JP2006205218A - Stopper for automatic pouring furnace and nozzle for automatic pouring furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stopper for an automatic pouring furnace and a nozzle for the automatic pouring furnace which have prolonged life and are stably operated. <P>SOLUTION: A refractory layer 4 in the stopper head 3 of the stopper 1 does not become an oxygen supply source to molten metal since slaking-decomposition of agalmatolite grains does not occur even when coexisting with graphite or carbon. Further, a glassy film is formed on the operating surface of the stopper in contact with the molten metal to flatten the operating surface structure, and the entrapping of the air through the refractory can be restrained, and the refractory layer has excellent heat resistance, high erosion resistance and oxidizing resistance and little wettability with the molten metal. Consequently, as for the automatic pouring furnace 21, the optimum stopper 1 can be provided and further a refractory layer 15 forming the inner peripheral surface 14 of the nozzle 12 opened/closed with the stopper 1 shows the same action as the above refractory layer 4, and has excellent high strength and high erosion resistance and little wettability with the molten metal, and therefore the optimum nozzle 11 can be provided as for the automatic pouring furnace 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an automatic pouring furnace stopper and an automatic pouring furnace nozzle.

In automatic pouring furnaces such as cast iron and copper alloys, carbon and alumina / carbon stoppers are used. As the nozzle, those of zircon, high alumina and alumina / carbon are used. With these materials, slag or metal adheres to the stopper head as the stopper and the nozzle hole surface as the nozzle after pouring. These deposits increase as the operation is repeated. For this reason, it is impossible to completely close the nozzle hole, and there is a problem that the operation is stopped.
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  The present invention has been made to solve the above-described problems, and is a stopper for an automatic pouring furnace and an automatic pouring capable of suppressing the adhesion of slag and metal, prolonging the service life and stabilizing the operation. It aims at providing the nozzle for furnaces.

  A stopper for an automatic pouring furnace according to claim 1 for solving the above-mentioned problem, the outer peripheral surface of the nozzle head for opening and closing the nozzle hole of the automatic pouring furnace is a rholite whose main component is pyrophyllite as a mineral It consists of 45 to 85% by weight, graphite 10 to 35% by weight, and silicon carbide 1 to 10% by weight. It is characterized in that it is kneaded and molded by adding a binder and fired in a non-oxidizing atmosphere.

  The stopper for an automatic pouring furnace according to claim 2 is the structure according to claim 1, wherein the rholite mainly composed of pyrophyllite is calcined at 800 ° C. or more to evaporate crystal water. And containing 1 to 5% by weight of an alkali component.

  The automatic pouring furnace stopper according to claim 3 is the structure according to claim 1 or 2, wherein the rholite mainly composed of pyrophyllite has an average particle size of 250 μm or less. It is characterized by being a stone blending weight ratio of 60% or less.

  In the nozzle for automatic pouring furnace according to claim 4, the inner peripheral surface of the nozzle hole opened and closed by the stopper is 45 to 85% by weight of rholite whose main component is pyrophyllite as a mineral, and 10 to 35% by weight of graphite. %, 1 to 10% by weight of silicon carbide, added with a binder, kneaded and molded, and fired in a non-oxidizing atmosphere.

  The automatic pouring furnace nozzle according to claim 5 is the structure according to claim 4, wherein the rholite mainly composed of pyrophyllite is calcined at 800 ° C. or more to evaporate crystal water. And containing 1 to 5% by weight of an alkali component.

  The automatic pouring furnace nozzle according to claim 6 is the configuration according to claim 4 or claim 5, wherein the rholite mainly composed of pyrophyllite has an average particle size of 250 μm or less. It is characterized by being a stone blending weight ratio of 60% or less.

  According to the stopper for an automatic pouring furnace described in claim 1, the refractory structure forming the outer peripheral surface of the stopper head is not digested and decomposed of rholite grains even in the presence of graphite or carbon, like silicon dioxide. It does not become a source of oxygen into the melt. In addition, the half-melting temperature of rholite is around 1,500 ° C, and it forms a glass film on the working surface that comes into contact with the molten metal to smooth the working surface structure and suppress air entrainment through the refractory. It has excellent thermal shock resistance, high corrosion resistance, and oxidation resistance, and has low wettability with molten metal. For this reason, it is possible to provide a stopper for an automatic pouring furnace that can suppress adhesion of slag and metal, prolong the service life, and stabilize the operation.

  According to the stopper for an automatic pouring furnace according to claim 2, the rholite mainly composed of pyrophyllite is calcined at 800 ° C. or higher to remove crystal water, and the alkaline component is 1 to 5% by weight. Therefore, cracks are not generated in the refractory structure on the outer peripheral surface of the stopper head due to thermal expansion when crystal water evaporates.

