CN116851730A - Method and device for reducing fine inclusions in molten steel - Google Patents
Method and device for reducing fine inclusions in molten steel Download PDFInfo
- Publication number
- CN116851730A CN116851730A CN202210314053.5A CN202210314053A CN116851730A CN 116851730 A CN116851730 A CN 116851730A CN 202210314053 A CN202210314053 A CN 202210314053A CN 116851730 A CN116851730 A CN 116851730A
- Authority
- CN
- China
- Prior art keywords
- retaining wall
- molten steel
- flow guide
- flow
- internal rotation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 162
- 239000010959 steel Substances 0.000 title claims abstract description 162
- 238000000034 method Methods 0.000 title claims abstract description 51
- 239000003381 stabilizer Substances 0.000 claims abstract description 72
- 239000002893 slag Substances 0.000 claims abstract description 17
- 238000005266 casting Methods 0.000 claims abstract description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 12
- 239000007788 liquid Substances 0.000 claims abstract description 7
- 239000002245 particle Substances 0.000 claims abstract description 6
- 239000000463 material Substances 0.000 claims description 9
- 239000000126 substance Substances 0.000 claims description 9
- 229910052742 iron Inorganic materials 0.000 claims description 8
- 238000002347 injection Methods 0.000 claims description 7
- 239000007924 injection Substances 0.000 claims description 7
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 5
- 230000009471 action Effects 0.000 claims description 5
- 230000004888 barrier function Effects 0.000 claims 1
- 238000007667 floating Methods 0.000 abstract description 10
- 230000008569 process Effects 0.000 description 15
- 238000009749 continuous casting Methods 0.000 description 12
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 238000007670 refining Methods 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 230000001976 improved effect Effects 0.000 description 8
- 230000009286 beneficial effect Effects 0.000 description 7
- 238000011282 treatment Methods 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 238000009628 steelmaking Methods 0.000 description 6
- 238000007664 blowing Methods 0.000 description 5
- 230000003749 cleanliness Effects 0.000 description 5
- 230000001965 increasing effect Effects 0.000 description 5
- 230000002035 prolonged effect Effects 0.000 description 5
- 238000003723 Smelting Methods 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 238000009489 vacuum treatment Methods 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 239000011575 calcium Substances 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000001914 filtration Methods 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000006477 desulfuration reaction Methods 0.000 description 2
- 230000023556 desulfurization Effects 0.000 description 2
- 230000005672 electromagnetic field Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000011449 brick Substances 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000004581 coalescence Methods 0.000 description 1
- 238000010835 comparative analysis Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000010436 fluorite Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/11—Treating the molten metal
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- 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
- B22D41/02—Linings
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
A method and apparatus for reducing fine inclusions in molten steel comprising: a) An internal rotation type current stabilizer is arranged at the bottom of the tundish below the corresponding long water gap, and front and rear porous diversion retaining walls are respectively arranged at the two sides of the internal rotation type current stabilizer to form a double-layer retaining wall structure; b) The molten steel after casting enters the internal rotation type flow stabilizer through the long nozzle impact, the casting molten steel turns to disturb the initial flow field of the molten steel in the tundish to form a rotational flow, micron-sized inclusions in the flow can be gathered towards the center and collide and grow up at the center, and cluster-shaped inclusion particle clusters with a certain size are removed after floating up to the liquid level of the steel slag; c) Molten steel enters a double-layer retaining wall structure from the front porous flow guide retaining wall, and unsteady flowing molten steel passes through the double-layer retaining wall structure to obtain a stable flow field; the front and rear porous flow-guiding retaining walls are utilized to adjust the flow field direction of molten steel in the tundish, and fine inclusions are adsorbed and removed by top slag. Compared with the prior tundish molten steel, the method improves the removal rate of fine inclusions by 15 percent, and fully ensures the high purity of the molten steel required by high-quality steel.
Description
Technical Field
The invention relates to the field of steelmaking, in particular to a method and a device for reducing fine inclusions in molten steel.
Background
The inclusion in the molten steel is an important factor affecting the production and application of steel, the quantity, the size and the dispersion degree of the inclusion in the steel have great influence on the quality of the steel, and the effective control of nonmetallic inclusion in the steel is a key for improving the quality of steel products and is always an important point of attention in steel production and scientific research. However, with the increasing demands of people on the cleanliness of steel, the requirements on the performance of specific steel are continuously improved, and the removal of inclusions below 20 μm is continuously emphasized, especially for high-clean steel such as pipeline steel, automobile plate steel, high-grade silicon steel and the like. The inclusion control is a system engineering related to each process of the whole process of steel production, so that the control technology of the inclusion of the high-purity molten steel generally relates to the whole process of molten iron pretreatment, smelting, refining and continuous casting.
Chinese patent CN102676725a discloses a method for controlling inclusions in steel: 1) And (5) performing strong desulfurization by blowing Mg to perform molten iron pretreatment. 2) Adding fluorite, active lime, aluminum blocks and alloy into the tapping of the converter for pre-refining. 3) Deep desulfurization is carried out in the refining process, and high-alkalinity strong-reducibility slag is adopted to control the S content in molten steel; the LF treatment process satisfies [ Als ] of 0.03-0.06%. 4) Vacuum treatment is carried out on molten steel, and Ca treatment is carried out after the vacuum treatment. Thus greatly reducing the number of large-size inclusions in molten steel and meeting the severe requirements of X70 pipeline steel on the inclusions. The technique adopts a smelting process method to reduce and control inclusions in steel, thereby meeting the steel quality requirement; the smelting and refining treatment period is longer, and certain difficulty is brought to the improvement of the production efficiency.
