Name of the invention: refractory and casting nozzle
Technology areas

[0001]
Invention is the long nozzle used in molten steel container such as continuous casting plant chiefly, especially converters, ladles, tundishes, nozzle for casting, refractories and refractory products used, immersion nozzle and sliding nozzle plate (hereinafter referred to as "SN plate". ) The top nozzle on the casting nozzles and nozzle at the bottom.
His innovations.

[0002]
As used in SN plate used for water flow control used in purpose to take used pots for long nozzle, tundish and mold oxygen casting refractories for continuous casting areas, for example the ladle and tundish submerged entry nozzle and molten steel flow control refractories, excellent thermal shock resistance from traditional Al2O3ultafine2-c series material, Al2O3 -C series material has been applied.
[0003]
Effect of damage caused on the other hand, increasing the variety of steel grades in recent years to use continuous casting refractories and its extent is supplied from the molten steel strongly affected by as it has been. For example, vitrifiable enamels of inclusions in molten steel in high-oxygen steel such as steel and high manganese steel and Ca treated steel, (inclusions consisting of oxides in molten steel in non-metallic components, hereinafter referred to as 'slag' and also. ), For example (FeO), (MnO) (CaO), (V2O5) (herein below, means components in slag by round brackets enclosing chemical ingredient labeling. ), That add to the decarburization action of molten steel composition of refractory tissue or flowing effect of molten steel flow velocity, low melt produced continuously generates a low melt and penetrate the strong composite oxides of erosion due to the ongoing impact of refractory on molten steel, refractory and reacting, generated at the contact interface in organizational refractories, early damage of refractories significantly, have become diminished public life.
[0004]
Therefore, reactions and how to reduce the carbon content to prevent tissue degradation due to degassing coal as the most common way to increase its damage resistance of Al2O3is generally applied to continuous casting nozzle ultafine2-c series material, or wherein slag by low melting measures to SiO2 fire-resistant side could become the principal amount reduced or no composition has been tried. But decreased for SiO2 and C reducing certain effects, but with increased thermal expansion resistance to thermal shock cracking of problems increases the risk. Even Al2O3 is traditionally added as the main aggregate of material components (FeO), (MnO), (CaO), (V2O5) and of is not getting sufficient for low melting oxides and react in the situation.
[0005]
Whereas this situation, Al2O3 aggregate some or all these compositions were replaced by hard reaction of compound oxide slag composition and aggregate components have been proposed as a refractory composition.
[0006]
For example, in the patent literature 1, consisting of mainly alumina and graphite compound, particle size is 0. 02-1. less than 0 mm magnesia 3-containing 60% alumina - magnesia - graphite refractories or refractory spinel-containing refractory materials in have been proposed.
[0007]
In addition, continuous casting nozzle composed of refractory materials for below 3% by weight of impurity in the nozzle contact with molten steel in the patent literature 2 holes in whole or in part as Minister of mineral spinel and periclase, spinel and magnesite for Al2O3 and MgO have been proposed.
[0008]
Further, in the patent literature 3 nozzle body is spinel: 50-95% by weight, magnesite: 3-20%, graphite: 5-consisting of 30% by weight, of the unavoidable impurity: 3% by weight below spinel - magnesite - graphite-refractories submerged nozzle has been proposed.
[0009]
These examples of patent documents, previously often magnesia (magnesite) and MgO ingredients, such as spinel Al2O3 ingredients more (FeO), (MnO), (CaO), etc. of slag composition and low is selected to produce the fusion of hard.
[0010]
When compared to alumina, magnesia, however, the greater coefficient of thermal expansion, this casting nozzle for cracking will impose limitations in the amount applied, magnesia, and that increases the risk. Patent literature 3 mentioned above, for example, spinel: 50 ~ 95% by weight, magnesite: 3-20%, graphite: 5-30 weight % of the composition is disclosed, as described herein (paragraph 0017) MgO (magnesite) content is up 20% degree is a thermal shock resistance to worse if outside this range problem.
[0011]
If on the other hand the material thus containing magnesia aggregate and mechanical properties of low carbon-high corrosion resistance high thermal expansion characteristics applied to materials such as nozzle thermal shock resistance required for casting, cracking will take limit MgO content, because that increases the risk. Therefore have a problem excellent corrosion resistance for thermal shock resistance and corrosion resistance and juggle the MGO slag components originally has to sacrifice, not utilized for 10 minutes.
[0012]
So, in way to introduce systematic flaws and gaps between low 弾性化 of heat-resistant and has been made might also attempt to shock resistance and corrosion resistance and trying to reconcile.
[0013]
For example, in the patent literature 4, magnesia MgO content of 95% or more up 86% and stable degree of 80-100% stabilized zirconia (YSZ, CSZ) roughness added to grain, grain, and 未安定 zirconia (0. 044 mm) grain area in the 3-and the addition of 15% by weight carbon 3-15%, and containing metal Si powder and phenolic resin, metal Al kneading, fabrication of MgO-c of unburned brick molding after the hardening treatment, used in SN plate may have been disclosed. Because how to induce a microscopic defects in the organization is an invention and it uses a volume change of 未安定 zirconia crystals when the thermal shock resistance of refractories to thermal shock resistance improvement is limited.
[0014]
Study on pitch and polymer coating the aggregate particles around this in addition to raw materials formed by heat treatment gap of low elasticity of tissue, to improve thermal shock resistance are performed.
[0015]
On average in the patent literature 5, for example, diameter 10 mm-is disclosed by 50 mm fireproof quality coarse aggregate particles coated by polymer and phenolic resin creates a gap between fire-resistant coarse aggregate surface and the matrix to low modulus of refractory products.
[0016]
The thickness may become void and pitch a patent ref 6-MgO particles with around 100 µm layer 10-unburned MgO-c quality with capacity 50% including the bricks have been disclosed. Is this void and pitch layer prevents crack propagation and, increasing the resistance to thermal shock.
[0017]
In addition to grain size 0 to patent literature 7. magnesia ingredients 100 weight of less than 5 mm 6-raw materials obtained, coated with a high softening point pitch 30 mass of 80-99. 5 mass % and metal powder 0. 5-is up 20% from 500-continuous casting nozzle materials fired at temperatures of 1200 ° C in non-oxidizing atmosphere with a 1500 ° C coefficient of thermal expansion 1. Less than 5% may have been disclosed.
[0018]
Patented documents 5 & 6 are in on the surface of the aggregate particles before performing coating compounds and pitch technique. But for a technique like this with particle size distribution of refractory raw materials, especially due to the strong cohesion of powder particles these tend ubiquitous chemicals, such as polymers and pitch, to form a uniform coating on the surface of individual particles is difficult and problematic. Coating is required and excess chemicals additives for coating thickness control is difficult to. In addition, quality improvement was expected owing to peel or damage the coating polymer caused by friction of mixed mixing process, temperature, solvent, powder and pitch enough difficult and inconsistent quality of problem with.
[0019]
Description of technology thought that having expansion absorption cost MgO particles around a patent bibliography 7 may have been disclosed, although magnesia grains around providing air layer completely is impossible (paragraph 0039) and not become the ideal organization is unclear. Also established a layer containing a high softening point pitch around the particles coated with a patent bibliography 7, charcoal as a suitable material containing pores (air layer) around the particles and subjected to thermal load process, cushioned from the high softening point pitch, elastic properties with strength have been trying to solve the problems in the oxide layer (spring-like layers) to form around the particles, but 0. because it is in the processing of fine powder of less than 5 mm, high softening point pitch coating has a difficult enough quality improvement is obtained for control of thickness above patented documents 5 and 6 become more difficult, also no stable quality problem.
Prior art documents

Patent documents

[0020]
Patent literature 1: international publication No. 99 / 38818
Patent literature 2: special square 10-305355 of Gazette
Patent literature 3: special square no. 11-320047 bulletin
Patent literature 4: special square 1-305851 bulletin
Patent literature 5: open 2002-316878 bulletin
Patent literature 6: special square 6-321625 bulletin
Patent bibliography 7: open 2004-323260 bulletin
Summary of the invention

Inventors are trying to solve a problem

[0021]
Is to give the casting nozzle combines the main problems in trying to solve the present invention is a significant improvement in refractories containing MgO, slag or inclusions in steels for corrosion resistance, thermal shock resistance, in other words, conventional in technique get in corrosion protection and resistance to thermal shock and refractory and refractory products.
