JPS6247433A - Manufacture of ingot from virgin material - Google Patents

Abstract

PURPOSE:To easily and efficiently manufacture an ingot, by packing virgin material in a top-openable box material made of almost the same component as the virgin material, charging them into vacuum melting furnace to heat and melt them together with the box material by electron beam. CONSTITUTION:The top-openable box material 1 having U-shaped section is made of material quality of component compsn. without causing hindrance even if mixed with virgin material or/and a scrap material S, and a partition member 1a is provided. Into the material 1, virgin material or/and the scrap S are packed as they are, these are held horizontally on a water cooled mold 4 and charged. An electron beam or plasma electron beam 3 is provided above the mold 4 and the material 1 is entered little by little into the high temp. heating zone 6 from one end. Virgin material or/and is scrap S are dropped together with the material 1 by heating as molten metal 7 into the mold 4, cooled and solidified to an ingot 8. In this way, workability is improved and melting efficiency is raised.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to the production of virgin materials, especially virgin materials of refractory metals such as titanium, zirconium, or alloys thereof, or this virgin material and scrap in a vacuum melting furnace. and by melting with an electron beam or plasma electron beam, or
Alternatively, it relates to a method of manufacturing an ingot by melting an electrode made from the virgin material, or the virgin material and scrap (hereinafter collectively referred to as "molten raw materials") as a consumable electrode in a consumable electrode type arc melting furnace. It is something.

[Conventional technology]

Conventionally, when melting raw materials, especially refractory metals such as titanium, zirconium, or their alloys, to produce ingots, chips and granules fed into the hearth of a vacuum melting furnace are used. A small lump of molten raw material is melted by an electron beam or a plasma electron beam, and the RSM hot water that accumulates in the hearth is transferred into a water-cooled mold, and the solidified ingot is pulled out from below the mold, or by a consumable electrode type arc. In the 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 electrode and the molten metal in the copper crucible, thereby gradually dislodging the electrode itself from the tip. Ingots were produced by melting and dropping into a copper crucible to form a molten metal boule, which was then solidified from below.

[Problem that the invention seeks to solve]

However, in the former vacuum melting method, which uses an electron beam or a plasma electron beam to manufacture ingots, the melted raw materials must be sorted in advance according to their size, and in addition, it is necessary to sort the melted raw materials in advance according to their size. Because it can only process molten raw materials with small dimensions, the work is time-consuming and the range of molten raw materials that can be processed is limited.
In addition, in order to make the consumable electrode from the molten raw material using the latter consumable electrode type arc melting method, the molten raw material is first sorted according to its size, and then the large sized ones are made into contact with each other to make electrodes, and then cut. Powder and particles or small lumps are pressed and briquettes are welded together to make electrodes, and medium-sized lumps between the above three are crushed into fine particles. Since electrodes were made by pressing briquettes and then welding them together, there was a problem in that it took a lot of time and effort to make consumable electrodes.

[Considerations based on research]

Therefore, the inventors of the present invention have repeatedly conducted various studies in order to solve such problems, and as a result, (1) The melted raw materials having various dimensions are cut in the axial direction into a tube material having a polygonal cross section. It is a top-opening box material with a partition member at both ends or one end, or alternatively, a top-opening box material with a polygonal cross section and a partition member at both ends or one end. The box material or tube material packed with melted raw materials is packed into a tube having a partition member at one end or no partition member at both ends, and is held horizontally in a vacuum melting furnace. They can be rotated from one end to the other and heated with an electron beam or plasma electron beam, or they can be assembled in even numbers in a consumable polar arc bath melting furnace and held horizontally with their ends facing each other. If an arc is generated between these ends and the melted raw material is melted together with the box material or tube material, there is no need to sort the melted raw material according to its size in the former method using a vacuum melting furnace. Moreover, it is possible to melt raw materials of a wide variety of sizes, from small ones to large lumps, in one go, so the range of melted raw materials that can be processed can be expanded, and the consumption of the latter can be reduced. In the method using a polar arc melting furnace, there is no need to sort the molten raw materials by size, and there is no need for any troublesome processing such as crushing, pressing, or welding to create 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, the total amount of alloying elements is calculated in order to produce an ingot having a predetermined composition. (3) If the material of the box material or pipe material is not the same as that of the melted raw material, it can be melted together with the melted raw material. The box material or tube material mixed into the ingot will change its composition, but if the variation is within an allowable range, the box material or tube material may not be made of the same material as the melted raw material. Alternatively, it has been found that it is sufficient to make the material of the pipe material contain one or more constituents of the melted raw material.

