CN110548842A - Weak electrolyte protective slag - Google Patents
Weak electrolyte protective slag Download PDFInfo
- Publication number
- CN110548842A CN110548842A CN201910961335.2A CN201910961335A CN110548842A CN 110548842 A CN110548842 A CN 110548842A CN 201910961335 A CN201910961335 A CN 201910961335A CN 110548842 A CN110548842 A CN 110548842A
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- weak electrolyte
- mold flux
- covering slag
- flux according
- slag
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/11—Treating the molten metal
- B22D11/111—Treating the molten metal by using protecting powders
Abstract
The invention discloses weak electrolyte covering slag for continuous casting for smelting ultra-low carbon steel, which comprises the following components, by weight, 10-40% of CaO, 10-40% of SiO 2, 2-20% of Al 2 O 3, 2-10% of F, 10-30% of multi-component oxide, 0.5% of R 2 O, 0.2% of B 2 O 3, and the balance of inevitable impurities, wherein the multi-component oxide is one or more of oxides of magnesium, strontium, barium, titanium, zirconium, chromium, manganese or RE, and the R 2 O is Li 2 O + Na 2 O + K 2 O.
Description
Technical Field
The invention belongs to the technical field of covering slag in steel smelting, and particularly relates to weak electrolyte covering slag for continuous casting.
Background
In the prior art, the covering slag for continuous casting generally comprises three parts of materials, namely a base material part, a fluxing agent material and a melting speed regulator.
The base material of the mold flux generally has a composition of SiO2－CaO－Al2O3A ternary slag system. Since the lowest melting point of the ternary system is above 1300 ℃ and cannot meet the requirement of the melting point between 950 ℃ and 1200 ℃ of the mold flux, a small amount of flux material for adjusting physical properties such as melting point, viscosity, surface tension and the like, such asAlkali metal oxide(typically added as an alkali metal carbonate, e.g.: Li)2CO3、Na2CO3、K2CO3)、Fluoride compoundsSuch as: CaF2、NaF、Na3AlF6,Boron oxideSuch as B2O3Borax, and the like. The melting speed regulator is a framework material of the covering slag and is used for controlling the melting speed of the covering slag. The skeleton material mainly comprises carbon materials, including carbon black, graphite, coke and the like. Because the carbon is insoluble in the liquid slag, the carbon particles are distributed between the base material and the fluxing agent particles, between the base material and the liquid drops and between the liquid drops to form a framework, the slagging reaction is prevented or delayed, and the polymerization of the slag-dissolving drops is prevented, so that the melting speed of the casting powder is reduced. The skeleton material also includes silicon powder, nitride such as BN, carbide such as SiC, organic matter and the like. The addition amount of the framework material is generally 1.0-10% of the total weight.
With the development of the steel industry, ultra-low carbon steel (about 20 ppm) represented by automobile panels and high-grade non-oriented silicon steel is in great demand in the market, but carbon materials in the casting powder in the prior art are in contact with molten steel, so that the carburization of the surface of a casting blank and the recarburization of molten steel in a crystallizer are easily caused, and a series of problems of the reduction of the qualified rate of the casting blank, the deterioration of the surface quality and the like are caused. The carbon-rich layer between the liquid slag layer and the sintering layer of the casting powder is a main reason for the carburetion of the ultra-low carbon steel in the using process of the casting powder in the crystallizer. The thickness and carbon content of the carbon-rich layer are related to the kind and content of the original carbonaceous material in the mold flux. And also carbonaceous particles suspended in the slag layer, which are in direct contact with the molten steel, also carburette the molten steel.
A plurality of methods for solving the problem of recarburization of the ultra-low carbon steel covering slag are proposed at home and abroad, but the production requirements can not be met. Therefore, the production of the mold powder which can effectively solve the problem of recarburization is urgently needed.
Disclosure of Invention
the invention aims to provide weak electrolyte covering slag for continuous casting for smelting ultra-low carbon steel, which can effectively control the melting speed of the covering slag and solve the problem of recarburization in the steelmaking process by reasonably designing various base materials and the component proportion of the base materials.
In order to achieve the purpose, the weak electrolyte covering slag comprises the following components in percentage by weight: CaO: 10 to 40% of SiO2：10～40％、Al2O3: 2-20%, F: 2-10%, multicomponent oxide: 10 to 30% of R2O<0.5％、B2O3<0.2 percent and the balance of inevitable impurities, wherein the multicomponent oxide is one or more of oxides of magnesium, strontium, barium, titanium, zirconium, chromium, manganese or RE, R2O is Li2O+Na2O+K2And O. R herein2O and B2O3In fact, impurities are introduced into the raw material. Because the properties of the metal oxides such as calcium, magnesium, strontium, barium, manganese and the like are the same, the metal oxides can be partially substituted with each other, but the calcium, magnesium and manganese oxides are cheap and can be used in large quantities.
Preferably, the weak electrolyte mold flux of the present invention comprises the following components in percentage by weight:
CaO：25～35％、SiO2：25～35％、Al2O3: 5-15%, F: 2-10%, MgO: 3-8%, MnO: 3-10%, and other multicomponent oxides: 3 to 15% of R2O<0.5％、B2O3<0.2％。
Preferably, the weak electrolyte mold flux has a hemispherical point temperature of 1100-1300 ℃.
Preferably, the weak electrolyte mold flux of the present invention has a viscosity of 0.05 to 0.60pa · s at 1300 ℃.
Preferably, the sintering temperature of the weak electrolyte covering slag is 900-1100 ℃, and the solidification temperature is 1000-1150 ℃.
Preferably, the components of the composition also comprise 0.01 percent<CFixing device<0.1%, the CFixing deviceIs simple substance carbon. The scheme is used for producing ultra-low carbon steel.
Preferably, the components of the material also comprise 0.5-7 wt% of a framework material, wherein the framework material is as follows: one or more of carbon black, graphite, coke, silicon powder, nitride and SiC carbide. The scheme is used for producing steel grades insensitive to carburetion.
The principle of selecting each component and the dosage of the weak electrolyte covering slag is as follows:
The weak electrolyte covering slag of the present invention utilizes the different chemical activities of various base materials and adjusts the proportion of various base materials, so that other physical properties of the covering slag, such as melting temperature, viscosity, etc., can meet the requirements of continuous casting technology. Meanwhile, the components do not contain alkali metal oxide and fluoride, do not contain boron oxide, do not contain framework materials such as carbon materials and the like, and can effectively solve the problem of recarburization in the steelmaking process. The covering slag of the invention does not use alkali metal oxide and fluoride, and boron oxide as fluxing agent, but uses multicomponent oxide in the components, which can reduce the melting point of the mixture and reach the melting temperature value of common covering slag. And then the properties of the covering slag, such as viscosity, surface tension and the like, can be adjusted by adjusting the components and the proportion of the oxides so as to meet the requirement of continuous casting. The invention uses the oxides of calcium, magnesium, strontium, barium, titanium, zirconium, chromium, manganese, aluminum, silicon, mixed or single rare earth and calcium fluoride (fluorite) as the raw material of the mold flux, and of course, the invention also includes the composite oxides and the mixtures of the substances. The common point of the materials is that the melting point is high, the materials are not melted before the casting powder is melted, the slagging and melting process of the casting powder is solid-solid reaction, and the solid-liquid reaction and the liquid-liquid reaction are not performed when the common casting powder contains a low-melting-point fluxing agent, so the slagging speed is slow, the melting speed of the casting powder can be reduced when the common casting powder does not contain framework materials such as carbonaceous materials, and the purpose of avoiding the recarburization of the ultra-low carbon steel due to the casting powder is achieved. Alkali metal salts are alkaline strong electrolytes relative to other metals; borates are also strong electrolytes as opposed to silicates, aluminates. The strong electrolyte melts are also more aggressive towards the refractory material. Meanwhile, the weak electrolyte raw material is used, so that the solubility of the covering slag in cooling water is low, and the environmental pollution is reduced. The protective slag uses little or no carbon materials, so that the damage to human bodies can be reduced, because the carbon powder is a 2B carcinogen. Therefore, the technical scheme of the invention does not use compounds of alkali metal and boron as raw materials of the covering slag, thereby reducing or not using framework materials and reducing or avoiding recarburization; can also reduce erosion of the nozzle, prolong the service life of the nozzle and reduce the harm to human body.
Detailed Description
The weak electrolyte mold flux of the present invention will be described in further detail with reference to examples.
Example 1
A continuous casting weak electrolyte covering slag prepared from chemically pure raw materials comprises the following components in percentage by weight: SiO 2234.8 percent of CaO, 28.6 percent of Al2O34.8 percent of MgO, 6.5 percent of MgO, 7.1 percent of F and CFixing device0.08% of Na2O accounts for 0.08%, B2O30.15 percent of the total weight, and the balance of other materials and inevitable impurities.
The hemispherical point temperature is 1220 ℃, the viscosity (1300 ℃) is 0.23 pa.s, the melting speed is 22s, the sintering temperature is 1014 ℃, and the solidification temperature is 1075 ℃.
The viscosity, melting speed and solidification temperature of the casting powder are equivalent to those of common ultra-low carbon steel casting powder, so that the casting powder can meet the requirements of a continuous casting process. The hemispherical point of the casting powder is higher than that of the common casting powder, so that the melting speed of the casting powder is delayed, but the function of the casting powder is not influenced.
Example 2
Industrial raw materialThe weak electrolyte covering slag prepared by the method comprises the following components in percentage by weight: SiO 2232.7 percent of CaO, 27.9 percent of Al2O36.7 percent of MgO, 7.8 percent of F and CFixing device0.08% of Na2O is 0.45%, B2O30.15 percent of the total weight, and the balance of other materials and inevitable impurities.
The hemispherical point temperature was 1185 ℃, the viscosity (1300 ℃) was 0.26pa · s, the melting rate was 24s, and the sintering temperature was 986 ℃. The physical and chemical properties were comparable to those of example 1.
Example 3
The mold flux of example 2 was used, and 2% of carbon black was added, and the melting rate was 33 s. It can be said that the carbonaceous material can further reduce the melting speed of the weak electrolyte mold flux. The weak electrolyte covering slag containing carbon material can be used for steel grade of molten steel which is not sensitive to carburetion.
Example 4
The weak electrolyte covering slag prepared from industrial raw materials comprises the following components in percentage by weight: SiO 2235% of CaO, 26% of Al2O37% of MgO, 7% of F, 7% of MnO and CFixing device0.07% of Na2O is 0.4%, B2O30.12 percent of the total weight, and the balance of other materials and inevitable impurities.
The hemispherical point temperature is 1200 ℃, the viscosity (1300 ℃) is 0.42 pa.s, the melting speed is 21s, the sintering temperature is 950 ℃, and the solidification temperature is 1054 ℃.
In the laboratory, 150g of mold flux was melted at 1300 ℃ and poured into 1500ml of water, the solution having a pH of 7.89.
The conventional ultra-low carbon steel covering slag for comparison comprises the following components in percentage by weight: SiO 2232.5 +/-3.0 percent of CaO, 27.5 +/-3.0 percent of Al2O3Account for<9％,Na2O10.5 +/-3.0%, F6.5 +/-3.0%, CFixing device1.5-2.5% and the rest is other materials and inevitable impurities. The hemispherical point temperature is 1100 +/-30 ℃, the viscosity (1300 ℃) is 0.34 +/-0.1 Pa.s, and the melting speed is 19 s.
After 150g of mold flux was freed from carbonaceous material in the laboratory, it was melted at 1300 ℃ and poured into 1500ml of water, the solution having a pH of 8.44. Therefore, the covering slag of the invention has low solubility in water, is closer to neutrality (pH is 7.0), and has little environmental pollution after being used.
Example 5
The weak electrolyte mold flux of example 4 and the as-used ultra low carbon steel mold flux after removing the carbonaceous material were melted at 1400 ℃. And cutting the quartz immersed nozzle which is damaged when not used into blocks, immersing the quartz immersed nozzle into the casting powder slag, preserving heat for 4 hours, and taking out the blocks. After cooling, the depth of etching was measured. The erosion depth of the weak electrolyte covering slag is 0.5-1.0 mm, the erosion depth of the conventional ultra-low carbon steel covering slag is 2.0-3.5 mm, and the weak electrolyte covering slag has weak erosion force on a quartz submerged nozzle.
Example 6
A weak electrolyte covering slag prepared by industrial raw materials is used for producing industrial test products according to the existing covering slag production process, and the components in percentage by weight are as follows: SiO 2232.4 percent of CaO, 26.1 percent of CaO and Al2O34.5% of MgO, 4.3% of F, 6.2% of MnO and CFixing device0.09% of Na2O accounts for 0.42%, B2O30.15 percent of the total weight, and the balance of other materials and inevitable impurities.
The hemispherical point temperature is 1254 ℃, the viscosity (1300 ℃) is 0.45 pa.s, the melting speed is 26s, the sintering temperature is 1050 ℃, and the solidification temperature is 1083 ℃.
Continuous casting industry tests were conducted in a certain steel plant. Steel grade: high oxygen steel, C: 20ppm, 300kg of protective slag is used for producing 600t of steel; the situation of the mold flux in the mold: the steel plate is free of sintering and slag strips, the thickness of a slag layer is 10-12 mm, the slag consumption is 0.45kg/t steel, and the steel plate is equivalent to the conventional ultra-low steel casting powder and common plate blank casting powder; no recarburization condition exists, and the surface of the casting blank is free of defects. The immersion type water gap of the crystallizer is not obviously eroded; off-white, rather than black, mold flux is popular with field workers.
The production process of the weak electrolyte covering slag for continuous casting is the same as the production process of the common covering slag, namely, the raw materials of the components are uniformly mixed according to the proportion, and the raw materials can be mixed into powder, or can be extruded and granulated, or sprayed and granulated.
In this embodiment, the method for measuring the sintering temperature is to put the sample into a high temperature furnace, and raise the temperature to a certain temperature, at which the sample has a certain strength. The method for measuring the melting speed is toThe sample was placed in a 1300 ℃ high temperature furnace and the time to complete melting was measured.
Claims (7)
1. A weak electrolyte mold flux, characterized in that: the paint comprises the following components in percentage by weight: CaO: 10 to 40% of SiO2：10～40％，Al2O3: 2-20%, F: 2-10%, multicomponent oxide: 10 to 30%, R2O<0.5％，B2O3<0.2 percent and the balance of inevitable impurities, wherein the multicomponent oxide is one or more of oxides of magnesium, strontium, barium, titanium, zirconium, chromium, manganese or RE, R2O is Li2O+Na2O+K2O。
2. The weak electrolyte mold flux according to claim 1, characterized in that: the paint comprises the following components in percentage by weight: CaO: 25 to 35% of SiO2：25～35％，Al2O3: 5-15%, F: 2-10%, MgO: 3-8%, MnO: 3-10%, and other multicomponent oxides: 3 to 15%, R2O<0.5％，B2O3<0.2%, and the balance unavoidable impurities.
3. The weak electrolyte mold flux according to claim 1 or 2, characterized in that: the hemispherical point temperature is 1100-1300 ℃.
4. The weak electrolyte mold flux according to claim 1 or 2, characterized in that: the viscosity at 1300 ℃ is 0.05 to 0.60pa · s.
5. The weak electrolyte mold flux according to claim 1 or 2, characterized in that: the sintering temperature is 900-1100 ℃, and the solidification temperature is 1000-1150 ℃.
6. The weak electrolyte mold flux according to claim 1 or 2, characterized in that: it also contains CFixing device<0.1% of wherein CFixing deviceRefers to carbon in elemental form.
7. The weak electrolyte mold flux according to claim 1 or 2, characterized in that: the composite material also comprises 0.5-7 wt% of a framework material, wherein the framework material is as follows: one or more of carbon black, graphite, coke, silicon powder, nitride and SiC carbide.
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| CN201910961335.2A CN110548842A (en) | 2019-10-10 | 2019-10-10 | Weak electrolyte protective slag |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112195304A (en) * | 2020-07-28 | 2021-01-08 | 龙南龙钇重稀土科技股份有限公司 | Core-spun yarn containing rare earth crystallizer pre-melted slag and application thereof |
| CN113634726A (en) * | 2021-07-28 | 2021-11-12 | 武汉钢铁有限公司 | Free carbon-free covering slag for ultra-low carbon steel automobile plate |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6344463B2 (en) * | 1984-02-28 | 1988-09-05 | Shinnippon Seitetsu Kk | |
| JPS6354474B2 (en) * | 1983-12-15 | 1988-10-28 | Nitsutetsu Kenzai Kogyo Kk | |
| JPH02142653A (en) * | 1988-11-25 | 1990-05-31 | Kawasaki Steel Corp | Method for continuously casting steel |
| CN102000793A (en) * | 2010-12-01 | 2011-04-06 | 西峡龙成冶金材料有限公司 | Covering slag of large-section round blank pipeline steel continuous casting blank |
| CN104226947A (en) * | 2013-06-17 | 2014-12-24 | 上海梅山钢铁股份有限公司 | Tundish covering agent for ultra-low-carbon steel |
| CN104399921A (en) * | 2014-11-13 | 2015-03-11 | 北京首钢股份有限公司 | Casting powder |
| CN104707959A (en) * | 2013-12-11 | 2015-06-17 | 宝山钢铁股份有限公司 | Continuous casting mold flux for automobile sheet |
| CN109732048A (en) * | 2019-03-28 | 2019-05-10 | 西峡龙成冶金材料有限公司 | Covering slag, preparation method and application for Automobile Plate steel continuous casting crystallizer |
-
2019
- 2019-10-10 CN CN201910961335.2A patent/CN110548842A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6354474B2 (en) * | 1983-12-15 | 1988-10-28 | Nitsutetsu Kenzai Kogyo Kk | |
| JPS6344463B2 (en) * | 1984-02-28 | 1988-09-05 | Shinnippon Seitetsu Kk | |
| JPH02142653A (en) * | 1988-11-25 | 1990-05-31 | Kawasaki Steel Corp | Method for continuously casting steel |
| CN102000793A (en) * | 2010-12-01 | 2011-04-06 | 西峡龙成冶金材料有限公司 | Covering slag of large-section round blank pipeline steel continuous casting blank |
| CN104226947A (en) * | 2013-06-17 | 2014-12-24 | 上海梅山钢铁股份有限公司 | Tundish covering agent for ultra-low-carbon steel |
| CN104707959A (en) * | 2013-12-11 | 2015-06-17 | 宝山钢铁股份有限公司 | Continuous casting mold flux for automobile sheet |
| CN104399921A (en) * | 2014-11-13 | 2015-03-11 | 北京首钢股份有限公司 | Casting powder |
| CN109732048A (en) * | 2019-03-28 | 2019-05-10 | 西峡龙成冶金材料有限公司 | Covering slag, preparation method and application for Automobile Plate steel continuous casting crystallizer |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112195304A (en) * | 2020-07-28 | 2021-01-08 | 龙南龙钇重稀土科技股份有限公司 | Core-spun yarn containing rare earth crystallizer pre-melted slag and application thereof |
| CN112195304B (en) * | 2020-07-28 | 2022-02-18 | 龙南龙钇重稀土科技股份有限公司 | Core-spun yarn containing rare earth crystallizer pre-melted slag and application thereof |
| CN113634726A (en) * | 2021-07-28 | 2021-11-12 | 武汉钢铁有限公司 | Free carbon-free covering slag for ultra-low carbon steel automobile plate |
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