CN115502345A - High-drawing-speed continuous casting process for producing 25Mn4 steel - Google Patents
High-drawing-speed continuous casting process for producing 25Mn4 steel Download PDFInfo
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 61
- 239000010959 steel Substances 0.000 title claims abstract description 61
- 238000009749 continuous casting Methods 0.000 title claims abstract description 42
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000001816 cooling Methods 0.000 claims abstract description 75
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 45
- 238000003756 stirring Methods 0.000 claims abstract description 33
- 238000005266 casting Methods 0.000 claims abstract description 24
- 239000000498 cooling water Substances 0.000 claims abstract description 16
- 238000007711 solidification Methods 0.000 claims abstract description 6
- 230000008023 solidification Effects 0.000 claims abstract description 6
- 239000002893 slag Substances 0.000 claims description 22
- 238000005520 cutting process Methods 0.000 claims description 12
- 239000007788 liquid Substances 0.000 claims description 10
- 238000003780 insertion Methods 0.000 claims description 8
- 230000037431 insertion Effects 0.000 claims description 8
- 238000007670 refining Methods 0.000 claims description 7
- 229910000954 Medium-carbon steel Inorganic materials 0.000 claims description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 2
- RIRXDDRGHVUXNJ-UHFFFAOYSA-N [Cu].[P] Chemical compound [Cu].[P] RIRXDDRGHVUXNJ-UHFFFAOYSA-N 0.000 claims description 2
- QZLJNVMRJXHARQ-UHFFFAOYSA-N [Zr].[Cr].[Cu] Chemical compound [Zr].[Cr].[Cu] QZLJNVMRJXHARQ-UHFFFAOYSA-N 0.000 claims description 2
- 229910052804 chromium Inorganic materials 0.000 claims description 2
- 239000011651 chromium Substances 0.000 claims description 2
- 239000010949 copper Substances 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 238000002844 melting Methods 0.000 claims description 2
- 230000008018 melting Effects 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 22
- 238000001514 detection method Methods 0.000 description 11
- 230000007547 defect Effects 0.000 description 7
- 230000001681 protective effect Effects 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 238000005204 segregation Methods 0.000 description 4
- 229910000851 Alloy steel Inorganic materials 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 3
- 229910000915 Free machining steel Inorganic materials 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 238000009628 steelmaking Methods 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 238000003723 Smelting Methods 0.000 description 1
- 229910000746 Structural steel Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000012886 linear function Methods 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
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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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- 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
- B22D11/114—Treating the molten metal by using agitating or vibrating means
- B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields
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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
- B22D11/16—Controlling or regulating processes or operations
- B22D11/166—Controlling or regulating processes or operations for mould oscillation
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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
- B22D11/16—Controlling or regulating processes or operations
- B22D11/20—Controlling or regulating processes or operations for removing cast stock
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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
- B22D11/16—Controlling or regulating processes or operations
- B22D11/22—Controlling or regulating processes or operations for cooling cast stock or mould
- B22D11/225—Controlling or regulating processes or operations for cooling cast stock or mould for secondary cooling
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- 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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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
The invention discloses a high-casting-speed continuous casting process for producing 25Mn4 steel, which mainly comprises the following steps: the continuous casting drawing speed is 2.4-3.0 m/min, and the heat exchange quantity of the cooling water of the crystallizer is 1.0-3.0 MW; the specific water amount of the secondary cooling areas is 0.7-0.9L/kg, the number of the secondary cooling areas is 4-7, the secondary cooling areas are formed by full water cooling and gas water cooling, and the target temperatures of the outlets of the secondary cooling areas are 1050 ℃,1, 1020 ℃,2, 1000 ℃ and 3, 980 ℃ of a foot roll area respectively; the crystallizer vibrates, the vibration frequency is 210-250 times/min; the stirring frequency of the electromagnetic stirrer in the crystallizer is 6-8 Hz; the electromagnetic stirring frequency at the solidification tail end is 7-50 Hz; the pulling speed of the related 25Mn4 steel products produced by the production process is improved by more than 20 percent, the production efficiency is improved, and the obtained casting blank is qualified in quality and has no steel leakage accident.
