CN111230058A - Continuous casting crystallizer function protection material for air valve steel - Google Patents
Continuous casting crystallizer function protection material for air valve steel Download PDFInfo
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- CN111230058A CN111230058A CN202010246470.1A CN202010246470A CN111230058A CN 111230058 A CN111230058 A CN 111230058A CN 202010246470 A CN202010246470 A CN 202010246470A CN 111230058 A CN111230058 A CN 111230058A
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- air valve
- continuous casting
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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
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Abstract
The invention discloses a continuous casting crystallizer function protection material for air valve steel, which comprises the following raw material components in percentage by weight: 36.0-42.0% of premelting material, 14.0-17.0% of wollastonite, 9.0-11.0% of fine glass powder, 3.0-5.0% of lithium carbonate, 7.0-9.0% of fluorite, 2.0-4.0% of sodium fluoride, 3.0-5.0% of cryolite, 10.0-12.0% of graphite carbon, 2.0-3.5% of carbon black and 2.0-3.5% of binding agent. The casting powder disclosed by the invention not only ensures the heat preservation effect and the melting effect, but also effectively prevents the casting blank from being broken, the casting blank from being clamped with slag and sunken, and the surface of the obtained casting blank has no cleaning rate of more than 98%.
Description
Technical Field
The invention belongs to the technical field of metallurgical auxiliary materials, and particularly relates to a continuous casting crystallizer function protection material for air valve steel.
Background
The internal combustion engine comprises a gasoline engine and a diesel engine, is an automobile, a motorcycle, a tractor, a ship, an internal combustion locomotive, a tank, an oil drilling rig, engineering machinery, a mobile power station and the like, and plays an important role in the aspects of national economy, even national defense and military industry and the like. The development of the air valve steel of the internal combustion engine is closely related to the development of the internal combustion engine in China. In decades, especially since the development of the engine, advanced internal combustion engines in Germany, America, Japan, France and other countries are introduced into China, so that the level of internal combustion engines in China is rapidly improved, the inspiration of air valve steel and the rapid development of gold in China are promoted, and the process of seriation of air valve steel types in China is accelerated.
The air valve steel is an alloy material containing iron, carbon, nickel, chromium and niobium, is mainly used as a specific material for starting an air inlet valve and an air outlet valve, and is also a key material in the whole engine. The air valve steel is used for working under the severe conditions of high temperature, high pressure, high scouring and high abrasion, and has higher requirements on the performance of the air valve steel. At present, two main types of austenite type air valve steels are widely used, such as 5Cr21Mn9Ni4N (21-4N for short), 3Cr20Ni11Mo2PB (PB steel for short), 4Cr14Ni14W2Mo (double 14 for short), and the like. The other is martensite type air valve steel, such as 4Cr9Si2, 4Cr10Si2Mo and the like. The austenitic air valve steel is mainly used for exhaust valves with more severe conditions because the performance of the austenitic air valve steel is better than that of the martensitic air valve steel, and the martensitic air valve steel is mainly used for intake valves. The air valve steel continuous casting process is more complex than common carbon steel and even common stainless steel, the requirements of the process parameters such as pouring temperature, blank drawing speed, cooling system and the like are more strict, and the manufacturing process and the physical and chemical properties of the protective material must be strictly required and controlled so as to be adaptive to the air valve continuous casting process. Due to the high temperature characteristics of the air valve steel and the requirements of the related continuous casting process, the physical and chemical properties of the protective material, such as alkalinity, melting temperature, viscosity and the like, should be strictly controlled.
The continuous casting protection material is used as an important metallurgical auxiliary material for guaranteeing the smooth continuous casting, has obvious influence on the smooth continuous casting production of the air valve steel and the quality guarantee of a casting blank, and has a continuous casting ratio of over 95 percent in the world along with the vigorous development of a continuous casting technology. Meanwhile, the national economy of China is increased, the automobile industry is developed vigorously, the demand for the steel yield of the gas valve is increased day by day, and the gas valve production in China shows a trend of increasing year by year. At present, the output of China has leaped the world first as stainless steel with special application, but the stainless steel continuous casting technology has certain gap with foreign countries. Domestic stainless steel continuous casting protective materials still need a large amount of imports, even if import slag is used, the surface quality of continuous casting billets in some domestic stainless steel factories still has problems, vibration marks are deep, surface depressions are serious, and the defects directly cause that the casting billets have to be scalped and cleaned. The special protective material for stainless steel is a key technology for ensuring the smooth continuous casting production of stainless steel and reducing surface defects, so that improvement on the aspect of the stainless steel protective material is needed to solve the existing problems.
The scheme of the research aiming at the technology is less, an invention patent is reported before the company, and the publication number of the invention patent is CN104588602B, and the invention patent discloses a continuous casting crystallizer function protection material special for the air inlet valve steel of the internal combustion engine, which comprises 52.0-58.0% by weight of pre-melting materials, 5.0-8% by weight of fine glass powder, 8-9.5% by weight of sodium carbonate, 13-17% by weight of fluorite, 2-4% by weight of lithium carbonate, 3-5% by weight of carbon black and graphite carbon, 1-3% by weight of carbon black and 2.5-3.5% by weight of cryolite, wherein the pre-melting materials comprise 25.0-35.0% by weight of SiO2, 34.0-44.0% by weight of CaO, 2-8.0% by weight of Al2O3, R2O and F, and the weight of carbon black and the pre-3% by weight of SiO. The protective material has the characteristics of good quality, small loss, high shrinkage and strong toughness, but the protective material has the defects of more usage amount of carbon materials, insufficient quality stability of casting blanks and still unsatisfied continuous casting requirements with high standard requirements.
Disclosure of Invention
The invention aims to provide a continuous casting crystallizer functional protection material for air valve steel, aiming at solving the problems in the prior art, the functional protection material excellently stabilizes the liquid level of a crystallizer, the obtained protection material can not only meet the lubrication of the crystallizer during low-temperature casting, but also ensure better stability of slag, better casting blank quality and can meet the requirements of users.
The technical scheme of the invention is as follows:
a function protection material for a continuous casting crystallizer for air valve steel comprises the following raw material components in percentage by weight: 36.0-42.0% of premelting material, 14.0-17.0% of wollastonite, 9.0-11.0% of fine glass powder, 3.0-5.0% of lithium carbonate, 7.0-9.0% of fluorite, 2.0-4.0% of sodium fluoride, 3.0-5.0% of cryolite, 10.0-12.0% of graphite carbon, 2.0-3.5% of carbon black and 2.0-3.5% of binding agent.
Specifically, the premelted material comprises the following chemical components in percentage by weight: SiO2242-46%，CaO18-22%，Al2O38-10%，R2O 10-14%、F—8-10 percent of MgO 2-4 percent of trace elements, wherein the trace elements conform to R2O=K2O+Na2O。。
Specifically, the functional protection material comprises the following raw material components in percentage by weight: 40.0% of premelting material, 13.0% of wollastonite, 10.0% of fine glass powder, 4.0% of lithium carbonate, 8.0% of fluorite, 5.0% of sodium fluoride, 4.0% of cryolite, 11.0% of graphite carbon, 2% of carbon black and 3.0% of binding agent.
Specifically, the binary basicity of the slag of the functional protection material is 0.55-0.71, the hemispherical point is 1060-1120 ℃, and the viscosity is 0.50-0.70 Pa.s at 1300 ℃.
Specifically, the binary basicity of the slag of the functional protection material is 0.66-0.71, the hemispherical point is 1080 ℃, and the viscosity is 0.58 Pa.s at 1300 ℃.
Specifically, the chemical components of the continuous casting crystallizer function protection material for the air valve steel comprise the following components in percentage by weight: SiO2234.0-38.0%，CaO 20.0-24.0%，Al2O34.0-7.0%，Na2O 8.0-10.0%，F—5.0-7.0%，Fe2O30.5-3.0%, free carbon 14.0-17.0%, and trace elements in balance.
The stainless steel contains easily oxidized alloy elements such as Ti, Al, Cr and the like, so that the generated high-melting-point compound makes molten steel sticky, and different steel types have different solidification characteristics. When the slag absorbs the impurities to a certain degree, the melting point and viscosity of the slag are obviously increased, the glass state of the slag is damaged, and high-melting-point compounds such as wollastonite CS and the like are precipitated, so that the crystallizer protective material is crusted, and the defects of depression, cracks, deep vibration marks, slag inclusion and the like are generated on the surface of a casting blank in the continuous casting process, so that the grinding amount of the casting blank is increased, and the yield of stainless steel is seriously reduced.
The invention has the beneficial effects that: the protective material is added with a large amount of premelted material, so that the protective material has higher melting stability, and the carbon black is used as imported carbon black which has finer granularity, higher iodine absorption value and good dispersity and well plays a role of a skeleton compared with common carbon black; according to the invention, carbonate lithium carbonate of alkali metal is added into the protective material, and the heat release quantity of the molten steel in the crystallizer is utilized to ensure that the carbonate absorbs heat and decomposes, so that the melting speed of the protective material is reduced; by adding the chemical flux, the vitrification characteristic of the functional protection material can be improved, the lubricating capability of the functional protection material is improved, the melting uniformity of the functional protection material can be improved, and good melting characteristic can be obtained; according to the invention, the carbonaceous material and the binder are added into the protective material base material, the binder burns before the carbonaceous material in the continuous casting process and emits gas, so that the consumption of the carbonaceous material is reduced, and meanwhile, the residues after the binder burns and the carbonaceous material jointly prevent the base material from forming sinter cakes and slag strips, the melting speed of the protective material can be controlled, the thickness of a slag layer is kept stable, and the quality of a casting blank is improved.
The raw materials are combined, and the obtained protective material has the binary alkalinity of 0.55-0.71, is proper and has good lubricating effect; the hemispherical point is 1060-; the viscosity is 0.50-0.70 Pa.s at 1300 ℃, the viscosity is moderate, the slag film on the surface of the solidified shell of the casting blank on the upper part of the crystallizer is in a viscous flow state, the depth of vibration marks and slag inclusion of the wave troughs of the vibration marks are reduced, the adhesive force of the slag to the vibration marks is reduced, the inflow of liquid slag is well controlled, the dent is reduced, and the quality of the casting blank is improved.
The protective material of the invention forms a composite silicate structure among chemical components, Si-O tetrahedrons are connected by sharing two angles to form a long chain, MgO, CaO and Na are added into the silicate melt2O、F-When the oxide and fluoride of divalent or monovalent alkali metal are used, the Si-O tetrahedral network structure is damaged, and the deformation resistance of the chain is reduced due to the increase of fracture, so that the crystallization temperature of the protective material is reduced, and the surface tension is improved. The viscosity-temperature curve has a gentle trend in the cooling process at 1300 ℃, the slag film is slowly crystallized and solidified, and the friction force in the slag film lubricating process is lower, so that the blank shell scratches caused by large friction force are reduced, and the phenomena of breaking and steel leakage in the casting process are reduced; the invention can stabilize the liquid level of the crystallizer well, and the obtained protective material not only can meet the requirement of the crystallizer lubrication during low-temperature casting, but also can ensure better stability of slag and better casting blank quality, and can meet the requirement of users.
Detailed Description
The technical solution of the present invention will be described in detail with reference to specific examples.
The present invention will be described in detail by the following 7 examples, and the functional protection materials for a continuous casting mold for air valve steel provided by the present invention are shown in table form, and the raw materials and the weight percentages thereof for the functional protection materials for a continuous casting mold for air valve steel provided by the 7 examples are shown in table 1.
The chemical compositions and weight percentages of the functional protective materials for the continuous casting crystallizer for air valve steel provided in examples 1-7 are shown in table 2.
The chemical compositions and weight percentages of the pre-melted materials of the continuous casting mold function protecting materials for the air valve steels provided in examples 1 to 7 are shown in table 3.
The physical and chemical properties of the functional protective materials for the continuous casting mold for air valve steel provided in examples 1 to 7 are shown in Table 4.
Table 1 examples 1-7 weight percent (wt%) of various raw material components of functional protective materials
Table 2 chemical composition and weight percent (wt%) of the functional protective materials provided in examples 1-7
Table 3 examples 1-7 weight percent (wt%) of the chemical composition of the premelt material
Table 4 performance parameters of the functional protective materials of examples 1-7
Application test
The process flow of the casting air valve in a certain steel plant is as follows: electric arc furnace smelting → AOD-VOD-LF → square billet continuous casting, wherein the square billet continuous casting is a 4-machine 4-flow 8-meter arc square billet continuous casting machine newly designed by Shanghai, the effective length of a crystallizer copper pipe is 900mm, and the casting section: 150X 150mm, casting pull rate: 1.5-2.5m/min, and the chemical compositions of the gas valve steel produced by adopting the functional protection material provided by the embodiment 1 of the invention are shown in the following table 5.
TABLE 5 molten steel composition of air valve steel
The field test shows that: the functional protection material can be well spread in the crystallizer, the flame is moderate, the melting is uniform, the slag strips are few, the thickness of liquid slag is 5-7mm, the consumption of each ton of steel slag is 0.25-0.30 Kg/ton, the surface quality of a casting blank is good, no groove is formed, the surface non-cleaning rate is more than 98%, and the requirements of users can be met.
Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and not to limit the same; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.
Claims (6)
1. A function protection material for a continuous casting crystallizer for air valve steel is characterized by comprising the following raw material components in percentage by weight: 36.0-42.0% of premelting material, 14.0-17.0% of wollastonite, 9.0-11.0% of fine glass powder, 3.0-5.0% of lithium carbonate, 7.0-9.0% of fluorite, 2.0-4.0% of sodium fluoride, 3.0-5.0% of cryolite, 10.0-12.0% of graphite carbon, 2.0-3.5% of carbon black and 2.0-3.5% of binding agent.
2. The continuous casting crystallizer function protection material for the air valve steel as claimed in claim 1, wherein the premelt material comprises the following chemical components in percentage by weight: 242-46% of SiO, 18-22% of CaO, 38-10% of Al2O 38, 10-14% of R2O 10, 8-10% of F, 2-4% of MgO and trace elements, wherein the trace elements meet the requirement of R2O = K2O + Na 2O.
3. The continuous casting crystallizer function protection material for the air valve steel as claimed in claim 1, which is characterized by comprising the following raw material components in percentage by weight: 40.0% of premelting material, 15.0% of wollastonite, 10.0% of fine glass powder, 4.0% of lithium carbonate, 8.0% of fluorite, 3.0% of sodium fluoride, 4.0% of cryolite, 11.0% of graphite carbon, 2% of carbon black and 3.0% of binding agent.
4. The continuous casting crystallizer function protection material for air valve steel as claimed in claim 1, wherein the binary basicity of the slag of the function protection material is 0.55-0.71, the hemispherical point is 1060-1120 ℃, and the viscosity at 1300 ℃ is 0.50-0.70 Pa.s.
5. The continuous casting crystallizer function protection material for air valve steel as claimed in claim 4, wherein the slag binary alkalinity of the function protection material is 0.66-0.71, the hemispherical point is 1080 ℃, and the viscosity at 1300 ℃ is 0.58 Pa.s.
6. The continuous casting crystallizer function protection material for the air valve steel as claimed in claim 1, wherein the chemical composition of the continuous casting crystallizer function protection material for the air valve steel comprises the following components by weight percent: 234.0-38.0% of SiO0, 20.0-24.0% of CaO, 20.0-7.0% of Al2O34.0, 8.0-10.0% of Na2O 8.0, 5.0-7.0% of F, 30.5-3.0% of Fe2O30.0%, 14.0-17.0% of free carbon and the balance of trace elements.
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| CN202010246470.1A CN111230058A (en) | 2020-03-31 | 2020-03-31 | Continuous casting crystallizer function protection material for air valve steel |
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| CN202010246470.1A CN111230058A (en) | 2020-03-31 | 2020-03-31 | Continuous casting crystallizer function protection material for air valve steel |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112620599A (en) * | 2020-12-29 | 2021-04-09 | 河南通宇冶材集团有限公司 | Ultralow-alkalinity high-vitrification protective slag for bloom medium-high carbon steel and preparation method thereof |
| CN114769533A (en) * | 2022-03-31 | 2022-07-22 | 西峡县西保冶金材料有限公司 | Function protection material for continuous casting crystallizer for industrial pure iron |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003094150A (en) * | 2001-09-19 | 2003-04-02 | Nippon Yakin Kogyo Co Ltd | CONTINUOUS CASTING POWDER AND CONTINUOUS CASTING METHOD FOR Ti AND Al STEEL |
| CN101967610A (en) * | 2009-07-28 | 2011-02-09 | 宝山钢铁股份有限公司 | High carbon high silicon martensite stainless steel billet and preparation method thereof |
| CN102218516A (en) * | 2011-07-29 | 2011-10-19 | 攀钢集团有限公司 | Continuous casting method of high chrome steel |
| KR20130009472A (en) * | 2011-07-15 | 2013-01-23 | 주식회사 포스코 | Mold powder for continuous casting |
| CN103381474A (en) * | 2013-07-26 | 2013-11-06 | 河南省西保冶材集团有限公司 | Special continuous casting mold protection material for bearing steel |
| CN104043797A (en) * | 2014-02-13 | 2014-09-17 | 攀钢集团攀枝花钢铁研究院有限公司 | Ultra-low-sulfur high-chromium steel continuous casting method and bloom prepared by same |
| CN104588602A (en) * | 2015-02-27 | 2015-05-06 | 河南省西保冶材集团有限公司 | Function protection material of special continuous casting crystallizer for internal combustion engine intake valve steel |
| CN109967706A (en) * | 2019-05-05 | 2019-07-05 | 西峡县西保冶金材料有限公司 | Ultra low carbon IF steel function protecting material of continuous casting crystallizer |
-
2020
- 2020-03-31 CN CN202010246470.1A patent/CN111230058A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003094150A (en) * | 2001-09-19 | 2003-04-02 | Nippon Yakin Kogyo Co Ltd | CONTINUOUS CASTING POWDER AND CONTINUOUS CASTING METHOD FOR Ti AND Al STEEL |
| CN101967610A (en) * | 2009-07-28 | 2011-02-09 | 宝山钢铁股份有限公司 | High carbon high silicon martensite stainless steel billet and preparation method thereof |
| KR20130009472A (en) * | 2011-07-15 | 2013-01-23 | 주식회사 포스코 | Mold powder for continuous casting |
| CN102218516A (en) * | 2011-07-29 | 2011-10-19 | 攀钢集团有限公司 | Continuous casting method of high chrome steel |
| CN103381474A (en) * | 2013-07-26 | 2013-11-06 | 河南省西保冶材集团有限公司 | Special continuous casting mold protection material for bearing steel |
| CN104043797A (en) * | 2014-02-13 | 2014-09-17 | 攀钢集团攀枝花钢铁研究院有限公司 | Ultra-low-sulfur high-chromium steel continuous casting method and bloom prepared by same |
| CN104588602A (en) * | 2015-02-27 | 2015-05-06 | 河南省西保冶材集团有限公司 | Function protection material of special continuous casting crystallizer for internal combustion engine intake valve steel |
| CN109967706A (en) * | 2019-05-05 | 2019-07-05 | 西峡县西保冶金材料有限公司 | Ultra low carbon IF steel function protecting material of continuous casting crystallizer |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112620599A (en) * | 2020-12-29 | 2021-04-09 | 河南通宇冶材集团有限公司 | Ultralow-alkalinity high-vitrification protective slag for bloom medium-high carbon steel and preparation method thereof |
| CN112620599B (en) * | 2020-12-29 | 2022-04-08 | 河南通宇冶材集团有限公司 | Ultralow-alkalinity high-vitrification protective slag for bloom medium-high carbon steel and preparation method thereof |
| CN114769533A (en) * | 2022-03-31 | 2022-07-22 | 西峡县西保冶金材料有限公司 | Function protection material for continuous casting crystallizer for industrial pure iron |
| CN114769533B (en) * | 2022-03-31 | 2024-08-20 | 西峡县西保冶金材料有限公司 | Functional protection material of continuous casting crystallizer for industrial pure iron |
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Application publication date: 20200605 |