Methods for controlling white spot defects and vacuum arc remelting device

Abstract

This application discloses a method for controlling white spot defects and a vacuum arc remelting device, belonging to the field of vacuum arc remelting technology. Its main purpose is to achieve real-time identification of electrode shavings and to adjust the power differentially based on the size of the shavings, thereby improving the control effect of white spot defects during the vacuum arc remelting process. The main technical solution of this application is as follows: The white spot defect control method includes: acquiring vacuum arc remelting process parameters; identifying shavings and determining the equivalent size of the shavings based on the process parameters; generating control commands based on the correspondence between the equivalent size of the shavings and at least two determined critical sizes; and adjusting the melting power of the vacuum arc remelting device in response to the control commands.

Description

Technical Field

[0001] This application belongs to the field of vacuum self-consuming remelting technology, specifically relating to a method for controlling white spot defects and a vacuum self-consuming remelting device. Background Technology

[0002] Vacuum arc remelting (VAR) is a core process for preparing high-end metal ingots such as high-temperature alloys and titanium alloys. Due to its advantages such as low impurity content, uniform ingot composition, and dense microstructure under vacuum conditions, it has been widely used in aerospace, high-end equipment manufacturing, and other fields. However, white spot defects are a common and fatal flaw in the production of vacuum arc remelting ingots. This defect manifests as white spots inside the ingot, essentially caused by the arc electrode flaking off during the melting process. The flaked portion fails to completely melt and remains in the ingot, forming a solidification defect. This not only severely affects the mechanical properties and fatigue life of the ingot but can even directly lead to ingot scrap, significantly reducing production efficiency and yield, and increasing production costs.

[0003] Therefore, it is urgent to control white spot defects. However, during vacuum arc remelting, electrode spalling is random and difficult to predict in advance. It is impossible to identify spalling in real time and obtain relevant information in a timely manner, which can easily lead to missing the best control opportunity and causing ingot scrap. At the same time, the correlation between spalling size and white spot defect formation is not clear, and there is a lack of quantitative critical spalling size thresholds as a basis for process control, making it difficult to improve defects in a targeted manner. In addition, existing process control mostly relies on operating experience or adopts fixed control strategies, which cannot be dynamically controlled according to spalling size. This can easily lead to over-control resulting in uneven ingot structure, or under-control resulting in white spot defect residue. Summary of the Invention

[0004] In view of this, this application provides a method for controlling white spot defects and a vacuum arc remelting device, which aims to achieve real-time identification of electrode detachment and differentiated power adjustment according to the size of the detachment, thereby improving the control effect of white spot defects during vacuum arc remelting.

[0005] To achieve the above objectives, this application mainly provides the following technical solutions: One aspect of this application provides a method for controlling vitiligo defects, comprising: Obtain parameters for the vacuum arc remelting process; Based on the process parameters, identify the missing blocks and determine their equivalent size; Based on the correspondence between the equivalent size of the dropped block and at least two determined critical sizes, control commands are generated; In response to the control command, the melting power of the vacuum consumable remelting device is adjusted; Wherein, the at least two determined critical dimensions include a first critical dimension and a second critical dimension; The first critical dimension and the second critical dimension are dynamic dimensions determined based on the smelting current, smelting voltage and molten pool depth before the block drop event occurs; The step of generating control commands based on the correspondence between the equivalent size of the dropped block and at least two determined critical sizes includes: When the equivalent size of the dropped block is less than the first critical size, a first control command is generated; When the equivalent size of the dropped block is greater than or equal to the first critical size and less than or equal to the second critical size, a second control command is generated. When the equivalent size of the dropped block is greater than the second critical size, a third control command is generated.

[0006] Optionally, the process parameters include real-time weight data of the consumable electrode, real-time voltage data of the melting arc, and real-time current data. The step of identifying missing blocks and determining their equivalent size based on the process parameters includes: When the slope of the change in the real-time weight data is abnormal, and the fluctuations in the real-time voltage data and the real-time current data are both abnormal, a block drop event is identified. The equivalent size of the dropped block is determined based on the quality of the dropped block corresponding to the identified dropped block event.

