JPS58103941A - Production of metallic material having specular surface - Google Patents

Abstract

PURPOSE:To prevent the danger of breakout in the outlet of a hollow mold for molding which contains heating elements by immersing said mold into the surface of molten metal. CONSTITUTION:Molten metal 2 is held in a molten metal holding furnace 1 at a specified level, and a hollow mold 3 contg. heating elements 4 is supported by a mold supporting frame 6 and is immersed in the metal 2. Here, if a dummy bar 7 located at the top end in the hollow part of the mold 3 is brought into contact with the metal 2, the metal 2 begins to solidify at the bottom end thereof. Thereafter, the bar 7 is pulled up and a cooling material such as air or gas is sprayed thereto from sprays 8, whereby a barlike metallic molding 9 is obtained. Here, the temp. in the inside walls of the mold 3 is controlled by the elements 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to the production of a metal material having a mirror-finished metal and having any cross-sectional shape such as a rod, plate, or tube, which is made of a unidirectionally solidified set f&, directly from molten metal. how to
Regarding poles.

More specifically, molds with built-in heating elements.
The Hawachi die is immersed in the surface of molten metal, and its inner wall surface is
By keeping the temperature of the casting above the solidification temperature of the molten metal to be solidified, at the upper outlet of the hollow mold,
The present invention relates to a method and apparatus for continuously producing wire, rod, plate and tubular coagulation material, depending on the shape of the coagulation outlet of the mold. It's made by someone else.

In general, the surface of a piece is usually not perfectly smooth, but has convexities and often cracks. In particular, for a lump obtained by the continuous zero method, when the ingot moves on the casting surface,
Surface defects such as neck patterns and cracks are likely to occur due to friction between the ingot and the mold, and in order to remove these surface defects, the ingot is usually subjected to plastic working such as direct rolling or rolling. The surface layer is polished or scraped. In addition, if the cracks on the surface are deep, the lumps cannot be used for plastic working, resulting in a defective product.

Therefore, it is desirable to produce an ingot without surface defects from the viewpoints of (1) omitting the grinding step and (2) improving the yield of the ingot.

In vertical continuous casting of metal ingots, it is usually necessary to slide the mold up and down. This is because when a solidified shell of the cast metal adheres to the inner wall of the cast metal, when a lump is pulled out of the cast metal, the friction with the cast wall causes the solid shell to break out, which is called a breakout, and the unsolidified metal surrounded by the solid shell. Otherwise, the molten metal will gush out.

For such alloys, for example cast iron, an intermittent casting method is used, in which the metal is completely solidified in the mold, then drawn out, and then drawn out again at tl-1 when the subsequent molten metal has solidified. ing.

There has been a strong desire to develop a continuous casting method that can eliminate such breakout-prone alloys. Furthermore, there have been expectations for the development of techniques for producing mirror-finished wires, rods, plates, and tubes directly from molten metal.

The present invention applies to all soluble metals and alloys.
It has a smooth surface with no surface defects and a unidirectionally solidified gold structure.

The object is to provide a method for manufacturing wire, rod, plate and tubular metal materials directly from liquid metal.

In order to obtain a solid metal with an m-plane, a hollow heating mold is used, and while heating the inner wall surface, molten metal is continuously fed from above in small increments, and the molten metal forms a solidified shell on the surface within the mold. Formation is possible by such a method as solidification by cooling outside the outlet at the lower end of the mold.

However, in order to obtain a material with a mirror surface using this method,
Strict control is always required to keep the height of the molten metal in the mold low. Also, if the cooling rate of a lump is too high, g* will solidify easily in the mold, and the friction with the mold will leave scratches on the surface of the drawn lump. , and it is easy to crack, and m-plane lumps cannot be obtained.

In this way, creating a single lump of hot water using this method requires extremely sophisticated level control technology.

The present invention is capable of completely eliminating the risk of molten metal spewing out at the exit of the mold, and is capable of continuously producing a material that has a mirror surface and has a structure that grows long and columnar in one direction. The present invention provides a method for manufacturing rod-shaped, plate-shaped, and tubular materials of all meltable metals and alloys by selecting appropriate molding materials.

A casting method without the risk of breakout due to bath water pressure is known as the continuous casting method for silicon single crystal thin plates, in which a hollow mold with a thin slint-like gap is floated on the surface of the molten metal. Another method is to continuously pull up a liquid film that rises due to capillary action from the top of the mold. However, with this method, if the drawn sheet metal is rapidly cooled, the bath water will solidify inside the mold, making it impossible to pull out the sheet due to friction with the mold. In this method, the cooling and drawing conditions of the plate must be controlled extremely strictly, and it is difficult to apply it to a method for producing metal materials in large quantities.

In addition, 'f & manufacturing method loss without the risk of breakout is L
Employs oriented continuous casting method. This involves floating a water-cooled graphite mold on the surface of molten copper and pulling a rough wire upward. In this method, there is no risk of molten metal ejecting from the mold outlet due to molten metal pressure. However, since the graphite mold is water-cooled, the molten metal forms a solidified shell within the graphite mold. Therefore, the surface of the rough drawn wire drawn out due to friction with the inner wall surface of the graphite mold has striped scratches, and it is impossible to obtain a mirror-like material. Furthermore, since solidification begins within the mold, crystals nucleated on the inner wall surface of the mold grow toward the center of the ingot against the heat flow, making it impossible to completely scale the unidirectional solidification group.

