JPS62292244A - Production of ingot - Google Patents

Abstract

PURPOSE:To obtain an ingot having no blowhole and no segregation of impurities or their overconcentration at the end part thereof by solidifying molten metal as differing solidifying progress at least one of surface in the surface of molten metal in a mold from the solidifying progress at the remaining surface. CONSTITUTION:The molten metal is solidified by water cooling only at the surface contacting with a bottom wall 1a of the mold 1 among the surface of mold 1 by flowing water along only the bottom wall 1a of mold 1. In this case, the water is not flowed along both side walls 1b of the mold 1 and upper part 2a of steel belt 2, but these parts are cooled naturally. As a result, most parts of heat of molten metal (for example, copper) poured into the mold 1 is radiated from the bottom wall 1a of the mold 1 as shown by the arrow mark in the attached drawing. Therefore, crystals of the molten copper don't uniformly grow from four direction in the drawing, but rapidly grow toward the upper part of mold 1 from the surface contacting with the bottom wall 1a. Reversely, the growth of crystals from the upper part of molten copper toward the bottom wall 1a is slow and the crystals from the surface contacting with the side wall 1a grows toward the upper part of molten copper and the finishing solidified range comes to the top end part of the ingot 3. Therefore, the blowhole and segregation of impurities 4 in the inner part of ingot 3 is not developed.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to the production of ingots, such as rough drawn metal wires (for example, rough drawn copper wires, rough drawn aluminum wires, etc.) by casting and rolling. The present invention relates to a method for producing an ingot used for production. More specifically, the present invention relates to an improvement in solidifying the hot water in the mold in the method for manufacturing the metal ingot.

[Conventional technology]

SCR% Properzz and Contiro are methods of melting, casting, and rolling metals such as copper and aluminum to produce rough-drawn w4 tightening, rough-drawn aluminum wire, etc.
Methods such as d are well known, and in particular, the SCR method has recently attracted the attention of electric wire and rough wire manufacturers around the world.

[Problem that the invention seeks to solve]

In the above-mentioned known method, when producing a copper ingot by solidifying metal, such as copper, poured into a casting mold, both sides of the mold 1 (generally made of copper) are A method is adopted in which the wall 1b, the bottom wall 1a, and the upper surface 2a of the steel belt 2 are cooled with running water. In this method, the heat of the copper poured between the mold 1 and the steel belt 2 is dissipated almost equally from four directions (in the direction of the arrow), so solidification is evenly directed toward the center of the molten steel from the four directions. The final solidification region will be located approximately at the center of the metal ingot. However, in the ingot 3 after solidification, gas and impurities are likely to be trapped near the boundaries between the crystals grown from four directions, that is, in the final solidification region. In this case, pores or impurity segregation 4 occur near the center of the finally solidified ingot 3.

If the ingot 3 in which the pores and impurity segregation 4 exist near the center is used as it is for subsequent hot-strength rolling or cold wire drawing, defects such as cracks and wire breaks are likely to occur in the pores and impurity segregation 4. That is, when the ingot 3 in which pores and impurity segregation 4 have occurred is successively hot-rolled to make a rough drawn wire, and then further cold-drawn to make a wire rod, the pores and impurities present inside the ingot 3 are removed. Cracks may occur in the area of impurity segregation 4 and the wire may eventually break, which poses a problem in that the workability and productivity of metal wire manufacturing are greatly impaired. In particular, this point becomes more noticeable when using thin wires.

Therefore, if an ingot without such pores and impurity segregation 4 is used, it is possible to produce a good metal wire, and even if pores and impurity segregation 4 exist, it is possible to produce metal wires at the ends of the ingot 3. Since the pores/impurity segregation 4 can be removed if the pores and impurities are unevenly distributed in the area, a metal wire without the above-mentioned problems can be manufactured.

Accordingly, an object of the present invention is to provide a method for producing an ingot in which pores and impurity segregation do not exist, or even if they do exist, they are unevenly distributed at the ends of the ingot.

[Means for solving problems]

The above object is the present invention, that is, in the production of an ingot using a mold, the solidification of the molten metal in the mold is determined by the solidification progress from at least one surface of the molten metal and the solidification progress from the remaining surfaces. This is achieved by a method for manufacturing an ingot, which is characterized in that the steps are performed in different ways.

In the ingot produced by this method, the final solidification region is unevenly distributed at the end of the ingot, so that pores and impurity segregation generated in the solidification region can be easily removed.

There is no particular restriction on the method of removing it, such as cutting, excision, peeling, etc., as long as it is possible to remove pores and impurity segregation within the coagulation region.

[Effect]

In the production method of the present invention, the rate of solidification from at least one of the surfaces of the hot water is made to be different from the rate of solidification from the remaining surfaces.Specific embodiments of this solidification method include: For example, the following means are exemplified. Namely, examples include a method of forcibly cooling one surface of the mold while leaving at least one of the other surfaces, and a method of heating at least one of the other surfaces of the mold while leaving one surface of the mold. Cooling and heating may be performed by any means.

Next, the method of the present invention will be explained in more detail.

The method of solidifying the hot water in the mold shown in FIG. 1 is applied to batch casting. The hot water is solidified by cooling only the surface of the hot water in the mold 1 that is in contact with the bottom wall 1a of the mold 1 with water. In this case, the surfaces of the mold 1 other than the surface in contact with the bottom wall 1a (the surface in contact with each side wall 1b of the mold 1 and the surface in contact with the steel belt 2) are naturally cooled.

Note that water cooling may be performed by known means.

According to this aspect, the heat of the metal (for example, copper) poured into the mold 1 is best dissipated from the bottom wall 1a of the mold 1 as shown by the arrow, so that crystals of molten steel grow uniformly from four directions. As is clear from the figure, crystals grow quickly from the surface in contact with the bottom wall 1a of mold 1 toward the top of mold 1 (the top of the molten steel), and conversely from the top of the molten steel to the bottom wall of mold 1. 1
The growth of crystals toward the direction a is slow, and the crystals from the surface in contact with the side wall 1b of the mold 1 grow toward the top of the molten steel, and the final solidified region becomes the top end of the ingot. Therefore, inside the ingot 3 after solidification, pores and impurity segregation 4 will occur in the upper part of the ingot 3 rather than in the center, and depending on the degree of crystal growth, pores and impurity segregation 4 will occur. It may not occur. If necessary, the pores and impurity segregation 4 that occur unevenly in the upper part can be removed by, for example, surface cutting the part above the dotted line shown in the figure in the ingot 3 after cooling, or as shown in Figure 2. As shown in the figure, rough rolling 1i after hot rolling! 5 can be removed by peeling the surface to a thickness of d. Pores and impurity segregation in the ingot after solidification4
If this does not occur, there is no need to remove it.

As another example, the water cooling may be performed on the bottom wall 1a of the mold 1 as described above.
This is done by running water only in the direction along the side walls 1 of the mold 1.
b and the upper surface 2a of the steel belt 2 can be maintained at a high temperature, for example, about 200°C. In this case, the surface in contact with both side walls 1b of the molten steel mold l and the steel belt 2
Since the growth of crystals from the surface in contact with the ingot is even slower than during natural cooling, the final solidification region is even more unevenly distributed at the upper end of the ingot. As a result, pore/impurity segregation 4
will occur near the upper surface of the molten steel.

In the example shown in FIG. 3, both side walls 1b of the mold 1 are
The bottom wall 1a of the mold 1 is cooled by water. By moving the heating element 7 upward, for example, as shown by arrow A, as the crystals grow, the final solidification region of the ingot 3 can be moved upward more reliably. Pore/impurity segregation 4 can be generated at the upper end of the ingot 3. At this time, by creating a temperature gradient in the heating element 7 provided along the side wall 1b so that the temperature increases toward the top, the pores and impurity segregation 4 can be removed as described above without moving the heating element 7. It can be reliably unevenly distributed at the upper end of the mass 3.

In still another embodiment, as shown in FIG.
are buried in both side walls lb of the mold 1, and the heating body 7
By creating a temperature gradient in which the temperature increases toward the top, the final solidification region of the ingot 3 can be shifted upward, and pores and impurity segregation 4 can be unevenly distributed at the upper end of the ingot 3. .

In the above example, the ingot manufacturing method of the present invention was explained based on batch casting, but it is obvious that the present invention can also be applied to continuous casting. The present invention is not limited to this example, and various methods may be employed as long as they do not depart from the spirit of the present invention, which is to prevent pores and impurity segregation from occurring in the center of the ingot.

〔Example〕

Example 1 Using the apparatus shown in FIG. 1, water at about 30°C was flowed only along the bottom wall 1a of the mold 1, and both side walls 1b of the mold 10 and the top surface 2a of the steel belt 2 were allowed to cool naturally. , base 3 c
ml %Height 3cI1), Top side 4C1)%Length 50c
m copper ingots were produced.

The thus produced copper ingot had pores and impurities unevenly distributed at a position approximately 6N below the top surface.

Example 2 Using the apparatus shown in Fig. 1, water at about 30°C was poured only on the bottom wall 1a of the mold 1, and both side walls 1b of the mold 10 and the top surface 2a of the steel belt 2 were maintained at 200°C. Example 1
A similar copper ingot was produced.

The thus produced copper ingot had pores and impurities unevenly distributed at a position approximately three fins below the top surface.

〔Effect of the invention〕

As explained above, the method for producing an ingot of the present invention allows the solidification of the molten metal in the mold to be performed on a small portion of the surface of the molten metal (in other words, the solidification progress from one surface is different from the solidification progress from the remaining surfaces). By doing this, the pores and impurity segregation that conventionally occurred in the center of the ingot can be unevenly distributed from the center of the ingot to the surface or near the surface of the ingot. Since pores and impurity segregation do not occur, it is possible to produce ingots of good quality.Also, even if pores and impurity segregation occur, they can be easily removed after producing the ingot, if necessary. , it is possible to solve the problem of wire breakage during the manufacture of wire rods by cold wire drawing.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the ingot manufacturing method of the present invention, and FIG. 2 is a cross-sectional view of a rough drawing line after hot rolling the ingot manufactured by the method shown in FIG. 1. , FIG. 3 is a cross-sectional view showing another embodiment of the ingot manufacturing method of the present invention, FIG. 4 is a cross-sectional view showing still another embodiment of the ingot manufacturing method of the present invention, and FIG. FIG. 2 is a cross-sectional view showing a conventional ingot manufacturing method. 1: Mold 2 Steel belt 3: Ingot 4: Pore or impurity segregation 5
: Rough line 7 : Heating element

Claims (2)

[Claims] (1) When manufacturing an ingot using a mold, the solidification of the molten metal in the mold is performed by making the rate of solidification from at least one of the surfaces of the molten metal different from the rate of solidification from the remaining surfaces. A method for manufacturing an ingot, characterized by the following. (2) The solidification of the hot water in the mold is performed by cooling only one surface of the hot water and allowing the remaining surfaces to cool naturally. The method for producing the described ingot.