[0007] Optionally, the abnormal slope of the real-time weight data is when the slope of the real-time weight data exceeds 1.3 to 1.8 times the slope of the weight change in the corresponding time period under the set smelting conditions; The fluctuations in the real-time voltage data and the real-time current data are both abnormal, with the fluctuation range of the real-time voltage data relative to the voltage setting value at the corresponding time under the set melting conditions, and the fluctuation range of the real-time current data relative to the current setting value at the corresponding time under the set melting conditions, both reaching 3% to 5%.

[0008] Optionally, the equivalent size of the dropped block conforms to the formula: ; In the formula, The equivalent size of the dropped block. ; For the quality of the dropped blocks, ; This is the shape correction factor, with a value ranging from 0.82 to 0.92; The density of consumable electrodes, .

[0009] Optionally, the first critical dimension conforms to the formula: ; In the formula, This is the first critical size. ; This is a correction factor, with a value ranging from 0.19 to 0.22; The value of the smelting current before the aforementioned block-dropping event occurred. ; The melting voltage value prior to the occurrence of the lump-dropping event. ; The depth of the molten pool before the block drop event occurred. ; The thermal conductivity of the consumable electrode is given. ; The latent heat of fusion of the consumable electrode. ; The density of the consumable electrode, ; The specific heat capacity of the consumable electrode is given. ; The second critical dimension conforms to the formula: ; In the formula, This is the second critical dimension. ; This is a correction factor, with a value ranging from 0.28 to 0.32; The value of the smelting current before the aforementioned block-dropping event occurred. ; The melting voltage value prior to the occurrence of the lump-dropping event. ; The depth of the molten pool before the block drop event occurred. ; The thermal conductivity of the consumable electrode is given. ; The latent heat of fusion of the consumable electrode. ; The density of the consumable electrode, ; The specific heat capacity of the consumable electrode is given. .

[0010] Optionally, adjusting the melting power of the vacuum arc remelting device in response to the control command includes: In response to the first control command, the vacuum self-consuming remelting device is controlled to operate according to a preset smelting process, without actively adjusting the smelting power; In response to the second control command, the vacuum consumable remelting device is controlled to increase the smelting power by 5% to 10% based on the power at the corresponding moment of the preset smelting process; In response to the third control command, the vacuum self-consuming remelting device is controlled to operate according to the preset smelting process, without actively adjusting the smelting power, and the axial height of the defect is marked according to the smelting time and the ingot growth height, so as to use the mark to directionally process the defect in the future.

[0011] Optionally, the smelting power is increased in response to the second control command for a duration of 30 to 60 seconds.

[0012] Another aspect of this application provides a vacuum arc remelting apparatus, comprising: Weighing sensor, voltage acquisition unit, current acquisition unit, smelting power supply and controller; The weighing sensor is used to collect real-time weight data of the consumable electrode; The voltage acquisition unit is connected in parallel across the two ends of the molten arc load to acquire real-time voltage data of the molten arc. The current acquisition unit is connected in series in the smelting power supply circuit and is used to acquire real-time current data of the smelting arc. The smelting power source is used to output the power required for smelting and to adjust the smelting power under the control of the controller; The controller is electrically connected to the weighing sensor, the voltage acquisition unit, the current acquisition unit, and the smelting power supply, respectively, and is used to execute the white spot defect control method described in any one of the above.

[0013] Optionally, the vacuum arc remelting apparatus further includes: Electrode feed transmission device, electrode lifting rod, electrode connecting rod, shielding protective sleeve and vacuum furnace body; The electrode feed transmission device is connected to the upper end of the electrode lifting rod and is used to drive the electrode lifting rod to rise and fall. The lower end of the electrode lifting rod is connected to the consumable electrode via the electrode connecting rod; The weighing sensor is installed between the electrode lifting rod and the electrode connecting rod to detect the weight of the consumable electrode in real time. The shielding sleeve is fitted over the outside of the weighing sensor to isolate thermal radiation and electromagnetic interference during the smelting process. The consumable electrode and the lower part of the electrode connecting rod are located inside the vacuum furnace.

