A simulation test device and test method for molten steel pouring process

Abstract

The invention discloses a simulation test device and test method for a molten steel pouring process. The test device is prepared based on a similar principle, has high accuracy, and can truly simulate the movement behavior and law of drainage sand in a tundish during the molten steel pouring process. Combined with the test method, the floating removal and outflow rate of the drainage sand are used as evaluation indicators. By designing different tundish flow control device structures and continuous casting process parameters, the optimal working conditions conducive to the floating removal of the drainage sand can be obtained, thereby obtaining the tundish structure and continuous casting process parameters that are conducive to the removal of the drainage sand in actual continuous casting production.

Description

Technical Field

[0001] The invention relates to a simulation test device and a test method for a molten steel pouring process, in particular to a device for simulating the movement behavior of drainage sand in a tundish and a test method using the device. Background Art

[0002] In the process of continuous casting of molten metal, automatic ladle pouring technology has been widely used. The automatic pouring technology is realized by filling drainage sand and automatic switching function of the slide plate. The basic principle is to pre-fill the drainage sand in the water inlet of the ladle. After the converter taps the steel, the high-temperature molten steel and the drainage sand contact to form a sintered layer, and a hard shell is formed on the upper part. When the ladle is poured, the slide plate is opened to allow the unsintered drainage sand at the bottom to flow out first, and then the hard shell close to the molten steel is broken under the action of the static pressure of the molten steel, and then the molten steel flows out.

[0003] Generally speaking, the drainage sand is made of silicon or chromium, and its main components are oxides such as SiO2, Cr2O3, Fe2O3, Al2O3, and MgO, and its size ranges from a few microns to several thousand microns. For example, the invention patent application CN201410380216.5 discloses a plate-shaped corundum drainage sand and its preparation method, which can effectively improve the automatic pouring rate. Although the use of drainage sand realizes the automatic pouring technology, a part of the molten steel will float up and be removed after entering the tundish, and a part will remain in the molten steel and pollute the molten steel, resulting in a sharp increase in the total oxygen content and the content of large inclusions during the bag change process, which is very unfavorable for the production of high-quality clean steel. Although some researchers have developed an overflow device for drainage sand, that is, to drain and export the drainage sand before it enters the molten pool of the tundish, it may cause problems with on-site operation safety. Studies have shown that the removal effect of these large inclusions can be improved by reasonably designing the flow control structure of the tundish and adjusting the continuous casting process parameters. For example, invention patent application CN201611141850.9 discloses an argon blowing refining device and argon control method for a continuous casting tundish, which improves the effect of the tundish in removing inclusions from molten steel; utility model patent application CN201822260226.1 discloses a flow control component for a rectangular tundish, which can effectively separate inclusions in steel and improve steel quality.

[0004] However, due to the complexity of the thermophysical behavior of drainage sand and the movement of high-temperature multiphase flow, the existing public data do not involve the evaluation of the movement behavior of drainage sand in the tundish, especially the lack of understanding of the relationship between the floating removal of drainage sand and the tundish flow control device, continuous casting process parameters, etc. This requires the development of corresponding basic research methods to obtain the optimal tundish structure and continuous casting process parameters in actual production to prevent the harm of these large inclusions and improve the cleanliness of molten steel and the stability of product quality. Summary of the invention

[0005] Purpose of the invention: In order to overcome the defects of the prior art, the present invention provides a simulation test device for the molten steel pouring process, through which the movement behavior of drainage sand in the tundish can be simulated, so as to obtain the tundish structure and continuous casting process parameters that are conducive to the removal of drainage sand in actual continuous casting production.

[0006] Another object of the present invention is to provide a test method using the simulation test device of the above-mentioned molten steel pouring process.

[0007] Technical solution: The simulation test device for the molten steel pouring process described in the present invention comprises a ladle model, a tundish model, a long nozzle model and a slide device which are formed in the same proportion according to the similar principle; the ladle model is arranged above the tundish model, the slide device is installed at the bottom of the outlet of the ladle model, and the long nozzle model is installed below the slide device and extends into the tundish model; a heating device is arranged in the tundish model, the tundish model has at least one liquid outlet, and a filtering and collecting device is arranged corresponding to the liquid outlet; it also includes a drainage sand simulation and a temperature monitoring device, and the temperature monitoring device is used to monitor the liquid temperature in the ladle model and the tundish model.