[Means for solving problems]

This invention was invented based on the above considerations, and is applicable to manufacturing ingots by completely melting the molten raw materials in a vacuum melting method or a consumable polarized arc melting method using an electron beam or a plasma electron beam as a heating source. , with the aim of processing molten raw materials of various sizes collectively and easily without sorting them, melts the molten raw materials in a vacuum melting furnace or consumable electrode type arc melting furnace, and molds the molten metal produced thereby into a water-cooled mold. In the method of manufacturing an ingot from the molten raw material by solidifying the material into an ingot within a tube, a tube material containing one or more of the same components as the molten raw material and having a polygonal cross section is cut in the axial direction. A top-opening box material that has a shape formed by a polygonal structure 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 partitions at both ends or one end. A pipe material having a partition member or no partition members at both ends filled with the melted raw material is held horizontally in the vacuum melting furnace and is heated with an electron beam or plasma from one end to the other end. The melting process is carried out by heating with an electron beam, or by combining an even number of them in the consumable electrode type arc melting furnace, holding them horizontally with their ends facing each other, and generating an arc between these ends. The raw material is melted together with the box material and pipe material, and the resulting molten metal is directly dropped into a water-cooled mold, or the molten metal is collected in a -1 hearth and the supernatant is allowed to overflow and fall into a water-cooled mold. The present invention provides a method for manufacturing the ingot, characterized in that the molten metal is solidified.

[Specific structure and operation of the invention]

Hereinafter, the specific structure and operation of the present invention will be explained.

1. Box material and tube material The box material or tube material filled with melted raw materials melts with the melted raw material and mixes into the ingot, which affects the material of the ingot. Although it is most preferable for the material to be the same as the raw material, there are cases where melted raw materials with slightly different materials are mixed and processed, and there is also a tolerance range for the composition of the ingot that becomes the product. Therefore, as long as the change in the composition of the ingot due to the mixing of the box material or pipe material does not fall outside the range of composition required for the ingot, the material of the box material or pipe material should not necessarily be the same as the material of the melted raw material. It is not necessary, and if the change in the composition of the ingot due to such contamination falls within the range of composition allowed for the ingot, the material of the box material may be changed to include one or more of the same components as the constituents of the melted raw material. It is enough.

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. Also, the pipe material may be of any shape as long as its cross section is polygonal, but the box material is usually
A box material 1 having a mouth-shaped cross section as shown in (at) in the figure, and a tube material 2 having a rectangular cross section as shown in FIG. 4(h) are conveniently used.

The plate-shaped partition members 1a and 2a, which are provided at one end or both ends of the box material 1 and the tube material 2, and shown, for example, in (a) and fbl of FIG. This is to prevent the molten raw material from spilling out of the box material or tube material during filling and before the box material or tube material filled with the molten raw material is fed into the melting furnace and melted. If such spillage is to be prevented, this partition member is not limited to a plate shape, and may be of any type.For example, if the size of the melted raw material is large enough, it may be formed into a net shape, a grid shape, or a slit. If there is no risk of melted raw materials spilling out, this partition member may be provided only at one end of the box material or pipe material, or its installation may be omitted altogether. can.

Although these box materials and tube materials can be manufactured by any method, it is generally advantageous to manufacture them by welding and assembling plates obtained by descaling after hot rolling. Not only can it be used with narrower plates than circular pipes, but it also has the advantage of not requiring hot rolling or heat treatment, which must be carried out under strict temperature control. Raw materials can be loaded from above, making the filling process easier.Furthermore, the state of filling inside the entire box material can be visually determined, and melted raw materials can be supplied from above throughout the entire box material. The molten raw material electrodes can be easily and uniformly packed into the ingot at a high filling rate, and the melting operation can be carried out with the top open like this, so the material can be saved and mixed into the ingot. In addition to reducing the concentration of undesirable components,
It also has the advantage of saving time and effort in its production.

2. Casting method In this invention, which manufactures ingots from melted raw materials, as shown in side views in FIGS. Scraps S of various sizes are packed as they are without sorting into a tube material 2 having a
While holding it horizontally on the hearth 5 (Fig. 1) or the hearth 5 (Fig. 2), gradually enter the zone 6 heated to a high temperature by the electron beam or plasma electron beam 3, which is the heating source, from one end. Then, the melted raw material S together with the box material 1 is placed in a water-cooled mold 4 as shown in FIG.
The melt will fall inside, or as shown in Figure @2,
After the melt falls into the hearth 5 and forms a pool of molten metal 7,
The supernatant of this molten metal 7 overflows from the eighth 5 into the water-cooled mold 4 and forms a pool of molten metal 7 above the water-cooled mold 4, while the molten metal 7 is cooled by the water-cooled mold 4 below. (11) The tube material 2 packed with the melted raw material S is placed horizontally on a water-cooled mold 4 with their ends facing each other, as shown in FIG. When these electrodes are used as consumable electrodes and an arc 9 is generated between them, the molten raw material S constituting both electrodes falls into the water-cooled mold 4 together with the tube material 2, and the molten metal 7 is formed above the water-cooled mold 4. Under the pool, the molten metal 7 is cooled and solidified by the water-cooled mold 4 to form an ingot 8.

In addition, in this method, as described in the above item (1), a part of the molten metal 7 may be collected in the space 5, and then the supernatant liquid may be allowed to fall into the water-cooled mold 4 by overflow. The method using a hearth is advantageously used to remove heavy impurities such as tungsten carbide contained in the molten raw material, while the method described above without the use of a hearth removes such impurities from the molten raw material. If there is no risk of contamination, it is advantageously used as a method of reducing power consumption.

In this invention, the box material or pipe material can be arranged in any way as long as the melting material does not slip or fall out of the box material or pipe material during the melting operation. Therefore, as used herein, the term "horizontal" refers not only to completely horizontal, but also to a semi-horizontal sideways position, which naturally includes the above meaning.

Partition member 1a that prevented melted raw materials from spilling out
Or, after the melt 2a has fallen, some of the melted raw material packed in the box material or pipe material is formed in the water-cooled mold 4 or the hearth 5 without being melted during the pouring operation. However, due to their relatively small size, such molten raw materials are easily melted in the bath boule heated by the electron beam or plasma electron beam or arc.

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.

In addition, this invention is particularly suitable for producing ingot Y from refractory molten raw materials such as titanium, zirconium, or alloys thereof.
Although it is conveniently applied in manufacturing, other molten raw materials may also be used if they are suitable for melting by vacuum melting using an electron beam or plasma electron beam as a heating source, or by polar arc melting in an expendable process. Of course, the present invention can be applied to any kind of melted raw material, and if it is desired to make the ingot obtained by the method of the present invention described above into a more homogeneous ingot, it is possible to apply the present invention to any melted raw material. Using the electrode-type arc melting method, this ingot is suspended as a consumable electrode in a water-cooled steel crucible, and an arc is generated between the tip of the ingot and the molten metal in the dopperu to remove the electrode body from the tip. By gradually melting, a more solid secondary ingot can be obtained.

[Real law cases and effects based on real law cases]

Next, the invention will be explained by way of examples.

Actual example 1 It has a shape as shown in Figure 4 (h), and 6
Prepare a pipe material made of pure titanium (JISI type) having dimensions of 01aI angle
g:174f! and Ag-50%V:640f were packed in layers as shown in FIG.

At this time, the total weight including the pipe material is s, iKf, and the filling rate is 3
It was 7%.

Next, as shown in Fig. 1, this was placed horizontally in a plasma beam melting furnace, and under vacuum (0.91 wHg),
A cylindrical ingot with dimensions of diameter: 82 fins x length: 6110 m was produced by irradiating the plasma electron beam under the conditions of plasma torch voltage: 35 V, open current = 80 OA, and tube material advancement speed: 0.4 w/min. did. The component analysis values of the ingot obtained at this time were as shown in Table 1.

Thereafter, using the above-mentioned cylindrical ingot as a consumable electrode, the conventional consumable electrode type arc melting method described above was performed at a vacuum level of 0.01 mHg or less and a voltage of 26V.

A cylindrical secondary ingot having dimensions of diameter: 110 m x length: 300+ m was produced under the conditions of tIM: 2000 A, and the component analysis values of it were as shown in Table 2, indicating that this ingot was more homogeneous. It shows that.

Example 2 A box material having the top cover removed from the pure titanium split tube material used in Example 1, that is, a box material having the shape shown in FIG. :41009. AJ: 130f and us
o *v470t and Ti-6T as scrap
4600f of i-6A alloy scrap was packed in layers as shown in FIG. The dimensions of the melted raw materials filled at this time ranged from a minimum of several tens of micrometers of powder to a maximum of 40 m square chunks of scrap, the total weight including the box material was 10.6 Kp, and the filling rate was 53%.

Next, this was melted using a plasma electron beam in the same manner as in Example 1 to produce a cylindrical ingot having a diameter of 82 w and a length of 600 m. Table 3 shows the component analysis values of this ingot.

In this melting operation, as mentioned above, we were able to pack the ingots uniformly into the box material at a high filling rate, so the melting rate could be easily adjusted to a constant level, and therefore the melting operation could be easily controlled. This not only shortens work time, but also reduces power consumption.

[Comprehensive effect of the invention]

As is clear from the above explanation, according to the present invention, it is not necessary to sort the melted raw materials according to their size, and in addition, in the vacuum melting method using an electron beam or a plasma electron beam, the materials are only small in size. 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.
To manufacture the consumable electrode, there is no need for any troublesome processes such as crushing, pressing, welding, etc., 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. For this reason, 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. The melting process can be easily controlled, and melted raw materials can be packed into the box material at a high filling rate.
Effects such as increased dissolution efficiency and improved workability can also be obtained.

[Brief explanation of drawings]

Figures 1 and 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. 4 fa) and (b) are perspective views showing an example of a box material and a tube material, respectively, used in the present invention. In the figure, 1... box material, 2... pipe material. 3... Plasma beam, 4... Water-cooled mold. 5... Hearth, 6... Heating zone. 7... Molten metal, 8... Ingot. 9...Arc, S...Scrap.

Claims (1)

[Claims] By melting virgin material or virgin material and scrap in a vacuum melting furnace or consumable electrode type arc melting furnace, and solidifying the resulting molten metal in a water-cooled mold to form an ingot, the virgin material, Alternatively, the method for producing an ingot from the virgin material and scrap includes one or more of the same components as the virgin material or the virgin material and scrap,
A top-opening box material that has a shape formed by cutting a tube material with a polygonal cross section in the axial direction, and that has partition members at both ends or one end, or has no partition members at both ends. , 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 is filled with the virgin material, or the virgin material and scrap. Either they are held horizontally in a vacuum melting furnace and heated with an electron beam or plasma electron beam from one end to the other, or they are combined in an even number in the consumable electrode type arc melting furnace and their ends are mutually connected. are held horizontally facing each other, and an arc is generated between these ends to melt the virgin material, or the virgin material and scrap together with the box material or pipe material, and the resulting molten metal is directly The method for manufacturing an ingot, characterized by solidifying the molten metal by dropping it into a water-cooled mold, or by once storing the molten metal in a hearth, and then letting the supernatant liquid fall into the water-cooled mold by overflow.