Chinese patent CN102816898A describes a method for improving the quality of the top slag and reducing the oxidizing properties of the top slag. And adding the composite deoxidizer for the second time during the vacuum treatment of the molten steel, and blowing argon to adjust the components. And adding a composite deoxidizer to the top slag of the steel ladle after the molten steel is treated for the third time. Thus, the number of the IF steel inclusions is reduced, and the surface quality of the automobile plate is improved.
Chinese patent CN103014220a describes a method for improving the composition and size of nonmetallic inclusions in steel grades to increase the purity of the molten steel. The melting point (1500-1650 ℃) and shape and size of nonmetallic inclusion in molten steel are changed by respectively carrying out calcium treatment and soft blowing at the end of LF refining white slag and the end of RH vacuum treatment and controlling the chemical composition of nonmetallic. So that cracks can be avoided in the process of rolling and using the pipeline steel. The technology is a method for modifying nonmetallic inclusion, and achieves the aim of improving the quality qualification rate of steel products.
Chinese patent CN102517419a discloses a method for improving the cleanliness of molten steel and reducing the inclusion content, which makes nonmetallic inclusions in steel enter a plastic zone, changes the morphology of nonmetallic inclusions, and improves the fatigue life of steel. The method comprises the processes of molten iron treatment, converter smelting, ladle refining and continuous casting. Particularly, the casting powder with the alkalinity of 0.8-0.85 is selected in the continuous casting process, and the crystallizer adopts electromagnetic stirring to control the current intensity and frequency. The technique controls inclusions in the whole steelmaking process, and achieves good steel quality.
By comparative analysis of the prior art, we found that various aspects of the whole steelmaking process have a method for reducing and controlling inclusions in molten steel.
1. In terms of steelmaking technology, such as component control, chemical components in steel are optimized, beneficial elements are increased, and harmful elements are reduced.
The chemical treatment is carried out, and the treatments of calcium and rare earth are mostly carried out, so that oxygen and sulfur-based inclusions in steel are removed as much as possible, the morphology of the inclusions is controlled, and the cast structure is improved.
Refining, slagging modification or electromagnetic stirring.
The method has the advantages of complex equipment, high input cost, difficult process accurate control and relative effectiveness on large-scale inclusion.
2. The continuous casting tundish is regarded as an important metallurgical vessel for connecting the ladle and the crystallizer, and can smoothly convey the molten steel with a predetermined flow rate and temperature to the crystallizer without pollution. The control of the inclusion in the molten steel in the tundish is the last and most critical process in the steelmaking and continuous casting process, and the inclusion removal effect and mechanism are of great concern.
In the continuous casting process, the more extensive methods for removing molten steel inclusions include a bubble adsorption method, an electromagnetic stirring method in a crystallizer and a filtering separation method.
1. Argon bubbling is adopted in the tundish for removing. Such as a tundish air curtain wall, buried air bricks, a tundish sealed argon blowing, etc. But the steel mill reflects unstable use effect: the inclusion removal effect with small size is not obvious; the gas blowing amount is limited, and the liquid level fluctuates; high cost, long service life and poor safety. Therefore, the bubble method has easy operation, wide application in production and good effect of removing large-scale inclusion. However, the effect of removing the fine inclusions is weak, and new bubble inclusions may be caused, and the temperature of the molten steel may be lowered.
2. The method for removing impurities by electromagnetic field in the crystallizer mainly comprises electromagnetic stirring and electromagnetic braking.
Under the action of electromagnetic field force, the flow field of molten steel in the crystallizer is changed, so that the recirculation zone is eliminated, the retention time of inclusions in molten steel is prolonged, the probability of collision of the inclusions is improved, and the collisions, coalescence and floating of the inclusions in the center of the crystallizer are promoted.
The electromagnetic braking is that the magnetic field generates electromagnetic force opposite to the flowing direction of molten steel, so that the impact depth of molten steel in the crystallizer is reduced, slag is prevented from being rolled up, and the method has no requirement on the size of inclusions. The electromagnetic purification method has the advantages of wide process, flexible operation, complex equipment and large required electric power resource.
3. The filtering separation method directly purifies impurities in molten steel if a filtering device is adopted, but the filter has the advantages of complex manufacturing process, expensive materials, easy blockage and high replacement frequency, and can not be suitable for continuous casting operation with high strength and long time, so that large-scale practical application is not seen at present.
The presence of inclusions, particularly inclusions smaller than 20 μm, in high-clean steels such as pipeline steels directly causes defects such as hydrogen induced cracking, which greatly affects the performance of the pipeline steels. In addition, inclusions in steel have a great influence on the physical properties of steel such as plasticity, toughness, fatigue strength, and the like. Therefore, in addition to the necessary technical measures adopted in the steelmaking refining process, a relatively simple, effective and low-cost method for reducing fine inclusions in molten steel in a tundish must be researched, so that the quality and market competitiveness of steel products are improved.
Disclosure of Invention
The invention aims to provide a method and a device for reducing fine inclusions in molten steel, which are designed through a tundish, buffer the injection flow of molten steel, control turbulent kinetic energy, promote the collision and floating of the inclusions, optimize the flow field of the molten steel of the tundish, prolong the residence time of the molten steel, promote the collision, agglomeration, growth and full floating of the fine inclusions smaller than 20um, so as to purify the molten steel.