[0014] By employing the above technical solution, this application has at least the following beneficial effects: The white spot defect control method and vacuum consumable remelting device provided in this application firstly utilize the real-time weight data of the consumable electrode collected by the weighing sensor and the real-time voltage and current data of the melting arc collected by the voltage and current acquisition units to make a joint judgment, which can identify consumable electrode detachment events and effectively avoid misjudgments caused by fluctuations in a single parameter. Then, the equivalent size of the detached piece is calculated based on the detached piece mass, and graded control commands are generated by combining the real-time determined first and second critical sizes, which can realize targeted treatment of detached pieces of different sizes. Afterwards, power adjustment is performed according to the process characteristics of the initial melting stage, steady-state melting stage, and melting end stage. The melting power of the corresponding time period is adjusted without changing the original melting power change trend, so as to promote the full melting of medium-sized detached pieces, reduce the generation of white spot defects from the source, and mark the defect locations that may be generated by ultra-large detached pieces, providing an accurate basis for subsequent directional detection and directional treatment of ingots. Attached Figure Description

[0015] Figure 1 This is a flowchart of a method for controlling white spot defects according to an optional embodiment of this application; Figure 2 This is a structural block diagram of a vacuum self-consuming remelting apparatus according to an optional embodiment of this application; Figure 3 This is a schematic diagram of the structure of a vacuum self-consuming remelting apparatus according to an optional embodiment of this application.

[0016] The reference numerals in the attached figures are as follows: 1. Weighing sensor; 2. Voltage acquisition unit; 3. Current acquisition unit; 4. Melting power supply; 5. Controller; 6. Electrode feed transmission device; 7. Electrode lifting rod; 8. Electrode connecting rod; 9. Shielding protective sleeve; 10. Vacuum furnace body; 11. Consumable electrode. Detailed Implementation

[0017] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0018] This embodiment provides a method for controlling vitiligo defects, see [link to relevant documentation]. Figure 1 As shown, the method includes: Step S1: Obtain the parameters of the vacuum arc remelting process.

[0019] The white spot defect control method provided in this application can be applied to the field of metal casting, specifically to the vacuum arc remelting process for preparing high-end metal ingots such as high-temperature alloys and titanium alloys. When controlling the vacuum arc remelting process in real time to suppress white spot defects in ingots, the vacuum arc remelting process parameters can first be obtained. Here, the vacuum arc remelting process parameters refer to parameters that characterize the real-time melting state of the vacuum arc remelting process and are related to electrode spalling identification and size quantization. Specifically, the parameters of the vacuum consumable remelting process may include the real-time weight data of the consumable electrode 11, the real-time voltage data of the melting arc, and the real-time current data. The real-time weight data of the consumable electrode 11 can be acquired in real time by the weighing sensor 1 installed between the electrode lifting rod 7 and the electrode connecting rod 8. The real-time voltage data of the melting arc can be acquired by the voltage acquisition unit 2 connected in parallel across the melting arc load. The real-time current data of the melting arc can be acquired by the current acquisition unit 3 connected in series in the melting power supply circuit. All the real-time data acquired are transmitted to the controller 5 in real time for analysis and processing, providing data support for subsequent block drop identification, block drop equivalent size determination, and melting power adjustment.

[0020] Step S2: Based on process parameters, identify the missing blocks and determine the equivalent size of the missing blocks.

[0021] In this embodiment, the real-time weight data of the consumable electrode 11, the real-time voltage data of the melting arc, and the real-time current data obtained in step S1 are used to determine whether the consumable electrode 11 has experienced blockage, and further determine the corresponding equivalent size of the blockage. Specifically, when the consumable electrode 11 experiences blockage, the slope of the real-time weight data of the consumable electrode 11 and the fluctuation amplitude of the real-time voltage and current data of the melting arc will show significant anomalies. Specifically, when the slope of the real-time weight data of the consumable electrode 11 exceeds 1.3 to 1.8 times the preset weight change slope for that period, the weight change slope is determined to be abnormal; when the fluctuation amplitude of the real-time voltage data of the melting arc relative to the preset voltage setting value at the corresponding time reaches 3% to 5%, the voltage fluctuation is determined to be abnormal; when the fluctuation amplitude of the real-time current data of the melting arc relative to the preset current setting value at the corresponding time reaches 3% to 5%, the current fluctuation is determined to be abnormal. It should be noted that the time window used to calculate the weight change slope is a short one, such as 0.2 to 1 second, which can accurately capture the instantaneous state of the falling block. Therefore, it can be synchronously matched with the corresponding time used for voltage and current anomaly detection, ensuring the consistency of the weight change slope, voltage, and current anomaly detection time and avoiding misjudgment of falling block identification due to asynchronous detection time. Here, the change slope of the real-time weight data of the consumable electrode 11 can amplify the signal characteristics of the falling block, making it easier to detect small mass falling blocks. This prevents small mass falling blocks from being overwhelmed by the weight changes caused by continuous melting loss of the consumable electrode 11 during normal and stable melting, thus improving the sensitivity of abnormal fluctuation detection. Furthermore, a falling block event of the consumable electrode 11 is only determined when abnormal weight change slope, abnormal voltage fluctuation, and abnormal current fluctuation occur simultaneously, thereby eliminating misjudgment caused by accidental fluctuation of a single parameter and improving the accuracy and reliability of falling block identification. It is understandable that the vacuum self-consuming remelting process can be roughly divided into the initial smelting stage, the steady-state smelting stage and the smelting end stage as the ingot grows. The smelting state of different stages is significantly different. The weight change slope and the voltage and current settings at the corresponding time points under the above-mentioned smelting conditions are all standard parameters preset according to the smelting process and matched with the actual working conditions of each time point.

