CN110315038B - Crystallizer casting powder capable of preventing slag entrapment and application thereof - Google Patents
Crystallizer casting powder capable of preventing slag entrapment and application thereof Download PDFInfo
- Publication number
- CN110315038B CN110315038B CN201810273478.XA CN201810273478A CN110315038B CN 110315038 B CN110315038 B CN 110315038B CN 201810273478 A CN201810273478 A CN 201810273478A CN 110315038 B CN110315038 B CN 110315038B
- Authority
- CN
- China
- Prior art keywords
- slag
- crystallizer
- sio
- entrapment
- cao
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Continuous Casting (AREA)
Abstract
The invention discloses crystallizer covering slag capable of preventing slag entrapment, which comprises the following components in percentage by mass: CaO + MgO: 34.0-39.0% of SiO2+Al2O3：39.0‑48.0％，Na2O+F：5.0‑13.0％，LiO2：0.25‑0.7％，TiO2: 1.0-2.5%, BaO: 0.5-1.5%, F.c: 0.9-1.2%, R: 0.80-1.3. The invention uses partial component SiO in molten steel2+Al2And O is lifted as a whole to improve the viscosity of the casting powder. Avoid using SiO2To increase the viscosity and at the same time increase the oxidizability of the liquid slag. Meanwhile, the Fc reduction is reduced, a proper liquid molten layer is formed, the liquid protection slag adsorbed by the molten steel quickly flows into a blank shell of the crystallizer, and the performance of the liquid protection slag is prevented from being deteriorated by long-time alumina adsorption. The casting powder can effectively prevent the slag entrapment of molten steel in the continuous casting process.
Description
Technical Field
The invention relates to the application field of continuous casting auxiliary materials in continuous steel casting machinery, in particular to protective slag used in the continuous casting steel casting process.
Background
In the continuous casting process, the casting powder is an artificially synthesized auxiliary material which is added into a crystallizer to cover the surface of molten steel in the continuous casting process of the molten steel. It is prepared from CaO and SiO2Al2O3, fluoride and Na-containing compound+The material is prepared by mixing the slag according to a proper proportion, melting the slag at a high temperature to prepare pre-melting powder, then mixing a certain amount of Carbon (Carbon, C for short) material and various additives, and uniformly mixing and drying the mixture to prepare the Carbon-based Carbon-based Carbon-based Carbon-based Carbon-based Carbon-Carbon composite material.
The protective slag mainly has the functions of lubrication, heat insulation, heat preservation, secondary oxidation prevention, inclusion adsorption and the like, and forms a four-layer structure of a powder slag layer, a sintered layer, a carbon-rich layer and a liquid slag layer on the liquid level of molten steel in the crystallizer, and the total thickness is generally 40-60 mm. The slag film between the blank shell and the crystallizer consists of a solid slag film and a liquid slag film, and the solid slag film is divided into crystals and glass bodies. The crystals have a greater influence on the heat transfer of the primary shell, while the glass body mainly has a lubricating effect. The molten layer of the covering slag flows into the gap between the billet shell and the crystallizer along with the vibration of the crystallizer, and the molten layer continuously flows along with the continuous casting, and simultaneously, the new slag is continuously added with CaO as the main component adsorbed in the new slag to complete the process.
The main problem of the existing covering slag is that the slag entrapment prevention in the continuous casting process cannot be guaranteed. In the continuous casting process in a Bao steel works, the situation that the mold powder is wrapped in the mold often occurs. The slag rolling is very serious and is reflected in the defect of slag inclusion in hot rolling, and the cold rolling is realized after the hot rolling is closed and polished. The slab after slag rolling causes the decline of contract matching of companies, and a lot of slabs become entrustless contracts. The existing ultra-low carbon steel mold flux has several problems. One of the main problems is the prevention of slag entrapment and insufficient adsorption capacity, and most importantly, the inability to prevent slag entrapment of the molten steel in the mold. Technical breakthroughs are needed to ensure the purity of molten steel and ensure the slag entrapment of the mold flux.
Disclosure of Invention
Therefore, the technical problem to be solved by the invention is to provide the mold flux which can prevent the slag from being rolled up by the crystallizer. While providing applications thereof.
The technical scheme of the invention is that the crystallizer covering slag capable of preventing slag entrapment comprises the following components in percentage by mass: CaO + MgO: 34.0-39.0% of SiO2+Al2O3：39.0-48.0％，Na2O+F：5.0-13.0％，LiO2：0.25-0.7％，TiO2：1.0-2.5％，BaO：0.5-1.5％，F.c：0.9-1.2％，R：0.80-1.3。
R is alkalinity, namely CaO/SiO2Due to the basicity of CaO, SiO2The acid property is shown, and the ratio is an index for evaluating the acidity and the alkalinity in the slag.
