JPS60184461A - Dip forming method - Google Patents

Abstract

PURPOSE:To enable long-time stable operation of a dip forming method by cleaning up the surface of a seed wire and maintaining the atmosphere of the inert gas or weak reducing gas above the atmospheric pressure in the passage atmosphere until the seed wire is dipped into a molten metal. CONSTITUTION:A seed wire 7 to be used as a core is dipped in a molten metal 5 to stick and solidify the molten metal 5 around the wire 7 and to manufacture a casting rod 9. Such rod is continuously hot rolled, by which a clad wire rod is obtd. A passage atmosphere 11 in which the seed wire 7 having the surface cleaned by scalping 6 travels to the insertion port 2 for the seed wire of a crucible 1 is maintained in the atmosphere of the inert gas or weak reducing gas under the pressure above the atmospheric pressure. The product having good quality is thus obtd. without requiring any special mechanism for maintaining airtightness around the machine or jig. The maintenance of the equipment is made simple and the long-term stable operation is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dip forming method, which is known as a method for continuous casting and rolling of copper.

Dip forming has been conventionally used as a method for producing copper wire. An outline of this dip forming method will be explained with reference to FIG. A crucible 1 made of a refractory material such as graphite is provided with a seed wire insertion opening 2 at its bottom. Molten copper 5 is supplied to the crucible 1 from a melting furnace 3 through a molten steel supply port 4. Further, the seed wire 7 from which the surface layer has been removed by the peeling die 6 is wound around a capstan 8, and is supplied from the capstan 8 into the grain wire 1 through the seed wire insertion opening 2 of the grain wire 1. . In the crucible 1, molten steel adheres to the seed wire 7 and solidifies, forming a cast rod 9. This casting rod 9 is water-cooled to an appropriate temperature in a cooling tower 10 installed above the crucible 1 and connected to the crucible 1, and is continuously rolled to a predetermined diameter in a hot rolling mill that does not use water infrequently. It will be finished.

As shown in Japanese Patent Publication No. 39-18204, in the above-mentioned conventional method, the atmosphere 11 of the passage of the seed line 7 from the peeling die 6 to the seed line insertion opening 2 of the crucible 1 is
The inside of the housing 12 was evacuated by a vacuum pump (not shown) connected to an exhaust port 13 provided in the housing 12, thereby maintaining a vacuum atmosphere. This is the boundary between the surface of the seed wire 7 and the adhesion mass of molten steel when the seed wire 7, whose surface layer has been removed and cleaned by the peeling die 6, is immersed in molten steel in the crucible 1 in contact with air. The purpose of this was to prevent adverse effects on close bonding between surfaces, and to prevent blisters and pinholes from occurring in the adhered solidified metal. The present inventors have studied this point and found that if the inside of the housing 12 is set to a sufficiently dehumidified dry air atmosphere, no blisters or pinholes are observed in the metal that adheres to and solidifies on the seed wire 7.
Therefore, blisters and bubbles in solidified metal do not occur because the surface of the seed wire is oxidized by oxygen in the air, but are caused by the adsorption of moisture in the air on the surface of the seed wire. I found out something.

Therefore, it is conceivable to create a dry air atmosphere within the housing 12 instead of creating a vacuum atmosphere as in the conventional case. In this way, there is no need to keep the inside of the housing 12 in a vacuum, and there is no need for special airtightness around machines and jigs, which can significantly reduce maintenance costs for various equipment. Another advantage is that there is no need to operate a vacuum pump.

In addition, the problem of the molten steel in the crucible 1 dripping from the gap between the seed wire 7 and the bottom insertion port 2 of the bottom 1, which occurred in the conventional method where the inside of the housing 12 is in a vacuum atmosphere, can be eliminated, and stable operation can be achieved. It also has the advantage of being possible.

However, if the interior of the housing 12 is made into an atmosphere of dry air, the bottom of the crucible 1 that houses the molten steel and is heated to a high temperature and comes into contact with the dry air will have a high ms, and the life of the crucible 1 will be shortened. Therefore, continuous operation for a long period of time is no longer possible, and in this respect, the problem arises that the economic efficiency is very poor.

This invention was made in view of the above-mentioned conventional circumstances, and there is no particular requirement for airtightness around machines or jigs, and stable operation can be carried out economically over long periods of time. The purpose is to provide a dip forming method.

In other words, the dip forming method of this invention is a dip forming method in which a seed wire serving as a core is immersed in molten metal, the molten metal is adhered and solidified around the seed wire, and then hot rolling is performed continuously. 3- The atmosphere in the passage of the seed wire from after cleaning the surface of the seed wire to immersion in the molten metal is an inert gas or weakly reducing gas atmosphere at a pressure of 1 s above atmospheric pressure.

The dip forming method of the present invention will be explained in more detail below.

FIG. 2 schematically shows an example of equipment used to carry out the dip forming method of the present invention. In the equipment shown in the figure, a pipe 14 for supplying the required gas is provided in the housing 12, and a valve 15 is provided in the pipe 14.

In the present invention, the dip forming method is performed as follows using the equipment as described above. That is, in the dip forming method of the present invention, after the seed wire 7 is cleaned by peeling 6 and before being immersed in the molten metal 5, the passage atmosphere 11 of the seed wire 7, that is, the atmosphere inside the housing 12, is greatly increased. The atmosphere is an inert gas and/or weakly reducing gas at a pressure higher than atmospheric pressure. Specifically, in the equipment shown in Figure 2,
First, the opening degree of the valve 15 is set appropriately, and an inert gas or weakly reducing gas is introduced into the housing 12 through the pipe 14-4.
to be sent within. On the other hand, existing atmospheric gas within the housing 12 is exhausted from the gas exhaust port 13. As a result, the inside of the housing 12 becomes an atmosphere of an inert gas or weakly reducing gas supplied from the pipe 14. In general, if the inert gas or weakly reducing gas is continuously supplied from the pipe 14, the inside of the housing 12 can be maintained in an atmosphere of inert gas or the like.

As described above, by creating an atmosphere of inert gas or the like at atmospheric pressure or higher in the housing 12, it is possible to prevent atmospheric air from entering the housing 12 without making the surroundings of the machine or jigs particularly airtight. I can do it. Therefore, it is possible to prevent blisters and pinholes from forming in the metal that adheres to and solidifies on the seed wire 7, and at the same time, it is possible to prevent the bottom of the crucible 1 from being oxidized.

In the equipment shown in FIG. 2, the means for cleaning the surface of the seed line 7 is the peeling die 6, but in this invention, the means for cleaning the surface of the seed line is not limited to this, and for example, shot blasting or Wire brushes, microchemical cleaning means can be used.

Next, an example of the present invention will be described.Example: The dip forming method of the invention was carried out using equipment not shown in FIG. 2 described above. When feeding the steel wire 7 having an outer diameter of 12, 7a+I++φ, whose surface layer has been removed and cleaned by the peeling tie 6, into the crucible 1 from the insertion opening 2 of the crucible 1 containing molten copper, #M In order to maintain a weakly reducing atmosphere in the line passage, 1001 is installed inside the housing 12.
N2 (95%) and Co (5%) at 11111H20 pressure
) was supplied every 11i), and the pressure of the mixed gas atmosphere of N2 and CO in the housing 12 was maintained at a pressure slightly higher than atmospheric pressure. Part J: Molten copper was deposited and solidified on a steel wire under the same conditions, and then subjected to a hot rolling process to obtain a rough drawn copper wire with an outer diameter of Bmm.

Using the roughly drawn copper wire obtained in the above example and the same seed wire as in the example, the inside of the housing 12 is made into a vacuum atmosphere,
The properties of this wire were compared with a roughly drawn copper wire obtained in the same manner as in the example. The results are compared and shown in Table 1.

As shown in Table 1, the rough drawn copper wires obtained in the examples have a quality comparable to that of the rough drawn copper wires obtained by the conventional method.

As described above, according to the dip forming method of the present invention, the passage atmosphere of the seed line after surface cleaning is made into an inert gas or weakly reducing gas atmosphere with a pressure higher than atmospheric pressure, thereby changing the passage atmosphere into a vacuum atmosphere. It is possible to produce products with comparable quality over time, with a significant reduction in maintenance costs for various equipment. Moreover,
Stable operation can be performed continuously for long periods of time = 7-,
It is possible to produce 14 products of uniform quality at low cost.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of equipment used in the conventional dip forming method, and FIG. 2 is a schematic sectional view of equipment used in the date forming method of the present invention. 1... Crucible, 2... Seed line insertion port, 5... Molten metal, 6... Peeling, 7... Seed line, 8...
Capstan, 11... Seed line passage atmosphere, 12...
・Housing, 13...exhaust port. Applicant Fujiyu Electric Cable Co., Ltd. Agent Patent Attorney Takehisa Toyoda (and 1 other person) 8-

Claims (1)

[Claims] In the dip forming method, in which a seed wire serving as a core is immersed in molten metal, the molten metal is adhered and solidified around the seed wire, and then hot rolling is performed continuously, the seed wire is immersed in molten metal after the surface of the seed wire is cleaned. A dip forming method characterized by setting the passage atmosphere of the seed line to an inert gas or weakly reducing gas atmosphere at a pressure higher than atmospheric pressure.