An experimental device and method for simulating the slag-metal reaction in electroslag remelting under vacuum or protective atmosphere

Abstract

The present invention discloses an experimental device and method for simulating the slag-metal reaction in vacuum or protective atmosphere electroslag remelting. The experimental device mainly includes a melting device, a slag-metal reaction device, a suspension device, and a cooling device. The melting device is an ordinary vertical tubular resistance furnace; the slag-metal reaction device mainly includes a graphite crucible, a corundum crucible with holes on the bottom surface, and a boron nitride crucible; the suspension device mainly includes a "Y-shaped" hook, a chain, a sprocket, a dial, and a rotating rod; the cooling device is directly below the furnace tube of the tubular resistance furnace. To prevent the coolant from splashing and the rapid expansion of steam from causing danger, two layers of asbestos nets are arranged above the coolant, and the upper opening of the coolant container is completely covered except for the central opening.

Description

Technical Field

[0001] The present invention relates to the field of electroslag metallurgy experiments, and particularly to an experimental device and method for simulating the slag-metal reaction in vacuum or protective atmosphere electroslag remelting. Background Art

[0002] Electroslag remelting can further purify metals and improve the solidification structure of ingots on the basis of primary metal smelting, thereby obtaining high-quality metal products. Therefore, it is widely used in the production of high-purity, low-segregation high-end special steels and special alloys. During the electroslag remelting process, a large amount of resistance heat is generated when the current passes through the slag pool. The end of the consumable electrode gradually melts under the action of the resistance heat, converges into metal droplets, and the metal droplets drip from the end of the consumable electrode and pass through the slag layer, and converge into a metal molten pool below the slag pool. Different from ordinary steelmaking methods, there is a process in electroslag remelting where metal droplets pass through the slag layer. During this process, the slag and metal are fully mixed, and inclusions undergo complex physical and chemical reactions to be removed from the droplets. In addition, the slag system used in the electroslag remelting process is also different from ordinary refining slags, mainly fluorine-containing slag systems, and its absorption and dissolution mechanism of non-metallic inclusions is quite different from that of ordinary oxide slag systems. Therefore, it is very necessary to simulate the slag-metal reaction, especially the slag-metal reaction in electroslag remelting, and study the effects of parameters such as slag composition, slag-metal ratio, droplet size, smelting temperature, reaction time, and smelting atmosphere on the removal of inclusions and the fluctuation of alloying elements during electroslag remelting.

[0003] In order to improve the experimental accuracy, the structure and design of the slag-metal reaction device are very important. First of all, it lies in the selection of the crucible material. Considering the experimental cost, oxides such as magnesia and corundum, high-melting-point metals such as tungsten and molybdenum, and graphite crucibles are generally selected. Among them, crucibles made of oxide materials have a high use temperature and do not contaminate the alloy liquid, but are not resistant to slag erosion, especially not resistant to fluoride slag systems. As the slag-metal reaction time prolongs, the slag system composition changes significantly, the experimental conditions change, and in severe cases, the crucible may even be eroded through, resulting in slag leakage. High-melting-point metal crucibles such as tungsten and molybdenum can resist the erosion of ordinary oxide slag systems, but their corrosion resistance to fluoride slag systems will weaken. In addition, such crucibles will form alloys with the metal liquid, thus changing the metal liquid composition. Although graphite crucibles can resist the erosion of molten slag and metal liquid, they will cause serious carbon increase and change the physical and chemical properties of the metal liquid and molten slag. Platinum crucibles can also be used. Such crucibles have stable physical and chemical properties and strong corrosion resistance to fluoride and oxide slag systems. However, platinum may also form alloys with low-melting-point metals and fail at high temperatures, and the cost is too high, which is not conducive to expanding the experiment.

[0004] Secondly, it lies in the choice of slag addition method. Generally speaking, the slag addition methods include adding slag at normal temperature and adding slag at high temperature. Adding slag at normal temperature is simple and easy to operate, but the slag material stays in the crucible for a long time, which erodes the crucible very seriously and easily causes the crucible to leak slag. Therefore, the problem to be solved by this method is the erosion of the crucible by the slag material; when adding slag at high temperature, the erosion of the crucible by the slag material is small, but due to the small density and particle size of the slag material, it is easily blown away by the thermal buoyancy or the protective gas in the furnace, and the mixing of slag and metal is not sufficient, and the temperature fluctuates severely.