[0022] In this process, after identifying the event of the self-consuming electrode 11 falling off, the equivalent size of the falling off is calculated based on the mass of the falling off. This size is determined by the mass of the falling off, the density of the self-consuming electrode 11, and the shape correction coefficient, thereby realizing the quantitative characterization of the size of the falling off and providing a basis for subsequent hierarchical control based on the critical size.

[0023] Specifically, the equivalent size of the missing block conforms to the formula: ; In the formula, For the equivalent size of the dropped block, ; For the quality of the dropped blocks, ; This is the shape correction factor, with a value ranging from 0.82 to 0.92; The density of the consumable electrode 11, .

[0024] Step S3: Generate control commands based on the correspondence between the equivalent size of the dropped block and at least two determined critical sizes.

[0025] In this embodiment, at least two critical dimensions are predetermined: a first critical dimension and a second critical dimension. These are dynamic dimensions determined based on the smelting current, smelting voltage, and molten pool depth before the block drop event occurs. The first critical dimension represents the maximum size threshold at which the block can melt on its own using the existing power, while the second critical dimension represents the minimum size threshold at which increasing the smelting power cannot guarantee sufficient melting. The equivalent block size obtained in step S2 is compared with the first and second critical dimensions, and corresponding control commands are generated based on the size correspondence between the equivalent block size and the first and second critical dimensions. Specifically, when the equivalent block size is less than the first critical dimension, a first control command is generated; when the equivalent block size is greater than or equal to the first critical dimension and less than or equal to the second critical dimension, a second control command is generated; and when the equivalent block size is greater than the second critical dimension, a third control command is generated. This achieves graded control for blocks of different sizes, providing a basis for subsequent differentiated adjustment of smelting power.

[0026] The first critical dimension conforms to the formula: ; In the formula, This is the first critical size. ; This is a correction factor, with a value ranging from 0.19 to 0.22; The smelting current value before the lumps fell off. ; The melting voltage value before the lumps fell off. ; The depth of the molten pool before the block drop event occurred. ; The thermal conductivity of the consumable electrode 11 is... ; The latent heat of fusion of the consumable electrode 11, ; The density of the consumable electrode 11, ; The specific heat capacity of the consumable electrode 11 ; The second critical dimension conforms to the formula: ; In the formula, This is the second critical size. ; This is a correction factor, with a value ranging from 0.28 to 0.32; The smelting current value before the lumps fell off. ; The melting voltage value before the lumps fell off. ; The depth of the molten pool before the block drop event occurred. ; The thermal conductivity of the consumable electrode 11 is... ; The latent heat of fusion of the consumable electrode 11, ; The density of the consumable electrode 11, ; The specific heat capacity of the consumable electrode 11 .

[0027] Step S4: In response to the control command, adjust the melting power of the vacuum consumable remelting device.

