CN111455125B - Production method for increasing continuous casting heat of high-aluminum steel - Google Patents
Production method for increasing continuous casting heat of high-aluminum steel Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
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- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
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- 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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- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
- B22D41/50—Pouring-nozzles
- B22D41/58—Pouring-nozzles with gas injecting means
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- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
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- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
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Abstract
The invention discloses a production method for improving the continuous casting heat of high-aluminum steel, which adopts the working procedures of molten iron pretreatment, a converter, LF refining, RH refining and slab continuous casting; in the converter process, steel grit aluminum is automatically added into a converter bin, and slag-free tapping is realized by front and back double slag blocking operations; the LF refining process is carried out through the micro-positive pressure operation of an LF furnace; in the continuous casting process, the tundish is poured and added with the high-alkalinity carbon-free low-silicon covering agent, and the tundish stopper uses an argon blowing stopper. By adopting the method, the number of continuous casting furnaces can be smoothly increased to 8 or more, and quality accidents such as water gap blockage, bonded bleed-out or casting blank cracks and the like do not occur; the obtained casting blank has good surface quality and no recess and crack, and reaches the international advanced level. The high-aluminum steel product produced by the method has high structure uniformity and good bending performance, and is widely applied to automobile parts with complex structures.
Description
Technical Field
The invention relates to a steelmaking method, in particular to a production method for improving the continuous casting heat of high-aluminum steel.
Background
The high-aluminum steel (Al content is 0.5wt% -2.0 wt%) realizes good matching of high strength and high toughness, has become an important group in advanced high-strength steel, and is widely applied to the automobile industry and widely paid attention by various automobile plate manufacturing enterprises.
However, the high aluminum content can change the property of the casting powder in the smelting process to form high-melting-point substances which are adhered to the wall of a nozzle to form nozzle nodulation, so that the problem of serious nozzle blockage is caused, the pouring is interrupted, and the smooth operation of the process is influenced; meanwhile, the problems of rising of a stopper rod, fluctuation of liquid level, slag entrapment and the like caused by the nodulation of a water gap affect the surface quality of a casting blank.
Disclosure of Invention
The invention aims to provide a production method for improving the continuous casting heat of high-aluminum steel, which has good casting blank quality.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows: the method adopts the working procedures of molten iron pretreatment, converter, LF refining, RH refining and slab continuous casting; in the converter process, steel grit aluminum is automatically added into a converter bin, and slag-free tapping is realized by front and back double slag blocking operations; the LF refining process is carried out through the micro-positive pressure operation of an LF furnace; in the continuous casting process, the tundish is poured and added with the high-alkalinity carbon-free low-silicon covering agent, and the tundish stopper uses an argon blowing stopper.
In the continuous casting process, submerged casting and full-process protective casting are adopted, a long water gap and argon blowing protection casting are adopted from a continuous casting ladle to a tundish, the protective casting pressure is 10-11 Mpa, and the argon flow is 100-110L/min.
In the continuous casting process, the argon flow of the argon blowing stopper rod is 3-4L/min, and the argon sealing flow between the immersion type water inlet plates is 6-9L/min.
In the continuous casting process, the adopted casting powder comprises the following components in percentage by mass: SiO 22 33%～37%，CaO 27%～30%，MgO 2.4%～2.5%，Al2O3 2.4%～3.5%，Fe2O3 0.6%～1.7%，MnO2 3%～4%，Na2O 10%～12%，CaF2 11%～13%，C 4.5%～6.0%。
Adopt the produced beneficial effect of above-mentioned technical scheme to lie in: the invention can smoothly realize that the number of continuous casting furnaces is 8 or more, and quality accidents such as water gap blockage, bonded bleed-out or casting blank cracks and the like do not occur; the obtained casting blank has good surface quality and no recess and crack, and reaches the international advanced level. The high-aluminum steel product produced by the method has high structure uniformity and good bending performance, and is widely applied to automobile parts with complex structures.
Drawings
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
FIG. 1 is a surface quality chart of a steel strip product obtained in example 1 of the present invention;
FIG. 2 is a surface quality chart of a steel strip product obtained in example 2 of the present invention;
FIG. 3 is a surface quality chart of a steel strip product obtained in example 3 of the present invention;
FIG. 4 is a surface quality chart of a steel strip product obtained in example 4 of the present invention.
Detailed Description
The production method for improving the continuous casting heat of the high-aluminum steel comprises the process flows of molten iron pretreatment, 100t converter, LF refining, RH refining and slab continuous castingAnd (5) producing a line. The duplex process route of the LF refining and RH deep treatment process can not only control the H content in the molten steel and prevent the hydrogen embrittlement phenomenon of high-aluminum steel, but also further remove the inclusion content in the steel, control the total oxygen content in the molten steel to be less than 10ppm, and improve the cleanliness and the castability of the molten steel. The materials added into the converter can inevitably bring in gases such as nitrogen, hydrogen and the like, and the gases can influence the quality of the casting blank; the method adds RH vacuum degassing treatment after LF, and RH mainly removes gases such as nitrogen, hydrogen, oxygen and the like and Al2O3And the quality of the high-aluminum steel smelting and casting blank can be ensured by impurities. The process of each procedure is as follows:
(1) a converter process: an automatic steelmaking model based on an infrared flue gas analysis system is adopted, and the alkalinity of the final slag is increased to 3.8-4.2, so that harmful elements such as sulfur, phosphorus and the like can be removed; the converter end point oxygen is controlled to be 400-600 ppm so as to reduce the generation amount of inclusions, and the front and rear double slag blocking operations realize slag-free tapping, so that the aluminum burning loss is reduced, and the cleanliness of molten steel is effectively improved. Controlling the end point temperature of the converter to be 1680 ℃ and above; the manual addition of the aluminum wire section in the tapping process is optimized to automatically add steel grit aluminum into the stock bin, so that the labor intensity of workers is reduced, the addition efficiency is improved, the absorption rate of aluminum is improved, and the addition uniformity and the timeliness of aluminum are ensured; the alloy charge was started at and after the time of tapping 1/5, and was completed at and before the time of tapping 4/5.
Under the conventional condition, the material bin is added with aluminum wires, aluminum particles or aluminum iron; the aluminum particles are light and are easy to stay in a slag layer to react with the steel slag, and the molten steel cannot be absorbed; the aluminum wire is directly driven into molten steel, so that the steel slag is easy to deoxidize insufficiently, and the steel slag on the surface of the molten steel reacts with Al to generate Al2O3Impurities are included, so that the cleanliness of molten steel is poor; the absorption rate of the aluminum and the iron is too low, which causes resource waste. Therefore, the method selects the steel grit aluminum with high density, the steel grit aluminum enters the molten steel from the steel slag, so that the steel slag and the molten steel can be fully deoxidized, and the absorption rate is obviously higher than that of aluminum iron. Meanwhile, steel sand aluminum is added into a converter bin instead of LF, so that the full floating time of impurities is ensured, and the cleanliness of molten steel can be effectively improved.
(2) An LF refining procedure: the LF furnace is operated at the micro-positive pressure, the micro-positive pressure is controlled to be 1.05-1.15 bar, and a micro smoke gas is emitted to ensure the micro-positive pressure atmosphere in the furnace and prevent the molten steel from sucking air to cause N increase and secondary oxidation of the molten steel, so that the cleanliness and the castability of the molten steel are improved. The alkalinity of the slag is controlled to be 11-14. And the LF furnace is used for refining and entering the station to perform white slag operation, so that the smelting process is completely in a reducing atmosphere. A bottom argon blowing system is adopted, the molten steel components are finely adjusted, the nitrogen content in the steel is strictly controlled, and the defect of a casting blank caused by the generation of a large amount of AlN is prevented; the bottom argon blowing system is divided into 4 modes, namely strong blowing, middle blowing, soft blowing and static blowing. The strong blow mold type single-path argon flow is 600-1000 NL/min, and the main purpose is to perform deoxidation and desulfurization through slag washing; the middle blowing mold type single-path argon flow is 300-500 NL/min, and the main purposes are uniform in components and temperature; the soft blowing mode single-path argon flow is 40-100 NL/min, and the molten steel temperature is uniform when power is supplied for the main purpose; the static blowing mold type single-path argon flow is 20-50 NL/min, and the static blowing standard is that the liquid level of molten steel is not exposed, a slag layer surges, the impurities in the molten steel are removed, and the purity of the molten steel is guaranteed. The fine adjustment of the standard of molten steel component achievement is based on the target component in the control plan, wherein the positive and negative deviation of Als is less than 50ppm, and the positive and negative deviation of other microalloy elements is less than 0.001%. Through micro-positive pressure operation and bottom blowing argon adjustment, the nitrogen content of the molten steel can be ensured to be less than 30 ppm.
(3) RH refining process: adopting an RH deep treatment method, ensuring that the vacuum degree is less than 2mbar, the treatment time is more than 15min, and ensuring that the H content and the N content in the molten steel are less than 1.5ppm and less than 30ppm after the treatment.
(4) And a slab continuous casting process: in the continuous casting process, the temperature of the molten steel in the tundish is 1540 ℃ or above, preferably 1540-1550 ℃; the superheat degree of the tundish is 25-30 ℃; the method is characterized in that immersion type casting and whole-process protection casting are adopted, a long nozzle and argon blowing protection casting are adopted from a continuous casting ladle to a tundish, the casting pressure is 10-11 Mpa, the argon flow is 100-110L/min, and secondary oxidation of molten steel when the molten steel is injected into the tundish from the ladle is prevented, so that the cleanliness of the molten steel is reduced, and the casting is difficult. Pouring, namely adding a high-alkalinity carbon-free low-silicon covering agent to avoid secondary oxidation of molten steel after the molten steel enters a tundish; the tundish stopper uses an argon blowing stopper, and the flow of argon is 3-4L/min. The magnesium aluminate spinel lining anti-blocking water gap is used as the submerged nozzle, and the argon sealing flow between the submerged nozzle plates is controlled to be 6-9L/min.
The alkalinity of the high-alkalinity carbon-free low-silicon covering agent is more than 10, and the main components require the weight as follows: SiO 22 3%±0.5%、CaO 45%±5%、MgO≤0.3%、Fe2O3Less than or equal to 1 percent and Al2O3 35%±5%。
When the molten steel for casting submerges a side hole of the submersed nozzle, special covering slag for high-aluminum steel is added, heat transfer and lubrication are controlled, good cooling conditions are provided for a casting blank, and the covering slag comprises the following components in percentage by mass: SiO 22 33%～37%，CaO 27%～30%，MgO 2.4%～2.5%，Al2O3 2.4%～3.5%，Fe2O3 0.6%～1.7%，MnO2 3%～4%，Na2O 10%～12%，CaF211 to 13 percent of C4.5 to 6.0 percent of C; 0.8 to 0.9 alkalinity, 0.15 to 0.20 Pa.s viscosity, 0.7 to 0.9kg/L density. The covering slag can quickly realize the stability of the performance of the steel slag after reaction and inclusion absorption. The high-silicon low-aluminum low-alkalinity covering slag is adopted, the production is started, and a large amount of acid oxide Si0 is consumed2The alkalinity of the slag is increased, and the alkalinity in the slag is balanced by adopting acid oxides, so that coarse slag strips are prevented from being formed to a certain extent. The mold flux with low viscosity is adopted to increase the consumption of the mold flux, perform good lubrication on the casting blank and prevent steel leakage. The continuous casting speed is controlled to be 1.4-1.5 m/min.
The obtained continuous casting billet comprises the following chemical components in percentage by mass: 0.070 to 0.100 percent of C, 2.0 to 2.4 percent of Mn, less than or equal to 0.010 percent of S, less than or equal to 0.015 percent of P, 0.10 to 0.15 percent of Si, 0.50 to 0.80 percent of Als, less than or equal to 0.0040 percent of N, 0.010 to 0.030 percent of Nb, 0.010 to 0.030 percent of Ti, 0.15 to 0.30 percent of Mo, 0.0010 to 0.0030 percent of B, and the balance of Fe and inevitable impurities.
Example 1: the production method for improving the continuous casting heat of the high-aluminum steel adopts the following specific process.
(1) Controlling the components of the high-aluminum steel: the chemical composition and the mass percentage of the high-aluminum steel are shown in the table 1.
(2) The high-aluminum steel process flow is a duplex process production line of molten iron pretreatment-100 t converter-LF refining-RH refining-slab caster.
(3) Controlling the end point temperature of the converter to be 1680 ℃, controlling the alkalinity of the final slag to be 4.0 and controlling the end point oxygen to be 400 ppm; the slag blocking mode of the front sliding plate for blocking slag, the rear slag blocking mark and the sliding plate for blocking slag is adopted, the steel sand aluminum is automatically added by using the bin, the alloy material is added when the steel is tapped 1/5, and the alloy material is added when the steel is tapped 4/5.
(4) The LF refining adopts 1.10bar micro-positive pressure operation, and enters a station to make white slag, so that the smelting process is completely in a reducing atmosphere; controlling the alkalinity of the slag to be 12; a bottom argon blowing system is adopted, the molten steel components are finely adjusted, the nitrogen content in the steel is strictly controlled to be less than 30ppm, and casting blank defects caused by a large amount of AlN are prevented from being generated.
(5) Adopting RH deep processing method with vacuum degree less than 2mbar and vacuum processing time 20 min; the H content was 1ppm and the N content was 25ppm after the vacuum treatment.
(6) In the continuous casting process, the temperature of molten steel in a tundish is 1545 ℃, and the superheat degree of the tundish is 27 ℃; the method comprises the steps of adopting immersion type casting starting and whole-process protection casting, adopting a long nozzle and argon blowing protection casting from a continuous casting ladle to a tundish, wherein the protection casting pressure is 10.4Mpa, the argon flow is 105L/min, adding a high-alkalinity carbon-free low-silicon covering agent during casting starting, and using an argon blowing stopper for the tundish stopper, wherein the argon flow is 3.4L/min. The submerged nozzle uses a magnesium aluminate spinel lining anti-blocking nozzle, and the argon sealing flow between the submerged nozzle plates is controlled to be 7.8L/min. When the molten steel for casting submerges a side hole of the submersed nozzle, special covering slag for high-aluminum steel is added, heat transfer and lubrication are controlled, good cooling conditions are provided for a casting blank, and the covering slag comprises the following components in percentage by mass: SiO 22 35%、CaO 28%、MgO 2.5%、Al2O3 2.9%、Fe2O3 1.0%、MnO2 3.4%、Na2O 11%、CaF211 percent, C5.2 percent, alkalinity of 0.84, viscosity of 0.20 Pa.s and density of 0.8 kg/L. The continuous casting speed is controlled to be 1.5 m/min.
The continuous casting heat number of the embodiment is 8; the surface quality diagram of the obtained strip steel product is shown in figure 1, and the surface quality diagram is good and has no recess and crack.
Example 2: the production method for improving the continuous casting heat of the high-aluminum steel adopts the following specific process.
(1) Controlling the components of the high-aluminum steel: the chemical composition and the mass percentage of the high-aluminum steel are shown in the table 1.
(2) The high-aluminum steel process flow is a duplex process production line of molten iron pretreatment-100 t converter-LF refining-RH refining-slab caster.
(3) Controlling the end point temperature of the converter to be 1690 ℃, the alkalinity of the final slag to be 3.8 and the end point oxygen to be 460 ppm; the slag blocking mode of the front sliding plate for blocking slag, the rear slag blocking mark and the sliding plate for blocking slag is adopted, the steel sand aluminum is automatically added by using the bin, the alloy material is added when the steel is tapped 1/5, and the alloy material is added when the steel is tapped 4/5.
(4) The LF refining adopts 1.15bar micro-positive pressure operation, enters a station to make white slag, ensures that the smelting process is completely in a reducing atmosphere, controls the alkalinity of slag at 13, adopts a bottom argon blowing system, finely adjusts the components of molten steel, strictly controls the nitrogen content in steel to be less than 30ppm, and prevents a large amount of AlN from generating casting blank defects.
(5) Adopting an RH deep processing method, wherein the vacuum degree is less than 2mbar, the vacuum processing time is 22min, and the H content and the N content are 1ppm and 22ppm respectively after the vacuum processing.
(6) In the continuous casting process, the temperature of molten steel in a tundish is 1548 ℃, and the superheat degree of the tundish is 30 ℃; submerged casting and whole-process protection casting are adopted, a continuous casting ladle to a tundish are subjected to long nozzle and argon blowing protection casting, the protection casting pressure is 10.5Mpa, and the argon flow is 102L/min; pouring, namely adding the high-alkalinity carbon-free low-silicon covering agent, wherein an argon blowing plug is used as a tundish plug, and the flow of argon is 4.0L/min. The immersion type water gap uses a magnesium aluminate spinel lining anti-blocking water gap, and the argon sealing flow between the immersion type water gap plates is controlled to be 7.5L/min. When the molten steel for casting submerges a side hole of the submersed nozzle, special covering slag for high-aluminum steel is added, heat transfer and lubrication are controlled, good cooling conditions are provided for a casting blank, and the covering slag comprises the following components in percentage by mass: SiO 22 33%、CaO 30%、MgO 2.4%、Al2O3 3.2%、Fe2O3 0.6%、MnO2 3.3%、Na2O 12%、CaF211 percent, C4.5 percent, alkalinity of 0.9, viscosity of 0.18 Pa.s and density of 0.7 kg/L. Argon blowing control is adopted among the ladle sleeve, the tundish upper nozzle, the lower nozzle and the sliding plate. Continuous casting drawing speed control 1.4m/min。
The continuous casting heat number of the embodiment is 8; the surface quality diagram of the obtained strip steel product is shown in figure 2, and the surface quality diagram is good and has no recess and crack.
Example 3: the production method for improving the continuous casting heat of the high-aluminum steel adopts the following specific process.
(1) Controlling the components of the high-aluminum steel: the chemical composition and the mass percentage of the high-aluminum steel are shown in the table 1.
(2) The high-aluminum steel process flow is a duplex process production line of molten iron pretreatment-100 t converter-LF refining-RH refining-slab caster.
(3) Controlling the end point temperature of the converter to be 1692 ℃, the final slag alkalinity to be 3.9 and the end point oxygen to be 600 ppm; the slag blocking mode of the front sliding plate for blocking slag, the rear slag blocking mark and the sliding plate for blocking slag is adopted, the steel sand aluminum is automatically added by using the bin, the alloy material is added when the steel is tapped 1/5, and the alloy material is added when the steel is tapped 4/5.
(4) LF refining adopts 1.05bar micro-positive pressure operation, enters a station to make white slag operation, ensures that the smelting process is completely in a reducing atmosphere, controls the alkalinity of slag at 14, adopts a bottom argon blowing system, finely adjusts the components of molten steel, strictly controls the nitrogen content in steel to be less than 30ppm, and prevents a large amount of AlN from generating casting blank defects.
(5) Adopting an RH deep processing method, wherein the vacuum degree is less than 2mbar, the vacuum processing time is 18min, and the H content and the N content after the vacuum processing are 1.2ppm and 28ppm respectively.
(6) In the continuous casting process, the temperature of molten steel in a tundish is 1550 ℃, and the superheat degree of the tundish is 30 ℃; submerged casting and full-process protection casting are adopted, a continuous casting ladle to a tundish are subjected to long nozzle and argon blowing protection casting, the protection casting pressure is 11Mpa, and the argon flow is 108L/min; pouring, namely adding the high-alkalinity carbon-free low-silicon covering agent, wherein an argon blowing plug is used as a tundish plug, and the flow of argon is 3.6L/min. The submerged nozzle is a magnesium aluminate spinel lining anti-blocking nozzle, and the argon seal flow between the submerged nozzle plates is controlled to be 9L/min. When the molten steel for casting submerges a side hole of the submersed nozzle, special covering slag for high-aluminum steel is added, heat transfer and lubrication are controlled, good cooling conditions are provided for a casting blank, and the covering slag comprises the following components in percentage by mass: SiO 22 37%、CaO 27%、MgO 2.5%、Al2O3 2.4%、Fe2O3 1.1%、MnO2 3.0%、Na2O 10%、CaF211 percent, C6.0 percent, alkalinity of 0.8, viscosity of 0.16 Pa.s and density of 0.9 kg/L. Argon blowing control is adopted among the ladle sleeve, the tundish upper nozzle, the lower nozzle and the sliding plate. The continuous casting speed is controlled to be 1.5 m/min.
The continuous casting heat number of the embodiment is 8; the surface quality chart of the obtained strip steel product is shown in figure 3, and the surface quality chart is good and has no recess and crack.
Example 4: the production method for improving the continuous casting heat of the high-aluminum steel adopts the following specific process.
(1) Controlling the components of the high-aluminum steel: the chemical composition and the mass percentage of the high-aluminum steel are shown in the table 1.
(2) The high-aluminum steel process flow is a duplex process production line of molten iron pretreatment-100 t converter-LF refining-RH refining-slab caster.
(3) Controlling the end point temperature of the converter to be 1683 ℃, controlling the alkalinity of the final slag to be 4.2 and controlling the end point oxygen to be 500 ppm; the slag blocking mode of the front sliding plate for blocking slag, the rear slag blocking mark and the sliding plate for blocking slag is adopted, the steel sand aluminum is automatically added by using the bin, the alloy material is added when the steel is tapped 1/5, and the alloy material is added when the steel is tapped 4/5.
(4) The LF refining adopts 1.12bar micro-positive pressure operation, enters a station to make white slag operation, ensures that the smelting process is completely in a reducing atmosphere, controls the alkalinity of slag at 11, adopts a bottom argon blowing system, finely adjusts the components of molten steel, strictly controls the nitrogen content in steel to be less than 30ppm, and prevents a large amount of AlN from generating casting blank defects.
(5) Adopting an RH deep processing method, wherein the vacuum degree is less than 2mbar, the vacuum processing time is 15.5min, and the H content and the N content after the vacuum processing are respectively 1.4ppm and 21 ppm.
(6) In the continuous casting process, the temperature of molten steel in a tundish is 1540 ℃, and the superheat degree of the tundish is 25 ℃; submerged casting and whole-process protection casting are adopted, a continuous casting ladle to a tundish are subjected to long nozzle and argon blowing protection casting, the casting pressure is 10Mpa, and the argon flow is 110L/min; pouring, namely adding the high-alkalinity carbon-free low-silicon covering agent, wherein an argon blowing plug is used as a tundish plug, and the flow of argon is 3.2L/min. ImmersionThe magnesium aluminate spinel lining anti-blocking water gap is used as the formula water gap, and the argon seal flow between the immersion type water gap plates is controlled to be 6L/min. When the molten steel for casting submerges a side hole of the submersed nozzle, special covering slag for high-aluminum steel is added, heat transfer and lubrication are controlled, good cooling conditions are provided for a casting blank, and the covering slag comprises the following components in percentage by mass: SiO 22 34%、CaO 28%、MgO 2.4%、Al2O3 3.5%、Fe2O3 1.3%、MnO2 4%、Na2O 10.3%、CaF211.8 percent, C4.7 percent, alkalinity of 0.82, viscosity of 0.15 Pa.s and density of 0.8 kg/L. Argon blowing control is adopted among the ladle sleeve, the tundish upper nozzle, the lower nozzle and the sliding plate. The continuous casting speed is controlled to be 1.45 m/min.
The continuous casting heat number of the embodiment is 8; the surface quality chart of the obtained strip steel product is shown in figure 4, and the surface quality chart is good and has no recess and crack.
Example 5: the production method for improving the continuous casting heat of the high-aluminum steel adopts the following specific process.
(1) Controlling the components of the high-aluminum steel: the chemical composition and the mass percentage of the high-aluminum steel are shown in the table 1.
(2) The high-aluminum steel process flow is a duplex process production line of molten iron pretreatment-100 t converter-LF refining-RH refining-slab caster.
(3) Controlling the end point temperature of the converter to be 1688 ℃, controlling the alkalinity of the final slag to be 4.1 and controlling the end point oxygen to be 520 ppm; the slag blocking mode of the front sliding plate for blocking slag, the rear slag blocking mark and the sliding plate for blocking slag is adopted, the steel sand aluminum is automatically added by using the bin, the alloy material is added when the steel is tapped 1/5, and the alloy material is added when the steel is tapped 4/5.
(4) LF refining adopts 1.08bar micro-positive pressure operation, enters a station to make white slag operation, ensures that the smelting process is completely in a reducing atmosphere, controls the alkalinity of slag to be 12.5, adopts a bottom argon blowing system, finely adjusts the components of molten steel, strictly controls the nitrogen content in steel to be less than 30ppm, and prevents casting blank defects caused by the generation of a large amount of AlN.
(5) Adopting an RH deep processing method, wherein the vacuum degree is less than 2mbar, the vacuum processing time is 15.2min, and the H content and the N content after the vacuum processing are respectively 1.45ppm and 29 ppm.
(6) In the process of continuous casting and pouring, the temperature of the molten steel in the tundishThe temperature is 1542 ℃, and the superheat degree of the tundish is 28 ℃; submerged casting and whole-course protection casting are adopted, a continuous casting ladle to a tundish are subjected to long nozzle and argon blowing protection casting, the protection casting pressure is 10.7Mpa, and the argon flow is 100L/min; pouring, namely adding the high-alkalinity carbon-free low-silicon covering agent, wherein an argon blowing plug is used as a tundish plug, and the flow of argon is 3.0L/min. The immersion type water gap uses a magnesium aluminate spinel lining anti-blocking water gap, and the argon sealing flow between the immersion type water gap plates is controlled to be 8.2L/min. When the molten steel for casting submerges a side hole of the submersed nozzle, special covering slag for high-aluminum steel is added, heat transfer and lubrication are controlled, good cooling conditions are provided for a casting blank, and the covering slag comprises the following components in percentage by mass: SiO 22 33.5%、CaO 27.3%、MgO 2.5%、Al2O3 2.7%、Fe2O3 1.7%、MnO2 3.8%、Na2O 10.7%、CaF213 percent, C4.8 percent, alkalinity of 0.87, viscosity of 0.17 Pa.s and density of 0.8 kg/L. Argon blowing control is adopted among the ladle sleeve, the tundish upper nozzle, the lower nozzle and the sliding plate. The continuous casting speed is controlled to be 1.42 m/min.
The continuous casting heat number of the embodiment is 8; the obtained strip steel product has good surface quality and no recess and crack.
Table 1: the chemical composition and mass percentage (wt%) of the high-aluminum steel obtained in each example
The balance of the ingredients in table 1 is Fe and unavoidable impurities.
Claims (4)
1. A production method for improving the continuous casting heat of high-aluminum steel is characterized by comprising the following steps: the method adopts the working procedures of molten iron pretreatment, converter, LF refining, RH refining and slab continuous casting;
the converter process comprises: steel grit aluminum is automatically added into a converter bin, and slag-free tapping is realized through front and back double slag blocking operations; the final slag alkalinity is 3.8-4.2, the converter endpoint oxygen is controlled to be 400-600 ppm, the converter endpoint temperature is controlled to be 1680 ℃ and above, alloy materials are added when and after 1/5 steel is tapped, and the alloy materials are added when and before 4/5 steel is tapped;
the LF refining process comprises the following steps: carrying out micro-positive pressure operation on the LF furnace; controlling the alkalinity of the slag to be 11-14, performing refining station-entering white slag operation in an LF furnace, and finely adjusting the components of molten steel by adopting a bottom argon blowing system; the fine adjustment of the standard of molten steel component achievement is based on the target component in the control plan, wherein the positive and negative deviation of Als is less than 50ppm, and the positive and negative deviation of other microalloy elements is less than 0.001%;
the RH refining step: adopting an RH deep treatment method, ensuring that the vacuum degree is less than 2mbar, the treatment time is more than 15min, and ensuring that the H content and the N content in the molten steel are less than 1.5ppm and less than 30ppm after treatment;
the continuous casting process comprises the following steps: pouring the tundish, adding a high-alkalinity carbon-free low-silicon covering agent, and using an argon blowing stopper for the tundish stopper.
2. The production method for increasing the continuous casting heat of the high-aluminum steel according to claim 1, characterized by comprising the following steps of: in the continuous casting process, immersion type casting and full-process protection casting are adopted, a long water gap and argon blowing protection casting are adopted from a continuous casting ladle to a tundish, the protection casting pressure is 10-11 Mpa, and the argon flow is 100-110L/min.
3. The production method for increasing the continuous casting heat of the high-aluminum steel according to claim 1, characterized by comprising the following steps of: in the continuous casting process, the argon flow of the argon blowing stopper rod is 3-4L/min, and the argon sealing flow between immersion type water inlet plates is 6-9L/min.
4. The production method for increasing the continuous casting heat of the high-aluminum steel according to any one of claims 1 to 3, characterized by comprising the following steps of: in the continuous casting process, the adopted casting powder comprises the following components in percentage by mass: SiO 22 33%～37%，CaO 27%～30%，MgO 2.4%～2.5%，Al2O3 2.4%～3.5%，Fe2O3 0.6%～1.7%，MnO2 3%～4%，Na2O 10%～12%，CaF2 11%～13%，C 4.5%～6.0%。
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102069157A (en) * | 2009-11-24 | 2011-05-25 | 攀钢集团钢铁钒钛股份有限公司 | Method for preparing high-aluminum steel |
| CN104745767A (en) * | 2015-04-03 | 2015-07-01 | 甘肃东兴铝业有限公司 | Production method for steel shot aluminum for deoxidation |
| CN110724881A (en) * | 2019-10-13 | 2020-01-24 | 唐山钢铁集团高强汽车板有限公司 | Production method for 600MPa peritectic high-aluminum TRIP steel |
-
2020
- 2020-03-17 CN CN202010187520.3A patent/CN111455125B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102069157A (en) * | 2009-11-24 | 2011-05-25 | 攀钢集团钢铁钒钛股份有限公司 | Method for preparing high-aluminum steel |
| CN104745767A (en) * | 2015-04-03 | 2015-07-01 | 甘肃东兴铝业有限公司 | Production method for steel shot aluminum for deoxidation |
| CN110724881A (en) * | 2019-10-13 | 2020-01-24 | 唐山钢铁集团高强汽车板有限公司 | Production method for 600MPa peritectic high-aluminum TRIP steel |
Non-Patent Citations (2)
| Title |
|---|
| 38CrMoAlA高铝钢生产工艺实践;王丰产等;《天津冶金》;20140430(第2期);第18-21页 * |
| 利用还原钙渣配置高碱度低硅无碳中间包覆盖剂;李茂康等;《钢铁研究学报》;20140131;第26卷(第1期);第16-21页 * |
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