[0005] Finally, it lies in the choice of sampling method. Since the slag-metal reaction experiment is carried out at high temperature and sampling is inconvenient, process samples are generally extracted with a quartz tube. However, the amount of sampling by this method is too small, and the already stably stratified slag and metal are easily remixed during the extraction process, and the error is too large to explain the problem. Final samples are generally taken out after cooling with the furnace to room temperature. However, after cooling with the furnace, the tissue characteristics of the slag and metal are quite different from those in the liquid state, so the situation in the liquid state cannot be explained. It is also possible to directly lift the crucible out of the furnace mouth under high temperature conditions and quickly water-cool it to maintain the tissue in the liquid state. However, this operation is very dangerous, and during the lifting process, the slag and metal are easily cooled down and partially condensed, and the final tissue is also somewhat different from that in the liquid state. Different operation speeds and times have different degrees of influence.

[0006] Based on this, an experimental device and method for electroslag remelting slag-metal reaction under vacuum or protective atmosphere are designed. The present invention is relatively close to the actual process of electroslag remelting, can resist the erosion of the crucible by oxide and fluoride slag systems and metal liquid, the molten slag and metal liquid can be fully mixed and reacted, and the feeding and sampling are safe, convenient, simple and easy to operate, and the experimental cost is low. Summary of the Invention

[0007] The purpose of the present invention is to provide an experimental device and method for simulating the slag-metal reaction in electroslag remelting under vacuum or protective atmosphere. During the process of simulating electroslag remelting under vacuum or protective atmosphere, it includes the slag-metal reaction such as metal droplets passing through the slag layer and the interface between the metal molten pool and the slag pool, and at the same time solves problems such as crucible erosion, insufficient mixing of slag and metal, inconvenient feeding and sampling during the slag-metal reaction process.

[0008] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0009] An experimental device for electroslag remelting slag-metal reaction under vacuum or protective atmosphere includes a melting device, a slag-metal reaction device, a suspension device, and a cooling device, as Figure 1 and 2 shown.

[0010] The melting device is a vertical tubular resistance furnace, and the working temperature can reach above 1650 °C. The furnace mouth and the furnace bottom of the resistance furnace are sealed with water-cooled flanges and can be opened at any time when needed.

[0011] The slag-metal reaction device mainly consists of three crucibles, as Figure 3 shown. The crucible for holding slag materials and the crucible for holding alloy materials are arranged coaxially, with the crucible for holding slag materials at the bottom and the crucible for holding alloy materials at the top, and a graphite crucible is sheathed outside the crucibles for slag materials and alloy materials.

[0012] In the above slag-metal reaction device, the crucible for holding slag materials is defined as a boron nitride crucible because boron nitride can resist the corrosion of various metal, oxide, and fluoride slag systems, only has a slight reaction with titanium oxide at high temperatures, and using a boron nitride crucible does not significantly increase the experimental cost. In addition, since boron nitride will be oxidized in high-temperature air and the service temperature cannot exceed 1000 °C, while the service temperature can reach above 1800 °C under vacuum or inert gas protection conditions, so this device is only used to simulate the slag-metal reaction in electroslag remelting under vacuum or protective atmosphere.

[0013] In the above slag-metal reaction device, the material of the crucible for holding metal can be selected as corundum, which has a low cost and can resist the erosion of various metals. A round hole is opened at the bottom of the crucible, and the single-hole diameter D1 is 2 - 10 mm to simulate metal droplets of different sizes. The overall shape of the opening area is circular, and the center of the circle coincides with the center of the bottom surface of the crucible. The ratio of the diameter D2 of the opening area to the diameter D3 of the bottom surface of the crucible is 0.1 - 0.9 to simulate the diameter ratio (filling ratio) of the consumable electrode to the cross-section of the mold.

[0014] In the above slag-metal reaction device, the outer graphite crucible is mainly used to fix the relative positions of the boron nitride and corundum crucibles, and at the same time ensure that the atmosphere inside the furnace is a reducing atmosphere to prevent the boron nitride crucible and other structures from being oxidized. In addition, two symmetrically distributed holes are provided on the side wall of the mouth of the graphite crucible.