In order to achieve the above purpose, the technical scheme of the invention is as follows:
a method of reducing fine inclusions in molten steel comprising:
a) An internal rotation type current stabilizer is arranged below a corresponding long water gap in the middle ladle, the internal rotation type current stabilizer is a circular shell with an opening at the upper end, at least three arc-shaped stop blocks are annularly arranged in the center of the bottom surface of the internal rotation type current stabilizer, and overflow holes are formed in the side wall of the internal rotation type current stabilizer; the inner bottoms of the tundish at the two sides of the internal rotation type current stabilizer are respectively provided with a front porous flow guide retaining wall and a rear porous flow guide retaining wall in sequence to form a double-layer retaining wall structure; the front porous flow guide retaining wall and the rear porous flow guide retaining wall are porous retaining walls, a plurality of upper flow guide holes are formed in the upper portion of the front porous flow guide retaining wall, and a plurality of lower flow guide holes are formed in the lower portion of the rear porous flow guide retaining wall;
b) The molten steel after casting enters the internal rotation type flow stabilizer through long nozzle impact, the internal rotation type flow stabilizer turns the casting molten steel, the initial flow field of the molten steel in the tundish is disturbed to form rotational flow, micron-sized inclusions in the flow can be gathered towards the center and collide and grow at the center, and cluster-shaped inclusion particle clusters reaching a certain size can float up to the liquid level of steel slag under the action of Stokes buoyancy and then be removed;
c) The molten steel enters the double-layer retaining wall structure from the upper flow guide holes of the front porous flow guide retaining wall, the unsteady flowing molten steel passes through the double-layer retaining wall structure to obtain a stable flow field, and meanwhile, the movement track of the molten steel is changed through the upper flow guide holes and the lower flow guide holes which are uniformly distributed on the front porous flow guide retaining wall and the rear porous flow guide retaining wall; the flow field direction of molten steel in the tundish is adjusted by using the upper flow guide holes and the lower flow guide holes in different directions of the front porous flow guide retaining wall and the rear porous flow guide retaining wall, and fine inclusions are adsorbed and removed by top slag.
An apparatus for the method of reducing fine inclusions in molten steel according to the present invention comprises: the tundish further comprises an internal rotation type current stabilizer arranged in the tundish and porous diversion retaining walls positioned at two sides of the internal rotation type current stabilizer;
the internal rotation type current stabilizer is arranged below a corresponding long water gap in the bottom of the tundish, and comprises: the body is a circular shell with an opening at the upper end, overflow holes are arranged on two side walls of the circular shell, and preferably, the axis of the overflow holes forms an angle with the horizontal; four cuboid guide blocks which are annularly arranged are arranged on the inner bottom surface of the body, the centers of the guide blocks are uniformly distributed on a positioning circle taking the center of the inner bottom surface of the body as the center of a circle, and the guide blocks deflect at an angle; preferably, the angle between the guide block and the positioning circular tangent is 0-30 degrees;
the porous flow guide retaining wall is arranged in the middle injection area of the tundish at the two sides of the internal rotation type flow stabilizer, two layers of porous flow guide retaining walls, namely a front porous flow guide retaining wall and a rear porous flow guide retaining wall, are respectively arranged at the two sides of the internal rotation type flow stabilizer, an upper flow guide hole is arranged at the upper part of the front porous flow guide retaining wall, and a lower flow guide hole is arranged at the lower part of the rear porous flow guide retaining wall; preferably, the bottoms of the front porous flow guide retaining wall and/or the rear porous flow guide retaining wall are provided with flow guide holes.
Preferably, the external diameter of the internal rotation type current stabilizer is the same as the width of the bottom in the middle ladle.
Preferably, the axes of the upper diversion holes and/or the lower diversion holes of the front and rear porous diversion retaining walls form an angle of 20-40 degrees with the horizontal, and preferably, the diameters of the upper diversion holes and/or the lower diversion holes are 40-60 mm.
Preferably, the distance between the front porous flow guide retaining wall and the rear porous flow guide retaining wall is 300-400 mm.
Preferably, the front porous flow guide retaining wall is 1500-1800 mm away from the center line of the long nozzle.
Preferably, the central connecting line of the overflow holes at two sides of the internal rotation type current stabilizer is used as a positioning line, and the included angle between the connecting line of the center of a current guiding block and the center of a positioning circle and the positioning line is theta 1, and theta 1 = 65-70 degrees; preferably, the central lines of the diversion blocks are mutually perpendicular.
Preferably, the internal rotation current stabilizer, the front porous flow guide retaining wall and the rear porous flow guide retaining wall are fireproof material structural functional pieces, and the weight percentages of the chemical components are as follows: mgO+Al 2 O 3 >90.0％，Fe 2 O 3 <0.85 percent, the compressive strength of the material is more than or equal to 50MPa, and the volume density is more than or equal to 2.75g/cm 3 。
The internal rotation type current stabilizer for the method for reducing fine inclusions in molten steel comprises the following components: the body is a circular shell with an opening at the upper end, two side walls of the body are symmetrically provided with an overflow hole respectively, and the axis of the overflow hole forms an angle with the horizontal; four cuboid guide blocks which are annularly arranged are arranged on the inner bottom surface of the body, the centers of the guide blocks are uniformly distributed on the circumference of a positioning circle taking the center of the inner bottom surface of the body as the center of the circle, and the guide blocks deflect by an angle, preferably, the guide blocks form an angle of 0-30 degrees with the tangent line of the positioning circle.
