれか 1項に記載の合金溶湯の製造方法。 6. The method for producing a molten alloy according to any one of claims 1 to 5, wherein the slag is forged while being heated by a heating means.
[7] スラグの融点が 500〜1400°Cである請求項 1から請求項 6までのいずれ力 1項に 記載の合金溶湯の铸造方法。 [7] The method for forging a molten alloy according to any one of claims 1 to 6, wherein the melting point of the slag is 500 to 1400 ° C.
[8] スラグ厚さが 20〜： LOOmmである請求項 1から請求項 7までのいずれ力 1項に記載 の合金溶湯の铸造方法 [8] The method for producing molten alloy according to any one of claims 1 to 7, wherein the slag thickness is 20 to: LOOmm
[9] 合金溶湯は、 Feを主成分として、質量％でじ 3. 0%以下、 Fe以外の金属元素を[9] The molten alloy should contain Fe as the main component and not more than 3.0% by mass% and contain metallic elements other than Fe.
5%以上含有する請求項 1から請求項 8までのいずれか 1項に記載の合金溶湯の铸 造方法。 The method for producing a molten alloy according to any one of claims 1 to 8, comprising 5% or more.
PCT/JP2006/307484 2005-04-11 2006-04-07 Process for the casting of molten alloy WO2006109739A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015180509A (en) * 2014-03-04 2015-10-15 日立金属株式会社 casting method and casting mold
KR20200032369A (en) * 2018-09-18 2020-03-26 현대제철 주식회사 Slag discharging apparatus for tundish

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9994925B2 (en) * 2015-02-04 2018-06-12 Hitachi Metals, Ltd. Cold work tool material, cold work tool and method for manufacturing same
CN104624990B (en) * 2015-02-26 2023-08-25 周嘉平 Copper pipe of uniform cooling crystallizer and manufacturing method thereof
CN113458352B (en) * 2020-03-30 2023-11-24 日本碍子株式会社 Method for producing Cu-Ni-Sn alloy and cooler for use in same

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS624840A (en) 1985-06-29 1987-01-10 Daido Steel Co Ltd Refining method for metal
EP0448773A2 (en) 1990-03-30 1991-10-02 Nippon Steel Corporation Continuous caster mold and continuous casting process
JPH10328792A (en) 1997-06-04 1998-12-15 Nippon Steel Corp Continuous casting method
JPH11300448A (en) 1998-04-20 1999-11-02 Nippon Steel Corp Casting mold for continuous casting
JP2003181606A (en) * 2001-12-12 2003-07-02 Nippon Steel Metal Prod Co Ltd MOLD FLUX FOR CONTINUOUSLY CASTING STEEL HAVING HIGH Al, Y AND REM CONTENTS
JP2004098092A (en) 2002-09-06 2004-04-02 Sumitomo Metal Ind Ltd Method for continuously casting molten hyper-peritectic medium carbon steel

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5370037A (en) * 1976-12-03 1978-06-22 Kobe Steel Ltd Casting method
JPS5468724A (en) * 1977-11-11 1979-06-02 Hitachi Ltd Electroslag casting apparatus
DE3340844C1 (en) * 1983-11-11 1984-12-20 Mannesmann AG, 4000 Düsseldorf Continuous casting mold with cooling device for casting metal, especially steel
JPS6340664A (en) * 1986-08-05 1988-02-22 Chuetsu Gokin Chuko Kk Water cooled casting mold for melting and refining of metal
US6192970B1 (en) * 1999-04-28 2001-02-27 Rivindra V. Tilak Independently positioned graphite inserts in annular metal casting molds
CN2617499Y (en) * 2003-05-14 2004-05-26 中国科学院金属研究所 Continuous monotectic alloy sheet caster
CN1276811C (en) * 2004-07-28 2006-09-27 东北大学 Water seam-split body internal water cooling type flexible contact electromagnetic continuous casting crystallizer
JP4505811B2 (en) * 2005-04-11 2010-07-21 日立金属株式会社 Casting method for molten alloy

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS624840A (en) 1985-06-29 1987-01-10 Daido Steel Co Ltd Refining method for metal
EP0448773A2 (en) 1990-03-30 1991-10-02 Nippon Steel Corporation Continuous caster mold and continuous casting process
JPH10328792A (en) 1997-06-04 1998-12-15 Nippon Steel Corp Continuous casting method
JPH11300448A (en) 1998-04-20 1999-11-02 Nippon Steel Corp Casting mold for continuous casting
JP2003181606A (en) * 2001-12-12 2003-07-02 Nippon Steel Metal Prod Co Ltd MOLD FLUX FOR CONTINUOUSLY CASTING STEEL HAVING HIGH Al, Y AND REM CONTENTS
JP2004098092A (en) 2002-09-06 2004-04-02 Sumitomo Metal Ind Ltd Method for continuously casting molten hyper-peritectic medium carbon steel

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
M. BOBADILLA: "Continuous casting of steel: a close connection between solidification studies and industrial process development", MATERIALS SCIENCE AND ENGINEERING, vol. A173, 1993, pages 275 - 285, XP002484916, DOI: doi:10.1016/0921-5093(93)90229-8
See also references of EP1870182A4 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015180509A (en) * 2014-03-04 2015-10-15 日立金属株式会社 casting method and casting mold
KR20200032369A (en) * 2018-09-18 2020-03-26 현대제철 주식회사 Slag discharging apparatus for tundish
KR102166604B1 (en) 2018-09-18 2020-10-16 현대제철 주식회사 Slag discharging apparatus for tundish

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JP4548483B2 (en) 2010-09-22
EP1870182A1 (en) 2007-12-26
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CN101155653B (en) 2011-11-16
EP1870182B1 (en) 2016-10-19
EP1870182A4 (en) 2009-01-14

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