JP3462386B2 - Slide gate plate - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slide gate plate used for controlling the flow rate of molten metal such as molten pig iron and molten steel in the steel industry.

[0002]

2. Description of the Related Art A slide gate plate has been widely used as an indispensable refractory material in the iron and steel industry at present when secondary processing in a ladle and continuous casting are generalized as a member for controlling the flow rate of molten metal. Since the slide gate plate is a part that controls the flow of the molten metal, it is required to have a very advanced function, and it is desired that the slide gate plate has excellent characteristics in various severe conditions in terms of material. This slide gate plate is subject to physical and chemical erosion due to molten metal and molten slag in addition to the physical effects of rapid thermal shock and wear due to molten metal flow. Are roughly classified into thermal shock resistance, corrosion resistance and strength. Various studies have been conducted to equip this sliding gate plate with various characteristics in a well-balanced manner. Recently, an alumina (zirconia) -carbon type having the most stable durability has been widely used in the steel industry.

As a general technique for manufacturing a slide gate plate, a thermosetting resin (generally, an alumina-based material, a zirconia-based material, a silica-based material, a carbon-based material, a silicon carbide material, etc.) which is a binder is used. (Phenolic resin is often used) is added and kneaded, and a step of firing after molding is taken, and pitch or tar is often impregnated after firing to improve characteristics. As a method of improving the thermal shock resistance, it is common to use many raw materials having a low coefficient of thermal expansion such as silica-based, silicon carbide, and carbon-based materials, but silica-based, silicon carbide, carbon-based materials, etc. are molten steel. When it is added excessively in order to easily react with or to form a low melting point compound, there is a problem that the corrosion resistance is significantly lowered.

Therefore, as a means for improving the corrosion resistance, the fired body is often impregnated with pitch or tar for the purpose of reducing the porosity or exerting a force that gasifies and pushes back the steel when the steel comes into contact. . However, due to problems such as low porosity and small pore size of the fired body, and high viscosity of the liquid to be impregnated, only the surface layer is impregnated, and the impregnation effect is not sufficiently exerted. The current situation.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been earnestly studied in order to solve the problems of the conventional alumina- (zirconia) -carbon type slide gate plate, and the slide gate plate sintering By strictly controlling the porosity of the body, the pore diameter and the viscosity of the impregnated material, the impregnated material is appropriately impregnated into the slide gate plate sintered body to improve the characteristics such as corrosion resistance.

[0006]

Means for Solving the Problems The present invention is as follows: 1) Apparent porosity consisting of carbon-containing refractory obtained by adding a binder to an aggregate of a refractory inorganic material and firing it is 5% or more and less than 16%, The pore diameter located at 1/10 of the apparent porosity is 2 μm or more and less than 6 μm, that is, the pore diameter is 2 μm or more and 6
Those with a size of less than μm account for 10% of all apparent pores ,
And the pore diameter located at 1/2 is 0.5 μm or more and 2 μm
Is less than, that is, the pore diameter is 2 μm or more and less than 6 μm
For a fired body whose size is half of all apparent pores , 1
A slide gate plate, which is impregnated with a liquid containing carbonaceous matter having a viscosity of 1 poise or less at a temperature of 50 ° C. (2) The slide gate plate according to the above (1), wherein pitch or tar is impregnated as the carbonaceous liquid material. 3. The slide gate plate according to 1 or 2 above, which is impregnated with a carbonaceous material-containing liquid and then heated and carbonized in a reducing atmosphere. I will provide a

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. In the present invention, as described above, alumina- (zirconia)-
By controlling the porosity of the carbon-based slide gate plate sintered body, the pore diameter and the viscosity of the impregnated material, it is intended to improve the corrosion resistance, but in reaching such knowledge, the particle size of the raw material used was changed, A fired body having various apparent porosities and pore diameters was produced, and a slide gate plate impregnated with a liquid having different viscosities was set at the bottom of the ladle container, and the test in actual operation was repeated. as a result,
A large difference was found in the amount of damage to the slide gate plate depending on the apparent porosity of the fired body, the pore diameter, and the viscosity of the impregnated material. Further, depending on the type of the plate, problems such as welding of the sliding surface occurred. And these problems are the porosity of the fired body,
It became possible to solve this problem by strictly controlling the pore size and the viscosity of the impregnation rate.

In the present invention, the apparent porosity of the fired body is 5
% Or more and less than 16% is because when the content is less than 5%, the impregnated material does not sufficiently enter, and there is a problem that the sliding surface of the slide gate plate and the steel are welded during use. On the contrary, if it is 16% or more, the impregnation amount is not sufficient in one impregnation, and if impregnation is performed twice or more, the impregnation component becomes too much in the plate, and conversely damage tends to proceed. .
Further, the pore diameters at which the apparent porosity of the fired body is located at 1/10 and 1/2 are obtained by measuring the pore distribution, and taking the apparent porosity on the vertical axis and the pore diameter on the horizontal axis. Shows the pore diameters when the apparent porosity of the fired body located at the intercept of the vertical axis is 1/10 and 1/2. The fired body of the present invention has a pore diameter of 2 μm or less.
Those with a size of less than 6 μm are equivalent to 10% of all apparent pores
However, all of them have a pore size of 2 μm or more and less than 6 μm.
Equivalent to half of apparent pores. That is, the apparent porosity is 1
The pore diameter located at / 10 is 2 μm or more and less than 6 μm,
Also, the pore diameter located at 1/2 is 0.5 μm or more and 2 μm or less.
Be satisfied.

The reason why the pore diameter located at 1/10 of the apparent porosity is 2 μm or more and less than 6 μm is that when the thickness is less than 2 μm, the slide gate plate is too dense and the impregnated material is hard to enter, and the slide gate plate slides during use This is because there is a problem that the surface and the steel are welded. When the thickness is 6 μm or more, the impregnation amount is not sufficient in one impregnation, and when the impregnation is performed twice or more,
This is because the impregnated component becomes too much in the plate product, and conversely damage tends to proceed.

Further, the reason why the pore diameter at which the apparent porosity of the fired body is located at 1/2 is 0.5 μm or more and less than 2 μm is
If the thickness is less than 0.5 μm, the sliding gate plate is too dense and the impregnated material is difficult to enter, and there is a problem that the sliding surface of the sliding gate plate and steel are welded during use.
If m or more, the amount of impregnation is not sufficient for one impregnation,
This is because when the treatment is performed twice or more, the impregnation component becomes too much in the plate product, and conversely damage tends to proceed.

Further, the viscosity of the liquid substance to be impregnated is limited to 1 poise or less at a temperature of 150 ° C. because the viscosity is high and the impregnated substance is not sufficiently filled when it exceeds 1 poise. After impregnating the carbonaceous material, the material is heated in a reducing atmosphere to carbonize it, if necessary. Pitch or tar can be used as the carbonaceous liquid material. When such a carbonaceous liquid material is appropriately contained in the slide gate plate, the porosity of the plate is satisfactorily lowered, and when the steel comes into contact with the steel, gasification force is exerted to improve the corrosion resistance. Can be made. Only when the above conditions of the present invention are controlled, a sliding gate plate refractory product having excellent corrosion resistance and thermal shock resistance can be obtained without welding the sliding surface and steel.

[0012]

EXAMPLES AND COMPARATIVE EXAMPLES Next, examples and comparative examples of the present invention will be specifically described. However, the examples described below show one example described so that the present invention can be easily understood and carried out, and the present invention is described to limit the present invention. is not.

(Example) As shown in Table 1, sintered alumina-based raw material powder, electro-fused zirconia-based raw material powder and metallic silicon (Si) powder were used as raw materials for primary particles, and silicon carbide powder was used as required. The silica raw material powder and the carbon raw material powder were kneaded using a thermosetting resin (aromatic phenol resin) as a binder. In addition, as shown in Table 1, this thermosetting resin was further added with the total of the mixing ratio of the sintering raw material powder which is the refractory as 100%. Further, as described above, the silicon carbide powder, the silica-based raw material powder, and the carbon raw material powder are added as needed, but in the present Examples 1 to 6 shown in Table 1, all of them are added little by little. Shows.

The mixed powder kneaded as described above was molded into a plate shape, which was calcined to volatilize volatile components, and the molded body was calcined in a reducing atmosphere of coke powder. After that, the fired body dried at 150 ° C.
The pressure was reduced at rr for 1 hour, the liquid for impregnation preheated to 150 ° C. was pressurized at 0.8 MPa for 1 hour to impregnate, and further carbonized at 700 ° C. in a reducing atmosphere. Then, a strip-shaped iron skin is fitted on the outer periphery of the plate thus obtained,
The sliding gate plate was obtained by subjecting the sliding surface to surface treatment. A practical test was conducted using this slide gate plate in a 200-ton ladle, and the number of times of service was examined. The results are shown in Table 1.

[0015]

[Table 1]

[0016] Of the Examples 1 to 6 shown in Table 1, a concrete description will be given based on the representative Example 3. As for the sintered alumina-based raw material, 12.5% by weight of powder having a particle size of 3 to 1 mm is used. , 12.5% by weight of powder having a particle size of 1 to 0.3 mm, 33% by weight of powder having a particle size of 0.3 or less, and powder of particle size of 3 to 1 mm and particle size of 1 to 0.5 m for the electro-melting zirconia-based raw material.
m powder and powder having a particle size of 0.5 or less, 10.0% by weight, silica-based raw material powder 2% by weight, and silicon carbide powder 2
Wt%, carbon raw material powder 5 wt%, metallic silicon (S
i) A mixed powder with 3% by weight of powder was used. The phenol resin as a binder was blended in an amount of 4% by weight.

The liquid clay to be impregnated had a porosity of 0.05 poise at 150 ° C., an apparent porosity of 5.1%, a pore diameter located at 1/10 of the apparent porosity of 2 μm and an apparent porosity. The pore diameter located at ½ of the ratio is 0.7 μm, and both are within the range of the conditions of the present invention. In this case, the impregnation rate for one time is 1.1% by weight and the impregnation rate for two times is 1.
6% by weight. Here, the impregnation rate means [impregnation rate (% by weight) = (weight after impregnation-weight of fired body) × 100 /
Calcined body weight]. As a result, the corrosion resistance is very high and the thermal shock resistance is also good. Further, it can be seen that the number of times of practical use is 10 times, which is significantly improved as compared with the comparative example described later. The above has been described based on the third embodiment, but the same applies to the first, second, and fourth to sixth embodiments. As is clear from the above, the slide gate plate of the present invention has greatly improved corrosion resistance, thermal shock resistance and the like, and has an excellent effect.

(Comparative Example) As shown in Table 2, a sintered alumina-based raw material powder was used as a raw material powder for primary particles as in the case of the embodiment.
Electrofused zirconia-based raw material powder, metallic silicon (Si) powder, silicon carbide powder, silica-based raw material powder, and carbon raw material powder were used, and a thermosetting resin (aromatic phenolic resin) was kneaded as a binder. The mixed powder kneaded as described above was molded into a plate shape in the same manner as in the example, and this was calcined to volatilize volatile components, and this molded body was calcined in a reducing atmosphere in coke powder.

Thereafter, the calcined material dried at 150 ° C. is depressurized at 10 torr for 1 hour, and the impregnating liquid material preheated to 150 ° C. is pressurized at 0.8 MPa for 1 hour to impregnate it, and further in a reducing atmosphere. Carbonized at 700 ° C. Then, a strip-shaped iron skin was fitted on the outer periphery of the plate thus obtained, and the surface to be slid was processed to obtain a slide gate plate. This slide gate plate 20
A practical test was conducted using a 0 ton ladle, and the number of times of service was examined. The results are shown in Table 2.

[0020]

[Table 2]

As shown in Table 2, in Comparative Example 1, the pore diameter located at 1/10 of the apparent porosity was 7 μm, which was outside the upper limit of the present invention of less than 6 μm. The pore diameter located at 1/10 of the applied porosity is 7 μm, which is outside the range of less than the upper limit value of 6 μm of the present invention, and the liquid clay to be impregnated has a porosity of 1.5 poise at 150 ° C. It exceeds the upper limit of 1 poise and is out of range. Similarly, in Comparative Example 3, the apparent porosity, the pore diameter located at 1/10 of the apparent porosity, and the pore diameter located at 1/2 of the apparent porosity are both outside the scope of the present invention. Examples 4 and 6 are the clay of the liquid to be impregnated, the apparent porosity, 1/10 of the apparent porosity.
Both the pore diameters located at 1 and the pore diameters located at 1/2 of the apparent porosity are outside the scope of the present invention, and in Comparative Example 5, the apparent porosity, apparent porosity Both the pore diameter located at 1/10 of the applied porosity and the pore diameter located at 1/2 of the apparent porosity are outside the scope of the present invention.

As a result, Comparative Examples 1 and 2 are excellent in thermal shock resistance but inferior in corrosion resistance. Comparative Examples 3 and 4 have good corrosion resistance, but have poor thermal shock resistance, and chipping or welding occurs, and the number of cycles of service is 5. Further, Comparative Examples 5 and 6 are excellent in thermal shock resistance, but inferior in corrosion resistance, causing melting loss and having a service life of 6. As shown in these comparative examples, the slide gate plates outside the scope (conditions) of the present invention showed poor thermal shock resistance, corrosion resistance, or any of these results, and the effectiveness of the present invention was confirmed by comparison with these comparative examples. I can understand the sex clearly.

[0023]

EFFECTS OF THE INVENTION By strictly controlling the porosity, pore diameter and viscosity of the carbonaceous liquid material of the slide gate plate sintered body, the slide gate plate sintered body is appropriately impregnated with the impregnated product, The present invention provides a slide gate plate which has dramatically improved thermal shock resistance and corrosion resistance and dramatically improved durability, and is particularly suitable for controlling the flow rate of molten metal such as hot metal and molten steel in the steel industry.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Watanabe No. 1 Minamito, Ogakie-cho, Kariya city, Aichi Toshiba Ceramics Co., Ltd., Kariya factory (56) Reference JP-A-60-86567 (JP, A) JP-A-51 -87131 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B22D 41/30 B22D 41/32 B22D 11/10 340

Claims (3)

(57) [Claims] 1. An apparent porosity composed of a carbon-containing refractory obtained by adding a binder to an aggregate of a refractory inorganic material and firing it is 5% or more and less than 16%, and 1/10 of the apparent porosity. With a pore size of 2 μm or more and less than 6 μm, that is, a pore size of 2 μm
10% of all apparent pores have a size of m or more and less than 6 μm
Hit , and located at 1/2 the pore diameter is 0.5 μm or more and less than 2 μm, that is, the pore diameter is 2 μm or more and less than 6 μm
Of the size of the fired body that hits half of all apparent pores ,
A slide gate plate, which is impregnated with a liquid containing carbonaceous material having a viscosity of 1 poise or less at a temperature of 150 ° C. 2. The slide gate plate according to claim 1, wherein pitch or tar is impregnated as the carbonaceous liquid material. 3. A slide gate plate according to claim 1, wherein the slide gate plate is carbonized by heating in a reducing atmosphere after impregnating the carbonaceous liquid.