803 results about "Tundish" patented technology

The invention belongs to the technical field of metallurgical continuous casting, and particularly relates to a method for removing tundish inclusions based on cooperation of an external electric field and physics. The invention discloses a method for removing tundish inclusions based on cooperation of an external electric field and physics, and mainly aims at solving the problems that as the inclusions in tundish molten steel enter a subsequent continuous casting link, a submersed nozzle is clogged and blocked, and the quality of a casting blank is deteriorated. The key point is that an external electric field and physics synergistic effect is used; a bottom blowing device is arranged to provide power for floating of inclusions; an original baffle weir structure of the tundish is improved, and the probability of catching inclusions is increased; and an external electric field is cooperatively used, so that the inclusions are promoted to float towards the tundish covering agent and be attached to the blocking weir. By means of the method for cooperatively removing the tundish inclusions based on the external electric field and physics, the tundish molten steel inclusions can be obviously removed, the service performance of a subsequent water gap is optimized, the casting blank quality is improved, and the improvement of the high-quality steel smelting level in China is assisted.

The invention relates to the technical field of thin-strip cast rolling, and provides a thin-strip cast rolling tundish continuous casting device and method.The thin-strip cast rolling tundish continuous casting device comprises a base frame horizontally installed on the surface of a foundation, and the base frame is provided with a flow distribution ladle, a tundish and a large ladle from bottom to top; an adjusting mechanism is arranged below the position, where the casting position is arranged, of the base frame, the adjusting mechanism comprises two limiting plates which are symmetrically arranged, and one side of the middle of each limiting plate is fixedly connected with a second motor for driving a crystallizer roller; and a baking oven fixed on the placing rack is arranged above the middle parts of the two motors II. According to the method, molten steel qualified in smelting is directly poured into the molten pool defined by the two crystallization rollers rotating oppositely and the side sealing plates through the large ladle, the tundish and the flow distribution system, the molten steel is cooled through the two crystallization rollers rotating oppositely to form the steel belt with the thickness of 1-5 mm, the production cost can be saved, the casting continuity is improved, the production efficiency is improved, and the yield is increased.

The invention discloses steel for a battery shell and a preparation method of the steel, and relates to the technical field of steel preparation. The preparation method of the steel for the battery shell comprises the steps of converter treatment, LF refining, RH refining and continuous casting. Starting from the whole preparation process, free oxygen and the production rhythm are controlled through LF refining, time production of RH refining and continuous casting is achieved, converter end point free oxygen control is coordinated, and generation of molten steel inclusions is reduced; rH refining is momentalized and standardized, continuous casting and casting are implemented in a steady state, and the amount of residual steel is controlled, so that secondary generation of inclusions and pollution to tundish molten steel are reduced. The steel for the battery case has the good characteristics of being good in ultra-deep drawing high-plasticity strain ratio, small in anisotropy, high in surface quality and internal purity, fine and uniform in microscopic grain structure and free of the sand hole defect, and is applied to the field of smelting of high-purity steel. The device is expected to be applied to continuous unmanned large-scale production of the highest-speed shell punching machine tool in the world, import substitution is achieved, and the product quality reaches the international advanced level.

The utility model discloses an argon bottom blowing device for improving the purity of molten steel. The argon bottom blowing device comprises a tundish, a water gap is formed in one side of the bottom face of the tundish, an electromagnetic stirrer is arranged on the outer side of the water gap, an air brick is arranged above the water gap in the tundish, and an argon conveying pipe is arranged at the bottom of the air brick. The gas permeable brick is arranged above the water gap, argon is blown into molten steel, the argon directly acts on molten steel flow, a gas curtain wall is formed around the water gap, floating and removal of inclusions are promoted, the purity of the molten steel is improved, the gas permeable brick is used in cooperation with the electromagnetic stirrer, the molten steel can be effectively stirred, a stirring blind area is eliminated, and the service life of the molten steel is prolonged. And the heat transmission of the molten steel in the tundish is more uniform. And moreover, the uniform molten steel flowing is beneficial to keeping the water gap unobstructed, and the water gap is prevented from being blocked by inclusions or cold steel in the molten steel.

The invention relates to the technical field of continuous casting of copper materials, in particular to high-quality copper material pouring equipment which comprises a driving frame and a horizontal continuous casting machine body, an alignment frame is arranged on the top face of the driving frame, and a pouring assembly for pouring molten copper liquid into the horizontal continuous casting machine body is arranged on the alignment frame. A connecting assembly used for moving the alignment frame is arranged between the driving frame and the alignment frame, and two sets of alignment assemblies used for accurately aligning the alignment frame and the horizontal continuous casting machine body are symmetrically arranged on the side face of the alignment frame. Two sets of positioning assemblies matched with the alignment assemblies are symmetrically arranged on the side face of the horizontal continuous casting machine body. By means of the linkage design of the positioning assembly and the alignment assembly, the position of the alignment frame can be automatically adjusted, the tundish and the horizontal continuous casting machine body are accurately aligned to the same horizontal position, it is ensured that a pouring nozzle is aligned to the center of a material opening, and the problem of molten copper splashing or uneven pouring caused by position deviation is solved.

The invention discloses a novel quick-change mechanism with a flow control function for a tundish. The novel quick-change mechanism comprises a mounting part, a sliding part, a pressing part, a first driving part and a second driving part. And the functions of the stopper rod opening and closing device are integrated on the tundish quick-change nozzle device, so that the investment, the installation site, the maintenance cost, the spare part site and the cost of a set of equipment are saved. The two sets of equipment are combined into a whole, so that the number of operators in a steel mill is reduced, and meanwhile, preparation is made in advance for the subsequent steel mill if intelligent and automatic control over steel-making continuous casting is adopted, and the positive effect is achieved.

The invention discloses an environment-friendly tundish magnesium-calcium dry material for thin-strip cast-rolling short-process steelmaking, and belongs to the technical field of refractory materials. The invention discloses an environment-friendly tundish magnesium-calcium dry material for thin-strip cast-rolling short-process steelmaking. The tundish magnesium-calcium dry material is prepared from the following raw materials in percentage by mass: 44-62.5% of magnesia aggregate, 22.5-24% of dolomite aggregate, 11-28% of magnesia fine powder and 3-5% of a binding agent, the binding agent is silica sol modified by a phosphate esterification aluminic acid ester coupling agent. The preparation method comprises the following specific steps: putting magnesia fine powder, a binding agent, magnesia aggregate and dolomite aggregate into a V-shaped mixing mill, uniformly stirring for 5 minutes, putting the stirred mixture into a mold, ramming, vibrating and molding to obtain a molded green body, curing at room temperature for 24 hours, demolding, drying at 200 DEG C for 24 hours, and carrying out heat treatment in an air atmosphere to obtain a dry material sample. According to the invention, the binding agent with good compatibility with a matrix is prepared by improving the binding agent, so that the binding agent can play a reinforcing role.

The invention relates to a method for controlling cracks of a steel casting blank for a new energy automobile battery pack. The method comprises the steps of casting blank composition control, casting powder performance control, crystallizer inlet and outlet water temperature control, submersed nozzle insertion depth control, molten steel superheat degree control, secondary cooling water distribution specific water flow control, crystallizer taper control and continuous casting machine equipment precision control. The steel comprises, by mass, 0.08%-0.11% of C, 0.55%-0.70% of Si, 2.40%-2.70% of Mn, smaller than or equal to 0.018% of P, smaller than or equal to 0.008% of S, 0.020%-0.070% of Als, 0.015%-0.035% of Nb, 0.02%-0.04% of Ti, 0.15%-0.35% of Cr, smaller than or equal to 0.006% of N and the balance Fe. The alkalinity R of the casting powder ranges from 1.30 to 1.42; 0.6 wt%-0.8 wt% of Li2O is added into the casting powder; when the water inlet temperature of the crystallizer is 25-30 DEG C, the wide surface water inlet and outlet temperature difference of the crystallizer is 2-5 DEG C, and the narrow surface water inlet and outlet temperature difference is 4-8 DEG C; when the water inlet temperature of the crystallizer is 31-36 DEG C, the water inlet and outlet temperature difference of the wide surface of the crystallizer is 4-7 DEG C, and the water inlet and outlet temperature difference of the narrow surface is 5-9 DEG C; constant-pulling-speed pouring is adopted for continuous casting, the tonnage of a tundish is 35-70 tons, and the liquid level fluctuation of a crystallizer is smaller than or equal to + / -5 mm. The defect of'black lines' on the surface of the strip steel of the battery pack for the new energy automobile can be effectively improved, and the surface quality of the battery pack for the new energy automobile is guaranteed.

The invention relates to the field of metallurgy, in particular to a construction technology of a continuous casting tundish dry material and a tundish. According to the continuous casting tundish dry material construction technology, the thickness of a certain dry material is increased, the existing thickness of a tundish wall dry material is adjusted to be larger than or equal to 60 mm from 50-55 mm, and the thickness of a tundish bottom dry material is adjusted to be larger than or equal to 90 mm from 60 mm; meanwhile, the condition of the vibration process is adjusted, the original vibration time of 3 min is adjusted to be larger than or equal to 8 min, and vibration motors are changed into double motors; the baking conditions are adjusted, the baking time is shortened from original 70-90 min to 40-60 min, and the cooling and demolding time is prolonged to be larger than or equal to 4 h; by regulating and controlling the factors, the erosion resistance of the whole dry material is improved, and the service life of the dry material is further prolonged.

The application discloses a tundish dam structure with a flow guide pipe, which comprises a straight wall, a flow guide hole, a side wall, a dam and a flow guide pipe. The straight wall, the side wall and the dam are an integrated structure, and the integrated structure is embedded in the inner wall of the tundish at both ends. The straight wall in the inner cavity of the dam is provided with a plurality of flow guide holes, and the flow guide pipe is embedded on the flow guide hole. The application effectively promotes the removal of inclusions in the impact area and the casting area of the tundish.

The invention discloses a continuous casting tundish mixed steel section dynamic simulation method and system, and aims to solve the problems of physical distortion and dynamic response lag of an existing mixed steel model. The method comprises the steps that S1, the actual measurement size of the tundish is obtained, and the tundish is divided into multiple areas; s2, establishing a nonlinear volume mapping model representing the total volume of molten steel at different liquid levels and the volume ratio of each region; s3, dynamically calculating the weight of each region, the molten steel exchange weight between the regions and the components of new and old molten steel in each time step length; and S4, comparing the molten steel components with target requirements in real time, and determining the position of the mixed steel section. According to the method, the irregular structure and the technological parameter fluctuation of the tundish can be accurately reflected, and the positioning accuracy of the mixed steel section is improved.

The invention discloses a method for improving castability of aluminum-containing steel in a continuous casting process, which comprises the following steps of: S1, controlling components of molten steel, and accurately controlling the content of acid-soluble aluminum in molten steel of a continuous casting ladle to be 0.020-0.060% according to mass percent; s2, calcium treatment is conducted on the molten steel, and the calcium-aluminum ratio is controlled to range from 0.10 to 0.15; s3, continuous casting process control is conducted, specifically, the superheat degree of tundish molten steel is stably controlled to range from 15 DEG C to 30 DEG C, meanwhile, constant pulling speed operation is adopted, and the pulling speed fluctuation range is controlled within + / -0.1 m / min; and S4, the content of SiO in the casting powder is reduced to be smaller than or equal to 20%, and meanwhile, the alkalinity R of the casting powder is 1.5-2.0. The continuous casting process is ensured to be smooth, nozzle nodulation and casting blank surface defects are effectively prevented, and the production efficiency and the product quality are remarkably improved.

The invention relates to the technical field of slab continuous steel casting in the metallurgical industry, and discloses a method for rapidly replacing a high-carbon steel tundish in slab continuous casting. The method comprises the steps that when the tonnage of an old tundish is 45-50 t, the pulling speed is reduced to 0.8-0.9 m / min; when the tonnage of the old tundish is 22-25 t, the pulling speed is reduced to 0.35-0.45 m / min; when 16-18 t of old tundish molten steel is left, the pulling speed is reduced to 0.1-0.2 m / min; the casting speed is increased to 0.35-0.45 m / min when the liquid level of the crystallizer reaches a set value, and the casting speed is increased to 0.35-0.45 m / min when the casting speed is increased to 0.35-0.45 m / min when the casting speed is increased to 0.35-0.45 m / min; and when the new tundish molten steel reaches 45-50 t, the pulling speed is increased to 0.8-0.9 m / min. According to the method, the problem of tail blank chipping in the normal casting stopping process of the slab continuous casting high-carbon steel can be completely eradicated, and the problem that a joint blank is bumped or a casting blank cannot move in the slab continuous casting high-carbon steel tundish quick changing process is solved.

The invention discloses a universal cutting method for an all-casting machine. The universal cutting method comprises the steps that the all-casting machine is controlled; the all-casting machine comprises pouring equipment, cutting equipment and steel billet transferring equipment. The control step comprises the steps of calculating the length of molten steel of the whole furnace of steel in the fan-shaped section and the total weight of the molten steel of the large ladle as the amount of the molten steel of the fan-shaped section by utilizing a large ladle molten steel casting signal and the stock change of the molten steel of the tundish; the real-time casting blank length, the steel casting length instantaneous values corresponding to the steel head and the blank tail and the steel casting length range, obtained in the step A, of the molten steel of each furnace in the fan-shaped section are matched with the continuous starting and ending positions of each steel blank; the billet circulation module simulates billet circulation by combining billet data with each roller way operation signal, and matches the group of slabs according to the molten steel number of the corresponding smelting furnace number. The problem that finished steel billets with quality problems cannot be effectively and accurately positioned to corresponding molten steel sources due to inconsistent information matching between the steel billets and the corresponding molten steel during steel drawing of existing steel plate square billets can be solved.

The invention provides a heavy rail steel continuous casting tundish covering agent and application thereof, and the heavy rail steel continuous casting tundish covering agent comprises the following components by mass fraction: 40-55% of CaO, 25-35% of SiO2, 12-18% of MgO, 3-6% of Na2CO3, 2-5% of C, and less than or equal to 1% of FeO + MnO. The tundish covering agent does not contain aluminum, aluminum return of molten steel can be avoided, aluminum oxide inclusions are reduced, and the performance of a steel rail is improved. Meanwhile, the content of magnesium oxide is high, erosion to the tundish dry material can be reduced, and the service life is prolonged.

The present invention belongs to the field of metallurgical equipment technology, specifically relating to a continuous casting ladle drainage sand discharge device and its use method. The present invention utilizes an annular left-connected sand trough and an annular right-connected sand trough, forming a full-ring inner bore, as a channel for the molten steel to fall. A drainage cone is positioned at the upper end of the channel. As the drainage sand falls, the cone acts to cause it to fall into the interiors of the first and second sand holding chambers below, enabling recovery. When the molten steel contacts the drainage cone, the high temperature causes the cone to melt and flow along with the molten steel from the channel into the tundish below, preventing the molten steel from contacting the annular left and right sand troughs. After the drainage sand is recovered, a separation mechanism separates the annular left and right sand troughs to either side of the molten steel flow. This effectively prevents splashing caused by contact between the annular left and right sand troughs during movement, thereby extending the service life of the discharge device.

The utility model provides a continuous casting ladle casting flue gas cantilever type movable collecting cover, relates to the technical field of metallurgical environment-friendly flue gas dust removal auxiliary devices, and aims to solve the problems that the bearing weight of a steel structure of a casting span is increased due to an existing roof collecting cover structure, a plant needs to be reinforced when a dust removal cover is arranged, and the production and processing cost is increased; the problems of high energy consumption and large investment of a dust removal system due to the fact that the distance between a cover opening of a roof cover and a casting opening of a steel ladle is generally close to about 15 m, the flue gas collection efficiency is low, the flue gas collection effect is poor, and the air volume required by the dust removal system of a roof cover collection process is large are solved. Comprising steel beam structures, the steel beam structures are symmetrically distributed, a crown block is arranged at the tops of the steel beam structures, a ladle turret is arranged below the crown block, a steel ladle is arranged on the ladle turret, a steel structure frame is arranged on the left side of the ladle turret, and a tundish car is arranged on the right side of the steel structure frame. A tundish is arranged on the tundish trolley, and a supporting platform is fixedly connected to the steel structure frame.

The method comprises the following steps: descending a long nozzle before casting, enabling the end part of the long nozzle to be positioned below the lower surface of a middle ladle cover, and reserving a space for blocking and removing the stuffing sand between the end part of the long nozzle and the slag surface of casting powder; the casting disc is moved to the position under the long nozzle to be in a rotating state; a steel ladle sliding plate is opened, the stuffing sand and a small amount of molten steel fall on the disc face of the casting disc, and stuffing sand particles and smashed molten steel droplets are scattered on a sintering layer of the casting powder; and after the drainage sand is completely discharged, the casting disc is moved out of the molten steel flow flowing out of the long nozzle. The device comprises a conical casting disc, a driving device and a bearing structural member, the surface of the casting disc is made of refractory materials, and a disc shaft connected with the driving device is arranged at the bottom of the casting disc. According to the invention, harmful gases in the ladle filler sand, gaps of the ladle filler sand and a long nozzle and a small part of molten steel in contact with the ladle filler sand in a steel ladle can be discharged out of tundish molten steel, so that the purity of the molten steel is obviously improved.

The invention relates to the technical field of ferrous metallurgy casting, in particular to a drainage sand removing and recycling method and device. Comprising a mechanical arm, a lifting rotation controller, a controller arm, a sand suction cylinder, a sand conveying pipeline, a sand collecting tank and an injection pump. The lifting and rotating controller is fixedly mounted on the mechanical arm; the controller arm is connected with the lifting and rotating controller, and the lifting and rotating of the controller arm are controlled by the lifting and rotating controller; the sand suction cylinder is connected with the controller arm, the sand suction cylinder is of a U-shaped structure, and one end of the sand suction cylinder is a horn mouth used for sucking drainage sand; one end of the sand conveying pipeline is positioned above the tundish cover sprue gate, and the end part of the sand conveying pipeline is bent downwards to be connected with the other end of the sand suction cylinder; the other end of the sand conveying pipeline is connected with the sand collecting tank; the sand collecting tank is connected with an injection pump pipeline, and the injection pump provides suction power. The ladle filler sand, harmful gas in gaps of the ladle filler sand and a long nozzle and a small part of molten steel in contact with the ladle filler sand in a steel ladle can be discharged out of tundish molten steel and recycled.

The invention discloses equipment and a method for feeding easily oxidized alloy in a tundish into molten steel directly through a screw rod, belongs to the technical field of metal smelting, and solves the technical problem that materials do not make contact with a slag layer in the process of adding special alloy into the tundish. The feeding auger penetrates through the high-temperature-resistant feeding pipe in the vertical direction; alloy easy to oxidize stored in the hopper is fed into the high-temperature-resistant feeding pipe from the feeding port through the feeding auger, an air inlet is formed in the position, located above the surface of the slag layer, of the lower portion of the side wall of the high-temperature-resistant feeding pipe, the air inlet is communicated with a shielding gas pump station through an air pipe, and shielding gas is blown into the high-temperature-resistant feeding pipe from the air inlet. And the protective gas is discharged through the feeding auger and the feeding auger in sequence, that is, the flowing direction of the protective gas is opposite to the feeding direction of the easily oxidized alloy. Due to the fact that the system is protected by the protective atmosphere in the feeding process and is prevented from making contact with a slag layer in the feeding process, materials can be effectively prevented from being oxidized, and the yield of the materials is increased.

This invention discloses an online method for detecting and identifying cracks in continuously cast slabs, comprising the following steps: real-time collection of instrument detection information of the slab in the ladle, tundish, crystallizer, primary cooling, secondary cooling and air cooling zones at m time points to construct a dataset of dimension m×n, where n is the number of instrument detection information collected at each time point; for each time point, performing: (1) based on the dataset, using an anomaly detection algorithm to obtain the anomaly value I of each time point. i (2) Obtain the anomaly probability P of the slab at that time point: P = p / m, where p is the outlier value I. i (3) Collect steel grade information in real time and obtain the abnormal threshold S of the steel grade based on the steel grade information; (4) Compare the abnormal probability P of the steel grade with the abnormal threshold S. If P≥S, output the judgment that the production abnormality probability of the steel grade will lead to slab crack defects; otherwise, output the judgment that the slab is normal.

The utility model relates to the technical field of tundish protection plate structures, and discloses a continuous casting tundish special-shaped protection plate which comprises a first protection plate, a second protection plate and a tundish, vertical plates are fixedly connected to the middle positions of the left end and the right end of the first protection plate, and a fixing shaft penetrates through the middle position, close to the upper side, between the vertical plates. A rotating cylinder is rotatably installed at the position, corresponding to the middle of the first protection plate, of the outer side of the fixing shaft, three sets of evenly-distributed buffer plates are fixedly connected to the rotating cylinder, two sets of second protection plates are symmetrically installed at the positions, close to the left side and the right side of the first protection plate, of the second protection plates, and sliding grooves are formed in the middle positions of the second protection plates; and the outer sides of the fixed shafts are fixedly sleeved with limiting pieces at the sliding grooves. According to the device, the impact effect of molten steel is converted into rotating power of the rotary drum through the rotary drum and the buffer plate, direct scouring erosion of the molten steel to a tundish permanent layer and the protective plates is greatly relieved, meanwhile, the first liftable protective plate always floats on the surface of the molten steel, and the liquid level of the molten steel is stabilized.

The present invention discloses a method for preventing breakout in a high-speed billet continuous casting machine. During continuous casting, the billet continuous casting machine operates at a casting speed of 3.5 to 5.5 m / min and a mold taper of 1.9 to 2.2% / m. The mold flux used has a melting point of 1055 to 1095°C, a melting rate of 25 to 33 seconds, and a viscosity of 0.09 to 0.13 Pa·s. When the casting speed is 3.5 to 4.0 m / min, the tundish molten steel temperature must not exceed 1535°C. When the casting speed is 4.0 to 5.5 m / min, the tundish molten steel temperature must not exceed 1530°C. The present invention controls breakout in the mold or at the foot roll section by adopting an appropriate mold copper tube taper and using a mold flux with an appropriate melting point, melting rate, and viscosity. This method achieves stable high-speed production for the billet continuous casting machine, resolves the difficulty in handling breakouts and the inability to complete production plans due to high casting speed breakouts, and improves the billet yield.

The application discloses a stopper rod for inhibiting confluence vortex and a method thereof, and belongs to the technical field of water gap flow control of continuous casting tundish in metallurgy technology. The stopper rod comprises a stopper rod shell, a stopper rod core is embedded in the stopper rod shell, a magnetic field generating device is arranged on the outer circumferential wall of the stopper rod core, and the magnetic field generating device is used for exciting a magnetic field directly above the water gap. The magnetic field generating device is an electromagnetic coil or a rotating magnetic field stirrer. The application can effectively inhibit the generation of confluence vortex at the end of pouring by adding an electromagnetic field to make the molten steel generate induced current. Meanwhile, the magnetic field excited by the application is formed directly above the water gap and has the maximum strength at the vortex forming position, so that the inhibition effect of the magnetic field on the confluence vortex is more direct, the inhibition effect is obvious, and energy waste is avoided.

To provide a method for continuously casting a steel with which the natural opening ratio of a long nozzle can be improved by restraining the pressure rise in the long nozzle at the time of changing a ladle.SOLUTION: A molten steel flow rate control device (5) for controlling a flow rate of molten steel poured from a ladle (1) into a tundish (2) is closed, and a tip portion of a long nozzle (9) for pouring the molten steel from the ladle (1) into the tundish (2) is immersed in the molten steel in the tundish (2) with a filler (4) filled in a molten steel outflow hole (3) of the ladle (1).SELECTED DRAWING: Figure 4

This invention relates to the field of refractory materials technology, specifically to an anti-slag-adhesion environmentally friendly refractory spray coating adapted to the contact surface of an tundish cover and its preparation method. The dry powder of this spray coating mainly consists of corundum aggregate, modified spinel powder, composite binder, and modified anti-slag additives. Through precise gradation and spatial decoupling of components, a strong and tough skeleton is constructed. During water addition, rheological changes, and baking, the anti-slag additives spontaneously target and migrate outwards, reconstructing a superhydrophobic slag-repellent armor on the slag-facing surface. Combined with the internal spinel-based slag-locking and deformation buffer defense lines, a gradient synergistic defense is achieved. This invention is completely chromium-free and environmentally friendly, completely eliminating the pain point of high-temperature slag adhesion and spalling, extending its service life to 40 heats, and is suitable for large-scale adaptation to special steel continuous casting conditions.

The invention discloses a method for inhibiting the generation of TiN inclusions in a tundish and a high-nitrogen-capacity tundish covering agent.The method comprises the steps that before the tundish is cast, the high-nitrogen-capacity tundish covering agent is evenly added into the tundish, and a water gap outlet is completely covered with the high-nitrogen-capacity tundish covering agent. The adopted covering agent has high nitrogen capacity, nitrogen in air can be effectively prevented from spreading into molten steel, nitrogen increase of the molten steel in the pouring process is prevented, and therefore the generation probability of TiN inclusions is reduced, good economic benefits are achieved, and good market application and popularization prospects are achieved.

The invention discloses a method for controlling the internal quality of a spring steel casting blank. In the continuous casting process, the pulling speed is controlled to be 0.45-0.55 m / min, the specific water flow is 0.09-0.13 / kg, the superheat degree of a tundish is controlled to be 18-25 DEG C through induction heating of the tundish, the total rolling reduction of a pressing device is controlled to be 25-35 mm, and 2-6 pulling-straightening rollers are put. According to the method, the tundish is heated through induction, and the internal quality of the spring steel is improved through combination of crystallizer electromagnetic stirring and tail end electromagnetic stirring processes and a light and heavy pressing process; according to the spring steel casting blank manufactured through the method, the center porosity is greatly improved, the center porosity is smaller than or equal to 0.5 level, the center shrinkage cavity is smaller than or equal to 0.5 level, the center crack is smaller than or equal to 0.5 level, and the number of inclusions is smaller than or equal to 218 / 100 mm < 2 > (larger than or equal to 6 micrometers).

To provide an apparatus for heating molten steel in a tundish in continuous casting of steel.SOLUTION: In an airtight tundish, a resistance heating element made of graphite is arranged above the molten steel surface so as to closely face the molten steel surface in an inert atmosphere. A spiral coil is formed on the disc-shaped heating element. The temperature of the heating element is raised to about 2000°C by AC energization to radiate and heat the space in the tundish. On the other hand, induction heating and induction stirring occur immediately below the molten steel surface below the coil. The power loss due to the self-inductance contributes to heat generation, and a power efficiency of 90% is obtained. A ceramic coating is applied to the upper surface of the heating element to suppress upward radiation and to improve the durability of the inner wall of the refractory. The trouble that slag and molten steel are stuck to the inner wall is eliminated by suitable upward radiation.SELECTED DRAWING: Figure 1

The invention discloses a double-flow slab tundish with a double-electrode plasma heating function. The double-flow slab tundish comprises a tundish body and a tundish cover arranged at the top of the tundish body, and a turbulence controller is arranged at the bottom of the tundish body; a barrage structure is arranged at one end of the interior of the tundish, and a uniflow control wall structure is arranged at the other end of the interior of the tundish. And a dual-electrode plasma heating device is arranged on the ladle cover. Single-flow pouring of the double-flow tundish is achieved, the size of a low-temperature area and the size of a dead area are reduced, slag entrapment is prevented, the temperature in the tundish is uniform, and the plasma heating efficiency is improved. And meanwhile, the tundish casting allowance is reduced.