Preferably, the central connecting line of the overflow holes at two sides of the internal rotation type current stabilizer is used as a positioning line, and the included angle between the connecting line of the center of a current guiding block and the center of a positioning circle and the positioning line is theta 1, and theta 1 = 65-70 degrees; preferably, the central lines of the diversion blocks are mutually perpendicular.
Preferably, the length of the flow guide block is 160-170 mm, the width is 40-50 mm, and the height is 30-40 mm.
The molten steel after casting is impacted into the internal rotation type flow stabilizer at the bottom of the tundish through the long nozzle, and the internal rotation type flow stabilizer is annularly arranged at the bottom, so that the molten steel after casting is impacted into the internal rotation type flow stabilizer is turned in the cavity, the initial flow field in the tundish is disturbed to form rotational flow, the stay time of the molten steel is prolonged, and meanwhile, the movement distance and the collision probability of inclusions are increased.
In the inner circle formed by the inner sides of the guide blocks, the molten steel flowing out of the long water gap has higher speed, and a high-pressure area is formed in the area; when the molten steel flows out from the inner circle to the outside, the molten steel flows into the channels between the adjacent diversion blocks, the channels which are excessively round from the inner circle to the outside are gradually narrowed, part of molten steel is accelerated to flow out of the outer circle area through the channels, but most of the flow is blocked to form upward vortex and secondary vortex which are formed by the upward vortex; the strong vortex has lower central pressure, fine inclusions in the flow can gather towards the low-pressure center, collide and grow up at the low-pressure center, clusters of inclusion particles with a certain size can float up to the liquid level of steel slag to be removed under the action of Stokes buoyancy, and pressure changes formed in the inner circle and the outer circle areas of the internal rotation type flow stabilizer can effectively crush the flow, so that the inclusion particles are prevented from entering a casting blank along with the flow at the bottom of a tundish to influence the product quality. The first step greatly improves the removal efficiency of the inclusions in the tundish, thereby being beneficial to improving the cleanliness of molten steel and further improving the cleanliness of steel. And secondly, the molten steel and the inclusions enter the double-layer retaining wall structure from the flow guide holes of the front retaining wall, the double-layer retaining wall is equivalent to a molten steel flow inducing device, the unsteady flowing molten steel obtains a stable flow field through the double-layer retaining wall, and meanwhile, the movement track of the molten steel is changed through the flow guide holes uniformly distributed on the retaining wall, so that the occurrence of short-circuit flow is prevented. The flow guide holes in different directions of the front retaining wall and the rear retaining wall are utilized to adjust the flow field direction of molten steel in the ladle, so that fine inclusions are conveniently adsorbed and removed by top slag. The porous retaining wall is used for enabling the molten steel distributed to each submerged nozzle to be more uniform, the average residence time of the molten steel from the ladle long nozzle to the tundish submerged nozzle is increased, and the floating of fine inclusion components is facilitated. After the impurities of the high-quality steel are reduced through a series of refining process control, fine impurities are removed again in the tundish, so that the high-purity purification of the molten steel is realized.
In the method design of the invention:
1. an internal rotation type current stabilizer is designed below a long water gap of a tundish, so that the internal rotation type current stabilizer can prevent molten steel from splashing on one hand, and on the other hand, a flow guide block is annularly designed and arranged at the bottom of the internal rotation type current stabilizer, so that the molten steel generates a rotation belt, regular turbulent collision of the molten steel can be generated, the residence time of the molten steel can be prolonged, and micron-sized fine inclusions in the molten steel can be gathered, collided, grown up and removed towards the center.
The internal rotation type current stabilizer has the following functions and mechanisms:
(1) The turbulent kinetic energy of molten steel in the middle injection area is effectively inhibited, the flow field of the molten steel is stabilized, the fluctuation of the liquid level in the injection area is reduced, and secondary oxidation caused by slag rolling or exposure is prevented;
(2) The inner part of the internal rotation type flow stabilizer is provided with a certain deflection flow guide block, so that the molten steel in a middle injection area below a long water gap in the tundish forms a rotational flow, and the generated centrifugal force promotes the micron-sized inclusions to gather and grow up towards the center, thereby being beneficial to floating removal;
(3) The swirl flow of molten steel in the pouring area in the tundish is beneficial to the uniform mixing of the molten steel, improves the flow path, prolongs the residence time of the molten steel and the inclusions in the pouring area, and is beneficial to the removal of the inclusions.
2. Double-layer flow guide retaining walls, namely front and rear porous flow guide retaining walls, are arranged at two sides of a pouring area in the tundish, so that molten steel and a flow path can be well controlled, and impurities are prevented from entering a water gap area of the pouring area of the tundish, thereby reducing fine impurities and purifying molten steel.
The front and rear porous diversion retaining walls have the effect and mechanism of promoting inclusion removal as follows:
(1) The flow field of the molten steel of the tundish is effectively changed, erosion of the bottom of the tundish is reduced, short-circuit flow is eliminated, strong turbulence is limited in an impact area, the flow of the molten steel near the water gap of the tundish is stable, and a streamline is lengthened;
(2) The distributed upper and lower diversion holes are arranged to have a diversion effect on molten steel;
(3) The average residence time of the molten steel is properly prolonged, which is favorable for the full floating of the inclusions.
