JP2006175505A - Method and device for producing remelted raw material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for producing a remelted raw material where fine crushed matters suitable for remelting can be made, thus troublesome cutting operation is not required, further, neither reduction of a yield nor rise of cost due to cutting operation is caused, and, even in the case they include a high melting point material or a high vapor pressure material, among the obtained crushed matters, the ones having a nearly uniform composition can be obtained. <P>SOLUTION: When a remelted raw material is produced by vacuum-sucking molten metal floated and melted in a cold crucible furnace into a mold and solidifying the same, the molten metal is vacuum-sucked into the mold at which a plurality of mutually communicating small chambers are formed at the inside, and is solidified. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for producing a remelted raw material. When producing a relatively large alloy ingot, first, a remelted raw material corresponding to a secondary raw material is produced from a metal raw material having a predetermined composition corresponding to the primary raw material, and then a relatively large alloy ingot is produced from this remelted raw material. Manufacturing is performed. The present invention relates to an improvement in the method and apparatus for producing such a remelted raw material.

  Conventionally, as a method for producing a remelting raw material as described above, a metal melt having a predetermined composition is levitated and melted in the cold crucible furnace using a cold crucible furnace and a vacuum suction casting apparatus connected to the cold crucible furnace. The remelted raw material is casted by vacuum suction into a mold of the vacuum suction casting apparatus and solidifying (see, for example, Patent Documents 1 and 2). In such a conventional method, the remelted raw material produced is finely cut, and the cut product is remelted by a melting means such as a cold crucible furnace, a vacuum arc furnace, a plasma arc furnace, etc., and the remelted molten metal is formed into a mold having a predetermined shape. A relatively large alloy ingot is manufactured by casting into

However, in the conventional method, when a relatively large alloy ingot is produced from the produced remelted raw material, the remelted raw material must be finely cut in preparation for the remelting. In addition to this, there is a problem that this reduces the yield and costs. In the conventional method, when the metal raw material having a predetermined composition corresponding to the primary raw material contains a high melting point material such as Nb, Ta, or Zr, or contains a high vapor pressure material such as Mn or Mg, Remelting raw materials with different compositions are cast depending on the site due to segregation of melting point materials and evaporation of high vapor pressure materials, so if these remelting raw materials are cut finely, some of the cut products may deviate from their intended compositions. There is also a problem that it ends up.
Japanese Unexamined Patent Publication No. 7-16725 Japanese Patent Laid-Open No. 9-10916

  The problem to be solved by the present invention can be easily made into fine crushed materials suitable for remelting, and therefore, troublesome cutting work is not necessary, and there is no decrease in yield and cost increase due to the cutting work. In addition, the present invention provides a method and an apparatus for producing a remelted raw material which becomes a crushed material having a substantially uniform composition among crushed materials obtained even when it contains a high melting point material or a high vapor pressure material.

  The present invention for solving the above-mentioned problems is a method for producing a remelted raw material by sucking and solidifying a molten metal levitated and melted in a cold crucible furnace into a mold under reduced pressure. The present invention relates to a method for producing a remelted raw material characterized by solidifying by vacuum suction into a mold in which a small chamber is formed. The present invention also includes a cold crucible furnace and a vacuum suction casting apparatus connected to the cold crucible furnace, so that the molten metal floated and melted in the cold crucible furnace is solidified by vacuum suction into the mold of the vacuum suction casting apparatus. In the remelted raw material manufacturing apparatus, the mold is formed in a cylindrical shape as a whole, and a fractionation member is accommodated in the mold, and communicates with the interior of the mold by the fractionation member. The present invention relates to a remelting raw material manufacturing apparatus characterized in that a plurality of small chambers are formed.

  First, a method for producing a remelted raw material according to the present invention (hereinafter simply referred to as a production method of the present invention) will be described. Also in the manufacturing method of the present invention, the remelted raw material is manufactured by sucking and solidifying the molten metal levitated and melted in a cold crucible furnace into the mold in the same manner as the conventional method described above. In the production method of the present invention, in the production of such a remelted raw material, the molten metal is solidified by suction under reduced pressure into a mold in which a plurality of chambers communicating with each other are formed. As will be described in detail later, the plurality of small chambers can be formed by accommodating a fractionation member inside a mold.

  Next, the remelting raw material manufacturing apparatus (hereinafter simply referred to as the manufacturing apparatus of the present invention) according to the present invention will be described. The manufacturing apparatus of the present invention also includes a cold crucible furnace and a vacuum suction casting apparatus connected to the cold crucible furnace as in the conventional apparatus described above, and a molten metal floated and melted in the cold crucible furnace is a mold of the vacuum suction casting apparatus. It is designed to be solidified by suction under pressure. In the production apparatus of the present invention, in the remelting raw material production apparatus, the mold is formed in a cylindrical shape as a whole, and a fractionation member is accommodated in the mold, and the fractionation member is used to form the mold. A plurality of chambers communicating with each other are formed inside.

  The separation member is not particularly limited in structure or shape as long as a plurality of small chambers communicating with each other can be formed inside the mold, but the substrate and the substrate are supported at predetermined intervals. It is preferable to include a plurality of shelf boards. For example, a mold is formed in a cylindrical shape, and a separation member accommodated in the mold is formed by a substrate composed of four rectangular pieces joined in a cross shape at the end face along the longitudinal direction, and between adjacent rectangular pieces. A plurality of stages of shelves, and a mold is formed in a cylindrical shape, and a separating member accommodated in the mold is formed of a single rectangular piece of substrate, It can also be provided with a plurality of shelves attached to both sides of the rectangular piece.

  The plurality of small chambers formed by the fractionation member in the mold as described above include gaps formed between the inner peripheral surface of the mold and the shelf plate of each step of the fractionation member, The molten metal is communicated through a hole formed in the central portion of the substrate of the drawing member and the shelf plate of each stage, and the molten metal is sucked into each small chamber in the mold through such a communicating portion under reduced pressure. Thus, when the molten metal is vacuumed and sucked into each chamber in the mold and solidified, the communicating portion is much narrower than each chamber, so the stress strain during solidification is concentrated on the communicating portion, and the communicating portion The part corresponding to is a brittle casting. Even if it is a remelted raw material obtained as an integral casting immediately after production, it can be easily made into fine crushed material corresponding to each chamber unit by simply applying a weak impact thereto. According to the production method and apparatus of the present invention, the obtained remelting raw material can be easily made into fine crushed material suitable for remelting without intentionally cutting.

  In the production method and apparatus of the present invention, a metal raw material having a predetermined composition is floated and melted in a cold crucible furnace, and the melted and melted metal melt is sucked into a plurality of small chambers formed in a mold and solidified in each of the plurality of small chambers. Let The production method and apparatus of the present invention are suitable for producing a remelted raw material having an alloy composition based on an active metal such as Ti because the resulting remelted raw material is less contaminated by its properties. Moreover, since the solidification of the molten metal sucked under reduced pressure in each small chamber is fast, even when the molten metal contains a high melting point material such as Nb, Ta, Zr, the segregation thereof is prevented. Even when the molten metal contains a high vapor pressure material such as Mn and Mg, their evaporation can be prevented.

  According to the production method and apparatus of the present invention, a fine crushed material suitable for remelting can be easily obtained. Therefore, a troublesome cutting operation is not required, and there is no decrease in yield and increase in cost due to the cutting operation. Moreover, even if it contains a high melting point material or a high vapor pressure material, there is an effect that it is possible to produce a remelted raw material that becomes a crushed material having a substantially uniform composition among the obtained crushed materials.

  FIG. 1 is a longitudinal sectional view schematically showing the production apparatus of the present invention, and FIG. 2 is an enlarged perspective view showing a fraction member housed in a mold in the production apparatus of FIG. The manufacturing apparatus shown in FIG. 1 includes a cold crucible furnace 11 and a vacuum suction casting apparatus 21 connected thereto. The cold crucible furnace 11 includes a furnace body 14 composed of a plurality of water-cooled copper segments 12 and 12 and a hearth 13 that are insulated from each other and arranged in a cylindrical shape, and a coil 15 disposed around the outer periphery of the furnace body 14. And. In the cold crucible furnace 11, a metal material having a predetermined composition charged into the furnace body 14 is induction-heated by flowing a high-frequency current through the coil 15, and is levitated and melted by the Lorentz repulsive force generated at this time. . FIG. 1 shows a state in which a metal raw material having a predetermined composition is levitated and melted. In the furnace main body 14, the molten metal A is levitated and melted substantially at the center, and the solidified shell B is located in the hearth 13. Is formed.

  The vacuum suction casting apparatus 21 includes a chamber 22, a vacuum pump (not shown) connected to the exhaust port 23 of the chamber 22, a cylindrical mold 24 supported in the chamber 22, and a snout 25 extending from the mold 24. And a fractionation member 31 accommodated in the mold 24, and the chamber 22 is placed on the furnace body 14. The vacuum suction casting apparatus 21 operates a vacuum pump (not shown) to bring the inside of the mold 24 into a reduced-pressure atmosphere, and the molten metal A is fed into the mold 24 via the snout 25 inserted into the molten metal A in a floating and melted state. It is designed to perform vacuum suction.

  The fractionation member 31 has a predetermined interval between a substrate 36 composed of four rectangular pieces 32 to 35 joined in a cross shape on the inner end face along the longitudinal direction, and adjacent four rectangular pieces 32 to 35. 10-tiered shelf boards 37 to 40 (however, the shelf boards 39 and 40 are not shown, and the same applies hereinafter) are provided. When the fraction member 31 is accommodated in the mold 24, the outer end surfaces along the longitudinal direction of the four rectangular pieces 32 to 35 are in sliding contact with the inner peripheral surface of the mold 24, and each of the shelf plates 37 to 40 is A gap is formed between the front end surface and the inner peripheral surface of the mold 24. When the fractionation member 31 is accommodated in the mold 24, a total of 40 small chambers communicating with each other through the gap as described above except for a portion corresponding to the lowermost stage directly connected to the snout 25. It is designed to be formed.

  FIG. 3 is an enlarged perspective view showing another fraction member that can be used in the production apparatus of the present invention. 3 includes a substrate 43 formed of a single rectangular piece 42 and ten steps of shelf plates 44 and 45 attached to both sides along the longitudinal direction of the rectangular piece 42 at a predetermined interval. . When the fraction member 41 is housed in the mold 24 instead of the fraction member 31, both end surfaces along the longitudinal direction of the rectangular piece 42 are in sliding contact with the inner peripheral surface of the mold 24, and each shelf plate 44, A gap is formed between the front end surface of 45 and the inner peripheral surface of the mold 24. When the fraction member 41 is housed in the mold 24 instead of the fraction member 31, the mold 24 communicates with each other through the gap as described above, except for the portion corresponding to the lowest stage directly connected to the snout 25. Thus, a total of 20 small chambers are formed.

  FIG. 4 is an enlarged perspective view showing still another fraction member that can be used in the production apparatus of the present invention. 4 includes a substrate 51 composed of four rectangular pieces 47 to 50 arranged in a cross shape with a gap between inner end faces along the longitudinal direction, and four rectangular pieces 47 to 10 adjacent shelf plates 52 to 55 mounted at a predetermined interval between 50 adjacent ones (however, the shelf plates 54 and 55 are not shown, and the same applies hereinafter). When the fraction member 46 is housed in the mold 24 instead of the fraction member 31, the outer end faces along the longitudinal direction of the four rectangular pieces 47 to 50 and the outer end faces of the respective shelf plates 52 to 55 are the mold. 24 are slidably contacted with the inner peripheral surface, and gaps are formed on the inner end surfaces of the four rectangular pieces 47 to 50 and the shelf plates 52 to 55. When the fraction member 46 is accommodated in the mold 24 instead of the fraction member 31, the mold 24 communicates with each other through the gap as described above except for the portion corresponding to the lowermost stage directly connected to the snout 25. A total of 40 small chambers are formed.

  Although the manufacturing apparatus of the present invention has been described with reference to the drawings, the manufacturing apparatus of the present invention is not limited to the illustrated example. For example, the number of shelves provided in the fractionation member and the number of chambers formed in the mold by the fractionation member are fine crushed materials that can be easily remelted without having to bother cutting the resulting remelting raw material. It is optional as long as you can.

Examples 1 to 3 and Comparative Example 1
In Examples 1 to 3, a remelted raw material was produced using the production apparatus of the present invention described above with reference to FIGS. 1 to 4 and a carbon steel fraction member, and an impact was applied thereto to obtain a crushed material. In Comparative Example 1, a remelted raw material was produced without using a fractionation member, and this was divided into 10 stages in the longitudinal direction and divided into 4 parts at each stage to obtain a total of 40 cut products. Here, in each example, a Ti-30Ta alloy composition containing Ta that easily segregates was used as a metal raw material, and a carbon steel pipe having a diameter of 25 mm and a height of 300 mm was used as a mold. The Ta content was measured for each of the crushed material or the cut material obtained in each example, and the average value and the standard deviation were obtained. The results are summarized in Table 1.

Examples 4 to 6 and Comparative Example 2
In Examples 4-6, the remelting raw material was manufactured using the manufacturing apparatus of this invention mentioned above about FIGS. 1-4, and the fraction member made from carbon steel, and it applied to this and it was set as the crushed material. In Comparative Example 2, a remelted raw material was produced without using a fractionation member, and this was divided into 10 steps in the longitudinal direction and 4 steps in each step to obtain a total of 40 cut pieces. Here, in each example, a Ti-10Mn alloy composition containing Mn that easily evaporates was used as a metal raw material, and a carbon steel pipe having a diameter of 25 mm and a height of 300 mm was used as a mold. The Mn content was measured for each of the crushed material or the cut material obtained in each example, and the average value and the standard deviation were obtained. The results are summarized in Table 2.

  As is clear from the results of Tables 1 and 2, even when the metal raw material contains a high melting point material such as Ta that easily segregates, or when it contains a high vapor pressure material such as Mn that easily evaporates. Even if it exists, according to the manufacturing method and apparatus of this invention, the remelting raw material from which the crushed material of the uniform composition as expected can be obtained can be manufactured.

The longitudinal cross-sectional view which shows the manufacturing apparatus of this invention schematically. The enlarged perspective view which shows the fraction member accommodated in the casting_mold | template in the manufacturing apparatus of FIG. The expansion perspective view which shows the other fraction member which can be used for the manufacturing apparatus of this invention. The expansion perspective view which shows the other fraction member which can be used for the manufacturing apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Cold crucible furnace 12 Water-cooled copper segment 14 Furnace main body 15 Coil 21 Vacuum suction casting apparatus 22 Chamber 24 Mold 31, 41, 46 Separation member 36, 43, 51 Substrate 37, 38, 44, 45, 52, 53 Shelf

Claims (5)

  In a method of manufacturing a remelted raw material by vacuum suction and solidification of molten metal levitated and melted in a cold crucible furnace, the molten metal is vacuum sucked into a mold in which a plurality of chambers communicating with each other are formed. A method for producing a re-dissolved raw material characterized in that it is solidified.   The method for producing a remelted raw material according to claim 1, wherein the remelted raw material is a Ti alloy containing a high melting point material and / or a high vapor pressure material.   A remelted raw material comprising a cold crucible furnace and a vacuum suction casting apparatus connected to the cold crucible furnace, wherein the molten metal floated and melted in the cold crucible furnace is sucked into a mold of the vacuum suction casting apparatus and solidified by vacuum suction In the manufacturing apparatus, the mold is formed in a cylindrical shape as a whole, and a fractionation member is accommodated inside the mold, and the fractionation member forms a plurality of small chambers communicating with each other inside the mold. An apparatus for producing a remelted raw material, characterized in that it is configured as described above.   The apparatus for producing a remelted raw material according to claim 3, wherein the fractionation member comprises a substrate and a plurality of shelves supported by the substrate at predetermined intervals. The apparatus for producing a remelted raw material according to claim 3 or 4, wherein the remelted raw material is a Ti alloy containing a high melting point material and / or a high vapor pressure material.

Images