JP2799451B2 - Stopper for metal pouring gate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stopper used for a pouring port of a molten metal furnace.

[0002]

2. Description of the Related Art Conventionally, as a stopper used for a pouring port of a metal melting furnace used in a foundry, a molded product mainly composed of an alumina-carbon refractory or a material for preventing molten metal from being solidified. A molded article of inorganic fiber such as ceramic fiber and alumina fiber in consideration of heat insulation is used. For example, Japanese Unexamined Utility Model Publication No. 1-60742 discloses a casting gate type heat insulating material formed by mixing an organic or inorganic fiber and an organic or inorganic binder.
JP-A-154647 discloses that 10 to 20% by weight of C and A
l ₂ O ₃ stopper with refractory material the pouring nozzle and C using a refractory material containing 70-80 wt% containing 30 to 40 wt% and SiC35~55 wt% are described.

[0003]

However, the conventional stopper for the molten metal pouring spout is, for example, the above-described Japanese Utility Model Laid-Open No. 1-6.
In order to improve heat resistance, such as silica sand (SiO ₂ ), mullite,
In many cases, granular refractories such as alumina and brick debris are mixed in, and foreign matters caused by the refractory powder or the particulates mixed in inorganic fibers called "shots" in the molten metal are likely to be mixed. . Then, as a result of the refractory powder and shot being poured out together with the molten metal, a defect occurs in the product, resulting in a reduction in quality and yield. For example, an aluminum plate used for an aluminum can, etc.
Since it is manufactured by rolling to a thickness of about 00 μm, if such foreign matter is mixed in the molten metal at the time of manufacturing the ingot, defects such as pinholes may occur in the aluminum plate manufactured by rolling the ingot. Will occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a stopper for a molten metal pouring spout in which refractory powder and foreign matters caused by shots are not mixed into the molten metal. It is an object.

[0005]

According to the present invention, a stopper for a molten metal pouring port of the present invention is obtained by molding a mixture of inorganic fibers, organic fibers, and an inorganic binder not containing a shot into a shape matching the molten metal pouring port. It is characterized by. For example, carbon fiber is different from rock wool or ceramic fiber produced by the blowing method or the centrifugal method, in that the shots do not occur in the production process, or are present in a very small amount even if they are present. It is possible to prevent the generation of foreign substances due to shots when molded into a pouring port stopper. The carbon fiber includes a pitch type and a polyacrylonitrile (PAN) type, and any of them can be used. Further, the shape of the carbon fiber is not particularly limited, but is preferably set to an average fiber length of 0.2 to 15 mm,
Particularly preferred is 3 mm. If the fiber length is short, the strength is reduced. If the fiber length is too long, it is difficult to uniformly disperse the fiber, and the surface of the obtained stopper becomes rough, which adversely affects the sealing property as the stopper. In addition, carbon fibers can also be used because they do not contain shots, such as silica fibers obtained by acid-treating glass fibers produced by a method of continuously drawing a melt from a bushing. Fiber is most preferred.

Since a molded body using only carbon fiber is brittle and difficult to handle, an organic fiber is used in combination with the stopper for a metal melt pouring port of the present invention. Examples of the organic fiber include an aramid fiber, a polyester fiber, and a nylon fiber, and an aramid fiber having excellent heat resistance and strength is preferable. The average fiber length of this aramid fiber is 0.3
It is preferably from 20 to 20 mm, particularly preferably from 0.7 to 5 mm. If the fiber length is short, the strength is reduced. If the fiber length is too long, it is difficult to uniformly disperse the fiber, and the obtained stopper has a rough surface, which adversely affects the sealing performance as the stopper. The organic fibers may be used alone or in combination of two or more.

The mixing ratio of carbon fiber and organic fiber is suitably 65 to 98% by weight of carbon fiber and 2 to 35% by weight of organic fiber, and 80 to 95% by weight of carbon fiber and 5 to 20% by weight of organic fiber. It is particularly preferred that the content be% by weight.

Further, an inorganic binder is blended in the stopper for the molten metal pouring port of the present invention. Examples of the inorganic binder include colloidal smectite, colloidal silica, and alumina sol. These can be used alone or in combination of two or more. Above all, by containing colloidal smectite,
A coating with excellent adhesion is formed on the surface of the carbon fiber and the organic fiber, and a stopper for a molten metal pouring port with more excellent heat resistance and durability can be obtained. The blending amount of the inorganic binder is a mixture of carbon fiber and organic fiber 1
The solid content is preferably 3 to 40 parts by weight with respect to 00 parts by weight, and particularly preferably the blending amount is 6 to 25 parts by weight. If the amount of the inorganic binder is small, the heat resistance of the stopper
If the durability is lowered, and too much, the stopper loses its flexibility and becomes brittle.

The metal melt pouring stopper of the present invention forms a slurry by adding an appropriate amount of water to a mixture of the carbon fiber, the organic fiber and the inorganic binder, and forms a slurry so as to conform to the shape of the pouring port of the metal smelting furnace. It is manufactured by dehydration molding by a suction molding method and drying by heating. Further, the stopper for the molten metal pouring port of the present invention has a surface,
In particular, durability can be further improved by applying colloidal smectite to the inner surface which is in direct contact with the molten metal.

[0010]

According to the present invention, since the raw material of the stopper for the molten metal pouring spout does not include a shot that causes foreign matter to be mixed into the molten metal, a defect such as a pinhole does not occur in the product. .

[0011]

EXAMPLES 93 parts by weight of pitch-based carbon fiber (average fiber length 0.7 mm), 7 parts by weight of aramid fiber (average fiber length processed into pulp 1 mm), 3 parts by weight of colloidal smectite, 10 parts by weight of colloidal silica parts, and alumina sol 2 parts by weight mixture by adding water 1.2% by weight of the slurry, followed by drying at 100 ° C. after dehydration molding, bulk density 0.25 g / cm ^2, the stopper cone thickness 10mm Obtained. FIG. 1 shows a side sectional view of the obtained stopper cone. The thermal conductivity at 600 ° C. of the stopper cone obtained in this example was 0.10 Kcal / mh ° C. When the content of shots in the pitch-based carbon fiber used in this example was examined, no shots of 45 μm or more were included at all. Further, an aluminum ingot was manufactured using the stopper cone obtained in this example, and this was rolled to obtain an aluminum plate having a thickness of 100 μm used for a normal aluminum can.
No defects such as pinholes were found.

[0012]

As described above, according to the present invention,
Since a stopper for a molten metal pouring spout that does not include a shot that causes foreign matter to be mixed into the molten metal can be obtained, a high-quality ingot that is free from defects such as pinholes when an aluminum plate or the like is produced. can get.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a stopper for a molten metal pouring port manufactured in Example 1.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 35/66 C04B 35/66 X 35/80 35/80 AK (56) References JP-A-56-140080 (JP, A JP-A-56-140064 (JP, A) JP-A-54-26239 (JP, A) JP-A-54-160521 (JP, A) JP-A-3-198956 (JP, A) 52052 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B22D 41/18 B22D 41/32 C04B 35/66

Claims (6)

(57) [Claims] 1. A stopper for a molten metal pouring port, wherein a mixture of an inorganic fiber, an organic fiber, and an inorganic binder not containing a shot is formed into a shape matching the molten metal pouring port. 2. The stopper according to claim 1, wherein the inorganic fibers not containing shots are carbon fibers. 3. The stopper according to claim 1, wherein the organic fiber is an aramid fiber. 4. The stopper for a spout of molten metal according to claim 1, wherein the inorganic binder contains colloidal smectite. 5. 65 to 98% by weight of carbon fiber,
A mixture in which 3 to 40 parts by weight of a solid content of an inorganic binder containing colloidal smectite is blended with 100 parts by weight of a mixture of 2 to 35% by weight of aramid fibers is formed into a shape that matches a spout of a molten metal. A stopper for a molten metal pouring spout characterized by the above. 6. 65 to 98% by weight of carbon fiber,
100 parts by weight of a mixture of 2 to 35% by weight of aramid fibers, and a mixture in which 3 to 40 parts by weight of an inorganic binder containing colloidal smectite is mixed at a solid content into a shape matching the pouring port of the molten metal, Furthermore, a stopper for a molten metal pouring spout characterized by applying a colloidal smectite to the surface thereof.