JPH059596A - Heat treating device for metallic wire having metallic gloss - Google Patents

Abstract

PURPOSE:To provide the heat treating device for a metallic wire having metallic gloss which can shorten the time for heating up and has excellent productivity. CONSTITUTION:This heat treating device of a strand system has a heating furnace 1 and a cooler 2 and heat treats the wire 7 while continuously inserting the wire 7 therebetween. An oxidizing gas introducing port 40 for supplying an oxide film forming gas 4 in the inlet direction F of the wire 7 is disposed near the inlet of the heating furnace 1 and a reducing gas introducing port 60 for introducing a reducing gas 6 is disposed behind this oxidizing gas introducing port 40. An inert gas introducing port 50 for supplying an inert gas 5 may be installed between the oxidizing gas introducing port 40 and the reducing gas introducing port 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus for a metal wire rod having a metallic luster, which is capable of shortening a temperature rising time and is excellent in productivity.

[0002]

2. Description of the Related Art As a wire rod, there is a metal wire rod having a brilliant metallic luster which is peeled off with a die or the like. The metal wire is also referred to as a stripped wire, and as shown in FIGS. 8 and 9, it is subjected to quenching and tempering in a strand-type heat treatment apparatus and heat treatment for improving strength and other physical properties. ing. However, in the heat treatment, since the stripped wire is continuously heated at a relatively high temperature of 600 to 1200 ° C., an oxide film is formed on the surface of the stripped wire. Therefore, such stripped wire may lose its bright metallic luster. Therefore, in the conventional heat treatment device, in order to maintain the metallic luster of the stripped wire,
As shown in FIGS. 8 and 9, in the heating furnace 1 and the cooling device 2, the heat treatment is performed in a reducing gas atmosphere. Examples of such reducing gas include H ₂ and ammonia decomposition gas (N
₂ + H ₂ ) or the like is used.

Since the above stripped wire is heated at a high temperature for a long time even if it is heat-treated in a reducing gas atmosphere, the surface of the stripped wire inevitably becomes silvery white. .. In this way, even if the surface of the stripped wire material becomes silver-white, it still has a metallic luster, so that its appearance is within the allowable range. As shown in FIGS. 8 and 9, the strand-type heat treatment apparatus is a system in which the wire 7 is continuously heat-treated in the supply pipe 8 while traveling in its axial direction, and then wound. is there.

[0004]

However, the above-mentioned conventional technique has the following problems. That is, the surface of the stripped wire is
Since it has metallic luster, its heat absorption rate is low. for that reason,
Stripped wire requires a long time to heat up. As a result, it takes about 80 seconds or more to heat the stripped wire to 1000 ° C. (see FIG. 4). Therefore, the productivity of heat treatment is reduced and the cost of the wire rod increases.

Such a problem also applies to metal wire rods such as peeling wire rods and pickling wire rods, which will be described later, in addition to the peeled wire rods. The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a heat treatment apparatus for a metal wire rod having a metallic luster, which can shorten the temperature rise time and is excellent in productivity.

[0006]

According to the present invention, there is provided a strand-type heat treatment apparatus having a heating furnace and a cooling device and heat-treating the plurality of wire rods while continuously inserting the plurality of wire rods between the heating furnace and the cooling device. An oxidizing gas inlet for supplying an oxide film forming gas is provided near the inlet of the wire,
Further, there is provided a heat treatment apparatus for a metal wire having a metallic luster, which is characterized in that a reducing gas introducing port for introducing a reducing gas is provided behind the oxidizing gas introducing port. What is most noticeable in the present invention is that an oxidizing gas inlet for supplying an oxide film forming gas to the inlet of the wire is provided in the vicinity of the inlet of the heating furnace, and the oxidizing gas introducing port is provided behind the oxidizing gas introducing port. In the above, a reducing gas inlet for introducing the reducing gas is provided.

As the oxide film forming gas, for example, air, water gas (H ₂ O + H ₂ ) or water vapor (H ₂ O) is used. In addition, a gas supply adjusting device such as a valve is installed at the oxidizing gas inlet so that the oxide film forming gas can be appropriately supplied according to the heating temperature of each heating temperature in the heating furnace (see FIG. 3). The air can be supplied in a small amount (Fig. 5). Further, as the reducing gas, for example, hydrogen gas (H ₂ ) or ammonia decomposition gas (N ₂ + H ₂ ) is used. In addition, a gas supply adjusting device using a valve is arranged at the reducing gas introducing port, like the oxidizing gas introducing port.

An inert gas inlet for supplying an inert gas such as argon gas (Ar) or nitrogen gas (N ₂ ) is provided between the oxidizing gas inlet and the reducing gas inlet. It is preferable to install it. As a result, the oxide film forming gas and the hydrogen gas (H ₂ ) as the reducing gas are obtained.
It is possible to prevent the explosion from being generated by mixing with and. However, when water gas (H ₂ O + H ₂ ) is used as the oxide film forming gas, it may be mixed with hydrogen gas (H ₂ ) as the reducing gas. Therefore, in such a case, it is not necessary to provide the inert gas introduction port (Fig. 6). The above-mentioned strand-type heat treatment apparatus has a wire rod supply device that can feed a plurality of wound metal wire rods in parallel while stretching them one by one (FIG. 2).

Further, in the present invention, as the wire rod, for example, SUS440B, SUS410, SUS304, S
A metal wire made of US316, Ti alloy can be used. Further, the maximum temperature at which these metal wires may be heated in the atmosphere of the oxide film forming gas is as follows. That is, for example, SUS440B is 600 ° C., SUS4
10 is 390 ℃, SUS304 is 500 ℃, SUS31
6 is 520, and Ti alloy is 300 ° C.

The metal wire rod is continuously fed to the heating furnace, the cooling device and the tempering furnace while running in the axial direction thereof, and is wound by a winding device after heat treatment (FIG. 1). Examples of the metal wire rod having the metallic luster include a peeled wire rod peeled with a die, a peeled wire rod peeled with a bite, and a drawn wire rod. Examples of the drawn wire rod include an acid-washed wire rod, a peeled wire rod, and a peeling wire rod.

[0011]

In the present invention, an oxidizing gas inlet for supplying an oxide film forming gas toward the inlet of the wire is provided near the inlet of the heating furnace. Therefore, in the initial heating stage until the metal wire is heated to, for example, about 600 ° C., the metal wire is heated in an oxidizing atmosphere. Then, in this initial heating stage, an oxide film having a thickness of, for example, about 0.5 μm is formed on the surface of the metal wire. In this way, the heat absorption rate of the metal wire is improved due to the formation of the oxide film. Therefore, the metal wire is likely to be heated immediately thereafter, and the heating time up to, for example, about 1000 ° C. can be shortened (FIG. 4).

On the other hand, a reducing gas introducing port for introducing a reducing gas is provided behind the oxidizing gas introducing port. Therefore, the metal wire is, for example, 600 to 1200.
In the middle or final stage of heat treatment at a relatively high temperature of ° C, the oxide film does not grow any further. Therefore, the surface of the metal wire has a metallic luster while retaining silver-white color, for example, to the extent that an oxide film having a thickness of about 0.5 μm is formed. As described above, according to the present invention, it is possible to provide a heat treatment apparatus for a metal wire rod having a metallic luster, which is capable of shortening the temperature rising time while maintaining the silver-white metallic luster and is excellent in productivity. it can.

[0013]

【Example】

Example 1 A heat treatment apparatus for a metal wire having metallic luster according to an example of the present invention will be described with reference to FIGS. That is, the heat treatment apparatus of this example has a heating furnace 1 and a cooling apparatus 2 as shown in FIGS.
This is a strand type device that heat-treats the wire rod 7 while continuously inserting the wire rod 7. In addition, an oxidizing gas inlet 40 for supplying the oxide film forming gas 4 in the inlet direction F of the wire 7 is provided in the vicinity 11 of the inlet of the heating furnace 1 and behind the oxidizing gas inlet 40. A reducing gas introducing port 60 for introducing the reducing gas 6 is provided in the. Further, a tempering furnace 3 is provided behind the cooling device 2.

As the oxide film forming gas, air 44 is used as shown in FIG. In addition, the oxide film forming gas is, as shown in FIGS.
Through 0, it is sent into the heating furnace 1 using a blower or the like. As shown in FIGS. 1 and 2, the oxide film forming gas flows in the heating furnace 1 so that it flows in the inlet direction F of the wire 7.
Supply inside. Further, an inert gas inlet 50 for introducing the inert gas 5 is provided between the oxidizing gas inlet 40 and the reducing gas inlet 60 as shown in FIGS. As the inert gas 5, as shown in FIG.
Ar gas 55 is used.

The oxidizing gas inlet 40, the inert gas inlet 50, and the reducing gas inlet 60 are connected to the gas supply pipe 8 in the heating furnace 1, respectively. Further, a reducing gas discharge port 67 is provided in the upper rear part of the heating furnace 1. In addition, as shown in FIG. 3, the oxidizing gas inlet 40, the inert gas inlet 50, and the reducing gas inlet 60 are connected to the oxide film forming gas 4 and the oxide film forming gas 4 according to the temperature raising step (normal temperature to 1200 ° C.). A large number of valves 41 to 43, 51 to 53, 61 to 6 so that the inert gas 5 and the reducing gas 6 can be appropriately supplied.
A supply adjusting device using No. 5 is provided. By this,
It is possible to provide a heating temperature and an oxidizing, reducing, or inert gas atmosphere corresponding to the type and composition of the wire 7.

Further, as shown in FIG. 5, a small amount of air 44
Can also be used. Further, as shown in FIG. 6, water gas (H ₂ O + H ₂ ) 45 can be used. Note that, as shown in FIG. 6, when the water gas 45 is used as the oxide film forming gas, the above inert gas inlet is not provided. Combustion even if the oxide film forming gas and the reducing gas are mixed,
This is because no explosion will occur. A stripped wire is used as the wire 7. The stripped wire is, for example, 1 to
Four wire rods having a diameter of 5 mm are continuously fed from the wire rod feeding device into the heating furnace 1 so that they run in parallel. A cooling device 2 and a tempering furnace 3 are provided behind the heating furnace 1 as shown in FIGS. As shown in FIG. 2, the cooling device 2 is provided with a water cooling pipe 21. In addition, the tempering furnace 3 has about 400-
The atmosphere is set to 700 ° C.

Further, behind the tempering furnace 3, there is arranged a wire rod winding device 9 for continuously winding the heat-treated wire rod 7. Others are the same as the conventional strand type heat treatment apparatus. In the present example, an oxidizing gas inlet 40 for supplying the oxide film forming gas 4 in the inlet direction F of the wire 7 is provided near the inlet 11 of the heating furnace 1 as shown in FIGS. I am doing it. Therefore, when SUS440B is used as the wire 7, the wire 7 is heated in an oxidizing atmosphere in the initial stage of the heat treatment until it is heated to about 600 ° C. Then, in this initial stage, an oxide film having a thickness of about 0.5 μm is formed on the surface of the wire 7.

By thus forming the oxide film, the heat absorption rate of the wire 7 is improved. Therefore, wire 7
Is easily heated soon after, for example, about 1000
It is possible to shorten the heating time up to ° C. That is, as shown in FIG. 4, in the present invention (curve A), about 1
The elapsed time for heating to 000 ° C was a relatively short time of about 40 seconds. On the other hand, in the conventional example (curve B) in which only the reducing gas atmosphere is heated from the beginning, it took about 80 seconds to heat up to 1000 ° C., so the temperature rising time could be reduced to half. become. In addition,
FIG. 4 is a graph showing the relationship between the heating temperature (° C.) of the wire rod and the elapsed time (minutes).
0B is used. The wire diameter is 2.34 mm, the ambient temperature is 1000 ° C., the wire speed is 1.2 m / min, and the length of the heating furnace is 4 m.

On the other hand, an inert gas inlet 50 and a reducing gas inlet 60 are provided behind the oxidizing gas inlet 40. Therefore, the wire rod 7 is, for example, 1000 to 1.
At the final stage of heat treatment at 200 ° C., the oxide film is reduced. Therefore, the surface of the wire 1 has a silver white color. In this way, the heating time up to about 1000 ° C can be shortened (halved). Therefore, the productivity of heat treatment is improved.

Example 2 As shown in FIG. 7, this example shows the relationship between the wire heating temperature (° C.) and the amount of oxide film formed. That is, in this example, SUS440B having a wire diameter of 20 mm was used, and
Heating was carried out for 30 minutes (curve C) or 60 minutes (curve D) at each air atmosphere temperature of ℃ to 900 ℃.
The weight of the oxide film formed on the surface of the wire (mg / d
m ² ) was measured. The results are plotted in FIG. 7 for each temperature. As can be seen from the figure, the heating hold is 6
A larger amount of oxide film is formed in the case of 0 minute than in the case of shorter time (30 minutes).

What is important here is that even when heated in an air atmosphere, the oxide film formation is small up to about 600 ° C., and the oxide film formation amount rapidly increases at the high temperature. As is known from this, SUS440B
It can be seen that in (1), initial heating is performed in an oxidizing atmosphere up to 600 ° C., and heating is performed in a reducing gas atmosphere at a high temperature at which oxide film formation increases. The oxide film formed by initial heating is reduced in a high temperature reducing atmosphere. Further, the upper limit temperature for heating in the oxidizing atmosphere is different as described above, and is determined by the experiment as shown in FIG.

[Brief description of drawings]

FIG. 1 is a side view of a heat treatment apparatus according to an embodiment.

FIG. 2 is a plan view of the heat treatment apparatus according to the embodiment.

FIG. 3 is an explanatory view showing a mounting state of the gas supply adjusting device in the embodiment.

FIG. 4 is a graph showing the relationship between the heating temperature of the wire and the elapsed time.

FIG. 5 is an explanatory diagram showing another supply state of the oxide film forming gas and the inert gas in the example.

FIG. 6 is an explanatory view showing another supply state of the oxide film forming gas and the reducing gas in the first embodiment.

FIG. 7 is a graph showing the relationship between the wire heating time and the weight of oxide film produced in Example 2.

FIG. 8 is a plan view of a conventional heat treatment apparatus.

FIG. 9 is a side view of a conventional heat treatment apparatus.

[Explanation of symbols]

 1. ． ． Heating furnace, 2. ． ． Cooling device, 3. ． ． Tempering furnace, 4. ． ． Oxide film forming gas, 5. ． ． Inert gas, 6. ． ． Reducing gas, 7. ． ． Wire rod, 8. ． ． Gas supply pipe, A. ． ． The present invention, B. ． ． Conventional example,

Claims (1)

Claims: What is claimed is: 1. A strand-type heat treatment apparatus having a heating furnace and a cooling device, wherein a plurality of wire rods are continuously inserted between them to heat-treat the wire rods. An oxidizing gas introducing port for supplying an oxide film forming gas toward the inlet of the wire is arranged near the inlet, and a reducing gas introducing port for introducing a reducing gas is provided behind the oxidizing gas introducing port. A heat treatment device for a metal wire rod having a metallic luster, which is characterized by being arranged.