Means for resolving problems

[0022]
Basic materials such as magnesia containing MgO (magnesite) Ionic bond stronger for fire resistance of other particles generally thermal expansion is larger than. When considering using such basic materials as refractory particles (aggregate), Binder composition and other particles and combined with refractory organizations, depending on the ratio of "high fire resistance of particle shape and generally grow much as fire-resistant thermal expansion. Considered for refractory materials in General, various types of fire-resistant particle has engaged with bonding material composition, thermal expansion of refractories is total put the contribution of thermal expansion, individual volume fraction on the thermal expansion coefficient of each raw material, so-called additivity, thermal expansion of the whole is almost determined by.
[0023]
Improvement of thermal shock resistance of the past generally have been mentioned earlier, high expansion material is by adding stuff mainly, low inflation and low elastic effects, such as the addition of carbon and 未安定 zirconia may develop, or how physical pitches and polymers and coated magnesia aggregate particles around.
[0024]
For this invention is a particle containing MgO carbon containing Refractories in the MgO content (hereinafter referred to as the "MgO particles". ) Of the available nozzle for casting and refractory materials with low thermal expansion characteristics has formed around an ideal pore, (almost continuous air gap formation), to control the air gap thickness that the chemical composition of additivity, namely refractory refractory products of thermal expansion can be controlled, excellent. That is, the essence of the invention is to generate almost continuous air gap layer does not contain solids of carbon around the MgO particles indicating the high swelling characteristics.
[0025]
You mean this "almost continuous air gap layer and MgO particles around microscopy cross-sectional observation, having gap outline expanded almost similar shape with cross sectional shape outline, voids inside the particle exists in Bell ball (fig. 10 (a) reference). I.e. the pore layer is non-uniform in structure would interfere with thermal expansion of MgO particles porosity formation in first carbon structures exist, not (the first requirement), the second or to mean not that random, where the missing void MgO content particle interaction or MgO particles and the matrix is in direct contact with you (for second).
[0026]
Residual carbon (solid) is always present pore layer pore layer formed by coating particles around in pitch, traditionally in the form of one of technology (earlier patent document) regarding the requirements of the first, etc., in the form (Figure 11 references).
[0027]
Wherein the second requirement concerning the conventional in other forms of technology (earlier patent documents) of flammable liquid (also includes such pitch in trying to form a gap by a coating of liquid or its disappearance, regardless of whether or not they are flammable and how, if, as well as any. ), Which may cause the pore layer formed by coating the particles around it, in the form in the kneading process peeled off from the particles around flammable liquid and removed so cannot control this behavior as pore layer is thin or no parts (see Figure 11 (b)).
[0028]
Not fixed in space, so to speak, in the refractory of the invention in the MgO content particles around the whole IE there under a continuous air gap formation this microscopy attempts to validate and to produce MgO particles which exist as loose, so the sample preparation from refractory materials, in part of the MgO content particle surface around other MgO particles and the matrix and touching. (Refer to figure 10 (b)). So, considering the actual conditions in the validation, uses the expression "roughly contiguous". Actually there the pore layer on MgO content particles around the whole, but for example also had some contact with other MgO particles and the matrix during the verification on microscope observation sample areas part MgO content of fixed particles bond or bond is not a State. In different conventional technology invention for pore layer of MgO content particles around whether, in other words, this "join or glue" status is.
[0029]
Absorbed in the pore layer can generate almost continuous gap layers like this, without solids such as carbon, MgO particles around the MgO particles in the process of receiving thermal heat expansion almost contiguous of the particles around the MgO content as a result thermal expansion is lost on the apparent effect is obtained. That is, receiving heat process in pore formation around the MgO particles between thermal expansion of refractory became principal thermal expansion of carbon quality matrix areas primarily contiguous to 3-dimensional and can be very significantly reduce the thermal expansion of the refractory. In particular, MgO in refractories containing large amounts of conventional technology, heat shock loss reduction for MgO content and use restrictions joined, its excellent anti-corrosion characteristics did not utilized for 10 minutes. Do not follow additivity in the invention, on the other hand, MgO, high to provide combined thermal shock resistance and corrosion resistance without victims properties with the for slag or inclusions in steel corrosion from low expansion becomes possible in refractories containing MgO refractories becomes possible. Therefore, as MgO-c refractories applied parts, molten steel containers, converter, thermal shock resistance is required as Zhang material or material invention come into contact with the molten steel of immersion nozzle thermal shock resistance is required,, long nozzle, up and down, nozzles, such as SN plate continuous casting nozzle and casting materials in applications where possible.
[0030]
Namely, invention: (1)-(3) of refractories, and (5) to (7) of provides nozzle for casting in.
[0031]
(1).
1000 ° C after heat treatment in non-oxidizing atmosphere chemistry, MgO free, 40% or more of carbon compounds 4 mass %, 30% less than the B2O3, P2O5, SiO2 and TiO2 -to choose one or two more than a total 0. In the mass 3% more than 3 mass % below contains the remainder becomes refractory components and other refractory products
Containing carbon exist on both sides of the MgO particles in the refractories of at least the largest particle matrix organization and the largest particles at the interface between pore layer has a total thickness of this void is the particle size 0. 2% more than 3... And at a ratio of less than 0%, and wherein MgO content particles on the surface of all or selected from part a above B2O3, P2O5and SiO2 , TiO2 to one or are there inorganic compounds of two or more constituents with MgO refractories features.
[0032]
(2).
Rest other refractory components manufactured on or unless unavoidable ingredient derived from Al2O3 and a mass ratio of MgO and Al2O3 (Al2O3/MgO) greater than 0 0. In item (1) above, with less than 65 of refractories.
[0033]
(3).
1000 ° C except for free of carbon compounds in the State at room temperature after the heat treatment in non-oxidizing atmosphere the rest mass 100% and when the particles of 0. and 5 mass % and 45% less than in the total particles of less than 1 mm and up to 1500 ° C maximum thermal expansion coefficient is 1. Less than 1% in the above (1) or (2) above mentioned refractories.
[0034]
(4).
Total is 0, when the mass of the entire State went at 600 ° C non-oxidizing atmosphere annealing at 1000 ° C in a non-oxidizing atmosphere heat-treating fire 100 mass percent of Al, Si, and Mg to either choose from one or more metal. 6 mass % or less and 0. 5% or more. 1. 5% or more. Either 1 or 5 mass % below B4c (1) above, containing both from fire of one or more of the above (3).
[0035]
(5).
From (1) above to one or more of the above (4) placed some or all of refractory nozzle for casting.
[0036]
(6).
(5) above, placed on some or all of the parts from (1) above to one or more of the above (4) refractory materials in contact with molten steel casting nozzle provided.
[0037]
(7).
Layer consisting of a refractory composition differs from the refractories were placed in some or all of the sites placed on some or all of the parts from (1) above to one or more of the above (4) refractory materials in contact with molten steel and touching of molten steel on the back side one or more layer layers arranged in and adjacent to each other in direct contact with Earth structure and have been, wherein (5) or (6) in casting nozzle.
[0038]
Below, describe the invention.
[0039]
First, describe the chemical composition of the invention of fire. Refractories for the invention of chemical composition, 1000 ° C in the State after the heat treatment in non-oxidizing atmosphere, MgO, 40% more than the free carbon components 4% or more, 30% less than the B-2O3, P2O5, SiO2 and TiO2 choose from one or two or more with a total 0. In refractory products and other refractory raw materials will be 3% or more, 3% less than the rest.
[0040]
Here, chemical ingredients ' 1000 ° C after heat treatment in non-oxidizing atmosphere "in order meets the above-mentioned requirements to identify reasons for promoting carbon removal of volatile compounds of refractory materials in water, organic compounds, hydrates and carbonate compounds, and organic binder ingredients, ingredients in steady-state, if at a temperature of 800 ° C or more, but to improve analysis accuracy due to stabilization of chemical components in refractories, i.e., such components in refractories, Should be provided for heat treatment after the dispersal of the volatile components of the resin components is missing from the especially and avoid new substances produced by chemical reactions at temperatures above 1000 ° C to 1000 ° C in non-oxidizing atmosphere. From this point, the heat shall be until the time runs out the weight changes due to heating. Method for baking at 1000 ° C as examples of heat treatment in non-oxidizing atmosphere filled with carbon materials, such as coke-fired in to meet this objective, the oxygen concentration was 0. In an inert gas atmosphere was adjusted to 1% or less nitrogen or argon, etc. in the 1000 ° C in 1 hour-include how to keep about 3 hours. Select any to fit the purpose of the aforementioned specific conditions of the atmosphere, retention time, sample size, etc., and can be determined.