[0015] In the above slag-metal reaction device, the boron nitride and corundum crucibles are located in the constant-temperature working section of the tubular furnace, and the temperature can reach above 1650 °C, while the mouth of the graphite crucible is located in the low-temperature section of the tubular furnace, and the temperature does not exceed 1400 °C.

[0016] In the above slag-metal reaction device, the mass ratio of the slag materials to the alloy materials is 0.1 - 0.3 to simulate the slag-metal ratio in the electroslag remelting process.

[0017] The suspension device mainly consists of a "Y-shaped" hook, a chain, a sprocket, a dial, and a rotating rod, as Figure 4 shown. The lower end of the "Y-shaped" hook passes through the two symmetrically distributed holes on the side wall of the graphite crucible and is connected to the slag-metal reaction device, and the upper end is connected to the chain, and the chain meshes with the sprocket. A dial is fixed outside the furnace mouth, and the dial and the sprocket are arranged coaxially in the horizontal direction. Openings are made at the center of the dial, the side wall of the furnace mouth, and the center of the sprocket, and the rotating rod passes through the dial, the side wall of the furnace mouth, and the sprocket in sequence from outside the furnace body.

[0018] In the above suspension device, in order to accurately control the lifting position of the slag-metal reaction device, a chain and sprocket drive is selected. To ensure that the chain is always coaxial with the slag-metal reaction device during the lifting process and the meshing of the chain and sprocket is not easily detached, a protective shell is concentrically arranged outside the sprocket. The shape of the protective shell is 3 / 4 circle. As a whole, this part is detachably arranged between the furnace mouth and the furnace cover through a circular chuck.

[0019] In the above suspension device, the dial and the sprocket are arranged coaxially in the horizontal direction. The dial is fixed on the side wall of the furnace mouth, and the indication represents the effective movement distance of the sprocket or the chain.

[0020] In the above suspension device, the rotating rod is connected to the center of the sprocket through a metal key, and the rotation of the sprocket can be controlled by the rotating rod. The rotating rod is equipped with a pointer, and the effective movement distance of the sprocket or the chain and the position of the slag-metal reaction device can be determined through the pointer and the dial. In addition, the rotating rod is equipped with a bolt. After the slag-metal reaction device is lifted to a specific position, the rotating rod can be fixed to the side wall of the furnace mouth through the bolt to ensure that the relative position does not change during the experiment.

[0021] The cooling device is directly below the furnace tube. When it is necessary to quickly cool the sample to preserve its high-temperature microstructure, the water-cooled flange at the lower end of the furnace tube can be opened first, and then the sprocket is rotated by the rotating rod to quickly and stably lower the slag-metal reaction device into the coolant. To prevent the coolant from splashing and the vapor from expanding rapidly and causing danger, two layers of asbestos nets are arranged above the coolant. Except for the central opening, the asbestos nets completely cover the upper mouth of the coolant container.

[0022] A method for simulating the slag-metal reaction in vacuum or protective atmosphere electroslag remelting according to the present invention uses the above device and is carried out according to the following steps:

[0023] 1. At room temperature, weigh the slag material and the metal material according to the ratio, and load them into the boron nitride crucible and the corundum crucible respectively. The boron nitride crucible is at the bottom and the corundum crucible is on the top, and then a graphite crucible is put on the outside.

[0024] 2. Connect the slag-metal reaction device to the suspension device through the "Y-shaped" hook. Rotate the sprocket through the rotating rod to lift the slag-metal reaction device to a specific position, where the boron nitride crucible and the corundum crucible are located in the constant-temperature working section of the furnace body, and the upper mouth of the graphite crucible is located in the low-temperature section of the furnace body. Then fix the rotating rod to the side wall of the furnace mouth through the bolt to prevent the position of the slag-metal reaction device from shifting.

[0025] 3. Seal the furnace body, turn on the cooling water, and turn on the protective gas such as argon or evacuate to vacuum.

[0026] 4. Heat the tube furnace to the slag-metal reaction experiment temperature. At this time, the slag material and the alloy melt, and the liquid alloy slowly drips into the boron nitride crucible through the small holes at the bottom of the corundum crucible and passes through the molten slag layer, mixes fully with the slag material, and then converges into a metal molten pool below the molten slag layer.

