JPH0790334B2 - Production method for rough wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention uses a continuous melting casting and rolling method (SCR method) to produce a rough drawn metal wire (for example, a rough drawn copper wire, a rough drawn aluminum wire, etc.). To a method of manufacturing.

[Prior Art] As a method for producing a rough-drawn copper wire or a rough-drawn aluminum wire by melting, casting, or rolling a metal such as copper or aluminum,
Methods such as the SCR method, the Properzi method, and the Contirod method are well known, and in particular, the SCR method has recently attracted the attention of electric wire and rough drawn copper wire manufacturers around the world.

[Problems to be Solved by the Invention] In the above-mentioned SCR method, an ingot for manufacturing a rough wire is
When solidifying the metal poured into the casting mold, for example, copper to produce a copper ingot, as shown in FIG.
A method of cooling the side walls 1b and the bottom wall 1a of the mold 1 (generally made of copper) and the upper surface 2a of the steel belt 2 with running water is adopted. In this method, the heat of the copper poured between the mold 1 and the steel belt 2 is dissipated almost uniformly from the four directions (arrow directions), so solidification is evenly distributed from the four directions to the center of the molten copper. As it progresses toward the end, the final solidified region is located almost at the center of the metal ingot. However, in the ingot 3 after solidification, gas and impurities are easily trapped near the boundaries of the crystals grown from four directions, that is, in the final solidification region, so that the molten copper is uniformly solidified from four directions as in the method. 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 / impurity segregation 4 exists near the center is used as it is for the subsequent hot rolling or cold drawing, defects such as cracks or disconnections are likely to occur in the pores / impurity segregation 4. That is, after the ingot 3 in which the pores / impurity segregation 4 has occurred is continuously hot-rolled into a rough wire and then cold drawn to form a wire, the pores existing inside the ingot 3 are formed. There is a problem that cracks may occur in the portion of the impurity segregation 4 and the wire may eventually break, which greatly impairs workability and productivity of metal wire production. Especially when drawing thin wires,
This point becomes noticeable.

Therefore, it is ideal to use an ingot without such pores / impurity segregation 4, but even if there are pores / impurity segregation 4, if they are unevenly distributed at the end of the ingot 3, Since the pores / impurity segregation 4 can be easily removed, a metal wire without the above-mentioned problems can be manufactured.

It is an object of the present invention to provide a method for producing a rough wire without producing the rough wire in the presence of the pores / impurity segregation described above, based on the above findings.

[Means for Solving the Problems] The object is to close the mold of the bottom wall and the side wall and the opening of the mold in the present invention, that is, in the method of manufacturing a rough drawing line from the ingot by the continuous melting casting rolling method. The molten metal is poured into the space formed by the steel belt, the bottom wall of the mold is heated and the side wall is naturally cooled, and the final solidified region of the molten metal is in the vicinity of the steel belt. The surface of the rough drawn busbar obtained by forming and then hot-rolling the surface of the obtained ingot located near the steel belt or hot-rolling the ingot is thinly peeled. This is achieved by a method for manufacturing a rough wire, which comprises:

[Operation] In the ingot produced by the method, since the final solidification region is unevenly distributed in the vicinity of the steel belt, pores and impurity segregation generated in the solidification region are located in the ingot near the steel belt. Can be easily removed by face-cutting or by hot-rolling the ingot and thinly peeling the surface of the rough drawn busbar. That is, the bottom wall of the mold is heated and the side wall is naturally cooled so that the progress of solidification is different and pores and impurity segregation are generated at the end of the ingot. In this case, the portion in the vicinity of the steel belt can be face-cut, and in the post-rolling stage, the surface can be thinly peeled to surely remove it.

[Examples] Next, the method for manufacturing a rough wire according to the present invention will be described more specifically with reference to the drawings.

FIG. 1 shows a casting foil for making an ingot in the SCR system, that is, a cross section of a mold (which is basically the same in a batch system casting), and the bottom wall of the mold 1.
Only the surface of the molten metal poured into the mold 1 by running water along only 1a (not flowing along the side walls 1b of the mold 1 and the upper surface 2a of the steel belt 2) in contact with the bottom wall 1a of the mold 1 The water is solidified by cooling it with water. In this case, the hot water is naturally cooled on the surfaces other than the surface in contact with the bottom wall 1a of the mold 1 (the surface in contact with each side wall 1b of the mold 1 and the surface in contact with the steel belt 2). Water cooling may be performed by a known means.

According to this aspect, the heat of the metal (for example, copper) poured into the mold 1 is best dissipated from the mold 1a as shown by the arrow, so that the molten copper crystals do not grow uniformly from four directions, As is clear from the figure, crystals grow faster from the surface in contact with the bottom wall 1a of the mold 1 toward the upper part of the mold 1 (the upper part of the molten copper), and conversely from the upper part of the molten copper to the bottom wall 1a of the mold 1. The growth of the crystal toward the side is slow, the crystal from the surface in contact with the side wall 1b of the mold 1 grows toward the upper part of the molten copper, and the final solidified region is the upper end of the ingot. Therefore, ingot 3 after solidification
In the inside of the ingot, the pores / impurity segregation 4 is unevenly generated not in the central portion of the ingot 3 but in the upper portion.

There are various possible means for varying the solidification rate of the molten metal in the mold depending on the mold surface, but in the SCR type mold, the means involving heating is not practical, and the means involving the least addition of equipment, and the steel belt. The most rational means for concentrating pores and impurity segregation in the vicinity is to cool the bottom wall of the mold and naturally cool the side wall.

The porosity / impurity segregation 4 generated in the vicinity of the steel belt 2 is removed by surface cutting the portion above the dotted line shown in the drawing in the state of this ingot 3 after cooling, or as shown in FIG. The ingot 3 is hot-rolled as it is to the rough drawing bus bar 5
The surface of the rough drawn bus bar 5 including the pores and the impurity segregation 4 is thinly removed by a thickness d and removed.

Depending on the degree of crystal growth, porosity / impurity segregation 4
May not occur, and in this case, the above face cutting and peeling are unnecessary, but it is practically difficult to sequentially confirm whether or not pores and impurity segregation 4 occur in the SCR method. , It is reasonable to always carry out the steps of face cutting and peeling.

Experimental Example In the method for manufacturing a rough wire according to the present invention, the following experiment was conducted to confirm the depth to be face-cut from the ingot.

Using the apparatus shown in FIG. 1, water of about 30 ° C. is caused to flow only along the bottom wall 1a of the mold 1, both side walls 1b of the mold 1 and the upper surface 2a of the steel belt 2 are naturally cooled, and the bottom 3 cm, height 3 cm,
A copper ingot having an upper side of 4 cm and a length of 50 cm was manufactured. In the copper ingot thus produced, pores and impurities were unevenly distributed at a position about 6 mm below the upper surface.

[Effects of the Invention] As described above, according to the method for manufacturing a rough wire of the present invention, the bottom wall of the mold is heated and the side walls are naturally cooled to cause different solidification rates so that the final solidification region is near the steel belt. Unevenly distributed in the solidification area, and the segregation of pores and impurity segregation in the solidified region is performed by surface cutting the portion of the ingot located near the steel belt, or by thinning the surface of the rough drawn bus bar obtained by hot rolling the ingot. Because it is removed by peeling,
The obtained rough drawn wire can be of high quality that does not include pores and impurity segregation, and therefore can prevent problems such as disconnection in the subsequent processing, that is, in manufacturing the wire rod by cold drawing. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the ingot manufacturing process in the manufacturing method of the present invention, and FIG. 2 is a rough drawing bus bar after rolling an ingot manufactured by the method similar to that shown in FIG. Cross section of
FIG. 3 is a cross-sectional view showing a conventional ingot manufacturing method. 1; Mold, 1a; Bottom wall, 1b; Side wall, 2; Steel belt, 3; Ingot, 4; Pore or impurity segregation, 5; Roughing busbar

Claims (1)

[Claims] 1. A method for producing a rough drawing wire from an ingot by a continuous melting casting rolling method, in which a molten metal is placed in a space formed by a mold having a bottom wall and a side wall and a steel belt closing an opening of the mold. Is poured, the bottom wall of the mold is cooled and the side wall is naturally cooled to form an ingot in a state where the final solidified region of the molten metal is in the vicinity of the steel belt, and then the steel belt of the obtained ingot is obtained. A rough drawn wire characterized by obtaining a rough drawn wire by thinly peeling the surface of a rough drawn bus bar obtained by hot-rolling a portion that was located in the vicinity and then hot-rolling the ingot. Manufacturing method of wire.