[0008] Wherein, the slide device is constructed as a sliding valve structure for opening and closing the outlet of the ladle model and controlling the opening degree.

[0009] When the slide plate device is in a closed state, the drainage sand simulant is accumulated at the outlet of the ladle model.

[0010] Furthermore, the drainage sand simulation includes a particle simulation and a bonding layer, wherein the bonding layer covers the particle simulation. A hard shell is formed on the drainage sand simulation through the bonding layer to simulate the sintered layer of actual molten steel casting.

[0011] The tundish model is also provided with a flow control device, which includes at least one of a turbulence suppressor and a retaining wall, so as to more accurately simulate the shape and structure of the actual tundish and conveniently adjust the flow state in the tundish.

[0012] The ladle model, the tundish model, the shroud model and the slide device are all made of organic glass. On the one hand, organic glass has high strength, is light and transparent, can adapt to the impact of the test and more intuitively observe the flow conditions in each component, and on the other hand, organic glass is convenient for the assembly of components and the adjustment of the structure.

[0013] The particle simulant is a hollow glass particle with a particle size ranging from micrometers to hundreds of micrometers and a density less than that of water. The weight of the hollow glass particle is calculated based on a similar ratio, and its density is slightly smaller than that of water, and is relatively close to the relative density of water and the relative density of drainage sand in molten steel, so the use of hollow glass particles can more accurately simulate the movement behavior of drainage sand in molten steel.

[0014] Corresponding to the above-mentioned simulation test device for the molten steel pouring process, the technical solution adopted by the test method provided by the present invention comprises the following steps:

[0015] (1) The slide device is in an initial closed state, and a drainage sand simulant is filled at the outlet of the ladle model. The particle simulant is first piled up according to the pile method of drainage sand in actual production; after the pile is completed, a bonding layer is covered on the top to simulate the sintering layer, wherein the bonding layer is made of a material that is solid at room temperature, melts when heated, and dissolves in water;

[0016] (2) adding hot water to the tundish model to a stable pouring level, monitoring the water temperature in the tundish model using a temperature monitoring device, and turning on a heating device to maintain the water temperature within a preset temperature range;

[0017] (3) After the water temperature in the tundish model stabilizes, the liquid outlet of the tundish is opened to allow water to flow out at a certain speed; at the same time, hot water is added to the ladle model and the slide device is quickly opened so that the drainage sand simulant is flushed into the tundish model by the hot water;

[0018] (4) Gradually adjust the opening of the slide device to control the water level of the tundish model to maintain a stable pouring level;

[0019] (5) After pouring for a period of time, the particle simulant is collected and weighed at the liquid outlet and the top liquid surface of the tundish model, and their respective weight proportions are calculated, that is, the outflow rate and removal rate are obtained;

[0020] (6) By changing the simulation parameters, the optimal tundish structure and process control parameters that are beneficial to preventing drainage sand from flowing out of the tundish outlet are fitted and obtained.

[0021] The temperature of the hot water added to the ladle model is about 5-20° C. higher than the water temperature in the tundish model, so as to more accurately simulate the state of the molten steel in the ladle and the tundish.

[0022] Furthermore, the simulation parameters include the structure of the flow control device in the tundish model, the outlet flow rate of the tundish model and the opening method of the slide device.

[0023] Beneficial effects: The test device is prepared based on similar principles, has high accuracy, and can truly simulate the movement behavior and law of drainage sand in the tundish during the pouring of molten steel. Combined with the test method, the floating removal and outflow rate of drainage sand are used as evaluation indicators. By designing different tundish flow control device structures and continuous casting process parameters, the optimal working conditions conducive to the floating removal of drainage sand can be obtained, thereby obtaining the tundish structure and continuous casting process parameters that are conducive to the removal of drainage sand in actual continuous casting production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the test device of the present invention. DETAILED DESCRIPTION

[0025] Next, combine Figure 1 And embodiments further illustrate the present invention in detail.

[0026] Embodiment 1: According to the actually measured structures and sizes of the ladle, tundish, shroud and slide plate, at a similar ratio of 1 / 3, a ladle model 1, a tundish model 2, a shroud model 3 and a slide plate device 4 are made of plexiglass, wherein the tundish model 2 is a single-stream tundish; and each component is installed according to the positional relationship.

[0027] The drainage sand simulant is divided into two parts: a particle simulant 7 and a bonding layer 9. The particle simulant 7 is made of hollow glass particles with a particle size ranging from tens of microns to hundreds of microns; the bonding layer 9 is made of rock sugar; the filter collection device 6 is a porous filter structure, which is arranged below the liquid outlet 21.

[0028] The test method using the above device includes the following steps:

[0029] (1) closing the slide device 4 and filling 1.6 kg of hollow glass particles at the outlet of the ladle model 1, and stacking them according to the stacking method of drainage sand in actual production. After the stacking is completed, pouring melted rock sugar on the top of the hollow glass particle pile and cooling it, so that the top of the hollow glass particle pile is bonded to form a shell;

[0030] (2) adding hot water to the tundish model 2 to a stable pouring level of 300 mm, turning on the heating device 5 in the tundish to maintain the water temperature in the temperature range of 30-35° C., and monitoring the water temperature in the tundish model 2 using a temperature monitoring device;

[0031] (3) After the water temperature in the tundish model 2 is relatively stable, the liquid outlet 21 is opened to allow water to flow out at a flow rate of 3.0 L / min; at the same time, hot water is quickly added to the ladle model 1 and the slide device 4 is quickly opened, wherein the temperature of the hot water added to the ladle model 1 is higher than the water temperature in the tundish model 2, specifically 40° C.;

[0032] (4) The hollow glass particles and the crystal sugar bonding layer are then flushed into the tundish model 2 by the hot water in the ladle model 1, and the opening of the slide device 4 is gradually adjusted so that the water level in the tundish model is maintained at a stable pouring level of 300 mm.

[0033] (5) After 15 minutes of pouring, the hollow glass particles are collected and weighed at the liquid outlet 21 of the tundish model 2 and the top liquid surface, and their proportion to the total weight, i.e., the outflow rate and removal rate, can be calculated.

[0034] (6) By adjusting the flow control devices in the tundish model (such as the position of the turbulence suppressor and the retaining wall), the outlet flow rate of the tundish model, and the opening method of the slide device, the optimal tundish structure and process control parameters that are beneficial to preventing the drainage sand from flowing out of the tundish outlet can be fitted and obtained.

[0035] Embodiment 2: According to the actually measured structures and sizes of the ladle, tundish, shroud and slide plate, at a similar ratio of 1 / 2, plexiglass is used to make the ladle model 1, the tundish model 2, the shroud model 3 and the slide plate device 4, wherein the tundish model 2 is a single-stream tundish; and each component is installed according to the positional relationship.

[0036] The drainage sand simulant is divided into two parts: a particle simulant 7 and a bonding layer 9, wherein the particle simulant 7 is hollow glass particles with a particle size ranging from tens of microns to hundreds of microns; the bonding layer 9 is made of solid glue; the filter collection device 6 is a porous filter structure, which is arranged below the liquid outlet 21.

[0037] The test method using the above device includes the following steps:

[0038] (1) closing the slide device 4 and filling 2.5 kg of hollow glass particles at the outlet of the ladle model 1, and stacking them according to the stacking method of drainage sand in actual production. After the stacking is completed, pouring the melted solid glue on the top of the hollow glass particle pile and cooling it, so that the top of the hollow glass particle pile is bonded to form a shell;

[0039] (2) adding hot water to the tundish model 2 until the stable pouring level is 320 mm, turning on the heating device 5 in the tundish to maintain the water temperature in the temperature range of 28-32° C., and monitoring the water temperature in the tundish model 2 using a temperature monitoring device;

[0040] (3) After the water temperature in the tundish model 2 is relatively stable, the liquid outlet 21 is opened to allow water to flow out at a flow rate of 4.0 L / min; at the same time, hot water is quickly added to the ladle model 1 and the slide device 4 is quickly opened, wherein the temperature of the hot water added to the ladle model 1 is higher than the water temperature in the tundish model 2, specifically 38° C.;

[0041] (4) The hollow glass particles and the solid adhesive layer are then flushed into the tundish model 2 by the hot water in the ladle model 1, and the opening of the slide device 4 is gradually adjusted so that the water level in the tundish model is maintained at a stable pouring liquid level of 320 mm.

[0042] (5) After 15 minutes of pouring, the hollow glass particles are collected and weighed at the liquid outlet 21 of the tundish model 2 and the top liquid surface, and their proportion to the total weight, i.e., the outflow rate and removal rate, can be calculated.

[0043] (6) By adjusting the flow control devices in the tundish model (such as the position of the turbulence suppressor and the retaining wall), the outlet flow rate of the tundish model, and the opening method of the slide device, the optimal tundish structure and process control parameters that are beneficial to preventing the drainage sand from flowing out of the tundish outlet can be fitted and obtained.

Claims

1. A test method for a simulation test device of a molten steel pouring process, characterized in that: The simulation test device comprises a ladle model (1), a tundish model (2), a long shroud model (3) and a slide device (4) which are formed in the same proportion according to a similar principle; the ladle model (1) is arranged above the tundish model (2), the slide device (4) is installed at the bottom of the outlet of the ladle model (1), and the long shroud model (3) is installed below the slide device (4) and extends into the tundish model (2); a heating device (5) is arranged in the tundish model (2), and the tundish model (2) has at least one liquid outlet (21), and a filtering and collecting device (6) is arranged corresponding to the liquid outlet (21); It also includes a drainage sand simulant and a temperature monitoring device (8), wherein the temperature monitoring device (8) is used to monitor the liquid temperature in the ladle model (1) and the tundish model (2); The test method includes the following steps: (1) The slide device is in the initial closed state, and the drainage sand simulant is filled at the outlet of the ladle model. The particle simulant is first piled up according to the pile method of drainage sand in actual production; After the stacking is completed, a bonding layer is covered on top to simulate a sintering layer, wherein the bonding layer is made of a material that is solid at room temperature, melts when heated and dissolves in water; (2) Add hot water to the tundish model until the pouring liquid level is stable, monitor the water temperature in the tundish model using a temperature monitoring device, and turn on the heating device to maintain the water temperature within a preset temperature range; (3) After the water temperature in the tundish model stabilizes, open the liquid outlet of the tundish to allow water to flow out at a certain speed; at the same time, add hot water into the ladle model and quickly open the slide device so that the drainage sand simulant is flushed into the tundish model by the hot water; (4) Gradually adjust the opening of the slide device to control the water level of the tundish model to maintain a stable pouring level; (5) After pouring for a period of time, the particle simulant is collected and weighed at the liquid outlet and the top liquid surface of the tundish model, and their respective weight proportions are calculated to obtain the outflow rate and removal rate; (6) By changing the simulation parameters, the optimal tundish structure and process control parameters that are beneficial to preventing drainage sand from flowing out of the tundish outlet are fitted and obtained.

2. The test method of the simulation test device for molten steel pouring process according to claim 1, characterized in that: The slide device (4) is configured as a sliding valve structure, and is used to open and close the outlet of the ladle model (1) and to control the opening degree.

3. The test method of the simulation test device for molten steel pouring process according to claim 2, characterized in that: When the slide plate device (4) is in a closed state, the drainage sand simulant is accumulated at the outlet of the ladle model (1).

4. The test method of the simulation test device for molten steel pouring process according to claim 3, characterized in that: The drainage sand simulant comprises a particle simulant (7) and a bonding layer (9), wherein the bonding layer (9) covers the particle simulant (7).

5. The test method of the simulation test device for molten steel pouring process according to claim 1, characterized in that: A flow control device is also provided in the tundish model (2), and the flow control device comprises at least one of a turbulence suppressor (10) and a retaining wall.

6. The test method of the simulation test device for molten steel pouring process according to claim 1, characterized in that: The ladle model (1), the tundish model (2), the shroud model (3) and the slide plate device (4) are all made of organic glass.

7. The test method of the simulation test device for molten steel pouring process according to claim 4, characterized in that: The particle simulant (7) is a hollow glass particle with a particle size ranging from micrometers to hundreds of micrometers and a density less than that of water.

8. The test method according to claim 1, characterized in that: The temperature of the hot water added into the ladle model is 5-20° C. higher than the water temperature in the tundish model.

9. The test method according to claim 1, characterized in that: The simulation parameters include the structure of the flow control device in the tundish model, the outlet flow rate of the tundish model and the opening method of the slide device.

Images