Description
Technical Field
The invention relates to a high-drawing-speed continuous casting process for steel, in particular to a high-drawing-speed continuous casting process for producing 25Mn4 steel.
Background
At present, with the promotion of a double-carbon policy, the energy conservation and emission reduction of the steel industry are previously regarded. Continuous casting is a link between steel making and steel rolling, which affects the production efficiency and energy consumption of steel products. The developed high-drawing-speed continuous casting technology is widely applied to common steel and reaches the level of saving or avoiding the energy consumption of a heating furnace.
For alloy steel, the production period can be shortened by improving the continuous casting drawing speed, the equipment loss and the labor cost are reduced, the heat consumption and the emission are reduced, and the quality stability of products can be improved. However, how to ensure the product quality of the alloy steel at high drawing speed is still a technical difficulty.
Because the steel-making efficiency is improved and the smelting period is shortened, the matching of a furnace and a machine is poor in the production process, and the continuous casting production pressure is huge. At present, the drawing speed of 25Mn4 series pipe-making steel is 2.0-2.2m/min, although a Chinese patent with the application number of 201911027407.2 discloses a continuous casting production process for preparing low-carbon high-sulfur high-oxygen free-cutting steel at a high drawing speed, the patent only provides a direct production scheme for the high-drawing speed continuous casting of the low-carbon high-sulfur high-oxygen free-cutting steel, the characteristics of different steel types, different blank types and different products are different, and the production technical conditions are also different, so that a process suitable for producing 25Mn4 series pipe-making steel and the like is required to be provided according to the component characteristics of the 25Mn4 steel.
Disclosure of Invention
The invention aims to: the invention aims to provide a high-casting-speed continuous casting process for producing 25Mn4 steel, which can improve the casting speed of continuous casting while ensuring the production quality.
The technical scheme is as follows: the invention relates to a high drawing speed continuous casting process for producing 25Mn4 steel, which comprises the following steps of a converter, a refining furnace, a ladle, a tundish, a crystallizer, a withdrawal and straightening machine, secondary cooling, air cooling and cutting, and the specific process comprises the following steps:
(1) Producing molten steel by a converter and refining the molten steel by a refining furnace, filling the molten steel into a ladle, injecting the molten steel into a tundish through a long nozzle, controlling the superheat degree of the molten steel in the tundish at 15-25 ℃, and injecting the molten steel into a round billet crystallizer with the nominal diameter of a casting blank section of 150-180 mm; medium carbon steel high-pulling-speed crystallizer covering slag is adopted, and the thickness of a liquid slag layer is 13-15 mm;
(2) The continuous casting drawing speed is 2.4-3.0 m/min; the slag consumption is 0.35-0.5kg/t steel; the heat exchange quantity of the cooling water of the crystallizer is 1.0-3.0 MW; the blank is simultaneously vibrated by a crystallizer, the vibration frequency is 210-250 times/min, the amplitude is within +/-4 mm, and the skewness is not more than 0.2; the stirring frequency of an electromagnetic stirrer in the crystallizer is 6-8 Hz, and the current is 380-500A;
(3) The specific water amount of the secondary cooling area is 0.7-0.9L/kg, the number of the secondary cooling areas is 4-7, and the secondary cooling areas are a foot roller area, a secondary cooling 1 area, a secondary cooling 2 area and a secondary cooling 3 area from top to bottom in sequence, wherein the foot roller area is fully water-cooled and the number of the foot roller area is 1, the other areas are air-water-cooled, the number of the air-water-cooled areas is 1-2 respectively, the cooling mode is dynamic secondary cooling control based on target temperature, the target temperatures of outlets of the areas are 1050 ℃, 1020 ℃, 1000 ℃ and 980 ℃ of the foot roller area, and the temperature of each area is allowed to be +/-20 ℃ deviation;
(4) Electromagnetic stirring is carried out at the solidification end of the air cooling zone, the stirring frequency of the electromagnetic stirrer is 7-50 Hz, and the current is 550-850A;
(5) Slowly cooling for more than 24h after cutting the continuous casting slab.
Further, the crystallizer uses a submerged nozzle, the outlet of the nozzle can be in the form of 1 hole, 2 holes, 3 holes, 4 holes, 5 holes and the like, and the insertion depth of the nozzle is 140-180mm; the insertion depth of the water gap is deeper, so that the resistance of molten steel to upward flow is increased, the liquid level fluctuation of the crystallizer is more stable, and the slag entrapment risk is reduced.
Furthermore, the length of the crystallizer is 0.7-1.2m, the material is one of pure copper, deoxidized phosphor copper and chromium zirconium copper, the inner surface is plated with a Cr or Ni layer, and the inner cavity is a continuous inverted cone with the depth of 0.5-2.0% from top to bottom.
Firstly, the cooling water quantity of the crystallizer is 140-170 m 3 H, the water temperature difference is 5-9 ℃, the outer surface of the crystallizer is cooled by water, the width of a water seam is 3-4mm, and the water flow speed is not lower than 6m/s; faster water flow rate and higher heat exchange efficiency can be achieved for the same total water volume.
Furthermore, the high-pulling-speed covering slag is high-melting-speed covering slag with medium alkalinity, low viscosity and low melting temperature, and can realize efficient and uniform heat transfer and lubrication.
Further, the number of each area of the air cooling area in the step (3) is increased along with the increase of the drawing speed, when the drawing speed is the maximum, the secondary cooling area is composed of 1 full water-cooled foot roll area and 6 air-water cooling areas, specifically two areas 1, two areas 2 and two areas 3, the increase of the number of the secondary cooling areas is beneficial to the control of the surface temperature and the solidification process of the casting blank under the high drawing speed, and the high-efficiency heat transfer under the high drawing speed is realized by adopting a mode of a plurality of groups of cooling areas and enhanced cooling.
Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: the pulling speed of related products such as 25Mn4 steel produced by the production process is improved by more than 20 percent, the production efficiency is improved, and the obtained casting blank is qualified in quality and has no steel leakage accident.
Detailed Description
The technical solution of the present invention is further explained below.
Following the steps of the above method, a specific example of producing 25Mn4 steel is provided below.
25Mn4 Steel composition, wt.%, as set forth in Table 1 below
TABLE 1
The invention mainly provides a 25Mn4 steel high-pulling-speed continuous casting process, wherein the 25Mn4 steel belongs to medium-carbon steel alloy steel, the specific components of molten steel are shown in Table 1, the production requirements of casting blank sections of different circles of 150-180mm can be met, the larger the diameter of the casting blank section is, the corresponding pulling speed is properly reduced within the range of 2.4m/min-3.0m/min for ensuring the casting blank quality, the pulling speed of a 150mm circle blank is 2.7-3.0m/min, the pulling speed of a 160mm circle blank is 2.7-2.9m/min, the pulling speed of a 170mm circle blank is 2.5-2.8m/min, and the pulling speed of a 180mm circle blank is 2.4-2.6m/min; among other parameters, the water heat exchange value of the crystallizer and the total water ratio of the secondary cooling area are positively correlated with the pulling speed, and the parameter values are properly adjusted along with the change of the pulling speed; in order to meet the solidification characteristic of 25Mn4 steel at a high drawing speed, a larger electromagnetic stirring frequency and a larger current are adopted at the solidification tail end, molten steel feeding at the tail end is enhanced, the internal quality of a casting blank is ensured, and the larger the diameter of the section of the casting blank is, the higher the required tail end stirring frequency is; the electromagnetic stirring frequency of the crystallizer is higher, the crystallizer is combined with the insertion depth of a deeper submerged nozzle, high-frequency electric stirring is used, and meanwhile, high current is adopted, so that the isometric crystal rate requirement and the isometric crystal uniform distribution of different casting blank sections of 150-180mm are met, the flow field of molten steel in the crystallizer is ensured to be stable, a better metallurgical effect is achieved, and the stirring frequency in the crystallizer is improved along with the increase of the pulling speed; the vibration frequency is higher, the amplitude is lower, the shallow depth of the casting blank vibration mark can be obtained under the condition of higher pulling speed, the control on the surface quality of the casting blank is more accurate, and the vibration frequency is also adjusted in positive correlation with the pulling speed. The parameters of each process in the whole process are matched with each other, so that the production quality of the 25Mn4 steel at a high drawing speed can be guaranteed, and the following examples and comparative examples are provided for specific description.
