JPH0154419B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] This invention is a method for producing ingots by melting metal scraps, particularly scraps of refractory metals such as titanium, zirconium, or alloys thereof, with an electron beam or a plasma electron beam in a vacuum melting furnace. Regarding the method. [Prior Art] Conventionally, metal scraps, particularly scraps of refractory metals such as titanium, zirconium, or alloys thereof, are melted to produce ingots.
Chips or small lumps of scrap fed into the hearth of a vacuum melting furnace are melted by an electron beam or plasma electron beam, and the molten metal collected in the hearth is transferred to a water-cooled mold and solidified into cast metal. How to pull out the lump from below in the mold,
Alternatively, metal scrap is compressed into briquettes, melted with an electron beam or plasma electron beam while held horizontally, and the resulting molten metal is solidified in a water-cooled mold to produce ingots (Japanese Patent Application Laid-Open No. 10201/1983). (see official bulletin), etc. are known. [Problems to be Solved by the Invention] However, in the method of melting chips or small chunks of scrap supplied into the hearth of the vacuum melting furnace using an electron beam or a plasma electron beam, the scraps are melted in advance. Not only does it have to be sorted by size, but it can only process scraps that are small in size, such as chips or small lumps, which makes the work time-consuming and not only limits the range of scraps that can be processed, but also makes it difficult to process scraps once they are melted on the hearth. There is a problem that power consumption increases accordingly, and
The method of compressing the scrap in advance to form briquettes and melting the scrap with an electron beam or a plasma electron beam has a problem in that it is expensive because it requires a large-scale apparatus for the compression process. . [Means for solving the problem] Therefore, the present inventors have developed a method that consumes no power and
In addition, as a result of research to develop a method for manufacturing ingots from metal scraps that would reduce manufacturing costs, it was found that the molten material obtained by simply packing metal scraps into a bottomed pipe material by gravity has the rigidity of the pipe material. Therefore, they found that the metal scrap can be held horizontally, and that the metal scrap can be melted together with the pipe material in this horizontal state. The present invention has been made based on this knowledge, and includes a method for manufacturing ingots from metal scraps, which includes water-cooling metal scraps packed without pressure into a bottomed pipe material made of the same material as the metal scraps. An ingot is manufactured from metal scrap that is held horizontally on a mold and sequentially melted with an electron beam or plasma electron beam from the tip of the scrap, and the resulting molten metal is dropped into the water-cooled mold and solidified. The method is unique. This invention will be specifically explained below. [Detailed Description of the Invention] In this invention for manufacturing ingots from metal scraps, as shown in a side view of the outline of the manufacturing state in FIG.
Scraps 1 of various sizes are packed into a vacuum melting furnace by natural fall without being pressurized without being sorted, and while being held horizontally on a water-cooled mold 4 in a vacuum melting furnace, an electron beam or plasma electron beam is heated as a heating source. When the metal scrap 1 is gradually introduced into the zone 5 heated to a high temperature by the beam 3 from the bottom end to the other end, the metal scrap 1
melts down into the water-cooled mold 4 together with the pipe material 2, forming a pool of molten metal 6 above the water-cooled mold 4, while below it the molten metal is cooled and solidified by the water-cooled mold 4, forming an ingot 7.
form. Although the tube used in this invention may have any shape in cross section, it is usually preferable to use a tube with a circular or square cross section, and the bottom provided at one or both ends of the tube may be This is to prevent scrap from falling out of the pipe when it is filled with scrap and before the pipe filled with scrap is fed into the melting furnace and melted. If so, this bottom part may be of any shape; for example, if the size of the scrap is large enough, it may be shaped like a net, a lattice, or a slit, or may have a through hole formed therein; Although it is usually sufficient to provide this at one end of the tube, it may be provided at the other end, that is, at both ends, if necessary. After the bottom of the pipe material melts down, some of the scrap packed inside the pipe material may fall into the molten metal pool formed above the water-cooled mold without being melted during the melting operation. Because of their relatively small dimensions, such scrap easily dissolves in the molten metal pool into which the electron beam or plasma electron beam is poured. In the present invention, the number of tubes to be processed at a time is not necessarily limited to one; for example, in order to increase productivity, a plurality of tubes may be fed into the heating zone 5 at the same time. The present invention is particularly advantageous when producing ingots from scraps of refractory metals such as titanium, zirconium, or alloys of these metals, but other metal scraps may also be produced by electron beam or plasma electron processing in a vacuum melting furnace. It goes without saying that the present invention can be applied to any metal scrap suitable for beam melting. [Example] Next, the present invention will be explained by referring to an example. It has a composition of Ti-6%Al-4%V and is 60mm
Prepare a titanium alloy pipe with a bottom with dimensions of square x length: 1200 mm x thickness: 1 mm, and add to this pipe a piece of scrap board with a minimum size of 10 mm square and a maximum size of 40 mm square having the same composition as above. of various dimensions ranging from

〔Effect of the invention〕

As is clear from the above description, according to the present invention, (1) metal scrap is melted and ingot is filled into a bottomed pipe made of the same material as the prepared metal scrap without applying pressure; Since it is possible to produce briquettes, there is no need for large-scale press equipment for producing briquettes, and therefore costs are low. (2) There is no need to sort metal scraps by size, and metal scraps of a wide range of sizes, from small ones to large lumps, can be collected into long pipes. Since the metal scrap can be melted while being held horizontally, the range of metal scrap that can be processed can be expanded. (3) Metal scrap is melted in space without using a hearth, and the resulting molten metal is immediately dropped into a water-cooled mold to solidify, reducing power consumption. This industrially useful effect can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram drawn from the side to show the main points of the method of the present invention. In the figure: 1... Metal scrap, 2... Tube material, 3... Heat source, 4... Water cooling mold, 6... Molten metal, 7...
Ingot.

Claims (1)

[Scope of Claims] 1. In a vacuum melting furnace, the metal scrap is held horizontally on a water-cooled mold and sequentially melted with an electron beam or plasma electron beam from the tip of the metal scrap, and the molten metal thus generated is directly melted. In the method of producing an ingot from metal scrap by dropping it into a water-cooled mold and solidifying it, the metal scrap is packed without being pressurized into a bottomed pipe made of the same material as the metal scrap. A method for producing an ingot from metal scrap, characterized in that the tube material is sequentially melted by electron beam or plasma electron beam starting from the bottom end.