3. The internal rotation current stabilizer, the front porous flow guide retaining wall and the rear porous flow guide retaining wall are fireproof material structural functional pieces, and the chemical composition of the materials meets the requirements of MgO+Al 2 O 3 >90.0％，Fe 2 O 3 <0.85 percent, the compressive strength is more than or equal to 50MPa, and the volume density is more than or equal to 2.75g/cm 3 Can meet the service life requirement of continuous casting furnaces required by steel mills.
The invention has the beneficial effects that:
the impure molten steel can cause serious problems in the continuous casting blank, and has influence on the use performance and the use range of the steel. The last container with refractory property that the molten steel needs to pass before entering the crystallization container is a tundish, and the cleaning degree of the molten steel, the size and the quantity of the inclusion substances are closely related to the flow of the molten steel and refractory materials in the tundish. In order to remove fine inclusions, various flow control devices are designed in the continuous casting tundish to promote floating removal of the inclusions. However, inclusions having a diameter of less than 20 μm are hardly removed by floating in a continuous casting tundish, and thus removal of inclusions of less than 20 μm has become an increasingly difficult problem in restricting the cleanliness of steel.
The invention constructs a mode of an internal rotation type current stabilizer and a double-layer diversion retaining wall in the tundish to reduce fine inclusions in molten steel in the tundish, can effectively inhibit the turbulent kinetic energy of molten steel in a pouring area, forms rotational flow to enable micron-sized inclusions to gather and grow towards the center, and is beneficial to floating removal of the fine inclusions; meanwhile, the flow path of the molten steel is optimized, short-circuit flow is prevented, uniform mixing of the molten steel is facilitated, the separation and residence time of the molten steel and inclusions are prolonged, the removal rate of fine inclusions smaller than 20 mu m in the molten steel is improved by 15% compared with that of the prior molten steel, 86.45%, the high purity of the molten steel required by high-quality steel is fully ensured, the defects of hydrogen-induced cracks and the like can be greatly reduced, and the quality of high-purity steel such as pipeline steel is improved.
Drawings
FIG. 1 is a schematic diagram of an embodiment of the present invention;
FIG. 2 is a top view of an internal rotation type flow stabilizer according to an embodiment of the present invention;
FIG. 3 is a front view of an internal rotation type flow stabilizer according to an embodiment of the present invention;
FIG. 4 is a front view of a front porous retaining wall according to an embodiment of the present invention;
FIG. 5 is a side view of a front porous retaining wall according to an embodiment of the present invention;
FIG. 6 is a front view of a rear porous retaining wall according to an embodiment of the present invention;
fig. 7 is a side view of a rear porous retaining wall according to an embodiment of the present invention.
Detailed Description
Referring to fig. 1 to 7, the method for reducing fine inclusions in molten steel according to the present invention includes: d) An internal rotation type flow stabilizer 2 is arranged below a corresponding long water gap 100 in the inner bottom of the tundish 1, the internal rotation type flow stabilizer 2 is a circular shell with an opening at the upper end, at least three arc-shaped stop blocks 3 are annularly arranged in the center of the inner bottom surface of the internal rotation type flow stabilizer 2, overflow holes 22 are formed in the side wall of the internal rotation type flow stabilizer 2, and preferably, the axis of each overflow hole 22 forms an angle with the horizontal; the inner bottom of the tundish 1 at two sides of the internal rotation type current stabilizer 2 is respectively provided with a front porous diversion retaining wall 4 and a rear porous diversion retaining wall 5 in sequence to form a double-layer retaining wall structure; the front porous flow guide retaining wall 4 and the rear porous flow guide retaining wall 5 are porous retaining walls, a plurality of upper flow guide holes 41 are formed in the upper portion of the front porous flow guide retaining wall 4, and a plurality of lower flow guide holes 51 are formed in the lower portion of the rear porous flow guide retaining wall 5;
b) The molten steel after casting enters the internal rotation type flow stabilizer 2 through the long nozzle 100, the internal rotation type flow stabilizer 2 turns the molten steel after casting, the initial flow field of the molten steel in the tundish 1 is disturbed to form rotational flow, micron-sized inclusions in the flow can be gathered towards the center and collide and grow up at the center, and cluster-shaped inclusion particle clusters reaching a certain size can float up to the liquid level of steel slag under the action of Stokes buoyancy and then be removed;
c) The molten steel enters the double-layer retaining wall structure from the upper guide holes 41 of the front porous guide retaining wall 4, the unsteady flowing molten steel obtains a stable flow field through the double-layer retaining wall structure, and meanwhile, the movement track of the molten steel is changed through the upper guide holes 41 and the lower guide holes 51 which are uniformly distributed on the front porous guide retaining wall 4 and the rear porous guide retaining wall 5; the flow field direction of molten steel in the tundish 1 is adjusted by using the upper and lower diversion holes 41 and 51 of the front and rear porous diversion retaining walls 4 and 5 in different directions, and fine inclusions are adsorbed and removed by top slag.