[0027] 5. Select the time for the slag-metal reaction according to the experimental requirements. After the time is reached, open the fixed bolts of the water-cooled flange at the bottom of the furnace tube and the rotating rod, rotate the rotating rod, and quickly and stably lower the slag-metal reaction device into the cooling medium to preserve the liquid tissue characteristics of the molten slag and metal.

[0028] The following will further illustrate the concept, specific structure and technical effects of the present invention in conjunction with the drawings to fully understand the purpose, features and effects of the present invention. Description of the Drawings

[0029] Figure 1 is the front view of an experimental device for simulating slag-metal reaction in electroslag remelting under vacuum or protective atmosphere according to the present invention. In the figure: 1 - water-cooled furnace cover; 2 - circular chuck; 3 - sprocket protection shell; 4 - sprocket; 5 - metal key; 6 - dial; 7 - rotating rod; 8 - rotating rod bolt; 9 - rotating rod pointer; 10 - chain; 11 - "Y-shaped" hook; 12 - graphite crucible; 13 - corundum crucible; 14 - metal charge; 15 - metal droplet; 16 - boron nitride crucible; 17 - slag pool; 18 - metal molten pool; 19 - water-cooled furnace bottom; 20 - asbestos net; 21 - cooling medium.

[0030] Figure 2 is the left view of an experimental device for simulating slag-metal reaction in electroslag remelting under vacuum or protective atmosphere according to the present invention.

[0031] Figure 3 is the front view of a partial slag-metal reaction device according to the present invention.

[0032] Figure 4 is the front view of a partial suspension device according to the present invention.

[0033] Figure 5 is the alloy ingot after rapid condensation of the metal molten pool in the boron nitride crucible in Example 1 of the present invention.

[0034] Figure 6 [[ID=3G]]is the slag shell after rapid condensation of the slag layer in the boron nitride crucible in Example 1 of the present invention.

[0035] Figure 7 is the alloy ingot after rapid condensation of the uncompletely dripped alloy liquid in the corundum crucible in Example 1 of the present invention.

[0036] Figure 8 is the line scanning diagram of element distribution on the side wall of the corundum crucible in Example 1 of the present invention.

[0037] Figure 9 is the line scanning diagram of element distribution at the interface between the side wall of the boron nitride crucible and the molten slag in Example 1 of the present invention.

[0038] Figure 10 is the line scanning diagram of element distribution on the side wall of the corundum crucible in Example 2 of the present invention.

[0039] Figure 11 It is the line scanning diagram of the element distribution at the interface between the side wall of the boron nitride crucible and the slag in Example 2 of the present invention. Specific embodiments

[0040] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0041] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0042] For the purpose of illustration, some exemplary embodiments of the present invention are described. It should be understood that the present invention can be implemented in other ways not specifically shown in the drawings.

[0043] The heating furnace adopted in the embodiment of the present invention is a molybdenum disilicide vertical tube resistance furnace. The inner diameter of the corundum furnace tube is 120 mm, the outer diameter is 130 mm, the height is 1400 mm, the heating rate is 5 - 10 °C / min, and the maximum heating temperature can reach 1700 °C.

[0044] The embodiment of the present invention is carried out under an argon protection atmosphere, and the pressure gas flow rate is 2 - 4 L / min.

[0045] In the embodiment of the present invention, the inner diameter of the boron nitride and corundum crucibles is 50 mm, the outer diameter is 60 mm, and the height is 70 mm. The ratio of the diameter D2 of the perforated area at the bottom of the corundum crucible to the bottom diameter D3 is 0.8, and the single hole diameter D1 is 4 mm. The inner diameter of the graphite crucible is 72 mm, the outer diameter is 85 mm, and the height is 300 mm.

[0046] In the embodiment of the present invention, the material of the "Y-shaped" hook is molybdenum metal, and the materials of the remaining suspension structures such as the chain, sprocket, key, and rotating rod are stainless steel.

[0047] The metal material adopted in the embodiment of the present invention is the GH4975 alloy melted by a vacuum induction furnace, and the specific components are shown in Table 1.

[0048] Table 1 Composition of the GH4975 alloy material in the embodiment (mass fraction, %)

[0049]

[0050] The slag used in the embodiments of the present invention is prepared from analytical pure chemical reagents.

[0051] The cooling medium used in the embodiments of the present invention is water.

[0052] Example 1

[0053] The slag used in this example is the "622" slag system commonly used in electroslag remelting, as shown in Table 2.

[0054] Table 2 Slag Composition in Example 1 (mass fraction, %)

[0055]

[0056] This example uses 50 g of slag, 500 g of alloy material, a slag-to-metal ratio of 0.1, an experimental temperature of 1600 °C, and a holding time of 20 min.

[0057] This example uses Figure 1 the device shown to conduct the slag-metal reaction experiment. The specific experimental steps are as follows:

[0058] 1. At room temperature, weigh 50 g of slag and 500 g of alloy material in proportion, and load them into a boron nitride crucible and a corundum crucible respectively. The boron nitride crucible is placed below and the corundum crucible is placed above, and then a graphite crucible is put on the outside.

[0059] 2. Connect the slag-metal reaction device to the suspension device through a "Y-shaped" hook. Rotate the sprocket through the rotating rod to lift the slag-metal reaction device to a specific position, where the boron nitride crucible and the corundum crucible are located in the constant-temperature working section of the furnace body, and the upper opening of the graphite crucible is located in the low-temperature section of the furnace body. Then fix the rotating rod to the side wall of the furnace mouth through bolts to prevent the position of the slag-metal reaction device from shifting.

[0060] 3. Seal the furnace body, turn on the cooling water, turn on the argon gas, and the argon gas flow rate is 2 L / min.

[0061] 4. Heat up the tubular furnace. The heating rate in the low-temperature stage is 10 °C / min. When it reaches 900 °C, adjust the heating rate to 5 °C / min, increase the argon gas flow rate to 4 L / min, and continue to heat up to 1600 °C.

[0062] 5. Hold at 1600 °C for 20 min, then open the water-cooled flange at the bottom of the furnace tube and the fixing bolts of the rotating rod, rotate the rotating rod, and quickly and stably lower the slag-metal reaction device into the cooling water to preserve the liquid tissue characteristics of the molten slag and metal.

[0063] After the sample cooled, it was found that under the experimental conditions, part of the molten metal ( Figure 5 ) had passed through the molten slag layer ( Figure 6)Drop onto the boron nitride crucible, and the remaining molten metal does not drip. Metal droplets that are forming can also be observed. Figure 7 )This indicates that after the metal melts in this experiment, it slowly enters the slag layer in the form of droplets, and the slag and metal are fully mixed. This device can well simulate the process in electroslag remelting where metal droplets drip through the slag layer and then aggregate into a metal molten pool.

[0064] Longitudinally cut the boron nitride and corundum crucibles, and observe the cross-sectional tissue characteristics and element distribution with a scanning electron microscope. Figure 8 This is the morphological feature and line scanning diagram of the element distribution of the side wall of the corundum crucible in this embodiment. It can be seen that the tissue of the side wall of the corundum crucible is uniform, there is no obvious transition layer, the element distribution is uniform, the main elements are Al and O, there is a small amount of Ca, and the elements of the GH4975 alloy are hardly detected, indicating that the corundum crucible is not eroded by the molten metal during the melting and dripping process of the alloy.

[0065] Figure 9 This is the tissue feature and line scanning diagram of the element distribution at the interface between the side wall of the boron nitride crucible and the slag in this embodiment. It can be seen that the interface between the boron nitride crucible and the slag is clear, and the element distribution near the interface changes abruptly. On the left side are B and N elements, and on the right side are Al, Ca, O, and F elements, with basically no transition phenomenon, indicating that the boron nitride crucible is not eroded by the fluoride slag system under these experimental conditions.

[0066] Example 2

[0067] Since TiO2 will have a slight erosion effect on the boron nitride crucible at high temperatures, and when electroslag remelting some alloys containing Ti elements, to prevent the burning loss of Ti elements, a small amount of TiO2 is generally added. Therefore, in this embodiment, based on the "622" slag system, 10% of TiO2 is added, as shown in Table 3.

[0068] Table 3 Composition of the slag materials in Example 2 (mass fraction, %)

[0069]

[0070] In this embodiment, 100 g of slag materials and 500 g of alloy materials are used, the slag-to-metal ratio is 0.2, the experimental temperature of the slag and metal is 1600 °C, and the reaction time of the slag and metal is 100 min.

[0071] This embodiment uses Figure 1 the device shown to conduct the slag-metal reaction experiment. The specific experimental steps are as follows:

[0072] 1. At room temperature, weigh 100 g of slag materials and 500 g of alloy materials in proportion, and load them into the boron nitride crucible and the corundum crucible respectively. The boron nitride crucible is at the bottom and the corundum crucible is on top, and then coat them with a graphite crucible.

[0073] 2. Connect the slag-metal reaction device to the suspension device through a "Y-shaped" hook. Rotate the sprocket through the rotating rod to lift the slag-metal reaction device to a specific position. Among them, the boron nitride crucible and the corundum crucible are located in the constant-temperature working section of the furnace body, and the upper mouth of the graphite crucible is located in the low-temperature section of the furnace body. Then fix the rotating rod to the side wall of the furnace mouth through bolts to prevent the position of the slag-metal reaction device from shifting.

[0074] 3. Seal the furnace body, turn on the cooling water, turn on the argon, and the argon flow rate is 2 L / min.

[0075] 4. Heat up the tube furnace. The heating rate in the low-temperature stage is 10 °C / min. When it reaches 900 °C, adjust the heating rate to 5 °C / min, increase the argon flow rate to 4 L / min, and continue heating to 1600 °C.

[0076] 5. Keep it at 1600 °C for 100 min. Then open the water-cooled flange at the bottom of the furnace tube and the fixing bolts of the rotating rod, rotate the rotating rod, and quickly and stably lower the slag-metal reaction device into the cooling water to preserve the liquid tissue characteristics of the molten slag and metal.

[0077] After the sample is cooled, it is found that under the experimental conditions, all the molten metal in the corundum crucible has dripped into the boron nitride crucible. Cut the boron nitride and corundum crucibles longitudinally and observe the cross-sectional tissue characteristics and element distribution with a scanning electron microscope. Figure 10 It is the morphological characteristics and element distribution line scanning diagram of the side wall of the corundum crucible in this embodiment. It can be seen that the tissue of the side wall of the corundum crucible is uniform, there is no obvious transition layer, the element distribution is uniform, the main elements are Al and O, there is a small amount of Ca, and the elements of GH4975 alloy are hardly detected, indicating that the corundum crucible is not eroded by the molten metal during the melting and dripping process of the alloy.

[0078] Figure 11 It is the tissue characteristics and element distribution line scanning diagram of the interface between the side wall of the boron nitride crucible and the molten slag in this embodiment. It can be seen that the interface between the boron nitride crucible and the molten slag is clear, and the element distribution near the interface changes suddenly. On the left side are B and N elements, and on the right side are Ti, Al, Ca, O, and F elements, with basically no transition phenomenon, indicating that even if the holding time is extended to 100 min and 10% TiO2 is added to the fluoride slag system, the boron nitride crucible can still resist the erosion of the molten slag.

[0079] In summary, the experimental device and method for simulating the slag-metal reaction in electroslag remelting under vacuum or protective atmosphere according to the present invention can simulate the process of molten metal droplets dripping and passing through the molten slag layer and converging into a molten metal pool in electroslag remelting under vacuum or protective atmosphere, can prevent the erosion of molten metal and molten slag, especially has good corrosion resistance to fluoride slag systems for electroslag remelting (including fluoride slag systems containing a small amount of TiO2), so as not to affect the composition of molten metal and molten slag; feeding and sampling are safe and easy to operate.

[0080] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. An experimental device for simulating the slag-metal reaction in electroslag remelting under vacuum or protective atmosphere, characterized in that: It mainly includes a smelting device, a slag-metal reaction device, a suspension device, and a cooling device; The smelting device is a vertical tubular resistance furnace, and the working temperature can reach above 1650 °C. Both the furnace mouth and the furnace bottom are sealed with water-cooled flange plates and can be opened at any time; The slag-metal reaction device is mainly composed of three crucibles; The crucible for holding slag materials is defined as a boron nitride crucible, and the crucible for holding metals is defined as a corundum crucible. A round hole is opened at the bottom of the corundum crucible, and the single-hole diameter D1 is 2 - 10 mm to simulate metal droplets of different sizes. The overall shape of the opening area is circular, and the ratio of the area diameter D2 to the bottom diameter D3 of the crucible is 0.1 - 0.9 to simulate the diameter ratio (filling ratio) of the consumable electrode to the cross-section of the mold. The mass ratio of the slag materials and metal materials held is 0.1 - 0.3 to simulate the slag-metal ratio in the electroslag remelting process; The boron nitride and corundum crucibles are arranged coaxially a, with the boron nitride crucible at the bottom and the corundum crucible on top. The two crucibles are located in the isothermal section of the tubular furnace. A graphite crucible is sheathed outside the two crucibles, and the mouth of the graphite crucible is located in the low-temperature section of the tubular furnace, with a temperature not exceeding 1400 °C; The cooling device is directly below the furnace tube. When the sample needs to be quickly cooled, open the flange plate at the lower end of the furnace tube, rotate the rotating rod, and quickly and stably place the slag-metal reaction device into the coolant; at the same time, two layers of asbestos nets are arranged above the coolant. Except for the central opening, the asbestos nets completely cover the upper mouth of the coolant container to prevent coolant splashing and the rapid expansion of steam from causing danger.

2. The experimental device for simulating the slag-metal reaction in electroslag remelting under vacuum or protective atmosphere according to claim 1, wherein: The suspension device is mainly composed of a "Y-shaped" hook, a chain, a sprocket, a dial, and a rotating rod; The lower end of the "Y-shaped" hook is connected to the slag-metal reaction device, and the upper end is connected to the chain. The chain meshes with the sprocket; a protective shell is arranged concentrically outside the sprocket. The shape of the protective shell is 3 / 4 circle to ensure that the chain and the slag-metal reaction device are coaxial and prevent the chain from falling off; a dial is arranged coaxially with the sprocket in the horizontal direction and is fixed on the side wall of the furnace mouth; the rotating rod passes through the dial, the side wall of the furnace mouth, and the sprocket in sequence and is connected to the center of the sprocket through a metal key. The rotation of the sprocket can be controlled by the rotating rod; the rotating rod is equipped with a pointer, and the effective movement distance of the sprocket or the chain and the position of the slag-metal reaction device can be determined through the pointer and the dial; in addition, the rotating rod is equipped with a bolt. After the slag-metal reaction device is lifted to a specific position, the rotating rod is fixed to the side wall of the furnace mouth through the bolt to ensure that the relative position does not change during the experiment.

3. An experimental method for simulating the slag-metal reaction in electroslag remelting under vacuum or protective atmosphere, characterized in that Using the device described in claim 1, the following steps are carried out: (1) At room temperature, weigh the slag materials and alloy materials in proportion and load them into the boron nitride crucible and the corundum crucible respectively. The boron nitride crucible is at the bottom and the corundum crucible is on top, and then a graphite crucible is sheathed outside; (2) Connect the slag-metal reaction device to the suspension device through the "Y-shaped" hook, rotate the sprocket through the rotating rod, and lift the slag-metal reaction device to a specific position, where the boron nitride crucible and the corundum crucible are located in the isothermal working section of the furnace body, and the upper mouth of the graphite crucible is located in the low-temperature section of the furnace body. Then fix the rotating rod to the side wall of the furnace mouth through the bolt to prevent the position of the slag-metal reaction device from shifting; (3) Seal the furnace body, turn on the cooling water, turn on the protective gas such as argon or evacuate to vacuum; (4) Heat the tubular furnace to the experimental temperature for the slag-metal reaction. At this time, the slag material and the alloy melt, and the liquid alloy slowly drips into the boron nitride crucible through the small holes at the bottom of the corundum crucible and passes through the molten slag layer, fully mixing with the slag material, and then converges into a metal molten pool below the molten slag layer; (5) Select the slag-metal reaction time according to the experimental requirements. After the time is reached, loosen the fixing bolts of the flange at the bottom of the furnace tube and the rotating rod, rotate the rotating rod, and quickly and stably lower the slag-metal reaction device into the cooling medium to preserve the liquid tissue characteristics of the molten slag and the metal.

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