Example 1
The process flow for producing the 150mm round billet of the 25Mn4 steel by adopting a high-casting-speed continuous casting mode comprises the following steps: converter → refining furnace → ladle → tundish → crystallizer → withdrawal and straightening unit → secondary cooling → air cooling → cutting.
The method comprises the steps of firstly, checking the precision condition of equipment before production, controlling the arc alignment deviation of a crystallizer and a foot roller within +/-1.0 mm, controlling the centering deviation of a water gap of the crystallizer within +/-3 mm, ensuring the unobstructed rate of a nozzle to be 100 percent, and ensuring that a withdrawal and straightening machine and a cutting machine have no faults. The converter produces molten steel meeting the continuous casting requirement, the molten steel is refined by a refining furnace, the molten steel temperature, the composition, the deoxidation degree and the purity quality meet the requirement, the molten steel is contained and conveyed by a ladle, the ladle is placed on a rotary table, the rotary table receives the refined molten steel, the ladle rotates and moves to the position above the crystallizer, the molten steel is poured into a tundish through a long nozzle, the molten steel is poured into the crystallizer through an immersion nozzle by the tundish, the nozzle outlet is 1 hole, the nozzle insertion depth is 180mm, the diameter of the section of the upper opening of the crystallizer is 161mm, and the molten steel is poured into a round billet crystallizer with the nominal diameter of the casting blank section of 150 mm;
step two, when the liquid level height of the molten steel reaches two thirds of the total height of the crystallizer, starting a withdrawal and straightening machine, starting vibration and adding protective slag at the same time, wherein the protective slag is high-melting-speed medium-alkalinity low-viscosity low-melting-temperature performance protective slag, the thickness of a liquid slag layer is 15mm, and the consumption of the protective slag is 0.35kg/t; protective pouring is adopted in the whole process, so that secondary oxidation of molten steel is prevented; setting the initial drawing speed to be 0.5-0.8m/min, and then increasing the drawing speed to the working drawing speed by the amplitude of 0.6-1.2m/min per minute; the liquid level fluctuation of an unsteady-state crystallizer is controlled to be +/-6 mm, the steady-state fluctuation is controlled to be +/-3 mm, molten steel in the crystallizer is condensed with a dummy bar after casting, the molten steel is pulled by a withdrawal and straightening machine, a casting blank with a liquid core is continuously pulled out from the lower opening of the crystallizer along with the dummy bar, the pulling speed is 3.0m/min, the back taper of the crystallizer is 1.1%, the length of the crystallizer is 1.0m, water is introduced outside the crystallizer for cooling, the water temperature difference is 8.6 ℃, the water gap width is 4mm, the flow rate of cooling water is 15m/s, and the heat exchange capacity of cooling water of the crystallizer is 1.2MW; the blank is pulled and simultaneously vibrated by a crystallizer, the vibration frequency of the crystallizer is set to be a linear function increasing along with the pulling speed, the vibration frequency is 243 times/min, the amplitude is +/-3 mm, and the skewness is 0.1; opening a crystallizer at a normal pulling speed for electromagnetic stirring, wherein the stirring current intensity is 380A, and the frequency is 8Hz;
thirdly, secondarily cooling the casting blank discharged from the lower opening of the crystallizer, wherein the secondary cooling specific water amount is 0.9L/kg, the number of secondary cooling zones is 7, and the secondary cooling zones are respectively a foot roll zone, a secondary cooling 1 zone, a secondary cooling 2 zone and a secondary cooling 3 zone; the foot roll area is fully water-cooled, and the number is 1; the number of the secondary cooling area 1, the secondary cooling area 2 and the secondary cooling area 3 is two respectively, and the secondary cooling areas are used for air-water cooling; the cooling mode is dynamic secondary cooling control based on target temperature, and the target temperature at the outlet of each area is 1050 ℃, 1020 ℃, 1000 ℃ in 2 ℃ and 980 ℃ in 3 ℃ of a foot roll area, and the deviation is allowed to be +/-20 ℃.
Fourthly, performing electromagnetic stirring at the tail end of the air cooling area, wherein the stirring current is 550A, and the frequency is 7Hz;
and fifthly, cutting the casting blank into a cutting position by adopting flame. And (5) carrying out off-line stacking and slow cooling for 24h during cutting.
And (3) quality detection results: the continuous casting slab is eroded according to GBT 226-2015 'macrostructure and defect acid erosion inspection method for steel', and is rated according to YB/T153-2015 'macrostructure defect rating diagram for high-quality structural steel continuous casting slab', the inner center shrinkage rating is 0.5, the center segregation rating is 0.5, and no obvious defect exists on the surface.
Example 2
The 25Mn4 steel 160mm round billet is produced by adopting a high-casting-speed continuous casting mode, the technological production flow is basically the same as that of the example 1, and the difference parameters are as follows: the outlet of a water gap of the crystallizer is 3 holes, the insertion depth of the water gap is 170mm, the pulling speed is 2.8m/min, the thickness of a liquid slag layer is 14mm, the length of the crystallizer is 1.0m, the outside of the crystallizer is cooled by water, the water temperature difference is 7.8 ℃, the width of a water gap is 3.9mm, the flow rate of cooling water is 12m/s, and the heat exchange quantity of the cooling water of the crystallizer is 1.6MW; the blank is simultaneously vibrated by a crystallizer, the vibration frequency is 232 times/min, the amplitude is +/-3 mm, and the skewness is 0.1; a crystallizer is adopted for electromagnetic stirring, the stirring current intensity is 420A, and the frequency is 7Hz; the consumption of the covering slag is 0.38kg/t; the secondary cooling specific water amount is 0.86L/kg, the number of secondary cooling areas is 6, and the secondary cooling areas are a foot roller area, a 1 area, two 2 areas and two 3 areas respectively; performing electromagnetic stirring at the tail end in an air cooling area, wherein the stirring current is 620A, and the frequency is 16Hz; and (5) slowly cooling the wire stack for 36h when cutting.
And (3) quality detection results: the detection standard is the same as that of the example 1, the surface of the continuous casting billet has no obvious defects, the rating of the internal center shrinkage cavity is 1.0, and the rating of the center segregation is 1.0.
Example 3
The 170mm round billet of 25Mn4 steel is produced by adopting a high casting speed continuous casting mode, the process production flow is basically the same as that of the embodiment 1, and the difference parameters are as follows: the outlet of a water gap of the crystallizer is 4 holes, the insertion depth of the water gap is 160mm, the pulling speed is 2.6m/min, the thickness of a liquid slag layer is 14mm, the length of the crystallizer is 0.9m, the outside of the crystallizer is cooled by water, the water temperature difference is 7.5 ℃, the width of a water gap is 3.6mm, the flow rate of cooling water is 12.0m/s, and the heat exchange quantity of the cooling water of the crystallizer is 2.4MW; a crystallizer is adopted for vibration while throwing, the vibration frequency is 223 times/min, the amplitude is +/-3.2 mm, and the skewness is 0.1; electromagnetically stirring by adopting a crystallizer, wherein the stirring current intensity is 450A, and the frequency is 7Hz; the consumption of the covering slag is 0.4kg/t; the secondary cooling specific water amount is 0.78L/kg, the number of secondary cooling zones is 5, and the secondary cooling zones are a foot roll zone, a 1 zone, a 2 zone and two 3 zones respectively; performing electromagnetic stirring at the tail end in the air cooling area, wherein the stirring current is 760A, and the frequency is 30Hz; and (5) stacking and slowly cooling the wires for 48h when cutting.
And (3) quality detection results: the detection standard is the same as that of example 1, the surface of the continuous casting billet has no obvious defects, the internal center shrinkage rating is 1.0, and the center segregation rating is 1.0.
Example 4
The method for producing the 180mm round billet of the 25Mn4 steel by adopting the high casting speed continuous casting mode has the process production flow basically the same as that of the example 1, and the difference parameters are as follows: the outlet of a water gap of the crystallizer is 5 holes, the insertion depth of the water gap is 140mm, the pulling speed is 2.4m/min, the thickness of a liquid slag layer is 13mm, the back taper of the crystallizer is 1.1%, the length of the crystallizer is 0.9m, water is introduced outside the crystallizer for cooling, the temperature difference of water is 7.5 ℃, the width of a water gap is 3.2mm, the flow rate of cooling water is 10m/s, and the heat exchange quantity of the cooling water of the crystallizer is 3.0MW; a crystallizer is adopted to vibrate when the billet is pulled, the vibration frequency is 210 times/min, the amplitude is +/-3.5 mm, and the skewness is 0.1; electromagnetically stirring by adopting a crystallizer, wherein the stirring current intensity is 500A, and the frequency is 6Hz; the consumption of the covering slag is 0.42kg/t; the secondary cooling specific water amount is 0.7L/kg, the number of secondary cooling zones is 4, and the secondary cooling zones are a foot roll zone, a 1 zone, a 2 zone and a 3 zone respectively; performing electromagnetic stirring at the tail end in an air cooling area, wherein the stirring current is 850A, and the frequency is 50Hz; and (5) stacking and slowly cooling the wires for 72h during cutting.
And (3) quality detection results: the detection standard is the same as that of example 1, the surface of the continuous casting billet has no obvious defects, the rating of the internal center shrinkage cavity is 1.5, and the rating of the center segregation is 1.5.
Comparative example 1
The 150mm round billet of 25Mn4 steel is produced by adopting a high-casting-speed continuous casting mode, the technological production flow is basically the same as that of the example 1, and the difference parameters are as follows: the continuous casting drawing speed is 3.5m/min, the heat exchange quantity of cooling water of the crystallizer is 3.4MW, the vibration frequency of the crystallizer is 260 times/min, the amplitude is +/-5 mm, the electromagnetic stirring frequency of the crystallizer is 8Hz, the current is 380A, the secondary cooling specific water quantity is 1.0L/kg, the electromagnetic stirring frequency of the tail end is 6Hz, and the current is 520A.
And (3) quality detection results: the detection standard is the same as that of the example 1, the surface of the continuous casting billet has longitudinal cracks and transverse cracks, the central shrinkage rating is 2.5, and the central porosity rating is 3.0.
Comparative example 2
The method adopts a conventional drawing speed continuous casting mode to produce 150mm round billets of 25Mn4 steel, the process production flow is basically the same as that of the example 1, and the difference parameters are as follows: the continuous casting speed is 2.0m/min, the cooling water quantity of the crystallizer is 120m 3 The heat exchange quantity of cooling water of the crystallizer is 0.8MW, the vibration frequency of the crystallizer is 280 times/min, the amplitude is +/-3 mm, the electromagnetic stirring frequency of the crystallizer is 3Hz, the current is 300A, the secondary cooling specific water quantity is 0.6L/kg, the electromagnetic stirring frequency at the tail end is 5Hz, and the current is 340A.
And (3) quality detection results: the detection standard is the same as that of example 1, the surface of the continuous casting billet has no obvious defects, the central shrinkage rating is 1.5, and the central porosity rating is 1.0.
The pulling rate used in comparative example 2 was lower than that of example 1, the quality test results were slightly inferior to that of example 1, the pulling rate was slower, the production time was longer than that of example 1, and the efficiency was lower.
Claims (6)
1. A high drawing speed continuous casting process for producing 25Mn4 steel comprises a converter, a refining furnace, a ladle, a tundish, a crystallizer, a withdrawal and straightening unit, secondary cooling, air cooling and cutting, and is characterized by comprising the following specific processes:
(1) After molten steel is produced by a converter and refined by a refining furnace, molten steel is filled in a ladle, the molten steel is injected into a tundish through a long nozzle, the superheat degree of the molten steel in the tundish is 15-25 ℃, and the molten steel is injected into a round billet crystallizer with the nominal diameter of a casting blank section of 150-180 mm; adopting medium carbon steel high drawing speed crystallizer covering slag;
(2) The continuous casting drawing speed is 2.4-3.0 m/min; the heat exchange quantity of the cooling water of the crystallizer is 1.0-3.0 MW; the blank is pulled and simultaneously vibrated by a crystallizer, the vibration frequency is 210-250 times/min, the amplitude is within +/-4 mm, and the skewness is not more than 0.2; the stirring frequency of an electromagnetic stirrer in the crystallizer is 6-8 Hz, and the current is 380-500A;
(3) The specific water amount of the secondary cooling area is 0.7-0.9L/kg, the number of the secondary cooling areas is 4-7, and the secondary cooling areas are a foot roller area, a secondary cooling area 1, a secondary cooling area 2 and a secondary cooling area 3 from top to bottom in sequence, wherein the foot roller area is fully water-cooled and the number of the foot roller area is 1, the other areas are air-water-cooled, the number of the air-water-cooled areas is 1-2 respectively, the cooling mode is dynamic secondary cooling control based on target temperature, the target temperatures of outlets of the areas are 1050 ℃, 1020 ℃, 1000 ℃ and 980 ℃ of the foot roller area, 980 ℃ of the area 2 and 980 ℃ of the area respectively, and the temperature deviation of the areas is +/-20 ℃;
(4) Electromagnetic stirring is carried out at the solidification end of the air cooling zone, the stirring frequency of the electromagnetic stirrer is 7-50 Hz, and the current is 550-850A;
(5) Slowly cooling for more than 24h after cutting the continuous casting slab.
2. The high casting speed continuous casting process according to claim 1, wherein the crystallizer uses a submerged nozzle, the nozzle outlet can be in the form of 1 hole, 2 holes, 3 holes, 4 holes, 5 holes and the like, and the nozzle insertion depth is 140-180mm.
3. The high-pulling-rate continuous casting process according to claim 2, wherein the crystallizer has a length of 0.7-1.2m, is made of one of pure copper, deoxidized phosphorus copper and chromium zirconium copper, is plated with a Cr or Ni layer on the inner surface, and has an inner cavity with a continuous inverse taper of 0.5-2.0% from top to bottom.
4. The high-casting-speed continuous casting process according to claim 1, wherein the amount of cooling water of the crystallizer is 140-170 m 3 H, the temperature difference of water is 5-9 ℃, water is introduced to the outer surface of the crystallizer for cooling, and water seams are formedThe width is 3-4mm, and the water flow rate is not less than 6m/s.
5. The high-casting-speed continuous casting process according to claim 1, wherein the high-casting-speed covering slag is high-melting-speed covering slag with medium alkalinity, low viscosity and low melting temperature performance, the thickness of a liquid slag layer is 13-15 mm, and the slag consumption is 0.35-0.5kg/t steel.
6. The high casting speed continuous casting process according to claim 1, wherein the number of the zones of the gas cooling zone in the step (3) is increased as the casting speed is increased.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101147966A (en) * | 2007-10-29 | 2008-03-26 | 江苏沙钢集团淮钢特钢有限公司 | Continuous casting columnar crystallizer small square blank and its columnar crystal control method |
| CN101653822A (en) * | 2009-05-25 | 2010-02-24 | 莱芜钢铁股份有限公司 | Electric furnace continuous casting short process production method of oil well pipe billets |
| JP2010172930A (en) * | 2009-01-29 | 2010-08-12 | Kobe Steel Ltd | Continuous casting method for medium carbon steel by means of change in casting speed and molten metal surface level |
| CN102303108A (en) * | 2011-09-22 | 2012-01-04 | 首钢贵阳特殊钢有限责任公司 | Continuous casting production process for improving quality of free cutting steel casting blank |
| CN102527956A (en) * | 2012-02-21 | 2012-07-04 | 衡阳华菱钢管有限公司 | Continuous-cast P91-steel round pipe billet and production process thereof |
| CN103639384A (en) * | 2013-12-17 | 2014-03-19 | 河北钢铁股份有限公司唐山分公司 | Continuous casting crystallizer mold powder of sheet billet at high casting speed |
| CN106312000A (en) * | 2016-10-12 | 2017-01-11 | 中原特钢股份有限公司 | 18CrNiMo7-6 round billet continuous casting method for vertical type continuous casting production gear steel |
| CN107186192A (en) * | 2017-04-26 | 2017-09-22 | 江苏省沙钢钢铁研究院有限公司 | Continuous casting method for improving segregation of billet cord steel |
| US20180056348A1 (en) * | 2016-08-25 | 2018-03-01 | Jiangsu Shenyuan Special Steel Co.,Ltd. | Method for Producing Polishing Bar Made of Valve Steel 53Cr21Mn9Ni4N |
| CN111590043A (en) * | 2020-06-30 | 2020-08-28 | 广东韶钢松山股份有限公司 | Design method of secondary cooling water in high-carbon steel continuous casting process and continuous casting billet preparation method |
| CN113430449A (en) * | 2021-06-24 | 2021-09-24 | 河南中原特钢装备制造有限公司 | Smelting and continuous casting production process of sulfur-containing free-cutting steel ASTM1141 |
| CN114086081A (en) * | 2021-11-19 | 2022-02-25 | 中天钢铁集团有限公司 | Method for controlling center loosening in cold forging steel production by small-section casting blank |
-
2022
- 2022-07-14 CN CN202210824267.7A patent/CN115502345A/en active Pending
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101147966A (en) * | 2007-10-29 | 2008-03-26 | 江苏沙钢集团淮钢特钢有限公司 | Continuous casting columnar crystallizer small square blank and its columnar crystal control method |
| JP2010172930A (en) * | 2009-01-29 | 2010-08-12 | Kobe Steel Ltd | Continuous casting method for medium carbon steel by means of change in casting speed and molten metal surface level |
| CN101653822A (en) * | 2009-05-25 | 2010-02-24 | 莱芜钢铁股份有限公司 | Electric furnace continuous casting short process production method of oil well pipe billets |
| CN102303108A (en) * | 2011-09-22 | 2012-01-04 | 首钢贵阳特殊钢有限责任公司 | Continuous casting production process for improving quality of free cutting steel casting blank |
| CN102527956A (en) * | 2012-02-21 | 2012-07-04 | 衡阳华菱钢管有限公司 | Continuous-cast P91-steel round pipe billet and production process thereof |
| CN103639384A (en) * | 2013-12-17 | 2014-03-19 | 河北钢铁股份有限公司唐山分公司 | Continuous casting crystallizer mold powder of sheet billet at high casting speed |
| US20180056348A1 (en) * | 2016-08-25 | 2018-03-01 | Jiangsu Shenyuan Special Steel Co.,Ltd. | Method for Producing Polishing Bar Made of Valve Steel 53Cr21Mn9Ni4N |
| CN106312000A (en) * | 2016-10-12 | 2017-01-11 | 中原特钢股份有限公司 | 18CrNiMo7-6 round billet continuous casting method for vertical type continuous casting production gear steel |
| CN107186192A (en) * | 2017-04-26 | 2017-09-22 | 江苏省沙钢钢铁研究院有限公司 | Continuous casting method for improving segregation of billet cord steel |
| CN111590043A (en) * | 2020-06-30 | 2020-08-28 | 广东韶钢松山股份有限公司 | Design method of secondary cooling water in high-carbon steel continuous casting process and continuous casting billet preparation method |
| CN113430449A (en) * | 2021-06-24 | 2021-09-24 | 河南中原特钢装备制造有限公司 | Smelting and continuous casting production process of sulfur-containing free-cutting steel ASTM1141 |
| CN114086081A (en) * | 2021-11-19 | 2022-02-25 | 中天钢铁集团有限公司 | Method for controlling center loosening in cold forging steel production by small-section casting blank |
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