The device for reducing the fine inclusions in the molten steel comprises: the tundish 1 further comprises an internal rotation type current stabilizer 2 arranged in the tundish 1 and porous flow guiding retaining walls positioned at two sides of the internal rotation type current stabilizer 2;
the internal rotation type flow stabilizer 2 is disposed below the corresponding long nozzle 100 in the bottom of the tundish 1, and includes: the body 21 is a circular shell with an opening at the upper end, and two side walls of the body are provided with overflow holes 22, and preferably, the axis of the overflow holes 22 forms an angle with the horizontal; four cuboid guide blocks 3 which are annularly arranged are arranged on the inner bottom surface of the body 21, the centers of the guide blocks 3 are uniformly distributed on a positioning circle a taking the center of the inner bottom surface of the body 21 as the center of the circle, and the guide blocks 3 deflect by an angle, preferably, the guide blocks 3 form an angle of 0-30 degrees with the tangent line of the positioning circle a;
the porous flow guide retaining walls are arranged in the middle injection area of the tundish 1 at two sides of the internal rotation type flow stabilizer 2, two layers of porous flow guide retaining walls, namely front porous flow guide retaining wall 4 and rear porous flow guide retaining wall 5, are respectively arranged at two sides of the internal rotation type flow stabilizer, an upper flow guide hole 41 is arranged at the upper part of the front porous flow guide retaining wall 4, and a lower flow guide hole 51 is arranged at the lower part of the rear porous flow guide retaining wall 5; preferably, the bottoms of the front porous flow guide retaining wall and/or the rear porous flow guide retaining wall are provided with flow guide holes.
Preferably, the external diameter of the internal rotation type current stabilizer 2 is the same as the inner bottom width of the middle bag 1.
Preferably, the axes of the upper diversion holes 41 and/or the lower diversion holes 51 of the front and rear porous diversion retaining walls 4 and 5 form an angle of 20-40 degrees with the horizontal, and preferably, the diameters of the upper diversion holes and/or the lower diversion holes are 40-60 mm.
Preferably, the distance between the front porous flow guiding retaining wall 4 and the rear porous flow guiding retaining wall 5 is 300-400 mm.
Preferably, the front porous flow guide retaining wall 4 is 1500-1800 mm away from the central line of the long nozzle 100.
Preferably, the central connecting line of the overflow holes 22 at two sides of the internal rotation type flow stabilizer 2 is used as a positioning line, and the included angle between the connecting line of the center of a flow guiding block 3 and the center of a positioning circle and the positioning line is θ1, θ1=65-70 degrees; preferably, the central lines of the guide blocks 3 are perpendicular to each other.
Preferably, the internal rotation current stabilizer, the front porous flow guide retaining wall and the rear porous flow guide retaining wall are fireproof material structural functional pieces, and the weight percentages of the chemical components are as follows: mgO+Al 2 O 3 >90.0％，Fe 2 O 3 <0.85 percent, and the compressive strength of the material is more than or equal to 50The volume density is more than or equal to 2.75g/cm under the pressure of MPa 3 。
Referring to fig. 2 and 3, the internal rotation type stabilizer 2 for the method for reducing fine inclusions in molten steel according to the present invention comprises: the body 21 is a circular shell with an opening at the upper end, and two side walls of the body are symmetrically provided with an overflow hole 22 respectively; four cuboid guide blocks 3 are arranged on the inner bottom surface of the body 21 in an annular arrangement, the centers of the guide blocks 3 are uniformly distributed on the circumference of a positioning circle a with the center of the inner bottom surface of the body 21 as the center of a circle and the diameter d1, and the guide blocks 3 deflect at an angle, preferably, the guide blocks form an angle of 0-30 degrees with the tangent line of the positioning circle.
Preferably, the central connecting line of the overflow holes 22 at two sides of the internal rotation type flow stabilizer 2 is used as a positioning line b, and the included angle between the connecting line of the center of a flow guiding block 3 and the center of a positioning circle a and the positioning line b is θ1, θ1=65-70 degrees; preferably, the central lines of the guide blocks 3 are perpendicular to each other.
Preferably, the length l1=160-170 mm, the width l2=40-50 mm and the height 30-40 mm of the flow guiding block 3.
Examples
Corresponding internal rotation type current stabilizer, front and back porous flow guiding retaining wall are prepared according to the volume of the tundish, and the physical and chemical properties of the material reach MgO+Al 2 O 3 >90.0％，Fe 2 O 3 <0.85%, compressive strength not less than 50MPa, bulk density not less than 2.75g/cm 3 The functional parts of the tundish refractory material structure are guaranteed to have good melting loss resistance and service life, and the continuous casting furnace number requirement of a steel plant is met.
An internal rotation type flow stabilizer is built under a long water gap in a manner shown in fig. 1; and (5) constructing a front porous flow guide retaining wall and a rear porous flow guide retaining wall in the tundish. The maintenance and baking methods of the tundish and the casting method are the same as those of the existing tundish.
TABLE 1 removal rate of inclusions at each level
Referring to Table 1, through the practical application of the invention and analysis of steel-like inclusions of casting blanks, the metallurgical effect is better than that of the original tundish, the removal rate of inclusions smaller than 20um is increased by 15% compared with that of the original tundish, 86.45% is achieved, the defects of hydrogen induced cracks and the like can be greatly reduced, and the quality of pipeline steel is improved.
The foregoing is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.
