JPH0159341B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides virgin material,
Virgin material, in particular of refractory metals such as titanium, zirconium or alloys thereof, or this virgin material and scrap, is melted with an electron beam or plasma electron beam, or said virgin material is melted in a consumable electrode arc melting furnace. Alternatively, the present invention relates to a method of manufacturing an ingot by melting an electrode made from the virgin material and scrap (hereinafter, both are simply referred to as "molten raw materials") as a consumable electrode. [Prior Art] Conventionally, when melting raw materials, especially refractory metals such as titanium, zirconium, or alloys thereof, were melted to produce ingots, melting materials were supplied into a hearth in a vacuum melting furnace. Chips and granular or small chunks of molten raw material are melted with an electron beam or plasma electron beam, and the resulting molten metal collected in the hearth is transferred into a water-cooled mold, and the solidified ingot is pulled out from below the mold. Alternatively, using the consumable electrode type arc melting method, a consumable electrode made from the melted raw material is suspended in a water-cooled copper crucible, and a direct current arc is generated between the tip of the consumable electrode and the molten metal in the copper crucible. Ingots were manufactured by gradually melting the metal from its tip and dropping it into a copper crucible to form a molten metal pool, which was then solidified from below. [Problems to be Solved by the Invention] However, in the former vacuum melting method, which uses an electron beam or a plasma electron beam to produce ingots, the melted raw materials must be sorted in advance according to their size. However, since only chips and small-sized molten raw materials such as granules or small lumps can be processed, the work is labor-intensive and the range of molten raw materials that can be processed is limited; To make electrodes, first the molten raw materials are sorted according to their size, then larger ones are welded together to make electrodes, and chips and granular or small lumps are pressed and made into briquettes. are welded together to make an electrode, and the medium-sized lumps between the above two are crushed into fine particles and pressed to make briquettes, which are then welded together. However, the problem was that it took time and effort to make consumable electrodes. [Findings based on research] Therefore, the present inventors have conducted various studies in order to solve such problems, and as a result, (1) The melted raw materials having the various dimensions described above are transformed into tubes with polygonal cross sections. A top-opening box material having a shape formed by cutting in the axial direction and having partition members at both ends or one end, or having no partition members at both ends, or a box material with a polygonal cross section. The box material or tube material packed with melted raw materials is placed horizontally in a vacuum melting furnace. Either they are held and heated from one end to the other with an electron beam or a plasma electron beam, or they are combined in an even number in a consumable electrode arc melting furnace and held horizontally with their ends facing each other. When an arc is generated between these ends and the melted raw material is melted together with the box material or tube material, the former method using a vacuum melting furnace requires sorting the melted raw material according to its size. In addition, it is possible to melt raw materials of a wide range of sizes, from small ones to large lumps, so the range of melted raw materials that can be processed can be expanded.
In addition, the latter method, which uses a consumable electrode type arc melting furnace, does not require the molten raw materials to be sorted by size, and also requires troublesome processes such as crushing, pressing, and welding to make the consumable electrodes. (2) According to the method of directly packing the melted raw material into the box material or pipe material without producing briquettes from the melted raw material, in order to produce an ingot having a predetermined component composition, It is only necessary to calculate the total amount of alloying elements, and there is no need to weigh each briquette, which greatly saves time and effort. (3) If the material of the box material or pipe material is not the same as the material of the melted raw material, The box material or tube material that melts together with the melted raw material and mixes into the ingot changes its composition, but if the variation is within an allowable range, the material of the box material or pipe material must not be the same as the melted raw material. It has also been found that it is sufficient to make the material of the box or pipe material contain one or more constituents of the melted raw material. [Means for Solving the Problems] This invention was invented based on the above knowledge, and is a method for melting raw materials in a vacuum melting method or a consumable electrode type arc melting method using an electron beam or a plasma electron beam as a heating source. When manufacturing ingots by melting, the purpose of this method is to process melted raw materials of various sizes all at once without sorting them and to easily process them in a vacuum melting furnace or consumable electrode type arc melting furnace. , a method for producing an ingot from the molten raw material by solidifying the molten metal thereby produced in a water-cooled mold to form an ingot, the ingot containing one or more of the same components as the molten raw material, and A top-opening box material having a shape formed by cutting a tube material having a polygonal cross section in the axial direction, and having a partition member at both ends or one end, or having no partition member at both ends; Alternatively, a pipe material having a polygonal cross section and having partition members at both ends or one end, or having no partition members at both ends, filled with the melted raw material, is held horizontally in the vacuum melting furnace. heating it with an electron beam or a plasma electron beam from one end to the other, or combining an even number of them in the consumable electrode type arc melting furnace and holding the ends horizontally with their ends facing each other, generating an arc between these ends to melt the melted raw material together with the box material or pipe material, and causing the resulting molten metal to fall directly into a water-cooled mold;
Alternatively, the present invention provides a method for manufacturing the ingot, characterized in that the molten metal is once stored in a hearth, and then the supernatant is allowed to fall into a water-cooled mold by overflow to solidify the molten metal. [Specific structure and operation of the invention] Hereinafter, the specific structure and operation of the present invention will be explained. 1 Box material and pipe material Box material or pipe material filled with molten raw materials melts together with the molten raw material and mixes into the ingot, which affects the material of the ingot. Although it is most preferable for the ingot to be made of the same material as the ingot, there are cases in which melted raw materials of slightly different materials are mixed and processed, and there is a certain tolerance range for the composition of the ingot that becomes the product. The material of the box or tube does not necessarily need to be the same as the material of the melted raw material, as long as the change in the composition of the ingot due to the mixing of the box or tube does not fall outside the range of composition required for the ingot. If the variation in the composition of the ingot due to such mixing falls within the range of composition allowed for the ingot, it is sufficient to make the material of the box material contain one or more of the same components as the constituents of the melted raw material. It is. The box material and tube material used in this invention may have any shape in cross section. In other words, the box material may have any shape as long as its cross section is a polygon with some sides missing. It can be anything,
The pipe material may be of any shape as long as its cross section is polygonal, but the box material is usually shaped like a in Figure 4 because it is easy to manufacture and handle.
A box material 1 having a U-shaped cross section as shown in FIG. 4, and a tube material 2 having a rectangular cross section as shown in FIG. 4b are conveniently used. The plate-shaped partition members 1a and 2a, for example, shown in a and b in FIG. 4, provided at one or both ends of the box material 1 and the tube material 2 fill the melted raw material into the box material or tube material. This is to prevent the molten raw material from spilling out from inside the box or tube during the melting process, and before the box or tube filled with the molten raw material is fed into the melting furnace and melted. This partition member is not limited to a plate shape and may be of any shape as long as it prevents spillage.For example, if the size of the melted raw material is large to a certain extent, it may be made into a net shape, a grid shape, or a slit shape. The partition member may be provided with a through hole, and if there is no risk of the melted raw material spilling out, the partition member may be provided only at one end of the box material or pipe material, or its installation may be omitted altogether. Note that this box material and tube material can be manufactured by any method, but it is generally advantageous to manufacture them by welding and assembling plates obtained by descaling after hot rolling. In the manufacture of pipes and pipes, not only can narrower plates be used compared to circular pipes, but they also have the advantage of not requiring hot rolling or heat treatment, which must be carried out under strict temperature control. Furthermore, the box material allows melted raw materials to be packed from above, making the filling process easier.Furthermore, it is possible to visually determine the filling state of the entire inside of the box material. Since the melted raw material can be supplied into the box material, it is possible to pack the melted raw material into the box material very easily and uniformly with a high filling rate.Also, since the melting work can be carried out with the top open like this, The advantage is that material is saved, the amount of undesirable components introduced into the ingot is reduced, and the manufacturing effort is reduced. 2. Casting method In this invention, which manufactures ingots from melted raw materials, as shown in side views of the main points of the manufacturing state in FIGS. 1 to 3, a box material having a partition member 1a or a partition member 2a is Scraps S of various sizes are packed as they are without sorting into the tube material 2 having a While holding the material, the melted raw material S is gradually introduced from one end into the zone 6 which is heated to a high temperature by the electron beam or plasma electron beam 3 which is a heating source, and the melted raw material S together with the box material 1 enters the first zone 6. As shown in the figure, the water-cooled mold 4
After melting down into the hearth 5 or forming a pool of molten metal 7 as shown in FIG. A pool of molten metal 7 is formed above in the water-cooled mold 4, while below it the molten metal 7 is cooled and solidified by the water-cooled mold 4 to form an ingot 8, and (ii) the molten raw material S is packed. The third pipe material 2
As shown in the figure, their ends are placed horizontally on the water-cooled mold 4 facing each other,
When these are used as consumable electrodes and an arc 9 is generated between them, the molten raw material S constituting both electrodes is
melts down into the water-cooled mold 4 together with the pipe material 2, forming a pool of molten metal 7 above the water-cooled mold 4, while below it the molten metal 7 is cooled and solidified by the water-cooled mold 4, forming an ingot 8. . In addition, in this method as well, as mentioned in the above item (i), the molten metal 7 is once placed in the hearth 5.
After collecting the supernatant in the water cooling mold 4, the supernatant may be allowed to fall into the water-cooled mold 4 by overflow.The method using such a hearth removes heavy impurities such as tungsten carbide contained in the melted raw material. The above-mentioned method without the use of a hearth is advantageously used as a method of saving power consumption when there is no risk of such impurities being introduced into the melted raw material. In the present invention, the box material or tube material may be arranged in any manner as long as there is no problem such as the melted raw material slipping or rolling down from the box material or tube material during the melting operation. ,
Therefore, as used herein, "horizontal"
The term refers not only to a completely horizontal position, but also to an almost horizontal horizontal position, which naturally includes the above meaning. After the partition member 1a or 2a, which prevents the melted raw material from spilling out, melts down, some of the melted raw material packed in the box material or pipe material remains undissolved during the melting operation. , it may also fall into the molten metal pool formed in the water-cooled mold 4 or the hearth 5, but since such molten raw materials are relatively small in size, they cannot be heated by the electron beam, plasma electron beam, or arc. It easily dissolves in the molten metal pool. In this invention, the number of boxes or tubes to be processed at a time is not necessarily one or one pair; for example, in order to increase productivity, a plurality of boxes or tubes may be fed into the heating zone 6 at the same time, or Two or more pairs of consumable electrodes may be opposed to each other and the arc 9 may be generated between them. The present invention is particularly advantageous when producing ingots from refractory molten raw materials such as titanium, zirconium, or their alloys, but other molten raw materials can also be heated by electron beam or plasma electron beam. Of course, the present invention can be applied to any melted raw material as long as it is suitable for melting by the vacuum melting method or the consumable electrode type arc melting method. If you wish to make the ingot obtained by the above method into a more homogeneous ingot,
Using the conventional consumable electrode type arc melting method, this ingot is suspended as a consumable electrode in a water-cooled copper crucible, and an arc is generated between the tip of the ingot and the molten metal in the copper crucible, and the electrode itself is gradually melted from the tip. It is possible to obtain a more homogeneous secondary ingot. [Examples and effects based on the examples] Next, the present invention will be explained with reference to examples. Example 1 A pure titanium (JIS Class 1) pipe material having the shape shown in Fig. 4b and having dimensions of 60 mm square x length: 1200 mm x plate thickness: 1 mm was prepared, and this pipe material was , as virgin material, sponge titanium: 6000
g, Al: 174 g and Al-50%V: 640 g in the third
Packed in layers as shown in the figure. At this time, the total weight including the tube material was 8.1 kg, and the filling rate was 37%. Next, as shown in Fig. 1, this was placed horizontally in a plasma beam melting furnace and placed under vacuum (0.01mm
Under Hg), plasma torch voltage: 35V, same current:
A cylindrical ingot having dimensions of 82 mm in diameter and 600 mm in length was produced by irradiating with a plasma electron beam under the conditions of 800 A and a tube advancing speed of 0.4 cm/min. The component analysis values of the ingot obtained at this time were as shown in Table 1.

[Table] Then, using the above-mentioned cylindrical ingot as a consumable electrode, the conventional consumable electrode type arc melting method described above was performed, vacuum degree: 0.01 mmHg or less, voltage: 26 V,
Under the condition of current: 2000A, diameter: 110mm x length:
A cylindrical secondary ingot with dimensions of 300 mm was produced and its component analysis values are as shown in Table 2, indicating that this ingot is more homogeneous.

[Table] Example 2 A box material having the top cover removed from the pure titanium pipe material used in Example 1, that is, a box material having the shape shown in a in Fig. 4, was prepared, and a sponge material was added to this box material as a virgin material. Titanium: 4100g, Al: 130g
and Al-50%V470g and as scrap
4600g of Ti-6Al-4 alloy scrap was packed in layers as shown in Figure 1. The size of the melted raw material filled at this time ranges from a minimum of several tens of microns to a maximum of 40 microns.
It is a block of scrap with mm squares, and the total weight including the box material is
The weight was 10.6Kg, and the filling rate was 53%. Next, this was melted using a plasma electron beam in the same manner as in Example 1.
mm cylindrical ingots were produced. The component analysis values of this ingot are shown in Table 3.

[Comprehensive effect of the invention]

As is clear from the above description, according to the present invention, there is no need to sort melted raw materials according to their size, and in addition, vacuum melting using an electron beam or plasma electron beam can In addition, it is possible to melt a wide range of molten raw materials of various sizes, including large lumps, at once, expanding the range of molten raw materials that can be processed.
In order to manufacture the consumable electrode, there is no need for any troublesome processing such as crushing, pressing, or welding, and an industrially beneficial effect can be obtained in that molten raw materials of various sizes can be processed all at once. Furthermore, when a box material is used as a holding member for molten raw materials, since it opens upward, it becomes extremely easy to pack the molten raw materials, and the molten raw materials can be evenly filled into the box material. Therefore, the vacuum melting method using an electron beam or plasma electron beam can easily adjust the melting rate to a constant value, and the consumable electrode arc melting method can stably obtain a uniform arc. As a result, it becomes easier to control the melting operation, and furthermore, the melting raw materials can be packed into the box material at a high filling rate, so that effects such as increased melting efficiency and workability can be obtained.

[Brief explanation of drawings]

Figures 1 to 3 are explanatory diagrams drawn from the side to show the main points of this invention, and Figures 1 and 2 show a vacuum melting method using an electron beam or plasma electron beam as a heating source. , FIG. 3 shows the consumable electrode type arc melting method, and FIGS. 4a and 4b are perspective views showing an example of the box material and tube material, respectively, used in the present invention. In the figure: 1...Box material, 2...Pipe material, 3...Plasma beam, 4
...Water cooling mold, 5...Hearth, 6...Heating zone, 7
... Molten metal, 8... Ingot, 9... Arc, S... Scrap.

Claims (1)

[Claims] 1. The virgin material, or the virgin material and the scrap, are melted in a vacuum melting furnace, and the resulting molten metal is solidified in a water-cooled mold to form an ingot. Alternatively, in the method for producing an ingot from the virgin material and scrap, the tube material containing one or more of the same components as the virgin material or the virgin material and scrap and having a polygonal cross section is cut in the axial direction. A top-opening box material that has a shape formed by and has partition members at both ends or one end, or has no partition members at both ends, or a box material that has a polygonal cross section and has a partition member at both ends or one end. Does it have a partition member?
Alternatively, a pipe material having no partition members at both ends filled with the virgin material or the virgin material and scrap is held horizontally in the vacuum melting furnace and is heated by electrons from one end to the other end. The virgin material or the virgin material and the scrap together with the box material or tube material are melted by heating with a beam or a plasma electron beam, and the resulting molten metal is directly dropped into a water-cooled mold, or the molten metal is A method for producing an ingot, which comprises once storing the molten metal in a hearth, and then dropping the supernatant liquid into a water-cooled mold by overflow to solidify the molten metal. 2 Melting virgin material or virgin material and scrap in a consumable electrode type arc melting furnace,
A method for producing an ingot from the virgin material or from the virgin material and scrap by solidifying the resulting molten metal in a water-cooled mold to form an ingot. It has a shape formed by cutting a tube material having a polygonal cross section in the axial direction, and has a partition member at both ends or one end, or has a partition member at both ends or at both ends. The above-mentioned virgin material is applied to a top-opening box material having no partition member at all, or a pipe material having a polygonal cross section and having a partition member at both ends or one end, or having no partition member at both ends, or the above-mentioned virgin material. Combining an even number of virgin material and scrap in the consumable electrode type arc melting furnace,
The ends are held horizontally opposite each other and an arc is generated between the ends to melt the virgin material, or the virgin material and scrap together with the box material or tubing material, thereby The molten metal is solidified by directly dropping the molten metal produced by the cooling process into a water-cooled mold, or by once storing the molten metal in a hearth, and then dropping the supernatant liquid into the water-cooled mold by overflowing the molten metal. Method of manufacturing ingots.