According to the crystallizer covering slag for preventing slag entrapment of the present invention, it is preferable that the alkalinity of the covering slag is 0.80 to 1.1.
According to the crystallizer protection slag for preventing slag entrapment, the preferable ratio of CaO and MgO in the CaO + MgO combination is 33-36%, and the ratio of MgO is 1-5%.
According to the crystallizer mold flux for preventing slag entrapment of the present invention, it is preferable that the SiO is2+Al2O3In combination, SiO236-41% of Al2O33 to 10 percent.
The mold flux for preventing slag entrapment according to the present invention is preferably,the Na is2In the combination of O + F, Na2The proportion of O is 2-6 percent, and the proportion of F is 3-7 percent.
According to the crystallizer casting powder for preventing slag entrapment, the components of the casting powder are preferably mixed, pelletized, calcined and granulated to form hollow spherical continuous casting powder; wherein the spherical particle size is 0.3mm-0.35mm, and the void is 1/3-1/2 by volume.
The invention also provides application of the covering slag in preventing slag from rolling in the continuous casting process.
The invention relates to a mold powder for preventing crystallizer mold powder from rolling up. The technical scheme mainly comprises four parts:
1. the alkalinity of the protective slag of the ultra-low carbon steel is improved, and the capability of the protective slag for absorbing alumina is ensured. While ensuring fusibility and spreadability. Reduction of Na2The content of O is used for reducing the fluidity of the casting powder, improving the low viscosity and the consumption, and simultaneously ensuring the characteristic of low melting point. Na (Na)2The content of O + F is 9-11% of the total amount.
2. Elemental carbon (F.c) is reduced in an attempt to reduce the melting rate. The melting speed is reduced, the covering slag is transformed into a liquid slag layer to cover the surface of the molten steel after being melted, and Al in the molten steel2O3After being absorbed by the liquid covering slag, the covering slag timely flows into the gap between the crystallizer and the blank, and the phenomenon that the covering agent liquid layer is too thick to deteriorate the performance of the covering slag is avoided. The content of the simple substance carbon is 0.9-1.2% of the total amount.
3. Using TiO2To partially replace Li2And O. Due to Li2The price of the O raw material is greatly increased, and the capacity exertion can not be ensured. By optimizing Li2O content of 0.25-0.7%, TiO2The content of (A) is 1.0-2.5%.
4. Making Al in the mold flux2O3To partially replace SiO2Can be used as a network former and improve the viscosity of the casting powder. The increase in viscosity can avoid the entrainment of the mold flux. SiO22The reduction of (b) may reduce the occurrence of the following reaction. This reaction is the reason why the mold flux cannot effectively adsorb alumina.
[Al]+(SiO2)＝(Al2O3)+[Si]
The three raw materials (1), (2), (3) and (4) are mixed, pelletized, calcined and granulated according to the designed components, and then processed into the hollow spherical continuous casting mold flux.
Wherein, Al2O3The network formation is a little bit more and the FC is a little less. The communication of the liquid level is increased. The viscosity is increased, slag entrapment is prevented, and slag gold is reduced directly. A part of TiO2As with the perovskite produced by CaO, the melting point can be increased and the viscosity increased, at which time these molten liquid slags with high melting point are required to be released into the middle of the shell, so that the molten layer is relatively thin. Meanwhile, to adsorb alumina and reduce non-metallic inclusions in molten steel, a certain proportion of BaO is needed to complete the adsorption, so as to offset the increase of Al2O3The increase in viscosity causes a problem of poor adsorption ability. Because of B of BaO2+Ions, with O2-If combined, can be combined with Al2O-Forming pairing, adsorbing the alumina in the molten steel on the liquid level of the bottom layer, and flowing into the blank shell at a certain speed. The upper part is continuously melted, and the lower part is continuously adsorbed and flows into the blank shell. Low melting point, proper viscosity and thinner liquid slag layer.
In order to solve the problem of slag entrapment of molten steel in a crystallizer, part of the components SiO in the molten steel2+Al2And O is lifted as a whole to improve the viscosity of the casting powder. Avoid using SiO2To increase the viscosity and at the same time increase the oxidizability of the liquid slag. Meanwhile, the Fc reduction is reduced, a proper liquid molten layer is formed, the liquid protection slag adsorbed by the molten steel quickly flows into a blank shell of the crystallizer, and the performance of the liquid protection slag is prevented from being deteriorated by long-time alumina adsorption.