Claims (11)
1. A method for reducing fine inclusions in molten steel comprising:
a) An internal rotation type current stabilizer is arranged below a corresponding long water gap in the middle ladle, the internal rotation type current stabilizer is a circular shell with an opening at the upper end, at least three arc-shaped stop blocks are annularly arranged in the center of the bottom surface of the internal rotation type current stabilizer, and overflow holes are formed in the side wall of the internal rotation type current stabilizer; the inner bottoms of the tundish at the two sides of the internal rotation type current stabilizer are respectively provided with a front porous flow guide retaining wall and a rear porous flow guide retaining wall in sequence to form a double-layer retaining wall structure; the front porous flow guide retaining wall and the rear porous flow guide retaining wall are porous retaining walls, a plurality of upper flow guide holes are formed in the upper portion of the front porous flow guide retaining wall, and a plurality of lower flow guide holes are formed in the lower portion of the rear porous flow guide retaining wall;
b) The molten steel after casting enters the internal rotation type flow stabilizer through long nozzle impact, the internal rotation type flow stabilizer turns the casting molten steel, the initial flow field of the molten steel in the tundish is disturbed to form rotational flow, micron-sized inclusions in the flow can be gathered towards the center and collide and grow at the center, and cluster-shaped inclusion particle clusters reaching a certain size can float up to the liquid level of steel slag under the action of Stokes buoyancy and then be removed;
c) The molten steel enters the double-layer retaining wall structure from the upper flow guide holes of the front porous flow guide retaining wall, the unsteady flowing molten steel passes through the double-layer retaining wall structure to obtain a stable flow field, and meanwhile, the movement track of the molten steel is changed through the upper flow guide holes and the lower flow guide holes which are uniformly distributed on the front porous flow guide retaining wall and the rear porous flow guide retaining wall; the flow field direction of molten steel in the tundish is adjusted by using the upper flow guide holes and the lower flow guide holes in different directions of the front porous flow guide retaining wall and the rear porous flow guide retaining wall, and fine inclusions are adsorbed and removed by top slag.
2. An apparatus for use in the method of reducing fine inclusions in molten steel of claim 1 comprising: the tundish is characterized by further comprising an internal rotation type current stabilizer arranged in the tundish and porous flow guiding retaining walls positioned at two sides of the internal rotation type current stabilizer;
the internal rotation type current stabilizer is arranged below a corresponding long water gap in the bottom of the tundish, and comprises: the body is a circular shell with an opening at the upper end, overflow holes are arranged on two side walls of the circular shell, and preferably, the axis of the overflow holes forms an angle with the horizontal; four cuboid guide blocks which are annularly arranged are arranged on the inner bottom surface of the body, the centers of the guide blocks are uniformly distributed on a positioning circle taking the center of the inner bottom surface of the body as the center of a circle, and the guide blocks deflect by an angle, preferably, the guide blocks form an angle of 0-30 degrees with the tangent line of the positioning circle;
the porous flow guide retaining wall is arranged in the middle injection area of the tundish at the two sides of the internal rotation type flow stabilizer, two layers of porous flow guide retaining walls, namely a front porous flow guide retaining wall and a rear porous flow guide retaining wall, are respectively arranged at the two sides of the internal rotation type flow stabilizer, an upper flow guide hole is arranged at the upper part of the front porous flow guide retaining wall, and a lower flow guide hole is arranged at the lower part of the rear porous flow guide retaining wall; preferably, the bottoms of the front porous flow guide retaining wall and/or the rear porous flow guide retaining wall are provided with flow guide holes.
3. The apparatus of claim 2, wherein the internal rotational flow stabilizer has an outer diameter of 600 to 700mm, preferably the internal rotational flow stabilizer has an outer diameter equal to the width of the bottom of the tundish.
4. The apparatus of claim 2, wherein the axes of the upper and/or lower deflector holes of the front and rear porous deflector walls are at an angle of 20-40 ° to the horizontal, preferably the diameter of the upper and/or lower deflector holes is 40-60 mm.
5. The apparatus of claim 2 or 4, wherein the front and rear porous deflector walls are spaced apart by 300 to 400mm.
6. The apparatus of claim 2, 4 or 5 wherein the front porous deflector wall is 1500-1800 mm from the long nozzle centerline.
7. A device as claimed in claim 2 or 3, wherein the central line of the overflow holes on both sides of the internal rotation type flow stabilizer is used as a positioning line, and the included angle between the line between the center of a flow guiding block and the center of a positioning circle and the positioning line is θ1, θ1=65-70 °; preferably, the central lines of the diversion blocks are mutually perpendicular.
8. The apparatus of any one of claims 2 to 7, wherein the internal flow stabilizer and the front and rear porous flow-guiding barriers are refractory structural functional members comprising the following chemical components in percentage by weight: mgO+Al 2 O 3 >90.0％，Fe 2 O 3 <0.85 percent, the compressive strength of the material is more than or equal to 50MPa, and the volume density is more than or equal to 2.75g/cm 3 。
9. A internal rotation type stabilizer for use in the method of reducing fine inclusions in molten steel according to claim 1, comprising: the body is a circular shell with an opening at the upper end, two side walls of the body are symmetrically provided with an overflow hole respectively, and the axis of the overflow hole forms an angle with the horizontal; four cuboid guide blocks which are annularly arranged are arranged on the inner bottom surface of the body, the centers of the guide blocks are uniformly distributed on the circumference of a positioning circle taking the center of the inner bottom surface of the body as the center of the circle, and the guide blocks deflect by an angle, preferably, the guide blocks form an angle of 0-30 degrees with the tangent line of the positioning circle.
10. The internal rotation type current stabilizer according to claim 9, wherein a central connecting line of overflow holes at two sides of the internal rotation type current stabilizer is used as a positioning line, and an included angle between a connecting line of a center of a current guiding block and a center of a positioning circle and the positioning line is θ1, θ1=65-70 degrees; preferably, the central lines of the diversion blocks are mutually perpendicular.
11. The internal rotation type flow stabilizer as set forth in claim 9 or 10, wherein the flow guide block has a length of 160-170 mm, a width of 40-50 mm and a height of 30-40 mm.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210314053.5A CN116851730A (en) | 2022-03-28 | 2022-03-28 | Method and device for reducing fine inclusions in molten steel |
| PCT/CN2023/084475 WO2023185874A1 (en) | 2022-03-28 | 2023-03-28 | Method and apparatus for reducing fine inclusions in molten steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210314053.5A CN116851730A (en) | 2022-03-28 | 2022-03-28 | Method and device for reducing fine inclusions in molten steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116851730A true CN116851730A (en) | 2023-10-10 |
Family
ID=88199248
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210314053.5A Pending CN116851730A (en) | 2022-03-28 | 2022-03-28 | Method and device for reducing fine inclusions in molten steel |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN116851730A (en) |
| WO (1) | WO2023185874A1 (en) |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005103567A (en) * | 2003-09-29 | 2005-04-21 | Nippon Steel Corp | Tundish for continuous casting, and method for continuous casting |
| CN102303113B (en) * | 2011-08-29 | 2013-11-27 | 武汉钢铁(集团)公司 | Continuous casting tundish porous baffle wall having functions of casting and calcium treatment |
| CN202845761U (en) * | 2012-09-17 | 2013-04-03 | 北京科技大学 | Novel tundish for highly purified liquid steel |
| CN103240406B (en) * | 2013-04-28 | 2015-05-27 | 首钢总公司 | Continuous casting tundish and continuous casting tundish casting control method |
| CN103990786B (en) * | 2014-05-16 | 2016-05-25 | 莱芜钢铁集团有限公司 | A kind of for removing the device and method of molten steel field trash in double flow tray billet continuous casting machine tundish |
| CN104057044B (en) * | 2014-06-06 | 2016-10-05 | 武汉科技大学 | A kind of continuous casting production inward turning type turbulence inhibitor |
| CN110947921B (en) * | 2018-09-27 | 2021-05-14 | 宝山钢铁股份有限公司 | Tundish flow control system capable of filtering impurities in steel |
| CN209754003U (en) * | 2018-12-28 | 2019-12-10 | 南京钢铁股份有限公司 | Tundish for continuous casting |
| CN110270679B (en) * | 2019-07-12 | 2024-06-14 | 南京钢铁股份有限公司 | Four-flow tundish for large square billets |
| CN110653366B (en) * | 2019-11-18 | 2024-05-28 | 武汉科技大学 | Spiral-flow type turbulence inhibitor for continuous casting middle belting buffer ball |
-
2022
- 2022-03-28 CN CN202210314053.5A patent/CN116851730A/en active Pending
-
2023
- 2023-03-28 WO PCT/CN2023/084475 patent/WO2023185874A1/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023185874A1 (en) | 2023-10-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103555889B (en) | Device and method for quickly removing occluded foreign substances in molten steel | |
| WO2021012201A1 (en) | Pneumatic swirling flow tundish for continuous casting | |
| WO2021031219A1 (en) | Long-nozzle argon-blowing refining device and method for effectively removing inclusions in tundish | |
| CN113564309A (en) | Tundish with function of removing molten steel inclusions by blowing argon | |
| CN110616293B (en) | Method for adding rare earth into molten steel | |
| CN108396109B (en) | Method for generating dispersed bubbles in molten steel in steel ladle | |
| CN103103315B (en) | The integral type soaking tub of RH equipment for vacuum refining | |
| CN116851730A (en) | Method and device for reducing fine inclusions in molten steel | |
| CN102145380B (en) | Method for continuously casting clean molten steel in tundish | |
| CN102560002A (en) | Method for removing fine inclusions in molten steel and blowing device | |
| CN209239047U (en) | A kind of continuous casting production air swirl filling pipe end brick cup | |
| CN202830077U (en) | Straight barrel type vacuum refining device | |
| CN110042266A (en) | A kind of method of aluminium alloy melt in-line purification | |
| CN102764867B (en) | Straight-through submerged nozzle with stirring effect | |
| CN214349589U (en) | Two-hole submerged nozzle for high-pulling-speed billet continuous casting crystallizer | |
| CN210506416U (en) | Tapping hole for inhibiting vortex generation in converter tapping process and tapping hole assembly | |
| Tang et al. | Cleaning IF molten steel with dispersed in-situ heterophases induced by the composite sphere explosive reaction in RH ladles | |
| CN110814330A (en) | Top rotating type turbulence controller for continuous casting tundish | |
| CN208033604U (en) | It is a kind of to be used for the low ingot mould for being mingled with steel ingot casting of core grade | |
| CN211689145U (en) | Device for adding rare earth into molten steel | |
| CN117862430A (en) | Device and method for removing inclusions in molten steel in tundish | |
| CN219025868U (en) | Inclusion adsorption filter for continuous casting tundish | |
| KR20000041671A (en) | Method for refining high purity steel | |
| CN215824258U (en) | Ladle upper nozzle for inhibiting foreign impurities in casting blank | |
| CN217600756U (en) | Impact pool for intermediate slag tank for wind slag crushing treatment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |