CN105057611B - A kind of assay device and its using method of simulation continuous casting billet solidification - Google Patents

Abstract

A test device for simulating the solidification of continuous casting slabs and its use method. The test device includes a base, an induction heating furnace is arranged on the base, an opening is arranged at the bottom of the induction heating furnace, a piston is installed in the opening, and a frame The guide rod, the first lifting platform and the second lifting platform are respectively installed on the upper and lower parts of the guide rod of the frame. The first lifting platform is provided with a first motor, a support platform and a vibration motor, and the support platform is provided with a second motor. And the worm, the bottom end of the worm is equipped with push refractory bricks, the vibrating motor is connected to the crystallizer through the connecting rod, there is a cavity in the middle of the crystallizer, the inside of the crystallizer is used for cooling water to enter and exit, and the second lifting platform is equipped with the first Three motors and screws, one end of the screw is connected to the second lifting table, the other end is connected to the piston, and the water spray device cools the formed billet. The solidification process of continuous casting slabs in actual production is simulated by the above-mentioned test device and method to obtain slabs, and the quality and microstructure of slabs are studied and analyzed to guide actual production.

Description

A test device for simulating solidification of continuous casting slab and its application method

technical field

The invention relates to the application field of iron and steel continuous casting simulation test technology, in particular to a test device for simulating solidification of continuous casting slabs and a use method thereof.

Background technique

With the advancement of science and technology and the improvement of process conditions, my country's steel production has leapt to the leading position in the world. However, modern enterprises have higher and higher requirements for the performance of metal materials, and the manufacturing level of high-performance steel still needs to be improved. As a revolutionary technology in the steel industry, continuous casting has become an indispensable process for steelmaking. The occurrence of defects in the continuous casting process, including surface cracks, subcutaneous cracks, vibration marks, uneven quality, etc., will seriously affect the quality of steel and reduce the benefits of enterprises.

The continuous casting mold is the most important part of the continuous casting process, known as the "heart" of the continuous casting machine. The molten steel in the tundish is poured into the mold through the submerged nozzle, and cooled in the mold to form a slab with a certain shell thickness. The slab with a liquid core is continuously pulled by the casting straightening device under the mold out, and then undergo secondary cooling, straightening, cutting, and finally form billets. The solidification of molten steel in the mold includes heat transfer, mass transfer, phase change, multiphase flow, etc., which is a complex dynamic process. Process parameters such as the operation process of the crystallizer, the performance of mold flux, and the amount of cooling water have a very important influence on the quality control of the slab.

To improve the quality of steel, it is necessary to improve the process conditions, control the solidification process of the metal in the continuous casting process, and obtain a refined grain structure. However, the high temperature and complex process factors of continuous casting make it very difficult to observe and study its solidification structure. The research on the billet quality is mainly through the analysis of the sample of the billet collected from the steel mill. Due to the continuity of actual production, there are certain limitations in the adjustment of the process parameters in the process of sample preparation, and the trial production process will It consumes a lot of manpower and material resources, and unqualified steel structure will lead to a large amount of steel being scrapped. In order to improve the quality of steel and reduce the loss of trial production, simulation technology must be used. With the rapid development of computer technology, computer simulation of the solidification process of continuous casting slabs has been realized, but the verification of the simulation results still needs to take samples from steel mills, which is a cumbersome process.

Therefore, it is necessary to establish continuous casting slab solidification simulation test equipment to study the continuous casting slab solidification behavior. The test data will provide certain guidance for actual production and provide verification conditions for the establishment of numerical simulation models.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a test device for simulating the solidification of continuous casting slabs and its use method, which can simulate the solidification of continuous casting slabs, so as to obtain the slabs for detection and analysis to guide actual production.

In order to achieve the above object, the present invention adopts the following technical solutions:

A test device for simulating solidification of continuous casting slabs, comprising:

base;

An induction heating furnace is arranged on the base, and there is molten steel in the induction heating furnace, and mold slag is provided on the top of the molten steel, and an opening is arranged at the bottom of the induction heating furnace, and a piston is installed in the opening. inside the hole;

rack guide rods are provided on at least one side of the base;

The first lifting platform is installed on the top of the frame guide rod, the first lifting platform is provided with a first motor, a support platform and a vibration motor, and the first motor drives the first lifting platform to move up and down, The support platform is fixed on the first lifting platform, and the support platform is provided with a second motor and a worm located on one side of the second motor, the second motor controls the worm to move up and down, and the worm The bottom end of the mold is provided with push refractory bricks, the vibration motor is connected to the crystallizer through a connecting rod, the vibration motor controls the vibration of the crystallizer, and there is a cavity in the middle of the crystallizer, and the push refractory bricks can be protruding into the cavity, and the cavity is for the upper part of the piston to enter, and the inside of the crystallizer is for cooling water to enter and exit;

The second lifting platform is installed on the bottom of the frame guide rod, the second lifting platform is provided with a third motor and a screw, the third motor drives the second lifting platform to move up and down, and one end of the screw rod connected to the second lifting platform, and the other end is connected to the piston;

The water spraying device is arranged on the guide rod of the frame and is located under the second lifting platform to cool the cast slab after forming.

Further, the two sides of the base are respectively provided with the rack guide rods, and one side of the rack guide rods is provided with a positioning scale.

Further, the lower part of the piston is in clearance fit with the opening, and the upper part of the piston is in clearance fit with the cavity.

Further, a sealing ring is provided between the piston and the bottom of the induction heating furnace for sealing.

Further, both sides of the crystallizer are respectively provided with water inlet pipes and outlet pipes for cooling water to enter and exit, a water inlet valve is provided between the water inlet pipe and the crystallizer, and a water inlet valve is provided between the water outlet pipe and the crystallizer. There is a water outlet valve.

Further, an oil injection device is provided on the top of the crystallizer, and the oil injection device evenly distributes high-temperature-resistant lubricating oil in the cavity.

Further, the lifting speed range of the first lifting platform, the second lifting platform and the worm is 0.5-4.5m/min, the frequency range of the vibration motor is 30-400 times/min, and the amplitude range is 2 —20mm.

A method of using the above test device, comprising:

Step 1: start the third motor to control the rise of the second lifting platform, the screw rod rises with the second lifting platform, and drives the piston to rise, the upper part of the piston enters the interior of the induction heating furnace, and the The lower part of the piston is installed in the opening;

Step 2: Add the required steel sample into the induction heating furnace, start the induction heating furnace, and after the steel sample is completely melted into molten steel, add mold slag to the upper part of the molten steel and melt it;

Step 3: Start the first motor to control the first lifting platform to descend, so that the crystallizer is inserted into the molten steel, when the crystallizer descends to a certain height that the upper part of the piston protrudes into the cavity , turning off the first motor;

Step 4: Set the vibration motor parameters, turn on the vibration motor, and turn off the vibration motor after the crystallizer vibrates for a certain period of time;

Step 5: start the second motor to drive the worm to move downward, when the pushing refractory brick touches the top surface of the mold slag, start the third motor, and set the lowering of the third motor The speed is the same as the descending speed of the second motor;

Step 6: Turn on the water spray device, cool the casting slab, and take out the casting slab after cooling;

Step 7: Detect and analyze the surface and internal quality of the cast slab taken out.

Further, before step 3, cooling water is passed into the crystallizer.

Further, after step 6, start the third motor to drive the second lifting table back to the position in step 1, then start the first motor to drive the crystallizer to rise until it leaves the induction heating furnace, completing a group test.

Beneficial effects of the present invention:

(1) The test device for simulating the solidification of continuous casting slabs in the present invention is consistent with the actual production conditions. Through the test data, different process parameters can be studied, including mold slag thickness, crystallizer vibration frequency, vibration amplitude, cooling water spray volume, etc. The influence of the solidification behavior of the slab and its organizational structure, and the actual production activities are guided by these parameters;

(2) The present invention can be combined with microcosmic numerical simulation to analyze and improve the quality of continuous casting slabs from the dual angles of experiment and numerical simulation. The test data can be compared with the results of the computer simulation system, and the error of the computer simulation system can be adjusted to make the computer simulation The results of the system are more accurate, so that it can be used in the simulation process of various billets, saving costs, saving manpower and material resources for testing and sampling.

Description of drawings

Fig. 1 is the structural representation of test device initial state of the present invention;

Fig. 2 is the structural representation of the crystallizer inserted in the molten steel of the test device of the present invention;

Fig. 3 is a schematic diagram of the structure of the test device of the present invention when the refractory brick pushes into the cavity and interferes with mold slag;

In the figure, 1. Crystallizer; 2. Induction heating furnace; 3. Pushing refractory brick; 4. First motor; 5. Second motor; 6. Third motor; 7. Vibration motor; 8. First lifting platform ; 9, the second lifting platform; 10, mold slag; 11, molten steel; 12, water inlet valve; 13, water outlet valve; 14, frame guide rod; 15, piston; 16, water spray device; 17, worm; 18. Base; 19. Connecting rod; 20. Support platform; 21. Water inlet pipe; 22. Water outlet pipe; 23. Sealing ring; 24. Screw rod; 25. Positioning scale; 26. Spray valve; 27. Oiling device; 28, opening; 29, cavity.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the test device for simulating continuous casting slab solidification of the present invention comprises a base 18, an induction heating furnace 2 is provided on the base 18, and a frame guide rod 14 is provided on at least one side of the base 18, in this embodiment In one example, frame guide rods 14 are respectively provided on both sides of the base 18 , and a positioning scale 25 is provided on a side of one of the frame guide rods 14 . A first lifting platform 8 is installed on the top of the frame guide rod 14 , a second lifting platform 9 is installed on the bottom, and a water spray device 16 is installed below the second lifting platform 9 .

The induction heating furnace 2 is equipped with molten steel 11, the top of the molten steel 11 has mold slag 10, the bottom of the induction heating furnace 2 is provided with an opening 28, the opening 28 is equipped with a piston 15, and the lower part of the piston 15 is in clearance fit with the opening 28 , the matching tolerance is 1-2mm, the upper part of the piston 15 extends into the induction heating furnace 2, preferably, the piston 15 is made of refractory material, and a sealing ring 23 is arranged between the piston 15 and the bottom of the induction heating furnace 2 to seal, so as to prevent Molten steel 11 seeps out.

The first lifting platform 8 is located on the top of the frame guide rod 14, on which the first motor 4, the support platform 20 and the vibration motor 7 are arranged, the first motor 4 can drive the first lifting platform 8 to lift, and the support platform 20 is fixed on On the first elevating platform 8, the supporting platform 20 extends upwards, on which a second motor 5 and a worm screw 17 positioned at one side of the second motor 5 are arranged, the second motor 5 can control the worm screw 17 to move up and down, and the bottom end of the worm screw 17 is provided with There are push refractory bricks 3, and the vibration motor 7 is connected to the crystallizer 1 through the connecting rod 19. The vibration motor 7 can control the vibration of the crystallizer 1, so that the crystallizer 1 vibrates at a specific vibration frequency. There is a cavity 29 in the middle of the crystallizer 1, and the pusher refractory brick 3 can extend into the cavity 29. When the crystallizer 1 enters the induction heating furnace 2, the cavity 29 can allow the upper part of the piston 15 to enter, and the upper part of the piston 15 It is clearance fit with the cavity 29, and the fit tolerance is 1-2mm. According to the shape and size of the slab, the upper part of the piston 15 corresponding to the shape and size of the cavity 19 of the crystallizer 1 can be selected. Both sides of the crystallizer 1 are respectively provided with a water inlet pipe 21 and an outlet pipe 22 for cooling water to enter and exit to cool the slab. A water inlet valve 12 is arranged between the water inlet pipe 21 and the crystallizer 1, and the water outlet pipe 22 is connected to the crystallizer 1. A water outlet valve 13 is arranged between them, and the cooling water flow can be controlled through the water inlet valve 12 and the water outlet valve 13 . The top of the crystallizer 1 is provided with an oil injection device 27, and the oil injection device 27 evenly distributes high-temperature-resistant lubricating oil in the cavity 29 to prevent the molten steel 11 from adhering to the cavity 29 inside the mold 1 .

The second lifting platform 9 is installed on the bottom of the frame guide rod 14. The second lifting platform 9 is provided with a third motor 6 and a screw rod 24. The third motor 6 can drive the second lifting platform 9 to move up and down, and the screw rod 24 is connected at one end. On the second lifting platform 9, the other end is connected to the piston 15. When the third motor 6 drives the second lifting platform 9 to move downward, the second lifting platform 9 can drive the screw rod 24 and the piston 15 to move downward, thereby moving the piston 15. Pull out the opening 28 of the induction heating furnace 2 .

The water spray device 16 is arranged on the frame guide rod 14, and is positioned at the bottom of the second lifting platform 9. After the billet is formed in the induction heating furnace 2, when it comes out downwards, the water spray valve 26 is adjusted to make the water spray device 16 pair The molded slab is cooled to simulate the cooling method in the actual production process, and the same slab as the actual production can be obtained.

In this embodiment, the lifting speed range of the first lifting platform 8 is 0.5-4.5m/min, the lifting speed range of the second lifting platform 9 is 0.5-4.5m/min, and the lifting speed range of the worm 17 is 0.5-4.5m/min. m/min, the frequency range of the vibration motor 7 is 30-400 times/min, and the amplitude range is 2-20mm.

As shown in Fig. 1 to Fig. 3, the present invention adopts the operation method of above-mentioned test device as follows:

Step 1: start the third motor 6 to control the second lifting platform 9 to rise, the screw rod 24 rises with the second lifting platform 9, and drives the piston 15 to rise, the upper part of the piston 15 enters the induction heating furnace 2, and the lower part of the piston 15 is installed In the opening 28, and fit with the opening 28, and then install the sealing ring 23 between the piston 15 and the induction heating furnace 2;

Step 2: Add the required steel sample into the induction heating furnace 2, start the induction heating furnace 2, after the steel sample is completely melted into molten steel 11, add mold slag 10 to the upper part of the molten steel 11 and melt it, and then open the The water valve 12 and the water outlet valve 13 allow cooling water to be injected into the crystallizer 1, and the oil injection device 27 is opened to make the oil film fill the cavity 29 inside the crystallizer 1;

Step 3: Start the first motor 4 to control the first lifting platform 8 to descend. At this time, the crystallizer 1 moves downward with the first lifting platform 8 and is inserted into the molten steel 11. Observe the positioning scale 25. When the crystallizer 1 falls to When the top of the piston 15 stretches into the cavity 29 to a certain height, the first motor 4 is closed, and the height can be 50mm;

Step 4: Set the parameters of the vibration motor 7, such as the amplitude is 4mm, the vibration frequency is 100 times/min, turn on the vibration motor 7, the crystallizer 1 vibrates according to the preset vibration parameters, and turn off the crystallizer 1 after vibrating for a certain period of time Vibration motor 7, this process is the molding process of cast slab;

Step 5: Start the second motor 5 to drive the worm 17 to move downward, observe the positioning scale 25, when the push refractory brick 3 touches the top surface of the mold slag 10, start the third motor 6, and set the descending speed of the third motor 6 Same as the descending speed of the second motor 5, at this time, the billet pushing refractory brick 3 pushes the cast billet downward, and at the same time, the piston 15 at the bottom leaves the induction heating furnace 2, releasing the upward push to the cast billet;

Step 6: Open the water spray valve 26 to make the water spray device 16 cool the cast slab, take out the cast slab after cooling, then start the third motor 6 to drive the second lifting platform 9 back to the position in step 1, and then start the first The motor 4 drives the crystallizer 1 to rise until it leaves the induction heating furnace 2, and completes a set of tests;

Step 7: Check and analyze the surface and internal quality of the cast slab, and guide the actual production through the analysis results. If there is a quality defect of the cast slab, you can adjust the vibration frequency and amplitude of the mold, or the type and thickness of mold flux, Or the amount of cooling water of the crystallizer, or the amount of water sprayed by the water spraying device, etc., many tests were carried out to obtain better quality slabs, so as to guide the actual production activities through these parameters. At the same time, the simulation of the solidification process of the continuous casting slab by this test device can be combined with the microscopic numerical simulation to analyze and improve the quality of the continuous casting slab from the dual perspectives of experiment and numerical simulation. The test data can be compared with the results of the computer simulation system to adjust the computer simulation system. The error makes the results of the computer simulation system more accurate, so that it can be used in the simulation process of various billets, saving costs, manpower and material resources for testing and sampling.

The above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without Any deviation from the spirit and scope of the technical solution shall be covered by the scope of the claims of the present invention.

Claims (10)

1. A test device for simulating continuous casting slab solidification, characterized in that it comprises: base; An induction heating furnace is arranged on the base, and there is molten steel in the induction heating furnace, and mold slag is provided on the top of the molten steel, and an opening is arranged at the bottom of the induction heating furnace, and a piston is installed in the opening. inside the hole; rack guide rods are provided on at least one side of the base; The first lifting platform is installed on the top of the frame guide rod, the first lifting platform is provided with a first motor, a support platform and a vibration motor, and the first motor drives the first lifting platform to move up and down, The support platform is fixed on the first lifting platform, and the support platform is provided with a second motor and a worm located on one side of the second motor, the second motor controls the worm to move up and down, and the worm The bottom end of the mold is provided with push refractory bricks, the vibration motor is connected to the crystallizer through a connecting rod, the vibration motor controls the vibration of the crystallizer, and there is a cavity in the middle of the crystallizer, and the push refractory bricks can be protruding into the cavity, and the cavity is for the upper part of the piston to enter, and the inside of the crystallizer is for cooling water to enter and exit; The second lifting platform is installed on the bottom of the frame guide rod, the second lifting platform is provided with a third motor and a screw, the third motor drives the second lifting platform to move up and down, and one end of the screw rod connected to the second lifting platform, and the other end is connected to the piston; The water spraying device is arranged on the guide rod of the frame and is located under the second lifting platform to cool the cast slab after forming. 2. The test device for simulating the solidification of continuous casting slabs according to claim 1, characterized in that: the two sides of the base are respectively provided with the frame guide rods, one of the sides of the frame guide rods With positioning ruler. 3. The test device for simulating solidification of continuous casting slabs according to claim 1, characterized in that: the lower part of the piston is in clearance fit with the opening, and the upper part of the piston is in clearance fit with the cavity. 4. The test device for simulating solidification of continuous casting slabs according to claim 1, characterized in that: a sealing ring is provided between the piston and the bottom of the induction heating furnace for sealing. 5. The test device for simulating the solidification of continuous casting slabs according to claim 1, characterized in that: water inlet pipes and outlet pipes are respectively provided on both sides of the crystallizer for cooling water to enter and exit, and the water inlet pipe and the water outlet pipe A water inlet valve is provided between the crystallizers, and a water outlet valve is provided between the water outlet pipe and the crystallizer. 6. The test device for simulating the solidification of continuous casting slabs according to claim 1, characterized in that: the top of the crystallizer is provided with an oil injection device, and the oil injection device evenly distributes high-temperature resistant lubricating oil in the cavity. 7. The test device for simulating solidification of continuous casting slabs according to claim 1, characterized in that: the lifting speed range of the first lifting platform, the second lifting platform and the worm is 0.5-4.5m/min , the frequency range of the vibration motor is 30-400 times/min, and the amplitude range is 2-20mm. 8. A method for using the test device according to claim 1, comprising: Step 1: start the third motor to control the rise of the second lifting platform, the screw rod rises with the second lifting platform, and drives the piston to rise, the upper part of the piston enters the interior of the induction heating furnace, and the The lower part of the piston is installed in the opening; Step 2: Add the required steel sample into the induction heating furnace, start the induction heating furnace, and after the steel sample is completely melted into molten steel, add mold slag to the upper part of the molten steel and melt it; Step 3: Start the first motor to control the first lifting platform to descend, so that the crystallizer is inserted into the molten steel, when the crystallizer descends to a certain height that the upper part of the piston protrudes into the cavity , turning off the first motor; Step 4: Set the vibration motor parameters, turn on the vibration motor, and turn off the vibration motor after the crystallizer vibrates for a certain period of time; Step 5: start the second motor to drive the worm to move downward, when the pushing refractory brick touches the top surface of the mold slag, start the third motor, and set the lowering of the third motor The speed is the same as the descending speed of the second motor; Step 6: Turn on the water spray device, cool the casting slab, and take out the casting slab after cooling; Step 7: Detect and analyze the surface and internal quality of the cast slab taken out. 9. The method according to claim 8, characterized in that: before step 3, cooling water is passed into the crystallizer. 10. The use method according to claim 8, characterized in that: after step six, start the third motor to drive the second lifting platform back to the position in step one, and then start the first motor to drive the second lifting platform The crystallizer rises until it leaves the induction heating furnace to complete a set of tests.