In the continuous casting process, mold flux is used. The effects of mold flux are known as oxidation resistance, heat insulation, heat preservation, inclusion adsorption, and casting blank lubrication. Wherein, the covering slag is melted into a three-layer structure in a crystallizer under the action of high-temperature liquid molten steel. The lowest part contacting with the liquid molten steel is liquid slag, the middle part is a sintering layer, and the uppermost layer is a powder slag layer. In the ingredients of the covering slag, CaO is alkaline and adsorbs Al2O3The main component of the casting powder is adsorbed by the action of the casting powder, namely CaO. SiO22Is a network former whose constituent viscosity is mainly reflected by the constituent. The addition of the component improves the viscosity of the casting powder, improves the viscosity and can reduce slag entrapment to a certain extent. But simply increasing SiO2The basicity of the mold flux is reduced and the adsorption performance is reduced. Therefore, the design is made from other components and the product of mold flux inside the mold.
Al in the mold flux2O3Below 10%, they are also network formers. The viscosity can be increased by appropriately increasing the amount of the component. A further component being TiO2The component and CaO form perovskite, the melting point is increased, and the viscosity can be improved to a certain degree. After the viscosity is improved, how to ensure the adsorption and lubrication is that the covering slag needs to be dynamically updated, so that the phenomenon that the fused layer is too thick is prevented, and the performance is changed after the too thick fused layer adsorbs more non-metallic oxides is avoided. Therefore, in designing the components, Free Carbon (abbreviated as Fc) can be reduced within a certain energy range. Therefore, after the liquid state of the casting powder is melted, the perovskite is formed, so that a non-metallic inclusion can be adsorbed under the condition of ensuring certain viscosity, but the liquid melting layer quickly flows into the shell due to less Fc. And the new upper sintering layer is converted into a liquid slag layer, so that less Fc can increase the liquid level communication. Through several technical means, viscosity is increased, slag entrapment is prevented, timely updating of the covering slag is guaranteed, and the performance of the covering slag is not changed. But compared with the increase of Al2O3Adsorption of Al2O3The capacity is reduced so that it is necessary to add other components, but the performance of the mold flux is not changed. Here, a certain proportion of BaO is required to complete, counteracting the increase in Al2O3The viscosity is increased, resulting in a problem of poor adsorption ability. Because of B of BaO2+Ions, with O2-If combined, with Al2O-Forming pairing, adsorbing the alumina in the molten steel on the liquid level of the bottom layer, and flowing into the blank shell at a certain speed.
The invention has the beneficial effects that:
the protecting slag for preventing the slag from being rolled up in crystallizer protecting slag can be widely used in the production process of continuous casting steel, reduce abnormal casting and stabilize continuous casting
Detailed Description
Example 1
The crystallizer casting powder is prevented from being rolled up, and the following processes are carried out according to the technical scheme and the important components of the components specified in the technical specification.
1. And (4) covering slag. According to 36% of Si2O, 10% Al2O335.5% of CaO, 2.5% of MgO, 5.5% of Na2O and 6.5% F (from CaF)2)，LiO20.7% of TiO21.5 percent of BaO, 0.8 percent of BaO and 1 percent of simple substance carbon. Wherein CaO and Al2O3Wollastonite may be used as a source of the feedstock. SiO2 can adopt quartz sand as the source of the raw material, MgO magnesite, the sintering temperature is controlled at 700-950 ℃, and the prepared MgO main component with the purity of more than 95 percent.
2. And mechanically mixing the prepared pre-melted material and magnesia to form the tundish covering slag which is used for preventing the covering slag from rolling. The ingredients of the mold flux prepared in the above were as follows in the entire composition.
| CaO+MgO | SiO2+Al2O3 | Na2O+F | LiO2+TiO2 | BaO | F.c | R |
| 38 | 46 | 12 | 2.2 | 0.8 | 1 | 0.99 |
3. The three parts of raw materials are processed into hollow spherical continuous casting covering slag after mixing, balling, calcining and granulating according to the designed components. The diameter of the sphere is 0.3mm, and the hollow volume accounts for half of the total volume of the sphere.
Example 2
1. And (4) covering slag. According to 41% Si2O, 5% of Al2O336% of CaO, 1.5% of MgO, 4.5% of Na2O and 7% F (from CaF)2)，LiO20.5% of TiO22 percent of BaO, 1.3 percent of BaO and 1.2 percent of simple substance carbon. Wherein CaO and Al2O3Wollastonite may be used as a source of the feedstock. SiO22Quartz sand can be used as a source of incoming materials, MgO magnesite, and the sintering temperature is controlled to be 700-950 ℃, so that the prepared MgO main component with the purity of more than 95 percent can be obtained.
2. And mechanically mixing the prepared pre-melted material and magnesia to form the tundish covering slag which is used for preventing the covering slag from rolling. The ingredients of the mold flux prepared in the above were as follows in the entire composition.
| CaO+MgO | SiO2+Al2O3 | Na2O+F | LiO2+TiO2 | BaO | F.c | R |
| 37.5 | 46.0 | 11.5 | 2.5 | 1.3 | 1.2 | 0.88 |
3. The three parts of raw materials are processed into hollow spherical continuous casting covering slag after mixing, balling, calcining and granulating according to the designed components. The diameter of the sphere is 0.32mm, and the hollow volume accounts for half of the total volume of the sphere.
Example 3
1. And (4) covering slag. According to 38% Si2O, 8% Al2O3, and 35% CaO, 3% MgO, 6% Na2O and 5% F (from CaF)2)，LiO20.35% of TiO22.5 percent of BaO, 1.5 percent of BaO and 1.1 percent of simple substance carbon. Wherein CaO and Al2O3Wollastonite may be used as a source of the feedstock. SiO22Quartz sand can be used as the source of the raw materials, MgO magnesite, the sintering temperature is controlled to 700-To more than 95% of MgO as the main component.
2. And mechanically mixing the prepared pre-melted material and magnesia to form the tundish covering slag which is used for preventing the covering slag from rolling. The ingredients of the mold flux prepared in the above were as follows in the entire composition.
| CaO+MgO | SiO2+Al2O3 | Na2O+F | LiO2+TiO2 | BaO | F.c | R |
| 38 | 46.0 | 11 | 2.85 | 1.05 | 1.1 | 0.90 |
3. The three parts of raw materials are processed into hollow spherical continuous casting covering slag after mixing, balling, calcining and granulating according to the designed components. The diameter of the sphere is 0.35mm, and the hollow volume accounts for half of the total volume of the sphere.
Claims (6)
1. The utility model provides a prevent crystallizer covering slag of curl slag which characterized in that: comprises the following components in percentage by mass: CaO + MgO: 34.0-39.0% of SiO2+Al2O3：39.0-48.0％，Na2O+F：5.0-13.0％，LiO2：0.25-0.7％，TiO2: 1.0-2.5%, BaO: 0.5-1.5%, F.c: 0.9-1.2%, R: 0.80-1.3; the SiO2+Al2O3In combination, SiO236-41% of Al2O33 to 10 percent.
2. The crystallizer mold flux for preventing slag entrapment of claim 1, wherein: the alkalinity R of the covering slag is 0.80-1.1.
3. The crystallizer mold flux for preventing slag entrapment of claim 1, wherein: in the CaO + MgO combination, the CaO accounts for 33-36 percent, and the MgO accounts for 1-5 percent.
4. The crystallizer mold flux for preventing slag entrapment of claim 1, wherein: the Na is2In the combination of O + F, Na2The proportion of O is 2-6 percent, and the proportion of F is 3-7 percent.
5. The crystallizer mold flux for preventing slag entrapment of claim 1, wherein: the components of the covering slag are mixed, pelletized, calcined and granulated to form hollow spherical continuous casting covering slag; wherein the spherical particle size is 0.3mm-0.35mm, and the void is 1/3-1/2 by volume.
6. Use of the mold flux of claim 1 for preventing slag entrapment during continuous casting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810273478.XA CN110315038B (en) | 2018-03-29 | 2018-03-29 | Crystallizer casting powder capable of preventing slag entrapment and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810273478.XA CN110315038B (en) | 2018-03-29 | 2018-03-29 | Crystallizer casting powder capable of preventing slag entrapment and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110315038A CN110315038A (en) | 2019-10-11 |
| CN110315038B true CN110315038B (en) | 2022-01-14 |
Family
ID=68111044
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810273478.XA Active CN110315038B (en) | 2018-03-29 | 2018-03-29 | Crystallizer casting powder capable of preventing slag entrapment and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110315038B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111500919B (en) * | 2020-05-29 | 2021-12-14 | 攀钢集团攀枝花钢铁研究院有限公司 | Production method of high-cleanliness high-titanium low-carbon steel |
| CN114082909A (en) * | 2021-10-22 | 2022-02-25 | 邯郸钢铁集团有限责任公司 | Continuous casting mold flux for low-alloy high-strength beam steel |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60234752A (en) * | 1984-05-07 | 1985-11-21 | Nippon Steel Corp | Flux for continuous casting of steel |
| CN104107890A (en) * | 2013-04-19 | 2014-10-22 | 宝山钢铁股份有限公司 | Continuously-cast mold powder for cold-rolled sheet steel and production method thereof |
| CN104511580A (en) * | 2013-09-30 | 2015-04-15 | 上海梅山钢铁股份有限公司 | Molten steel solvent for low-carbon steel |
| CN104858382A (en) * | 2015-05-25 | 2015-08-26 | 中南大学 | Tundish covering agent and application thereof |
| CN105642847A (en) * | 2016-01-26 | 2016-06-08 | 中南大学 | Casting powder for continuous casting of low-carbon steel and application of casting powder |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5356454A (en) * | 1992-07-08 | 1994-10-18 | Kawasaki Steel Corporation | Mold powder for continuous casting |
| CN107498013B (en) * | 2017-09-06 | 2019-09-24 | 中南大学 | One kind containing TiO2High-aluminum steel covering slag and its application |
-
2018
- 2018-03-29 CN CN201810273478.XA patent/CN110315038B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60234752A (en) * | 1984-05-07 | 1985-11-21 | Nippon Steel Corp | Flux for continuous casting of steel |
| CN104107890A (en) * | 2013-04-19 | 2014-10-22 | 宝山钢铁股份有限公司 | Continuously-cast mold powder for cold-rolled sheet steel and production method thereof |
| CN104511580A (en) * | 2013-09-30 | 2015-04-15 | 上海梅山钢铁股份有限公司 | Molten steel solvent for low-carbon steel |
| CN104858382A (en) * | 2015-05-25 | 2015-08-26 | 中南大学 | Tundish covering agent and application thereof |
| CN105642847A (en) * | 2016-01-26 | 2016-06-08 | 中南大学 | Casting powder for continuous casting of low-carbon steel and application of casting powder |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110315038A (en) | 2019-10-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101502871B (en) | Cogged ingot continuous casting crystallizer protecting slag and preparation method thereof | |
| CN101612653B (en) | Mold powder for continuous casting of high aluminium-titanium-rare earth steel | |
| CN105562641B (en) | A kind of high manganese crystallizer casting powder for high-aluminum steel continuous casting and preparation method thereof | |
| CN102764879B (en) | High-aluminum steel die casting protective slag | |
| CN101653819B (en) | Continuous casting tundish hollow particle carbon-free covering agent and preparation method thereof | |
| CN101954464B (en) | Low-oxidizability continuous casting covering slag | |
| CN103008590A (en) | Continuous casting mold covering slag for medium carbon steel containing manganese | |
| CN102389955A (en) | Crystallizer casting powder for high-aluminum steel continuous casting | |
| CN106270429B (en) | Hypoergia covering slag and preparation method | |
| CN104399922A (en) | Novel corrosion-resistant alloy steel continuous casting powder and application thereof | |
| CN104550797B (en) | A kind of hypoergia crystallizer protecting residue of rare earth steel continuous casting | |
| CN110315038B (en) | Crystallizer casting powder capable of preventing slag entrapment and application thereof | |
| CN102728797A (en) | Crystallizer protective slag for effectively controlling carbon steel cracks in compact strip production (CSP) | |
| CN104107890A (en) | Continuously-cast mold powder for cold-rolled sheet steel and production method thereof | |
| CN112605356B (en) | Special covering slag for austenitic stainless steel continuous casting crystallizer and application thereof | |
| CN104607608A (en) | Novel medium manganese steel casting powder for automobile and application thereof | |
| CN103990770A (en) | High-alkalinity high-lubricity continuous casting crystallizer casting powder and method for performing continuous casting on peritectic steel slab | |
| CN103551537A (en) | Ultra-low-carbon steel and low-carbon steel crystallizer mold flux for continuous casting of automobile sheet and preparation method thereof | |
| CN105642847A (en) | Casting powder for continuous casting of low-carbon steel and application of casting powder | |
| CN109454210B (en) | Double-layer tundish covering agent for ultrathin belt | |
| CN110538973B (en) | Light-weight fluorine-free environment-friendly continuous casting covering slag special for enamel steel | |
| CN101486587B (en) | Double-layer tundish covering agent | |
| CN103111592B (en) | Tundish covering agent | |
| CN103372636B (en) | Double-layer tundish covering agent for ultra-low carbon steel | |
| CN104874755A (en) | Tundish covering agent used for chrome-bearing steel and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB03 | Change of inventor or designer information |
Inventor after: Zhao Xianjiu Inventor after: Jiang Lixin Inventor after: Tang Huizhong Inventor before: Zhao Xianjiu Inventor before: Jiang Lixin Inventor before: Tang Huizhong Inventor before: Li Shanqing |
|
| CB03 | Change of inventor or designer information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |