TW590823B - Method for continuously casting steel - Google Patents

Abstract

The object of the present invention is to provide a continuous casting method of steel by restraining the erosion at an immersion nozzle portion in contact with molten steel and at an immersion nozzle portion in contact with mold powder and/or slag to reduce raw material components in a refractory invaded into the molten steel, in the continuous casting of clean steel. In this invention, the continuous casting method for steel employs a composition: mold powder having less than 3 wt.% fluorine content and 4-10,000 poise viscosity at 1,300 DEG C, and an immersion nozzle made of alumina based refractory material (practically, alumina family refractory material and/or alumina-carbonaceous family refractory material).

Description

590823 A7 _____B7 V. Description of the invention (2) In addition, for mold powder, 3Ca0,2Si〇2 # CaF2 fluorite, etc. which can be crystallized, etc. "raw materials containing fluorine component" are used as a flux to increase liquidity. And / or, a heat removal controller can be sought (hereinafter, known technology 3). However, the fluorine component promotes the melt loss of the impregnated nozzle, which indirectly causes the difficulty of cleaning the steel front. Therefore, there must be no Fluorine or a mold powder that minimizes the fluorine component. Among them, the conventional technique of 'Kung Pok Wu powder' is known (hereinafter referred to as the conventional technique 3-1):

• Keep the pH of each piece of cooling sprayed with cooling water or the secondary cooling water after cooling, and the pH of the machine cooling water to be neutral, and improve the durability of the metal structure and concrete equipment of the casting machine body or piping, etc., for this purpose Technology (Japanese Patent Laying-Open No. 5 8 _ 125349),

• Similarly, spray the cooling water for cooling the slabs or the secondary cooling water after cooling ′ p Η of the machine cooling water to maintain neutrality, and then prevent the corrosion of the main machine or piping, and maintain fluidity and purification. Technology for this purpose (Japanese Patent Laid-Open No. 5 1-93728), • Technology for the purpose of preventing the generation of toxic fluorine to humans and animals (Japanese Patent Laid-Open No. 5-86423), • To prevent environmental pollution, Techniques for the purpose of preventing corrosion of the peripheral equipment of the continuous casting machine and preventing damage to the immersion nozzle (Japanese Patent Application Laid-Open No. 5-208250), • To prevent deterioration of the working environment caused by silicon tetrafluoride that reacts with silicate, Technique for the purpose of contamination of subcooling water (Japanese Patent Application Laid-Open No. 5 κ7227). Also, the known techniques for mold powders that reduce the fluorine content as much as possible (hereinafter, known techniques 3-1 π) are as follows: -5- This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 590823 A7 ---------- B7 V. Description of the invention (5), according to

Fe (l) + 0— (FeO) .................. (2) The reaction of formula (2) will be saturated, and melt The dissolved elements in the steel are similarly saturated. For example, if M η is a dissolving element, according to the reaction of Mη + 0— (ΜηΟ) (...) (3), (ΜηΟ) is saturated with alumina. (In addition, in formula (2), (3), 0 and Mη represent oxygen and manganese dissolved in the molten steel, and Fe (l) represents iron components in the molten steel. The formation of ', Al2〇3_Fe〇 " "Al2〇3-Mn〇," further reacts with the intervening substance " FeO-MnO, " in the molten steel, etc., to generate, Al2〇3-FeO-MnO " The liquid mineral is produced. That is, the overlap of the two factors may cause melting loss. In addition, in order to increase the spalling resistance, the alumina and graphite nozzle materials generally contain molten silicon oxide. However, molten silicon oxide It is the same as alumina, or the above is damaged by dissolution, and it is not good. In addition, the spinel, (FeO), (MnO), etc. have little permeation amount, and even FeO-MnO and other intervening substances It adheres, does not generate a liquid phase, and maintains a solid phase. That is, a nozzle equipped with a spinel in a portion in contact with the molten steel has little melting loss, and therefore, it can reduce the pollution of the molten steel. The contact part, the body part, and the powder line part are made of black material, which is related to the increase in manufacturing costs. Also, the powder The immersion nozzle melt loss caused by slag will not be improved even with the use of spinel materials. This is due to the fluorine content in the powder slag. So 'the idea is to eliminate the fluorine content or use mold powder with low fluorine content. -8-This paper size applies to China National Standard (CNS) A4 specification (210 X 297 public love) 590823 A7 ______B7 ____ 5. Description of the invention (6) (disclosed in the conventional technology 3-1, 3-2 Japanese Patent Application Laid-Open No. 58-125349, Japanese Patent Application Laid-Open No. 5 1-93728, Japanese Patent Application Laid-Open No. 5-86423, Japanese Patent Application Laid-Open No. 5-208250, Japanese Patent Application Laid-Open No. 51-67227, Japanese Patent Application Laid-Open No. 5- Publication No. 269560, Japanese Patent Application Laid-Open No. 51_132113). However, because these mold powders do not contain fluorine components, or they are low-fluorine component mold powders, the viscosity adjustment and crystallization temperature adjustment will be worsened. Fracture, chipping, etc. often occur, and it is not possible to perform stable casting without practical use. That is, as long as the melting loss of the powder line material impregnating the nozzle cannot be solved, it is difficult to obtain clean steel. The inventor In view of the foregoing problems of the prior art, (Mold powder having a fluorine content of 3% by weight or less and a viscosity of i30〇t of 4 p0ise or more and 100000 poise or less), and "the specific mold powder described above, and a special hair π m nozzle (for melting with a dipping nozzle) Part of the steel contact part or the king's part? Another barite and / or spinel, carbon, powder line material is placed in the part in contact with the mold powder and / or slag, and the body is placed in other parts The invention of a continuous casting method of steel composed of a material immersion nozzle) has been proposed (see Japanese Patent Application Laid-Open No. 2001-1 13345). The inventors and others have accumulated the results of the research after the above-mentioned developed invention, using the seven-special mold powder, and found that it does not need to be combined with the aforementioned specific dipping nozzle: but also contains a powder line portion and even using "alumina as The impregnating nozzle made of the main material is resistant to 1 ". It has almost no melting loss, and does not generate alumina adhesion. It can stably cast clean steel, and finally completed the present invention. Therefore, an object of the present invention is to provide a casting method which prevents the pollution of steel originating from fire retardant materials, and can stably cast steel with high cleanliness, and

A7

, Silicon (Si), Ming (A1) ". Casting Hyun Steel is all kinds of steels such as Ming calm steel, calm steel, high and electromagnetic steel plates, processed steel, high and short steel, fast cutting steel, rotten steel, frost steel, case hardened steel and Gao Qin steel. &lt; Brief Description of Drawings &gt; Fig. 1 shows an example of a submerged nozzle structure used in an example of the present invention (including a comparative example) and having a type of a discharge port. Fig. 2 shows another example of the structure of an immersion nozzle used in an example (including a comparative example) of the present invention and having a discharge port portion. Fig. 3 shows an example of a linear nozzle structure used in an example (including a comparative example) of the present invention and having no discharge port portion. In addition, the symbols in the figure are the inner tube portion of the immersion nozzle in contact with the molten steel. 2 is the outlet of the immersion nozzle in contact with the molten steel, and 3 is the powder line of the immersion nozzle in contact with the mold powder. 4 is the main body portion of the impregnated nozzle, and 5 is the tip portion of the nozzle that is in contact with the molten steel of the linear impregnated nozzle. <The best form for carrying out the invention> The following describes the embodiment of the present invention. The mold powder used in the present invention is as described above, the fluorine content is less than 3% by weight, and the viscosity of 13000c is 4 ~ 100000 p〇ise 〇The amount of fluorine in the mold powder is more than 3% by weight. The melting loss of the nozzle, especially the powder line part, will increase, and the molten steel will be contaminated by the refractory raw materials flowing out of the steel. Get clean steel. In addition, the viscosity of the mold powder (the viscosity at 1300 ° C) is less than 4 p0ise, which will cause uneven inflow of the mold powder. In the melt mold powder, the double calcium silicate and calcium silicic acid-11-this paper is suitable for the standard Choi Ag Home Materials (CNS) A4_210x 297 Male Θ

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k 590823 A7 —________ B7 V. Description of the Invention (9) Double-grade osmium crystals, the temperature fluctuation of the mold steel plate will become larger, and it is not good because of the unstable heat removal. In addition, if the viscosity is more than 100,000 poise, it will cause poor melting, and it will cause bare slag to be formed, and it will not be stable for casting. In the present invention, for example, the viscosity can be adjusted to be high when the number of phases is large, such as Al2O3, Ca0 / Si02, etc., or when Ca0 / Si02 is low. Furthermore, in the mold powder used in the present invention, the mold powder is melted, and when a platinum cylinder with a diameter of 7 mm is pulled up at a constant speed, the maximum load when the platinum cylinder is cut off from the liquid surface is defined by the droplet of the I mold powder. The breaking strength of the melting mold powder is 130 ° C. The breaking strength of the melting mold powder should be above 37 g / cm2. If the breaking strength is below 37 g / cm2, it is easy to cause the liquid layer in the slag film to break. The mold powder used in the present invention can be made from the raw materials of base materials such as Portland cement, wollastonite, synthetic stone powder, etc., and the raw materials of SiO2 such as bead iron and fly ash. , Na2O, K2O, Li2O raw materials such as glass powder, transparent glaze, magnesium carbonate seawater Mg〇 powder, Mg〇 raw materials such as dolomite powder Coke powder, scaly graphite, carbon black and other sufficient carbonaceous raw materials are produced. However, it does not contain fluoride such as NaF, etc. Specifically, it is desirable to add the above-mentioned 〇2, Ν ^ 〇, 1 to the base material. ^ 〇, 1 ^ 〇, 103, and carbonaceous materials, and, as described above, the viscosity can be adjusted by AhOr Ca0 / Si〇2 For example, the chemical composition is ^ 12〇3 '5 ~ 25 weight 1%, Si02: 25 ~ 70 weight. /, Ca〇: 1〇 ~ 50 weight f%, selected from Na20, Li20 and K2〇 -One or two or more of the group. 3 to 20% by weight, MgO: 20% by weight or less, unavoidable impurity fluorine component: 3% by weight, carbon, 0.5 to 8% by weight, Moreover, 590823 A7

Adjust the weight of Ca0 / Si02 + seven Λ. The ratio of n to l is in the range of 0.2 to 1.5. After the above raw materials are mixed, they are uniformly mixed by a mixer. Add liquid (such as water) and organic binder or inorganic binder as required: granulate, stir granulate, rotate granulate, flow granulate, spray 4 k granules, etc. to granulate, Use it as a granule. An explanation will be given of an embodiment of the impregnating nozzle material used in combination with the above-mentioned mold powder. In the present invention, the material constituting the impregnating nozzle is a refractory material mainly composed of alumina, and a preferred embodiment is an alumina-based refractory and / or an oxide-carbon refractory. It is also possible to use one or more of the alumina-based refractory and alumina-carbon-based refractory selected from the group consisting of SiO2, Sic, BA, AIN, ZrB2, Mg ^, and ZrS04. This wide range of materials can be used. Furthermore, another preferred embodiment contains one or more of silicon and aluminum. By blending such a metal, the metal reacts with and impregnates the refractory material in the nozzle, especially the powder line portion, and / or components in the air at a high temperature during use to generate a metal reactant. This metal reactant reinforced powder line portion 'contributes to durability improvement. When carbon is contained in the powder thread portion, the above-mentioned metal also functions as a carbon oxidation inhibitor. In this way, by blending the above metals, an excellent impregnation nozzle can be provided. The content of silicon and A1 should be 0.1 ~ 15 weight. /. , More preferably 1 to 8% by weight. The content was 0.1 weight. /. In the following, the effect caused by the aforementioned metal cannot be obtained. If it exceeds 15% by weight, the amount of metal reactants generated will increase, so the increase in volume will cause the destruction of the refractory structure, and the effect of the refractory material of the main aggregate will be lost. And bad. -13- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)

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W0823 A7

In the present invention, the immersion nozzle has 3 persons and 3 beans, and can be used. The reason is to use the specific mold powder of the present invention (mold powder having a fluorine content of 3 weights: 1300t and a viscosity of 4 Po1Se to Ju_00 poise). For any material with high melting resistance of fluorine-containing mold powder, the main material is carbon and carbon materials. This material is more expensive than ordinary refractory materials, and even if the material and powder line The melting loss of the part is very large, which may cause the nozzle life. Furthermore, according to the present invention, high-viscosity mold powders containing little or no fluorine component are used, and the melting loss caused by the fluorine component is almost or completely absent. Therefore, it is not necessary to use zirconia or carbon in the powder line. The material can be arbitrarily used in the powder line part (the refractory material with alumina as the main material), and the knot cannot form the same material as the main body part. &lt; Examples &gt; 4 Next, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to the following examples. Here, the structure of the immersion nozzle which can be used in the following examples and comparative examples will be described with reference to Figs. Fig. 1 shows an example of an immersion nozzle structure having the shape of a discharge port portion, and Fig. 2 shows another example of an immersion nozzle having the same shape of a discharge port portion. Fig. 3 is an example of a linear immersion nozzle having no discharge port. The dipping nozzle shown in FIG. 1 is a dipping nozzle having a type of an outlet port, while 1 in FIG. 1 is an inner tube portion of the dipping nozzle in contact with molten steel, and 2 is in the same contact with molten steel. The ejection outlet portion of the impregnating nozzle 3 is a powder line portion in contact with the mold powder and / or slag, and 4 is a main body portion of the impregnating nozzle. ___—__- 14- This paper size applies to China National Standard (CNS) A4 (21〇 X 297 Public Love 0

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590823 A7 I. B7 V. INTRODUCTION TO THE INVENTION (12) As shown in Figure 1, this immersion nozzle is the part of the outlet 2a of the immersion nozzle that is in contact with molten steel. The structure in which the main body portion 4 and the discharge port portion 2 are integrated into one body is a submerged nozzle. The immersion nozzle shown in FIG. 2 is the same as the immersion nozzle shown in FIG. However, the structure is not a composite structure as shown in FIG. 1 (refer to “Part 2 a” in FIG. 1). As shown in FIG. 2, the part of the outlet port 2 b of the immersion nozzle in contact with the bright steel is formed by the same Submerged nozzle of the structure of the discharge outlet 2 made of a material. The reference numerals 1 to 4 in Fig. 2 are the same as those described above, and 1 is an inner tube portion, 2 is a discharge port portion, and 3 is a powder line portion. 4 is a main body portion. The immersion nozzle shown in FIG. 3 is different from the immersion nozzle shown in FIGS. 1 and 2 and is a linear immersion nozzle having no discharge port. In Fig. 3, 5 is the front end of the nozzle that is in contact with the molten steel. The other symbols are the same as above, 1 is the inner tube portion, 3 is the powder line portion, and 4 is the body portion. The chemical composition (sample numbers 1 to 7) of the mold powder used in the following examples is shown in Table 1 ', and the chemical composition (sample numbers 8 to 2 丨) of the comparative mold powder is shown in Table 2. The viscosity of each mold powder, the fluorine component, and the viscosity (at 1300t :) &quot;, and the breaking strength (at 1300C) are also shown in Tables 1 and 2 in the same manner. The sample powders of sample numbers 1 to 7, 8 to 10, and 1 to 3 to 17 are "powder products" obtained by mixing using a mixer at a specific chemical composition ratio. In addition, the sample powders i 11 2 and 8 to 21 which are other than the above-mentioned mold powder are raw material powders, and then a drop composed of 90% by weight of water and 100% by weight of sodium silicate is added. 20 to 30% by weight of the liquid to make a slurry, and the slurry is sprayed out and granulated, and dried to obtain a "granular product", and finally, a specific chemical composition is prepared. -——_ -15- This paper is suitable for financial institutions. S Home Standard (CNS) A4 specification (21 × 297 public love) 590823 A7 B7 V. Description of invention (13) Table 1 Chemical composition of mold powder used in the examples in Table 1 Sample number 1 2 3 4 5 6 7 Si02 36 39 50 49 48 31 31 Module ai2o3 7 21 10 10 18 7 7 Powder CaO 36 35 20 19 16 43 43 Weight of MgO 4 1 10 10 8 6 8 Chemical amount Na20 + Li20 + K20 5 2 6 8 6 8 6 credits MnO + BaO + SrO + B] 〇3 8 0 1 1 1 0 0 F 1 0 0 0 0 2 2 Total carbon content 3 2 3 3 3 3 3 Ca0 / Si02 (weight ratio) 1.00 0.90 0.40 0.39 0.33 1.40 1.40 • Fluorine content (% by weight) 1 0 0 0 0 2 2 • Viscosity (at 1300 ° C) (poise) 30 20 40 50 100 5 5 • Breaking strength (at 1300 ° C) (g / cm2) 5 8 10 3.7 5 6 5 Table 2 (Part 1) Sample composition number 8 9 10 11 12 13 14 Si0 2 25 26 34 32 27 29 29 Module Al2 0 3 9 5 3 3 2 12 11 Powder CaO 28 27 38 37 32 30 32 Weight MgO 7 9 10 12 10 11 7 Chemical volume Na20 + Li20 + K20 21 20 3 3 10 6 5% MnO + BaO + SrO + B〗 3 0 0 0 0 1 1 4 F 5 8 8 10 12 8 9 Total disc volume 5 5 4 3 6 3 3 Ca0 / Si02 (weight ratio) 1.12 1.04 1.12 1.16 1.19 1.05 1.10 • Fluorine content (% by weight) 5 8 8 10 12 8 9 • Viscosity (at 1300 ° C) (poise) 2.0 1.5 1.5 0.5 1.2 2.0 1.0 • Break strength (at 1300 ° C) (g / cm2) 3.5 3.0 3.2 1.0 2.5 3.0 2.0 -16- This paper size applies Chinese National Standard (CNS) A4 specification (210 X 297 mm) 590823 A7 B7 V. Description of the invention (Μ) Table 2 (Part 2) Chemical composition sample number for comparison mold powder 15 16 17 18 19 20 21 Sl0 30 30 29 27 26 25 22 Module ai2o3 10 7 9 8 7 4 Powder CaO 34 36 J 38 40 42 42 38 Weight MgO 6 8 3 5 5 0 8 Chemical amount Na20 + Li20 + K20 8 6 10 3 2 5 6% MnO + BaO + SrO + B2 03 0 0 0 0 0 0 0 F 9 10 11 13 15 18 19 Total carbon content 3 3 4 3 2 3 3 CaO / Si〇2 (weight ratio 1.12 1.20 1.30 1.50 1.60 1.65 1.70 • Shape! Air knife (weight 9 10 11 13 15 18 19 • Sticky summer ^ T300〇C) ~ 1.8 1.3 1.0 0.9 0.8 0.3 0.2 • Breaking strength (at 1300 ° c) (g / cm2) 2.7 2.4 2.8 1.3 1.5 · 0.5 0.5 (Examples 1 to 7 and Comparative Example 1 to Comparative Example 6) Examples 1 to 7 are shown in Tables 3 and 4 and Comparative Examples 1 to Comparative Example 6 are shown in Table 5. In each of the following Examples 1 to 7 and Comparative Examples 1 to 6, each of the molten steel (in the table, the steel type &quot;) is supplied into the mold by a nozzle, and at the same time, the mold The powder is fed into a mold, and continuous casting is performed. The structure of the nozzles used in each example is shown in the table with drawing numbers. In addition, the mold powder used in each example is composed of the chemical composition of sample numbers 丨 to 2 丨 in Table i and Table 2. The sample numbers are shown in the table, and only the `` fluorine component '' of the mold powder used is shown. "" Viscosity (at 1300 t), "" Break strength (at 1300 &lt; t). "The material of the nozzle part in the table is"% ","% by weight ". In each case, "stable casting", "melting loss of nozzle or alumina adhesion amount (melting loss of inner tube, inside of spout, powder line)", "steel cleanliness", "steel defect rate", evaluate as follows The evaluation results are shown in Tables 3 to 5 ^: -17- This paper size is applicable to China Standard A (CNS) M specifications (2ι〇χ 297 public love) 590823 A7

• The son-in-law's evaluation of the anti-manufacturing evaluation post is “Safety Casting”, which indicates whether casting can be stabilized, and the town ’s health warning “uses a continuous based on the mold surface temperature” two B 0 pre- (BW. Shun Sheng system Evaluation method at the time "ζ = B. 〇 Also," disruption of the soaked mouth "was caused by the disintegration of the powder line and / or the household, and the soaked mouth did not break during the transformation. Shao ", yes, the others are" No ". When it does not happen, • Nozzle melt loss assessment nozzle: Loss [mm / (steel t〇n)] &quot; refers to the shell size per casting amount. The larger the number of nozzles, not only the life of the nozzle ~ The misfortune of the nozzle entering the steel is also short, and the melting loss is 疋 夂 夂, so it just becomes the steel subject to the amount of alumina adhesion. F shows the time when casting aluminum quiet steel The alumina produced is attached to ... Attached to the inner tube and / or the spit of the mouth: inside: the amount of oxidized adhesion increases, it is impossible to be planted and grown, and if it is oxidized Pound made. Depending on the situation, the indium alkane in the nozzle may move, which may sometimes cause the production to stop. · Therefore, Zhongla Steel can be described as Good. Nozzle. Evaluation of steel, cleanliness, and cleanliness of steel. Steel cleanliness is based on the degree of stripe marks π '.. 〇, · For product love development, JL Η &amp;, + ^ k due to k scratches and the steel is not statistically staged in the meantime _ official • steel defect rate evaluation dyke sweat evaluation., Steel defect rate &quot; Evaluated by surface cracking. ^ &quot;, when the surface cracked and the steel cannot form a surface crack, the surface is the surface, and the product can be formed, Δ ,,, σ is X ", plus

And the aluminum aluminum will not be attached to Table 77?

k 18- paper ruler xx 297 $ 590823 A7 B7 V. Description of the invention (16) Table 3 (No. 1) Example 1 ~ 5 Example 1 2 3 4 5 Nozzle part (Fig. 1) (Fig. 2) (Fig. 1) (Fig. 2) (Fig. 1) Inner tube section Al2〇3 80 70 90 90 60 65 c 20 30 10 30 30 Si〇2 0 0 0 10 5 Spray additive type-----Additive amount---- -Spout port Al2〇3 80 70 90 60 65 Nozzle c 20 30 10 30 30 Si02 0 0 0 10 5 Additive type-----Additive amount-----Powder AI2 〇3 80 70 90 60 65 line Part C 20 30 10 30 30 and Si02 0 0 0 10 5 Types of additives in body part-----Additive amount-----Sample No. [5] [1] [7] [4] [1] Mold fluorine Composition (% by weight) 0 1 2 0 1 Powder viscosity (at 1300 ° C) (poise) 100 30 5 50 30 Breaking strength (at 1300 ° C) (g / cm2) 5.0 5.0 5.0 3.7 5.0 Steel aluminum clear aluminum clear is Qing IS Qingque Lv Qingjing Steel Jinggang Jinggang Jinggang Jinggang Jinggang Stable Casting Cocoa Cocoa Nozzle Melt Loss Inner Tube 0 0 0 0 0 Comment or-Inside the spit outlet 0 0 0 0 0 Estimated alumina adhesion powder line 0 0 0 0 0 Gang Qing Clarity 100 100 100 100 100 Steel defect rate 0 〇〇〇〇 This paper size is applicable to China National Standard (CNS) A4 specification (210 X 297 mm) 590823 A7 _______ B7 V. Description of the invention (17) Table 3 (which 2 ) Examples 6 to 10 Γ ------, Example 6 7 8 9 10 Nozzle material (Fig. 1) (Fig. 2) (Fig. 1) (Fig. 2) (Fig. 1) Inner tube portion Al2. 3 70 45 70 60 100 C 30 35 30 25 0 Si〇2 0 20 0 15 0 Spray additive type SiC; B4C Si; SiC Si3N4; A1 AIN; ZrB2 Mg3B2; A1 additive amount 3; 3 2; 5 3; 2 5; 4 2; 3 Outlet Al2〇3 70 45 70 60 100 mouth C 30 35 30 25 0 Si〇2 0 20 0 15 0 Additive type SiC; B4C Si; SiC Si3N4; A1 Α1Ν; ZnγΒ2 Mg3B2; A1 Additive amount 3; 3 2; 5 3; 2 5; 4 2; 3 powder Al2〇3 70 45 70 60 100 wire part C 30 35 30 25 0 and Si〇 2 0 20. 0 15 0 type of body part SiC ; B4C Si; SiC Si3N4; A1 Α1Ν; ZnγB2 Mg3B2; A1 additive amount 3; 3 on 5 3; 2 5; 4 2; 3 Sample number [6] [3] [1] [6] [2] Mold fluorine component (Wt%) 2 0 1 2 0 Powder viscosity (at 1300 C) (p oise) 5 40 30 5 20 Breaking strength (at 1300 ° C) (g / cm2) 6.0 10 5.0 6.0 8.0 Steel type Southern milk steel Non-converting steel Silicate electromagnetic Ca Static copper virtual steel Stable casting cocoa ητ 可 -ί * η Cocoa nozzle melting loss inner tube 0 0 0 0 0 Evaluate or ... the inside of the outlet 0 〇 π Λ estimate the alumina adhesion powder line 0. 0 u 0 υ 0 V 0 100 100 100 100 100 class defect rate 〇_0 〇 〇〇 ________- 20 &gt; ^ The paper size is applicable to China® Home Standard (CNS) A4 specification (21GX 297 public love) ':-590823 A7 B7 V. Description of the invention (18) Table 4 Example 1 1 ~ 1 7 Implementation Example 11 12 13 14 15 16 17 Nozzle part (Fig. 2) (Fig. 2) (Fig. 2) (Fig. 2) (Fig. 2) (Fig. 2) (Fig. 2) Inner tube part ai203 65 100 80 100 100 100 100 C 30--• • • Surface Si〇2 5. • • • Type of spraying material ZrSi04-Zr〇2-. • • Adding quantity 5-20---Mouth spit outlet 8 2 0 3 65 100 50 70 75 80 90 C 30-30 30 25 20 10 Si〇2 5-• • •. • Type of additives ZrSi04-Zr02-vertical-• Quantity of additives 5-20---. Powder End Al2〇3 65 100 100 70 75 80 90 Wire section C 30--30 25 20 10 and Si〇2 5--•. Type of main body additive ZrSi04----•--Additive amount 5---- Miscellaneous-Sample No. [1] [7] [4] [4] [3] [5] [2] Mold fluorine composition («%) 1 2 0 0 0 0 0 Powder viscosity (at 1300 ° C) (p〇) ise) 30 5 50 50 40 100 20 Breaking strength (at Ba / Otefcm2) 5.0 5 3.7 10 5 8 1.0 Steel type High surface hard aluminum clear Ca electromagnetic stainless steel coating Mn steel tempered steel static steel physical steel steel plate steel steel stable casting can be Cocoa Cocoa Nozzle Melt Loss Inner Tube 0 0 0 0 0 0 0 Comment or inside of a spit outlet 0 0 0 0 0 0 0 Estimated alumina adhesion powder line 0 0 0 0 0 0 0 Steel cleanliness 100 100 100 100 100 100 100 Steel defect rate 0 0 0 0 0 0 0 Staple

-21-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 590823 V. Description of the invention (19) A'7 B7

Table 5 Comparative Examples 1 to 6 Comparative Example 1 2 3 4 5 6 Nozzle parts ^^ (Figure 1) (Figure 2) (Figure 2) (Figure 2) (Figure 2) (Figure 1) Inner tube section AI2O3 100 100 1000 70 80 100 C--30 • 20-Si〇2------Type of spray additive------Additive amount------Al2〇3 100 70 90 70 80 100 Nozzle C-30 10 30 20-Si02------Additive type------Additive amount------Powder Al2〇3 100 70 90 60 70 50 Wire C-30 10 20 20 20 And Si02----10-Types of additives in the body----Zr02-Zr02 Additives---20-30 Sample No. [8] [10] [12] [20] [13] [11] Mold fluorine component (Wt%) 5 8 12 18 8 10 Powder viscosity (at 1300 ° C) (poise) 2 1.5 1.2 0.3 2.0 0,5 Breaking strength (at 1300 ° C) (g / cm2) 3.5 3.2 2.5 0.7 3.0 1.0 Steel electromagnetic Ca-coated aluminum clear stainless high-oxygen steel sheet steel steel static steel steel steel stable casting No No No No No Nozzle Melt Loss Inner Tube 0.02 0.03 0.04 0.01 0.05 0.02 Rating or-Inside of the outlet 0.07 0.05 0.08 0.04 0.09 0.03 Estimated alumina adhesion powder line 0.50 0.30 0.60 0.20 0.60 0.40 Steel cleanliness 30 40 30 50 20 40 Steel defect rate. X X X X X X

-22- This paper size is in accordance with Chinese National Standard (CNS) A4 specification (210 X 297 mm) Description of the invention (20) It is clear from Tables 3 to 5 that by using the specific mold powder of the present invention, Even if an impregnating nozzle made of an alumina-carbon refractory is used for any of the discharge port part, the powder line part, and the main body part (Example 丨 丨), even if an alumina refractory is used, The constructed immersion nozzle (implementation of J 1 2), that is, even if a homogeneous refractory is used, "stability scale evaluation, any-both are" may ", and stable casting can be used. Also, in the example of Example i 7 It can be seen that even if the same material is used for both the powder line part and the main body part, it can be stably casted in the same way. Further, "the melt loss of the nozzle or the adhesion of alumina is completely" quote. ", The "steel β almost degree" is 10 011, and the "steel defect rate" is also completely, and the surface crack of the steel can be ignored. However, in Comparative Examples 丨 to Comparative Example 6 where the specific mold powder of the present invention is not used: From Table 5, it can be seen that, stable casting, any one is "No," and it is impossible to settle the casting. Regarding the nozzle melt loss, "cleanliness of steel," the "steel defect rate," is also very poor. In addition, the material of the inner tube portion was also poor as in the embodiment. This is because the flow in the direction opposite to the flow direction of molten steel in casting k also occurs at the same time. Therefore, as the powder comes into contact with the inner tube portion as a result of backflow, melt loss and the like are caused, and the results are as shown in Table 5. Compare the evaluation results of the above Comparative Examples 丨 to 6 with the sweat evaluation results of Examples 1 to 17 of the present invention. 'Using the specific mold powder of the present invention, first, it can be stably cast, and the melt loss of the nozzle is extremely small. Therefore, the nozzle life can be improved. Furthermore, 'strip liquid is hardly seen, and cracks on the surface of the steel can be ignored. In addition, the immersion nozzles of FIGS. 1 and 2 used in the foregoing embodiments 1 to 17 (the immersion nozzle of FIG. 3 can of course also be used).

Claims (1)

823 Di 090130104 Patent Application No. g Patent Application Replacement (December 1992) _, Application Patent Scope 1 · A continuous casting method for steel, which uses molten nozzles to supply molten steel into the mold, and at the same time Continuously casting while supplying the mold powder into the mold, it is used in combination: the mold powder with a fluorine content of less than 3% by weight and a viscosity of 1300 ° C of 4 poise or more and 10000 poise or less, Impregnation nozzle made of refractory with alumina as the main material. 2. The continuous casting method for steel according to item 丨 of the patent application scope, wherein the above-mentioned mold powder has a breaking strength of 3.7 g / cm2 or more at 1300 ° C. 3. The continuous casting method for steel according to item 1 of the scope of the patent application, wherein the aforementioned chemical composition of the die powder is Ah03: 5-25% by weight, Si02: 25-77% by weight, CaO: 10% It is within a range of 50% by weight, Mg 〇 · 20% by weight or less, and ρ ·· 〇 ~ 2% by weight (unavoidable impurities). 4. The continuous casting method of steel according to item 2 of the scope of application for patent, wherein the aforementioned chemical composition of the die powder is Al2O3 .. 5 ~ 25% by weight, Si02: 25 ~ 70% by weight, CaO: Within a range of 10 to 50% by weight, Mg .. 2 to 0, ρ: 0 to 2% by weight (unavoidable impurities). 5. The continuous casting method for steel according to item 丨 of the application, wherein the aforementioned alumina refractory is composed of alumina-based refractory and / or alumina-carbon-based refractory. 6. The continuous casting method for steel according to item 5 of the scope of the patent application, wherein the aforementioned alumina-based refractory and / or alumina-carbon-based refractory system contains one or two or more selected from silicon oxide (SiO2), Silicon Carbide (SiC), Carbonization Test (B4C), Silicon Carbide (ShN4), Aluminum Nitride (A1N), Boron Hammer (ZγΒ2), Magnesium Boride (Mg3B2), Zirconium Sulfate (ZrS〇4), Silicon ( Si) and aluminum (A1). 72. Continuous casting of steel according to any one of items i to 6 of the scope of the patent application 590823 8 8 8 8 AB c D 2 々, patent application method, in which the molten steel is aluminum killed steel, silicon killed steel, high oxygen steel, stainless steel, electromagnetic steel, calcium treated steel, high manganese steel, fast Cut steel, boron steel, coated steel, case hardened steel or high titanium steel. -2- This paper size applies to China National Standard (CNS) A4 (210X297 mm)