The present invention eliminates the risk of breakout at the exit of the mold, has a mirror surface, and! In addition, the unidirectional solidification set d(i
- It is an object of the present invention to provide an extremely useful method for continuously obtaining a material having few internal defects. The present invention applies not only to pure metals but also to conventional LFCG.
It can also be applied to the forming of alloys with a wide solidification temperature range, which have been considered extremely difficult to form. This is because the mold is heated and the inner wall is kept at a temperature higher than the solidification temperature of the molten metal, so the solidification of the bath water progresses inside the mold avoiding the inner wall surface of the mold, and the inner wall surface of the mold is in contact with it. This is because there is no formation of a solidified shell to be rubbed.

That is, the present invention is a hollow die immersed in the surface of the molten metal, i.e., a wire or rod, which is characterized in that its surface layer solidifies at the same time as it emerges above a heating element that contains the temperature of the inner wall surface of the die. , a continuous VC manufacturing method for plate and tubular metal materials, and an apparatus used therefor.

FIG. 1 is a longitudinal cross-sectional front view showing one embodiment of an apparatus for carrying out the present invention and manufacturing a rod-shaped material.

(2) is a molten metal holding furnace in which the molten metal (2) is held so that one surface is constant. ■ is a hollow type, and the upper end of its inner wall is kept at the same level as surface #. The hollow type ■ has a built-in heating element (■), and the heating element is heated by the current supplied by the conductive wire (■). (2) is cooled by a seven-stroke coolant for mold support. When the dummy bar is placed at the upper end of the hollow part of the tl-type and brought into contact with the molten metal, solidification begins at the lower end of the dummy bar. By pulling up the meaver, a ■-shaped metal composition)□ shape is obtained. The lower end of this rod-shaped metal molded body protrudes downward into the mold when the cooling rate is high. At this time, the temperature of the inner wall of the mold must be controlled by the current sent to the heating element (2) so that solidification does not proceed on the inner wall of the mold. [Phase] is a shielding plate for the radiant heat of the molten metal.

FIG. 2 is a vertical cross-sectional front view showing one embodiment of an apparatus for carrying out the present invention and manufacturing a tube.

① is a molten metal holding furnace in which molten metal @ is held so that the level of the molten metal is constant. ■ has an outer mold and a core of ■.

The outer mold and the core have a heating element [phase] and are heated by being supplied with electric current by a conductive wire. ◎ is the mold support frame. ■ is a dummy of the metal tube to be formed, and is cooled by air, gas, and nol (sail-like coolant) injected by the [phase] spray.Dummy f[
Phase] When the dummy tube is positioned at the upper end of the hollow part of the mold and pulled up, the metal tube @l can be moved continuously as the dummy tube rises. @ is a shielding plate for the radiant heat of the molten metal.

What is important in carrying out the present invention is that the upper end of the inner wall of the hollow mold is maintained at the same height as or slightly below the molten metal level, and that the temperature of the inner wall surface is higher than the solidification temperature of the molten metal. Graphite molds can be used for alloys with low solidification temperatures, such as aluminum alloys and copper alloys, for which the material and wall thickness of the mold must be selected so that the temperature is maintained. Also,
For steel, iron, and alloys with high melting points, refractory materials such as alumina, glue, beryllia, magnesia, tolya, zirconia, boron nitride, and silicon carbide can be used. When selecting a material, it is necessary to choose a material that reacts with the molten metal and does not erode.

The method of the present invention is particularly superior to the conventional continuous casting method for ingots in that it allows the production of mirror-finished materials without the risk of surface cracks, and there is no danger of flakes9). wires, rods, plates, and tubes of any cross-sectional shape can be manufactured continuously from metals and alloys with a unidirectional solidification structure without any cross-sectional shapes.

According to the method of the invention, there is no cooling from the side walls of the mold, so that the solidification process progresses downward. Therefore, as in the conventional casting method, the material t' is sound and free from center segregation and shrinkage cavities caused by the growth of crystals from the casting wall surface toward the center of the block.
8 can be easily obtained.

The present invention is not only extremely useful for improving the surface condition of the ingot, but also eliminates the need for equipment and energy for sliding molds, which were required in conventional methods, and also eliminates the need for continuous steel Glassy surface additives for lubricating molds and ingots used in casting become unnecessary. In addition, it has the advantage of being able to form plates, wires, and tubes directly from molten metal, which conventionally had to be formed from an ingot by repeating plastic working and heat treatment, and from the point of view of energy savings and labor savings. , a revolutionary manufacturing method for metal materials. Furthermore, since it is possible to obtain an infinitely elongated columnar structure, gold, which has traditionally been cast one by one in a mold set for cold corrosion, such as magnetic steel, for which a unidirectional solidification structure is desired, is produced by casting long rod-shaped pieces at a time. It can also be used by forming a unidirectionally solidified material and then cutting it to the required length. What is especially good is that there are no equiaxed crystals, so -j! The present invention is advantageous for the production of metal materials in that it is possible to obtain extremely sound metal materials by simple solidification without the risk of microscopic defects forming at grain boundaries due to precipitation of P@ crystals. This is an innovative method.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional front view of a main part showing one embodiment of applying the present invention to a rod-shaped metal molded body, 7J7! Figure J2 is a longitudinal sectional front view of a main part showing another embodiment for implementing the present invention and obtaining a tubular metal molded body. L 11 Molten metal holding furnace II IQ Cooling spray 212 Molten metal 9 Metal molded body 3 Mold
IQ 21g plate 415 heating element 1
3 Outer mold 516 conductive wire 14 Core 617 mold support frame 18 Dummy tube 20
Metal tube patent applicant Sae 11] Fang Z IEI

Claims (1)

[Claims] L Table 1 of metal materials characterized by immersing a hollow mold for molding with a built-in heating element into the surface of mold 1 of molten metal
Manufacturing method 52
A device is characterized in that a hollow mold for forming with a built-in heating element is immersed in the forging surface of molten metal, and the solid metal material is manufactured completely continuously and with high strength.