[0041]
In the present invention, to 4% or more and 30% less than carbon component of free content. (Including fiber) particulate and crystalline carbon, graphite and carbon fraction produced by carbonaceous free here and receiving treatment in non-oxidizing atmosphere binder of organic quality, pitch, tar, and carbon black 1000 ° C carbide B4C, SiC, except of that carbon. Here's to"carbon-free" simply as "carbon" and also. Also, carbon base parts located between the particles, including carbon component of this free called "carbon matrix". Carbon matrix, and carbon mass 4% less than 3-dimensional consecutive organization cannot be developed, low expansion effect does not appear. Also, have a problem and 30 mass % more than the advantage in strength, thermal shock resistance, but intense damage caused by molten steel and slag, gas carbon matrix, increased refractory melt loss reduce the service life.
[0042]
To explain the Organization of the invention of fire. Organization of refractories for the invention of a refractory tissue was thick shape surrounding the MgO particles and MgO particles found in Carbonaceous matrices such as the carbon matrix revealed 3-dimensional surface, voids formed. Specifically the refractories of the present invention is a maximum of MgO particles of refractory materials in the particle (hereinafter referred to as "maximum diameter particles". ) Of carbon matrix (matrix organization containing carbon) to exist on both sides and the largest particles at the interface between pore layer has a total thickness of this void is the maximum particle size of 0. 2% more than 3... With refractory organizations is at a ratio of less than 0%. Fire-resistant tissue, 1000 ° C can be determined by microscopy at room temperature after the heat treatment in non-oxidizing atmosphere. Promotes carbon removal of volatile compounds of refractory materials in water, organic compounds, hydrates and carbonate compounds, and organic binder ingredients as noted above, the reason, 1000 ° C such as the observation of refractory in non-oxidizing atmosphere heat treatment after, get the ingredients in steady state, because in the manufacturing of refractory products already undergoing heat treatment at temperatures of over 1000 ° C, or when going through the heat treatment at a temperature of 800 ° C or higher depending on the type of volatile components Allows to evaluate chemical ingredients except microstructure and metal components in products after its manufacture.
[0043]
Goal to form the pore layer thickness in place around the MgO content particles in the present invention a high particle is refractory to form upon preheating or when receiving steel or case temperature during cooling, expansion to MgO particles within the Organization's expansion before the particles around a self-effacing as fire-resistant thermal elongation of the prescribed temperature expansion for MgO particles absorbs around a particle of refractories within the pore layer. Mentioned traditional technology (patent literature 5-7) of it decreases the expansion absorption of air gap and void formation around the particles, as in materials such as carbon, preventing low-expansion effect. In contrast, invention, no foreign objects such as carbon in the void of almost continuous pore layer to form. This may dramatically reduce the heat expansion of the refractory materials become available.
[0044]
And that no foreign objects such as carbon particles around the MgO content, almost continuous air gap layers formed on MgO surface moisture-laden air or steam or carbon dioxide given time into contact with hydroxyapatite layer and carbon oxide layer to raw material stage and form in the heat treatment process of molding refractories containing MgO surfaces. Hydroxyapatite layer and adjust the thickness of the insulation layer from carbonic oxide layer can be done by varying the amount of additives such as concentration of water vapor and carbon dioxide, temperature, time, gas pressure, hydroxide. The formation temperature of the coating layer of these carbonate oxide layer when below 350 ° C, of hydroxyapatite layer if below 260 ° C should.
[0045]
Such as hydroxyapatite layer and MgO particles with surface coating comes from carbonic oxide layer is activated by heat decomposition temperature above the insulation layer, containing MgO micro porous surface layer (below this layer simply as also the MgO active layer. ) To form. This MgO layer is MgO fine, including many that have high reactivity and densification due to shrinkage by heating to high temperatures over the above decomposition temperature MgO layer can be promoted. Become a decreased thickness of the layer of MgO activity this was originally in the porous, allowing to observe the formation of 1000 ° C at room temperature observations in non-oxidizing atmosphere heat treatment after consecutive MgO particles around the pore layer. In order to further enhance this densification in the invention, refractory organization acidic oxide B2O3, P2O5, SiO2 and TiO2 to choose from one or two more than the total at 0. 3% or more 3 mass % content to. As a result, production and heat treatment during operation of the MgO layer and these will form the pore layer contraction reaction part by acidic oxide and prone to erosion reaction (densification) the almost consecutive MgO content particles around. Inorganic quality compounds due to densification to progress at the same time, all or part of the MgO content particle surface, B2O3, P2O5, SiO2, TiO2 -selecting one or two or more ingredients and the MgO thing (solid-solution including) generation to. These inorganic compounds are, can be confirmed by x-ray powder diffraction and EPMA observation.
[0046]
Among these acidic oxide at high temperature heating in the presence of carbon vapor pressure is high, easily dispersed as gas organization B2O3 and P2O5 is particularly favourable. In addition, these acidic oxide alone of in combination with two or more in addition to the use of the use or used in the form contains these acidic oxides as glass powder and compound where possible. You can hard to happen by itself, especially densification TiO2 and SiO2 , B2O3, P2O5 and by promptly densification.
[0047]
Further addition of glass powder and composite oxide powders, inorganic compound powder that can be added as oxides (metal oxide) from the very beginning these acidic oxides, as well as hydrated metal oxides, hydroxides, carbon oxide, organic compounds added to can. Case of glass powder containing the above-mentioned acidic oxide non-active ingredient in the total amount of active ingredients than for refractory products 1 mass % or less be limited is. These acidic oxides, preferably to present as a powder in refractory, 0. be present at less than 1 mm grain, and MgO layer of densification effect acting further on.
[0048]
The content of the active ingredient as mentioned in either case, acidic oxides in total 0... To make 3 mass % 3% or more. Its content is 0. 3 mass less than % MgO layer of densification effect 10 minutes only and mass 3% more than because of excessive reactant pore layer of MgO content particles around a low-expansion effect is obtained.
[0049]
Around the MgO content particle porosity layer thickness is low from the viewpoint of thermal expansion thicker as well, also the pore layer around all fire particles of thermal expansion greater than the carbon in preferable. You should, however, which can degrade the strength of refractory fire particles around the pore layer to adjust gap thickness while maintaining a balance of intensity and amount of thermal expansion.
[0050]
In the present invention pore layer of MgO content particles around the described above in a fire-resistant surface in the preliminary stages of the MgO content material or refractories production process gases and liquids and MgO as a chemical reaction, i.e., the MgO content particle hydroxyapatite layer and later generation comes from carbonic oxide layer coating at the temperature of decomposition temperature than those coated layer once thermal decomposition, even in high temperature region B2O3, P2O5 The reaction of SiO2, TiO2 and densification, the generated. Fire resistance of particles in General has a particle size distribution by sifting the aforementioned hydroxyapatite layer and carbon oxide layer is processed under the same conditions, even in different grain size of refractory particles generate almost evenly across its surface. Hence the formation of voids by annealing with subsequent decomposition temperature more than that gap thickness and particle size and ratio (pore layer thickness: micro space particles per (hereinafter simply referred to as MS value. )) When thinking about the larger particles so the ratio is small, as small particles that ratio will increase. Therefore, knowing MS value of coarse particle determine the minimum rate of pore layer thickness in refractory tissue particles per and MS values in the Organization at and roughly assess the organization becomes possible.
[0051]
Between particles to a maximum particle diameter D and carbon matrix porosity layer thickness L with the MS value here (on both sides of the particle porosity formation total thickness to L) of ratios, the following formula.
MS = L/D×100 (%)
[0052]
In other words wherein the MS value represents the expansion rate of particles in the tissue around the minimum value.
[0053]
MS inventors were calculated as follows. Microscopic observation of refractory materials, any line through the center of the circle inscribed in the individual particles, and selected 10 coarse particles of particle size largest to smallest. Further, line through the center of _said_ relative 45-degree pitch line further to pull three, four single particle per draw. Then on each line of the particle length of contour points at both ends of the particles as D1, D2, D3, D4, outside particle surface at the ends of each line of the pore layer, respectively, of total thickness is measured as L1, L2, L3, and L4. At this time, void of individual thickness measurement, particle surface to measure minimum thickness in vertical lines.
[0054]
4 these average values of those numbers to the MS for one particle, MS1, MS2, MS3, MS4, respectively calculated using the above equation, using figures obtained on line. Particles previously picked 10 MS values calculated by averaging the MS value for your organization to get.
[0055]
For MS of maximum diameter particles of microscopic observation field in this MS values and averages the coarse particles of 10 MS, large particle size in the above-mentioned order as it were, in one way. That is, to averages by measurement error to consider the large particle size of coarse particles of 10 MS maximum diameter particles of microscopic observation field in MS value shall be deemed to have (unless if MS value MS of maximum diameter particles that hereinafter. ）。
[0056]
Gap thickness of inventors, a study for low expansion of carbon-containing Refractories in combination with MgO organization results, low thermal expansion effect the balanced strength and corrosion resistance, abrasion resistance surface particles around the pore layer at maximum diameter particles around its particle size 0 is the thickness. 1. more than 1%. Make sure that less than 5%. Particles per pore layer on both sides for maximum diameter particles porosity layer on both sides two points because, described above, represented by MS value, which is the ratio of the thickness, and 0. 2% more than 3... 0% or less when it is found a significant improvement in thermal shock resistance.
[0057]
From the point of view of the thermal expansion of the constituent particles of all MgO particles, is the thermal expansion coefficient of MgO particles (aggregate particles) generally at 1500 ° C 2. If MgO contents to 0% more than at 1500 ° C 2 is the expansion rate of the particles. Coefficient of thermal expansion at the same temperature of 4% as the particles that surrounds the carbon matrix is 0. 4 percent estimate and the difference is 2... And 0%; To loss due to thermal expansion in steel casting temperature is around 1500 ° C for the expansion gap around the particles, i.e. the particle's pore layer thickness ratio (MS values) are two-particle size. If more than 0% up to 1500 ° C particle does not contact the carbon matrix and, as a result of refractories up to 1500 ° C thermal elongation of macroeconomic, expansion of the carbon matrix is dominant, does not depend on the chemical composition of traditional additivity, indicating a remarkable low thermal expansion property that becomes possible. Thus, the MgO content of individual particles from the point of view of thermal expansion depending on the operating conditions, with almost continuous air gap formation thickness rate (inflation's) that follow the additivity low expansion becomes possible.
[0058]
In that void formation around the MgO content particles described above for MgO content particles other than other fire-resistant material particles in a mixed organization, refractory low expansion in the whole expression should be. Make sure that low-expansion effect the content of MgO particles have the ability to form effective porosity formation inventors the study results, as MgO at least 40% or more. Of thermal expansion coefficient of reduction cannot be expected to increase continuity of ceramic particles does not have other valid pore layer and MgO (MgO constituent) particles mass 40% less. Also, should be able to develop an effective strength, low thermal expansion drawers enable carbon matrix continues in 3-d. Therefore, you need to often do not contain percentage must also apply refractory raw material particle number limit, lowering its continuity and enhance the continuity of fine range of granularity configuration. Refractory raw materials grain in the invention when % free carbon components, except the rest 100 mass of particles 0. with 45% less than the total percentage of particles of less than 1 mm, expressed low thermal expansion effect is also 0. percentage of less than 1 mm less than 5 weight percent and excellent thermal shock resistance, although prone to rough organization and molten steel composition, molten steel flow and oxidation by easy-to-progressive wear and tear. Common fireproofing ingredients, suitable ingredients except as a refractory material particles, B2O3, P2O5, SiO2, TiO2 , said here the other as is the Al2O3and ZrO2, Y2O3and CaO, Cr2 With refractory particles consisting of solid solutions consisting of two or more ingredients or simple ingredients selected from O3, SiC or compounds where possible.
[0059]
On the other hand, from the point of view of mechanical strength and can degrade the strength and decrease corrosion resistance to molten steel and wear resistant steel of the formation of voids around the particle. Similar to buckle and strength if you gave the force structure strength as a plastic bottle can be obtained if you liken this to plastic bottles and plastic bottles filled with the contents, but not filled with contents in plastic bottles with symptoms. That would be difficult given the moderate pressure for fire resistant particle fire particles around in if there is an excessive gap formation, in the contents, at the casting temperature level corresponds to the bottles around carbon quality bulkhead (matrix), weakened to carbon bulkhead reinforcement carbon partition corruption due to deformation and in extreme cases, to reduce the strength of materials. As stated above MS value is 2. Will be enough if even 0% refractory products for your organization, this from the somewhat greater MS (3. 0%) up in space balanced strength and coefficient of thermal expansion. MS value is 3. Microstructure is mentioned at the casting temperature level, and more than 0% in all over the place due to the macroeconomic strength can slow the degradation of physical properties such as corrosion resistance and wear resistance. MS value is 0. Below 2% and under good mechanical strength, low thermal expansion effects does not give.
[0060]
When the underwriter, invention, except for carbon-free and B2O3, P2O5, SiO2, TiO2 100 mass percent of particles 0. particles less than 1 mm is 45% less than the 5% or more in total, up to 1500 ° C maximum heat expansion coefficient is 1. As the necessary thermal shock to less than 1% refractory works effectively, so desirable. Increased oxides of carbon matrix has no oxide particles while in the Organization after forming the oxide particles are a chain of direct contact with the heat expansion ratio. Therefore, we found that performance even better low expansion characteristics by lowering MgO particles around with pore formation in the present invention, organization in addition to the continuity of the particles is obtained. Namely, 0... particles less than 1 mm to 45% less than 5% or more. 0. particles of less than 1 mm to 5 weight percent and refractory increases with roughness becomes molten steel flow velocity under wear. While more than 45 WT % more and greater coefficient of thermal expansion thermal shock resistance decreases.
[0061]
Content, particles of particles with proper porosity formation, almost continuous air gap to more than 0. determine the granularity of less than 1 mm will enable low expansion. In addition to invention, temperatures up to 1500 ° C maximum thermal expansion coefficient is 1. To enable acts as a refractory, particularly in molten steel and impact-resistant to abrasion is required and less than 1%. Because we can to overcome the weaknesses in thermal shock resistance high thermal expansion characteristics of MgO particles caused by the thermal expansion coefficients of the refractories containing MgO particles, thereby reducing nozzle for casting such as applied to numerous applications becomes possible.
[0062]
To explain the improvement in corrosion resistance in the invention. Role of MgO is distributing the molten steel and catalytic components in the CaO containing many well known to most consisting solely of slag melts (melting of origin exists, emerging on the so-called molten steel slag layer, etc.) and small (FeO), (MnO), (CaO), the because of ultramafic inclusions and catalytic reactions, a basic oxide is MgO low is to impart corrosion resistance difficult generate a fusion of. In addition, with increased MgO content of refractory materials in from the obtained low-expansion effect of refractory products by the method described above to generate particles around the MgO content pore layer invention, without compromising thermal shock resistance and can, as a result, get traditional storytelling with technology which is hard, high thermal shock resistance and corrosion resistance of refractory materials for becomes possible.
[0063]
Carbon MgO particles (aggregate) and bond components the addition depending on operating environment from containing 4% or more, 30% less than the invention, even free of carbon compounds, where the vapor-phase phenomena initialize a so-called reaction of MgO-c (MgO (solid) + C (solid) → Mg (gas) + CO (gas)) might happen. Such inner part of immersion nozzle and stopper head for purposes of the hot control used for environmental CO gas operation temperature rises as the operating environment susceptible to such reactions, occurring within the Organization (composed of refractory) easy to move out, for example, continuous casting, injection nozzle. To, especially in areas such as molten steel slag components such as inclusion of contact prone they are penetrating into the organization by MgO low melting MgO-c reaction was mentioned above, the reaction can be better facilitated if there is. MgO particles if you promote this reaction between MgO content particles to bond parts and aggregates in which gas result in loss to the vulnerable parts are formed, in addition to corrosion resistance and mechanical strength of infiltration behavior of metal and slag hemiarthroplasty. It also showed that may adversely affect low-expansion effect disappears and porosity formation in the pore layer around the MgO particles in your organization, and scatter these gases and fine particles or whiskers, such as deposit.
[0064]
We found the composition range corrosion resistance without compromising organizational soundness and low thermal expansion effects over the long run, during the composition of Al2O3 ingredients as a way to keep situations with the easy-to-progressive reaction of MgO-c as a result of the study of organizational health and low thermal expansion effect, fixed amount added to the inventors get and keep. Namely, invention, 1000 ° C after heat treatment in non-oxidizing atmosphere chemistry, part of the MgO and replace Al2O3 ingredients that (Al2O3/MgO) mass ratio greater than 0 0. You can adjust the composition of the range of less than 65. Furthermore, (Al2O3/MgO) stipulates "0" and the mass ratio is not doped Al2O3 ingredients in the invention may be.
[0065]
A thermodynamic stable the part of MgO doped Al2O3 ingredients are refractory organization Al2O3 ingredients to knowledge could be suppressed by changing the spinel phase reaction of MgO-c based on the. As a result, low-expansion effect of refractory cast, can keep the MgO content particles around the pore layer can inhibit the formation of whiskers by re-oxidation of volatile constituents in pore formation pore, especially around the MgO content particles as a result of the Suppression of MgO-c reaction from will be able to maintain until the end. By MgO-c reaction usually MgO and C solid skeleton tend particularly fragile layer is formed near the running surface, and gas dispersion is doped Al2O3 ingredients makes spinel and Al2O3 in your organization can be, organization of weakening suppression to effect and the corrosion resistance and mechanical strength operation in to stable shall be. Al2O3 ingredients can be added by using the particles consisting of single particles consisting of Al2O3 or spinel. These grain is from the point of view of a 0. often less than 3 mm, 0. less than 1 mm is more preferable.
[0066]
Pore layer forming a pore layer doped Al2O3 ingredients and suppress reaction of MgO-c as mentioned earlier, a very effective trick is almost contiguous between MgO content particles and carbon matrix in the present invention, although Al2O3 particles with carbon matrix for a remarkable little or not generated. Therefore Al2O3 increased the relative increase in coefficient of thermal expansion of lead, compared to MgO particles with sufficient space, impose limits on the amount that is preferred. Especially the high corrosion resistance of MgO premises while it requires low expansion characteristics in continuous casting nozzle materials that require thermal shock properties (Al2O3/MgO) mass ratio is 0. Range over 65, compared to other material thermal expansion and greater tendency to balance thermal expansion cracking as a crumbling structure should be tuned compositions in this range because of increased risk of.
[0067]
As a fire-resistant component of Al2O3 ingredients other than possible with doped ZrO2, Y2O3and CaO, Cr2O3, SiC. Various ZrO2 materials (未安定 zirconia, partially stabilized zirconia and fully stabilized zirconia, arminazirconia), chromia, magnesiakuromia, spinel can be used in these can be used alone. In this case MgO is at least 40% or more that can develop low-expansion effect and may be... SiC additive that reach 15% less than desirable.
[0068]
Refractory oxide protection becomes important to inevitable contact with air containing oxidizing gases in the refractory products used in the steel sector, and to demonstrate the feature until the end of the operation. In particular, refractories for steelmaking and SN plate flow control for especially strength and oxidation resistance and corrosion resistance is needed, top nozzle and nozzle at the bottom, unlike immersion nozzle and long nozzle, oxidation prevention layer coating will not be generally needed to ingredients in the antioxidant additives. When the mass of the entire State status before 1000 ° C in a non-oxidizing atmosphere heat treatment in the refractory of the invention, at 600 ° C in non-oxidizing atmosphere heat treatment and removal of volatile fire and 100 WT % Al, Si and Mg to either choose from one or more metal or alloy in total 0... You can increase 5% or more, 6 percent less than the primarily to demonstrate the antioxidant function runs on the way. Its content is 0. 5 mass % less than 10 minutes only antioxidant effect and undesirable to reduce thermal shock resistant properties of materials in addition to the difficult low-expansion effect is maintained by and mass 6% more than the pore openings and around the MgO content particle porosity layer deposit products derived from the additive.
[0069]
In addition to containing al, Si and Mg as a single metal alloyed powder state that where possible. Also, because the Si is inhibited the formation of carbide aluminum used during and after heat treatment, in conjunction with the Al, to use is desirable. If you require below 800 ° C, antioxidant, B4c that is more beneficial. Its content is 0. 1. 5% or more. Should be less than 5 weight percent. Its content is 0. 5 mass % less antioxidant capabilities not 10 minutes, 1. 5 mass more often and keep up with low expansion characteristics with will be easily brought decrease corrosion resistance. You can either al, Si and Mg to choose from and one or more metals or alloys with B4C to make coexistence extent each amount described above.
Advantageous effects of invention

[0070]
You can offer combines the traditionally get with technology that can significantly improve thermal shock resistance of carbon-containing refractories containing MgO according to the present invention, has excellent corrosion resistance and thermal shock resistance of refractory and casting nozzle for this.
A brief description of the drawings

[0071]
1 forms of immersion nozzle (casting nozzle) for refractory products of invention [Fig. 1] shows.
Showing 1 of applied [Fig. 2] the present invention refractories submerged entry nozzle (casting nozzle).
Showing 1 of applied [Fig. 3] the invention of fire long nozzle (casting nozzle).
Showing 1 of applied [Fig. 4] the invention of fire long nozzle (casting nozzle).
Showing 1 of applied [Fig. 5] the invention of fire at the bottom nozzles (casting nozzle).
SN plate (casting nozzle) [Fig. 6] the present invention refractories applied 1 form indicates.
[Fig. 7] molten steel give a general idea of rotation test methods.
Molten steel in rotating test of specimen [Fig. 8] shows, (a) the front, (b) is in the plan.
[Fig. 9] molten steel shows the outline of the measurement of loss rate of bond rotation test.
Image shows the structure of MgO particles [Fig. 10] invention refractory and its surroundings, and in (a), if if has a pore layer particle outline and similar MgO content particles around the particle is located in the Center (typical of the invention), (b) has a particle outline with similar pore layer around the MgO particles, particles are biased to either of the inner surface of the pore layer located (example of uneven distribution that occurs during the preparation of the observation for microscopic samples, etc.).
Image shows the structure of MgO particles [Fig. 11] conventional refractory and its surroundings which, (a) the particles around the MgO content in some particle outline with similar pore layer is porous or solid Organization (solid) solids pore formation in if (covered in remnant coal of pitch, that form the pore layer for example), (b) exist around the MgO content particle particle outline with similar pore layer In discontinuous voids layers or if you have a carbon matrix and the adhesive, do not have pore layer itself partly (for example, missing part of the cover had to pore by pore layers, coated with flammable material, etc.).
For carrying out the invention

[0072]
MgO particles used in the invention of the particle surface almost continuous corrosion resistance improved by low thermal expansion effect by forming a pore, and MgO. Particulate magnesia material as MgO particles, typically, and produced in natural or artificial synthesized MgO to the subject is mentioned. Magnesia raw materials, electric fusion, sintering products also can be used in the MgO purity of 90% or more are preferred. Also, as MgO particles, theory-composition (MgO and Al2O3) spinel materials including could use some. We should, however, develop noticeable MgO-expansion effect and improvement of corrosion resistance as MgO particles, i.e. MgO sources, at least partially using magnesia raw materials (magnesite).
[0073]
Refractory materials of the present invention is a metal oxide B2O3, P2O5, SiO2 and TiO2 to choose from one or two or more (hereinafter referred to as specific metallic oxides. ) Containing, as its raw material is B, P, and Si, Ti oxides or hydroxides, colloidal substances, esters, metal alkoxides by selecting either alone or in conjunction, can be used. For example, as a source of the B2O3 , suitable for a boric oxide, tetraborate, metaboric acid, Ortho acid, esters of boric acid, borates can be used to better include silica glass can be used in. As a source of P2O5 , phosphoric acid, esters of phosphoric acid in addition to possible as the use of various phosphates, such as aluminum phosphate, sodium phosphate and phosphate hydrate. Can be used as a source of SiO2 , Ortho-silicic acid and metasilicic acid, anhydrous silica powder and solution type, such as ethyl silicate, colloidal silica, silicates and Alumino silicate decrease quality. As a source of TiO2 can be used in the titanium dioxide and Titania-hydrate, titanium compounds, colloidal dispersions, etc.
[0074]
These B2O3, P2O5, SiO2 and TiO2 to choose from one or two or more specific metal oxide MgO particles surrounding segregation does not need are evenly dispersed. In addition to proper dispersion in kneading because, as these ingredients 0... preferable to use less than 1 mm of powder or liquid state.
[0075]
Further, in the present invention, carbonaceous, MgO, B2O3, P2O5, SiO2 and to the inclusion of other refractory components instead of TiO2 , is feasible. Above as a fire-resistant components and other reasons, most suitable with Al2O3 components, but as a component of other oxide components such as CaO, Cr2O3 and ZrO2, Y2O3and SiC application allows. Applied in solid solution, intermetallic compound can be in addition to these can be added by itself. 1 examples should be added various ZrO2 materials (未安定 zirconia, partially stabilized zirconia and fully stabilized zirconia, arminazirconia), chromia, magnesiakuromia and spinel. Which in this case MgO is at least a 40% or more, can develop low-expansion effect. SiC additive that reach 15% less than desirable.
[0076]
Possible to use natural materials such as fire-resistant as can in the refractory of the invention as mentioned above as a fire resistant particle using natural raw materials and other raw materials while production on that stuff or a raw material impurities (active ingredients other than inevitable ingredient) mixed (the production on or inevitable ingredients of material derived from simply unavoidable ingredient hereinafter referred to. ）。 For example, among the Fe2O3, R-2O (R = Na, K, Li). Such inevitable ingredient weight 3% or less, preferably weight 2% or less, more preferably 1 mass % less than desirable. By alternative content such as inevitable ingredients of select high-purity active ingredient for each raw material and manufacturing processes to reinforce cleansing can be adjusted somewhat.
[0077]
Become a binder as a carbon source, carbon source (carbon binders) can be used. A high percentage of carbon as a connective tissue remaining after a non-oxidizing atmosphere firing as Binder carbon phenolic resin, pitch and tar system preferred. You can use an optional carbon solid Binder carbon raw materials except the further invention in addition to the binder carbon sources of these raw materials. You can using fibrous carbon materials such as carbon fiber, graphite, carbon black particles and as solid Binder carbon material, except carbon materials. However, these carbon sources, 1000 ° C percentage of refractory in non-oxidizing atmosphere heat treatment after chemical ingredients, free of carbon compounds and 30% less than 4% or more will Binder carbon raw materials, like loss rate (excluding the residual carbon percentage rate), loss ratio of solid carbon materials (heating weight loss minute impurities, etc.), etc. have taken into consideration the addition of hai土.
[0078]
Formulated to be prescribed in the present invention wherein each raw material chemical composition, formulations of kneading, molding and heat treatment in non-oxidizing atmosphere over 800 ° C.
[0079]
In this kneading evenly and disperse around the MgO particles to each component of the B2O3, P2O5, SiO2 and TiO2 , liquid or particles turned to earlier B2O3, P2O5, SiO2 and TiO Each component of the 2 ingredients, including additives, preferably in the form alone or in combination, added directly to the MgO particles and mixing to.
[0080]
Below, illustrates the casting nozzles using the invention of fire.
[0081]
Figure 1(a) shows examples of immersion nozzle (casting nozzle) from certain areas of the site of invention of 20 contact with molten steel, and steel contact surfaces arranged as a single layer on the back side. From area of all of the sites you put your invention of 20 in the powder line material 21 parts fig. 1 (a), invention of 20 contact with molten steel, and steel side placed on the back side as a single-layer immersion nozzle (casting nozzle); Applying the refractory of the invention, Figure 1(a) shows a cylindrical casting nozzle can apply nozzles immersed without being limited to the shape of the nozzle is used such as but not limited to cylindrical, for example, as shown in Figure 1 (b) mainly thin slab casting flat, oval-shaped, funnel-shaped (funnel-shaped the diameter at the top), and many other shapes.
[0082]
Fig. 2 (a) is part of the invention of 20 steel side (here in the pore surface) to show examples of immersion nozzle (casting nozzle) with and without the multiple layer is placed on the back side and refractory products 20 different composition, refractory materials (powder line material 21 or 22 body material) from a layer is placed, the plurality of mutually direct contact with earth are structure and. Figure 2 (b), as the invention of 20 steel side fig. 2 (a) and discharge which when applied to the inner pore surface and the outer surface of the 1 discharge indicates the vents above Faculty consists in the invention of 20 all lower case. This structure, as well as the ejection, composed of 20 invention only come into contact with the molten steel in the lower area of the hole above the surface inside the alumina-can and other fire-resistant material graphite quality.
[0083]
Al2O3and SiO2, MgO, ZrO2 out of more than one type or one or more fire resistant particle consisting of these compounds and carbon refractories, refractories on the whole or part of the surface or in the refractory of the present invention is a contact of molten steel and refractory composition may vary as shown in Figure 2 rear refractory materials (material powder lines 21 and 22 body material) specific examples.
[0084]
Terms in the manufacture of casting nozzle consists of multiple layers, CIP molding molds in the area to contact with molten steel at a given thickness of radial dividers hai土 for the launch space filling and refractory products for hai土 of the invention on the surface, even on the back side of the above-mentioned Al2O3and SiO2, MgO, ZrO2 In out good filling of refractories for hai土 of more than one type or one or more fire resistant particle consisting of these compounds and carbon. If good molding by removing the jig plate and then using this partition ago molding, etc.
[0085]
Figure 3 shows the long nozzle is placed in certain areas of the site that contacts the invention of fire of 20 steel examples.
[0086]
Placed part of the invention of 20 contact with molten steel surface shown in Figure 4 and Figure 5 is the example of multiple layers composed of refractory on its rear side and the fire of 20 different compositions (body material 22) is placed, and forming a plurality of mutually direct contact with in what structure and long nozzle and nozzle at the bottom. Figure 6 shows examples of SN plate consisting of 20 of the present invention.
[0087]
Furthermore, for example figure should also apply refractory 20 invention of some or all of the back and middle-tier Cao refractory alumina adhesion material 23 apply to parts, as shown in 2 (b), (c) contact in the nozzle for casting molten steel surface hole, etc. Cases such as these depends on the reaction of each other, such as if the CaO system and MgO based materials of the present invention is not the same basic material and CaO based material made contact with Al2O3 systems material for example low can have the effect of preventing fusion, etc., or damage caused by it.
Implementation example
[0088]
Table 1 below-adjustments shown in table 9 with refractory materials (refractory particles) and added phenol resin as a binder, after mixing hai土 suitable for molding molding. After the hai土 by CIP forming, temperatures up to 300 ° C curing and drying process after 1000 ° C heat in a non-oxidizing atmosphere. Note that in this example, as MgO particles using fused magnesia clinker particles and spinel powders.
[0089]
Analyze the chemical composition of refractory products obtained, to observe organizational status and subjected to evaluation. Observations of the Organization States that refractory organizations resin is included, along with how to soak in the mirror due to mechanical polishing, mentioned by microscopy for MS values observed in the continuity of the pore layer and MgO content particle surface compounds with or without.
[0090]
As the evaluation of refractory products, estimation of the coefficient of thermal expansion, corrosion resistance (corrosion-resistant), shock-resistant and oxidation resistance.
[0091]
Up to 1500 ° C coefficient of thermal expansion of measurement (based on JIS R 2207-3) and evaluated up to 1500 ° C maximum heat expansion coefficient in evaluation of coefficient of thermal expansion.
[0092]
Evaluation of the refractories corrosion loss of (corrosion resistant) from molten steel in rotating test method by high-oxygen steel made. Molten steel rotation experiment is how to evaluate the corrosion resistance against molten steel refractory materials of the present invention provide as a premise. Herein that caused the damage and "melt" mechanism that seizure due to a chemical reaction (low corrosion due to melting, etc.), and used as a concept of comprehensive representation whether or the wear and tear of mechanical erosion wear resistance (so called erosion), the reduced dimensions of the sample after testing if the "resistance corrosion resistance" or "corrosion" is used as resistance "melt" which represent a comprehensive.
[0093]
Figure 7 shows the rotating test methods outlined in molten steel, Figure 8 shows the molten steel in rotating test of specimen, (a) the front view (image), (b) shows the top view (image).
[0094]
In molten steel in rotating test held at the bottom of the holder 11 specimen immersed in molten steel in the Crucible 12 13 10. Specimens are fixed respectively at the bottom of the square pillar holder 11 4, 10 and 4 in the box. This specimen can be disconnected through mortar and inserted into the recess with a square pillar holder 11 pull tests have been completed, 10. Is connected to the axis of rotation does not illustrate the upper holder 11, rotates around the longitudinal axis to be retained.
[0095]
Holder 11 has a 40 mm square 1辺 in horizontal cross section in the longitudinal length of 160 mm, made of zirconia-carbon refractories. Specimen length 25 mm, height 20 mm, width 20 mm, protruding exposed holder 11-10. In addition, specimen end surface of the 10 from the bottom surface of the holder on the installed at 10 mm. Crucible-12 depth 190 mm cylindrical refractory at 130 mm, inner diameter. More than 50 mm in the submergence depth of the holder 11. Crucible 12 are decorated in high-frequency induction furnace 14. Also not shown, but you can cover on top.
[0096]
Molten steel in rotating testing test on molten steel 13 piece steel 13 preheated 10 hold for 5 minutes and then dissolved (high-oxygen steel steel oxygen concentration: 100-150 ppm) in specimens immersion and 10 specimen on the top surface of the 10 flat to rotate at the speed of 1 m / sec. The temperature in 1550-1600 ° c hold. Pull up after a three-hour specimens of 10 to measure the liquid loss rate (µ m/min).
[0097]
Measurement of loss rate of bond is shown in Figure 9 (b) after the test specimen holder from the cut in the horizontal plane to the axis of rotation 10. With respect to cutting from edge 10A toward the direction of the rotation and measure length of six with 3 mm pitch, on average. Before the test specimen measured length as well as shown in Figure 9 (a) of 10, you mean. Calculate the adhesion and soluble losses speed (mm/min) dividing in test duration 180 minutes before the test mean value (mm) minus after the test mean value (mm). Would require that the furnace, at least 35 m/min or less melting loss rate for the determination of melting loss rate for Yu (•): < 0-5 m/min, the good (x): < 5-20 µm m/min, available (in): 21-35 m/min, do not (x): > 36 μ m/min resistance of materials corrosion (corrosion-resistant) for evaluation.
[0098]
Describe the evaluation method for thermal shock resistance of the refractory of the invention should assumption. Evaluation of thermal shock resistance of refractory products, cylindrical sample (outer diameter and inner diameter (in diameter) height = 130 / / 55 / 300 mm) prescribed temperature Ts ° C Preheat, went on the way in after holding a one-hour isothermal state at that temperature 1600 ° C in hot metal pretreatment in the sample hole pouring to refractory samples affect the thermal shock test. I.e. the maximum temperature difference (Δ T temperature) affecting the sample in this study (1600-Ts) ° C, and cut on the pitch 50 mm horizontal cross section after the test, and checked for cracks. Δ T limit temperature of the fire and the maximum Δ T temperature cracks are not observed. Shock resistance as a prerequisite for continuous casting refractory products refractory products of the invention, in particular thermal shock resistance is required Δ T limit temperature is 800 ° C or more. Thus, Δ T limit temperature above 800 ° C to pass (circle), no preload to 1,200 ° C or higher as a heat level with Yu (◎). Also, below 700 ° C and cannot be (x), 700-compared-friendly (decrease) and then each of refractories as available if 800 ° C is devised.
[0099]
SN plate the oxide material will not be applied generally and bottom nozzles, nozzle at the top, steel brick material, it should be oxidation resistance of the material itself. As a result, is preferable to the capability to enhance the oxidation resistance of refractory products in your organization, or if you want. As evaluation of oxidation resistance of refractory samples (30 mm), under an air atmosphere after holding three hours at 800 ° C and 1400 ° C atmosphere, immediately remove the cooled samples in vertical cut after removal of average thickness measured. Thickness of decarburization in both temperature levels < 0. excellent for a 5 mm (•), < 1 mm good (y), or temperature level is > decarburization of 1 mm can be compared to each refractory as bad (x).
[0100]
Results table 1 and shown in table 9. Furthermore, table 1-table 9 score is 0 MS value. 2% more than 3... 0% or less, that one or are there inorganic compounds of two or more constituents with MgO to choose from the B2O3, P2O5, SiO2 and TiO2 particles MgO content in whole or part, 1500 ° C until the maximum heat expansion rate 1. Molten steel in rotating test (corrosion resistance), less than 1%. or ○, thermal shock resistance evaluations ◎ or evaluation of oxidation resistance, that is the: or in conditions that is (However, oxidation resistance evaluation table 9 only) when viewed in as excellent. During the evaluation of these x is include-if accepted as decrease in display, and x contain as non-x in displayed. Score is ○ or decrease the pass (available).
[0110]
Table 1 and table 2 shows example 1-examples 7 and comparative examples 1-10 is an example system using the system MgO, principal components, namely magnesite MgO particles investigated MgO content maximum diameter particles and carbon matrix between the pore layer thickness ratio (MS values) affect.
[0111]
Are free of carbon compounds and 4% or more, 30% less than the MS value is 0. 2% more than 3... Is less than 0%, and B2O3 content is 0. Example 1 in 3% or more, 3% less than-in examples 7, up to 1500 ° C maximum coefficient of thermal expansion and thermal shock resistance is good, and the resistance corrosion resistance even better results could.
[0112]
On the other hand, the MS value is 0. Comparative examples of less than 2%-couldn't get good results for thermal shock resistance, at 4. And slow the corrosion resistance comparison examples 5 and 6 graphite are often better thermal shock resistance, but as the score x became. Is this carbon increased conventional heat impact improvement methods by technology, and showed characteristics of corrosion resistance to molten steel (including the chemical damage, mechanical damage and wear) small graphite.
[0113]
These comparative example 1-9 no surface treatment of MgO particles if the content of the B2O3 is 0. If not (without the B2O3 ), range of 3% or more, 3% less than carbon components free of 4% or more 30 wt % range without at least one applicable, 0. If you do not have MS for more than 2% in.
[0114]
Comparison example 10 MgO particles of surface treatment and amount of the B2O3 1 mass %, MS value is 2. Exceeds % 30 weight free of carbon compounds is that the ratio of 7%, and excellent thermal shock resistance, although inferior resistance corrosion resistance of the evaluation results.
[0115]
Table 3 demonstrates that investigate the effects of each ingredient containing MgO content and the rest of the other as a refractory composition of alumina, zirconia, alumina - zirconia, Silicon Carbide.
[0116]
MgO content of 40% or more with MS values are 0. 2 %~3. You can see that in combination with any of the raw materials that contain refractory composition of the above examples is in the range of 0%, excellent thermal shock resistance.
[0117]
Evaluated corrosion resistance of refractories to slag of Foundry operations, etc. in the example in table 3, note that (in round numbers 4 corrosion resistance). Test methods in various types of refractory materials (shape: 20 x 20 x 160 mm) c/s (CaO/SiO2 -mass ratio) = 1. 8 synthetic slag 30mm層 about immersion in molten steel bare on 1550 ° C of the liquid steel in thickness, samples lower than 50 mm near the interface between molten slag and molten steel comes to you. After holding for 60 minutes, until room temperature after cooling to melt loss rate calculated from the maximum dimensions change in the width direction of immersing. Slows the melting loss < 25 μ m/min for Yu (◎), 25-50 µ m/min for good (y), > 50 m/min (however remained and) of cases evaluated as not (x) No Yes () (), remaining. Yes, decrease regarded the pass that can be used.
[0118]
As a result, the embodiment of both comparative examples excellent corrosion resistance, thermal shock of large casting operation that can. Also indicate the MGO for this corrosion, wherein each component containing raw materials with excellent corrosion resistance. Slag composition and is thought to be due to effects of densification due to reaction between the ingredients in the relationship between basicity, etc. and fire-resistant components and refractory materials in.
[0119]
Table 4 is that examined the effect of the B2O3 content of MgO principal component systems (systems using the magnesite MgO particles) in MgO particles coated with % (range 4% or more of the 30 mass %) free of carbon compounds are 17 mass per.
[0120]
B2O3 content is 0. 3 mass % over 3... In each example below % 0 mass, MS value is 0. 2% more than 3... You could became less than 0% and get a good result at all temperatures up to 1500 ° C maximum coefficient of thermal expansion, thermal shock resistance and corrosion resistance.
[0121]
Comparison example 9 on the other hand, does not contain a B2O3 and B2O3 content is 0. In 19% of the comparative example 14 MS value is 0. Could not get good results for thermal shock resistance and less than 2%. Also, the content of the B2O3 is 3... You couldn't get good results for shock resistance comparison example 15 1 mass % also. For this reason, B2O3 content is 0. Not 10 minutes of MgO layer 3 mass % less mentioned densification effect 0 MS. You can't get more than 2 percent, can not get low thermal expansion effects and mass 3% more than it reduced pore layer of MgO particles around generation of excess reactant.
[0122]
Table 5 shows that were examined in MgO to principal components and systems (systems using the magnesite MgO particles) MS range. B2O3 content 3 here. 0 mass % (maximum in the range of the invention) and the specimens, with varying degrees of surface treatment of MgO particles mainly.
[0123]
Table 5 than MS value is 0. 2 percent of enforcement cases 18 and 3. Know that you can get good results at all temperatures up to 1500 ° C maximum coefficient of thermal expansion, thermal shock resistance and corrosion resistance in example 19 0%. On the other hand, the MS value 3. You can be large melt in 2% of the comparative example 16 up to 1500 ° C maximum coefficient of thermal expansion and thermal shock resistance is good, although the score may be faulty.
[0124]
Table 6 the MgO principal component systems (systems using the magnesite MgO particles), B2O3 sources and by better using silica glass, as a component of the B2O3 other (identify metal oxide) containing P2O5, SiO2, TiO2 , and B2 In the investigation on the combination of two or more of these specific metal oxide containing O3 . Furthermore, more as a silicate glass, SiO2: 70 mass %, B2O3: 25 WT %, R2O (R = Na, K, Li): 5 mass % using.
[0125]
These specific metal oxide alone, added example 4 and example 20-24 implementation examples, the non implementation example 23, B2O3 and certain metal oxides with and implementation example 25, also as a source of the B2O3 more examples using silica glass is one of the 26 but reveals that you can get good results at all temperatures up to 1500 ° C maximum coefficient of thermal expansion, thermal shock resistance and corrosion resistance.
[0126]
Table 7 is that examined the effect of Al2O3 .
[0127]
Implementation example 27, implementation example 28, 30 implementation examples, implementation example 31 is here replaced with alumina powder, corundum is part of MgO particles. (Al2O3/MgO) mass ratio example 3 0 watching these criteria and this mass ratio is 0. 13 (implementation example 27), 0. 50 (implementation example 28), 0. You can see 65 (implementation example 30) and larger can be up to 1500 ° C maximum coefficient of expansion. And this mass ratio is 0. 65 (implementation example 30) up to 1500 ° C maximum heat expansion is one... 04 percent, further mass ratio is 0. 73 (implementation example 31) and up to 1500 ° C maximum coefficient of thermal expansion, goals fatigued 1's. 1 percent to nearly the same degree of... 08%, in thermal shock resistance are available decreases to the extent of what's "in" is understood. It's from does not exist on alumina particles surrounding void, even about the same due to the increase of alumina particles, reduces the pore layer of refractory products (present in the particles around the MgO content) in your organization to an absolute minimum, and increase alumina particles increases stress absorption is less rigid skeleton structures formed by alumina particles, the alumina particles coexist and MgO particles in pulverized from the air gap thickness around the MgO particles exist Spinel-forming reaction progresses over time due to.
[0128]
In addition, (Al2O3/MgO) alumina powders containing corundum is the mass ratio is 0. Implementation example 28 50 and same (Al2O3/MgO) implementation examples 29 mass ratio, and replaced the part of alumina spinel yielded comparable results in the various evaluation and implementation example 28.
[0129]
From the results of these (Al2O3/MgO) mass ratio was 0. You can preferably be under 65.
[0130]
Also due to the increase of Al2O3 content like this tends to improve corrosion resistance is being seen then proper (Al2O3/MgO) can be speculated that maintaining the corrosion resistance without compromising the operation over long periods of time in the mass range of organizational health and low thermal expansion effect.
[0131]
Table 8 of the MgO particles 0. which examined the effect of the percentage of particles of less than 1 mm. Furthermore. In table 8 see-0. MgO content fraction of 1 mm ", when the underwriter 1000 ° C in the State at room temperature after the heat treatment in non-oxidizing atmosphere free of carbon and boron oxide except that aggregate particles portion 100 mass percent of MgO particles 0. shows the percentage of particles of less than 1 mm. As in the other table.
[0132]
0 of MgO particles. You can get good results at all temperatures up to 1500 ° C maximum coefficient of thermal expansion, thermal shock resistance and corrosion resistance of both implementation example 33 is in the range of 5% or more, 45 percent less than the particles of less than 1 mm, example 3 and example 34 implementation. On the other hand, is 0. find implementation example 32, 4 WT % is the percentage of particles of less than 1 mm is resistant corrosion resistance range, it's a little lower, 47% of the implementation example 35 well shock resistance range, despite a little inferior. This is out of MgO particles 0. the MgO content particles surrounding the pore layer thickness decreases relative increases of less than 1 mm particles and surface area of the particles of refractory materials in your organization will be relatively large, nor small particles is considered attributable to that sort of larger particles with granulation, as if the air gap thickness of one small State. When excluding the free carbon compounds from these results, the rest 100 mass %, MgO particles of 0. You can see that particles of less than 1 mm in total 5 mass % and 45% less than that.
[0133]
Table 9 that investigated the effect of Al, Si and Mg to choose from either single or wherein metal or alloy with containing one or more metal or alloy, or B4C. The specimen samples of table 9, as particulate carbon comes from carbon-free fine graphite (grain size 0. 1 mm under) was adopted. The table 9 of Al, Si, Mg, or B4C chemical composition, mass % of the mass of the entire State went at 600 ° C non-oxidizing atmosphere annealing at 1000 ° C in a non-oxidizing atmosphere heat-treating fire 100 mass percent when and, or other chemical ingredients 1000 ° C after heat treatment in non-oxidizing atmosphere (WT %) is.
[0134]
Implementation example 38, implementation example 39 and example implementation 43 metal Al and Si metal system mass ratio in 3:01 Al-Si alloys containing the implementation example 40-example 42 is that of Al-Si alloy with more B4C.
[0135]
Examples 44-system alone, containing only the metals Al, implementation example 47 systems with metals Al, B4C is implementation example 46.
[0136]
Implementation example 48-implementation example 50 only metal on the single, containing the implementation example 51 is that systems with metal SI B4C.
[0137]
Implementation example 52 series B4C only single, containing the implementation example 53 metal aluminum and metal mg system containing Al-mg alloys in the 1:01 mass ratio.
[0138]
In Al-Si alloy, metal Al only the metal Si only with B4C each of Al-Si alloy and metal aluminum and metal on the Al-mg alloys and B4C only embodiment, these alloys or can be compared to metal B4C also does not contain implementation example 36 and example 37, excellent oxidation resistance. However, these shows tended to decrease slightly increases the content of these examples of alloys and metals a and B4C using a thermal shock resistance and shock resistance for these metals, alloys, B4c suggests that does not contain large amounts of.
[0139]
Alloy Al-Si and Al-mg alloys used in the examples above, but these get similar results on behalf of the alloy of Al and Si mixing and mixing of Al and Mg.
Sign description

[0140]
10 test specimens
edge 10A
11 holder
12th Crucible
13 steel
14 high-frequency induction furnace
Refractories for the invention of 20 books
21 powder line material (on the back refractories)
22 book material (rear side of the fire).
23 molten steel contact surface of other refractory materials (for example, CaO based refractory products, etc.)
Of the claims

[Paragraph 1]
1000 ° C after heat treatment in non-oxidizing atmosphere chemistry, MgO free, 40% or more of carbon compounds 4 mass %, 30% less than the B2O3, P2O5, SiO2 and TiO2 -to choose one or two more than a total 0. In the mass 3% more than 3 mass % below contains the remainder becomes refractory components and other refractory products
Containing carbon exist on both sides of the MgO particles in the refractories of at least the largest particle matrix organization and the largest particles at the interface between pore layer has a total thickness of this void is the particle size 0. 2% more than 3... And at a ratio of less than 0%, and wherein MgO content particles on the surface of all or selected from part a above B2O3, P2O5and SiO2 , TiO2 to one or are there inorganic compounds of two or more constituents with MgO refractories features.
[Paragraph 2]
Rest other refractory components manufactured on or unless unavoidable ingredient derived from Al2O3 and a mass ratio of MgO and Al2O3 (Al2O3/MgO) greater than 0 0. Be less than 65, to claim 1 in refractory products.
[Invoice section 3]
1000 ° C except for free of carbon compounds in the State at room temperature after the heat treatment in non-oxidizing atmosphere the rest mass 100% and when the particles of 0. and 5 mass % and 45% less than in the total particles of less than 1 mm and up to 1500 ° C maximum thermal expansion coefficient is 1. In less than 1% in claim 1 or claim 2 of refractories.
[Paragraph 4]
Total is 0, when the mass of the entire State went at 600 ° C non-oxidizing atmosphere annealing at 1000 ° C in a non-oxidizing atmosphere heat-treating fire 100 mass percent of Al, Si, and Mg to either choose from one or more metal. 6 mass % or less and 0. 5% or more. 1. 5% or more. Either less than 5 mass % B4c 1 or the claim 1, containing both from the fire of one of three.
[Bill 5]
From claim 1 on each of 4 placed in part or in whole in refractory nozzle for casting.
[Bill 6]
To claim 5, placed on some or all of the site claims 1 through 4 or described refractories are to contact with molten steel casting nozzle provided.
[Billing paragraph 7]
Layer consisting of a refractory composition differs from the refractories were placed in some or all of the sites placed on some or all of the claims 1 through 4 one described refractories are to contact with molten steel parts, touching on its back side of molten steel is one or more layer layers arranged in and adjacent to each other in direct contact with what structure is, claim 5 or claim 6 casting nozzle provided.