  According to the stopper for an automatic pouring furnace according to claim 3, the rholite whose main component is pyrophyllite has an average particle size of 250 μm or less, and the ratio of the weight of the rhostone is 60% or less. Structure defects such as lamination during molding of the refractory structure on the outer peripheral surface of the head are unlikely to occur. Further, softening deformation of rholite particles during actual use tends to occur.

  According to the automatic pouring furnace nozzle described in claim 4, the refractory structure forming the inner peripheral surface of the nozzle hole opened and closed by the stopper is free from digestion and decomposition of rholite grains even in the presence of graphite or carbon. Unlike silicon dioxide, it does not become an oxygen supply source into the molten metal. In addition, the half-melting temperature of rholite is around 1,500 ° C., and a glass film is formed on the working surface in contact with the molten metal to smooth the working surface structure and to suppress air entrainment through the refractory. It is excellent in high strength and corrosion resistance, and has little wetting with molten metal. For this reason, it is possible to provide an automatic pouring furnace nozzle capable of suppressing the adhesion of slag and metal, prolonging the service life and stabilizing the operation.

  According to the nozzle for an automatic pouring furnace according to claim 5, the rholite whose main component is pyrophyllite is calcined at 800 ° C. or higher to remove crystal water, and the alkali component is 1 to 5% by weight. Therefore, cracks are not generated in the refractory structure on the inner peripheral surface of the nozzle hole due to thermal expansion when the crystal water is evaporated.

  According to the nozzle for an automatic pouring furnace according to claim 6, since the rholite mainly composed of pyrophyllite has an average particle size of 250 μm or less, the rhostone compounding weight ratio is 60% or less. It is difficult to cause structural defects such as lamination during molding of the refractory structure on the inner peripheral surface of the material. Further, softening deformation of rholite particles during actual use tends to occur.

  The purpose of providing an automatic pouring furnace stopper and an automatic pouring furnace nozzle that can prevent the adhesion of slag and metal, prolong the service life and stabilize the operation, The inner peripheral surface of the nozzle hole is composed of 45 to 85% by weight of rholite whose main component is pyrophyllite as a mineral, 10 to 35% by weight of graphite, and 1 to 10% by weight of silicon carbide. Realized by molding and firing in a non-oxidizing atmosphere.

  Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an automatic pouring furnace 21 such as cast iron and copper alloy using an automatic pouring furnace stopper (hereinafter simply referred to as a stopper) 1 and an automatic pouring furnace nozzle (hereinafter simply referred to as a nozzle) 11. It is sectional drawing. In the automatic pouring furnace 21, a pressurizing chamber 23 is formed in the upper part of the molten metal storage tank 22. A hot water receiving port 24 and a nozzle mounting portion 25 are formed on the left and right sides of the pressurizing chamber 23. The nozzle 11 is mounted on the nozzle mounting portion 25. The stopper 1 is suspended by a vertical movement mechanism (not shown) so as to face the nozzle 11. The stopper 1 opens and closes the nozzle hole 12 of the nozzle 11 by moving up and down. A mold 26 is disposed below the nozzle 11.

  A stopper head 3 that opens and closes the nozzle hole 12 of the nozzle 11 is formed at the tip of the main body 2 of the stopper 1. As shown in FIG. 2A, a refractory layer 4 made of a mineral structure is formed on the outer peripheral surface of the stopper head 3. Further, as shown in FIG. 2B, a refractory layer 15 made of the same mineral structure as the stopper 1 is formed on the inlet 13 of the nozzle hole 12 of the nozzle 11 and the inner peripheral surface 14 of the nozzle hole 12. Is formed.

The refractory layers 4 and 15 are composed of 45 to 85% by weight of rholite whose main component is pyrophyllite, 10 to 35% by weight of graphite, and 1 to 10% by weight of silicon carbide, and an organic binder is added. Kneaded and molded, and fired in a non-oxidizing atmosphere. Further, rholite is a pyrophyllite-based natural raw material having a mineral composition that is calcined at 800 ° C. or higher to evaporate crystal water and contains 1 to 5% by weight of an alkali component such as K ₂ O or Na ₂ O. . And the rholite whose average particle diameter is 250 micrometers or less uses what is 60% or less of a rholite compounding weight ratio.

By sharing the rholite and silicon carbide as described above, the rote in the coexistence state of silicon carbide is likely to cause a bloating phenomenon, and the entrainment of air through the refractory structure can be suppressed even at a low temperature. This is because the half-melting temperature of rholite is around 1550 ° C, and air entrainment is suppressed on the working surface in contact with the molten metal. While the rate is 5.3 × 10 ⁻⁴ darcy, the addition of silicon carbide reduces the air permeability to 1.0 × 10 ⁻⁴ darcy.

  And the mixing | blending weight ratio of rholite is desirable to be 45 weight% or more and 85 weight% or less in order to produce | generate a glass film actively on an operation surface at the time of the actual use of the stopper 1 and the nozzle 11. FIG. If it is 85% by weight or more, softening deformation becomes large. Further, the mixing ratio of silicon carbide is preferably 1% by weight or more and 10% by weight or less in order to positively generate the roteing phenomenon. If it is 10% by weight or more, the melting is remarkably increased.

  The weight ratio of graphite is preferably 10% by weight or more and 35% by weight or less in order to suppress softening deformation of rholite and to retain thermal shock resistance. If it is 35% by weight or more, the volume ratio of graphite to rholite increases, and structural defects such as lamination tend to occur. Furthermore, the reason for using rholite calcined at 800 ° C. or higher to evaporate the crystal water is to prevent the refractory layer from cracking because of the large coefficient of thermal expansion when the crystal water evaporates. And it is desirable that the rholite having an average particle diameter of 250 μm or less is 60% or less of the rholite blending weight ratio. If it is 60% or more, structural defects such as lamination during molding tend to occur. Softening deformation of rholite particles is likely to occur during actual use.

  The types of rholite include pyrophyllite rholite, kaolinic rholite, and sericite rholite, any of which can be used. In view of the fact that the working surface that comes into contact with the molten metal during actual use is semi-molten to form a glass layer, and the resistance to erosion to the molten metal, pyrophyllite rholite having a fire resistance of SK29 to 32 is optimal. Kaolinite has a high fire resistance of SK33 to 36, and sericite loite has a low fireproof of SK26 to 29.

  As described above, the refractory layer 4 forming the outer peripheral surface of the stopper head 3 of the stopper 1 has no digestion decomposition of rholite grains even in the presence of graphite or carbon, and supplies oxygen into the molten metal like silicon dioxide. There is no source. In addition, the half-melting temperature of rholite is around 1,500 ° C, and it forms a glass film on the working surface that comes into contact with the molten metal to smooth the working surface structure and suppress air entrainment through the refractory. It has excellent thermal shock resistance, high corrosion resistance, and oxidation resistance, and has low wettability with molten metal. For this reason, it is possible to provide an optimal stopper 1 for the automatic pouring furnace 21 that can suppress the adhesion of slag and metal, prolong the service life and stabilize the operation.

  Further, the refractory layer 15 forming the inner peripheral surface 14 of the nozzle hole 12 opened and closed by the stopper 1 exhibits the same action as the refractory layer 4 and is excellent in high strength and high corrosion resistance, and wetted with molten metal. Is small. For this reason, it is possible to provide the optimum nozzle 11 for the automatic pouring furnace 21 which can suppress the adhesion of slag and metal, prolong the service life and stabilize the operation.

It is sectional drawing of the automatic pouring furnace using the stopper and nozzle which concern on an Example. It is a schematic sectional drawing of the stopper and nozzle which concern on an Example.

Explanation of symbols

1 Stopper
3 Stopper head 4,15 Refractory layer 11 Nozzle
12 Nozzle holes
13 Inlet part 14 Inner peripheral surface

Claims (6)

  The outer peripheral surface of the nozzle head that opens and closes the nozzle hole of the automatic pouring furnace is 45 to 85% by weight of rholite mainly containing pyrophyllite as a mineral, 10 to 35% by weight of graphite, and 1 to 10% by weight of silicon carbide. A stopper for an automatic pouring furnace, characterized in that a binder is added, kneaded and molded, and fired in a non-oxidizing atmosphere.   2. The automatic injection according to claim 1, wherein the rholite containing pyrophyllite as a main component is calcined at 800 ° C. or more to evaporate crystal water and contains 1 to 5% by weight of an alkali component. Stopper for water furnace.   The automatic pouring according to claim 1 or 2, wherein the rholite mainly composed of pyrophyllite has an average particle size of 250 µm or less, and the rholite compounding weight ratio is 60% or less. Stopper for the furnace.   The inner peripheral surface of the nozzle hole opened and closed by the stopper is composed of 45 to 85% by weight of rholite mainly composed of pyrophyllite as a mineral, 10 to 35% by weight of graphite, and 1 to 10% by weight of silicon carbide. A nozzle for an automatic pouring furnace characterized in that it is kneaded and molded and fired in a non-oxidizing atmosphere.   5. The automatic injection according to claim 4, wherein the rholite containing pyrophyllite as a main component is calcined at 800 ° C. or higher to evaporate crystal water and contains 1 to 5% by weight of an alkali component. Nozzle for water furnace.   The automatic pouring according to claim 4 or 5, wherein the rholite mainly composed of pyrophyllite has an average particle size of 250 µm or less, and the rholite compounding weight ratio is 60% or less. Nozzle for furnace.

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