[0028] In this embodiment, the controller 5 performs corresponding adjustment operations on the melting power of the vacuum arc remelting device according to different control commands generated in step S3. In response to the first control command, the vacuum arc remelting device operates normally according to the preset melting process without actively adjusting the melting power. In response to the second control command, the melting power is increased by 5% to 10% based on the current preset melting power and maintained at this increased state for 30 to 60 seconds to ensure that the corresponding sized chips can be fully melted, avoiding the formation of white spot defects. In response to the third control command, the device continues to operate according to the preset melting process without adjusting the melting power. Simultaneously, the axial positions where defects may occur are marked based on the current melting time and ingot growth height, facilitating subsequent directional inspection and treatment of the ingot. Directional inspection includes quality checks of the marked positions such as ultrasonic testing and low-magnification microstructure inspection. Directional treatment includes partial removal, machining, or thermal processing of the marked positions. Through the above-mentioned graded power adjustment method, white spot defects are effectively suppressed while ensuring the uniformity of the overall ingot structure and the stability of the melting process. Throughout the entire vacuum consumable remelting process, the controller 5 will continuously monitor the real-time weight data of the consumable electrode 11, the real-time voltage data of the melting arc, and the real-time current data through the weighing sensor 1, the voltage acquisition unit 2, and the current acquisition unit 3. It will repeatedly execute the risk judgment process of identifying falling blocks, determining the equivalent size of falling blocks, comparing critical sizes, generating corresponding control commands, and adjusting the melting power in stages until the entire melting process is completed and a high-quality metal ingot is obtained.

[0029] It should be noted that the first, second, and third control commands are applicable to any stage of the vacuum arc remelting process, including the initial melting stage, steady-state melting stage, and melting completion stage. At each melting stage, the controller 5 executes the corresponding commands based on the preset melting parameters and dynamically determined critical dimensions for that stage, ensuring that the power regulation strategy matches the actual melting state at each stage. The preset melting process is the overall execution plan for the vacuum arc remelting process, specifying the power increase, stabilization, or decrease trend for each stage. The preset melting parameters are specific quantitative indicators within this process framework, including preset power values, preset voltage settings, preset current settings, and preset weight change slope standard values ​​for different times / periods. When executing control commands, the controller 5 always bases its actions on the preset melting process and then completes the specific control by calling the preset melting parameters for the corresponding time / period, ensuring that the power regulation does not deviate from the overall trend of the preset process. For example, the power enhancement strategy of the second control command is adapted to the preset power change trend of each stage: In the initial melting stage, the preset melting power shows an upward trend. When the second control command is executed, it will increase the power curve that should have been output at that moment by 5% to 10%, that is, the power start and end points of the original process are simultaneously and proportionally amplified, the power increase trend remains unchanged, and only the amplitude is slightly enhanced; In the steady-state melting stage, the preset melting power remains stable. When the second control command is executed, it will increase the power curve that should have been output at that moment by 5% to 10%, and maintain this enhanced power for 30 to 60 seconds before returning to the original set value; In the melting end stage, the preset melting power shows a downward trend. When the second control command is executed, it will increase the power curve that should have been output at that moment by 5% to 10%, that is, the power start and end points of the original process are simultaneously and proportionally amplified, the power decrease trend remains unchanged, and only the amplitude is slightly enhanced. Through the above methods, the power regulation strategy of this application achieves differentiated treatment of different sized lumps without disrupting the preset melting process trend at each stage. This ensures the stability of the melting process, improves the melting effect of lumps, and effectively suppresses the formation of white spot defects.

[0030] It is understandable that the initial melting stage, steady-state melting stage, and melting end stage in the vacuum consumable remelting process are different process stages in the ingot forming process. Among them, the initial melting stage is the initial stage from the arc ignition of the consumable electrode 11 to the initial formation of the ingot and the molten pool tending to be stable. The steady-state melting stage is the main melting stage in which the molten pool morphology, melting state, and ingot growth rate are relatively stable. The melting end stage is the end stage in which the ingot growth is nearing completion, the melting parameters are gradually reduced, and the melting ends.

[0031] By applying the technical solution of this embodiment, firstly, by jointly judging the real-time weight data of the consumable electrode 11 collected by the weighing sensor 1 and the real-time voltage and current data of the melting arc collected by the voltage acquisition unit 2 and the current acquisition unit 3, it is possible to identify the event of the consumable electrode 11 falling off and effectively avoid misjudgment caused by fluctuations in a single parameter. Then, the equivalent size of the falling off is calculated based on the mass of the falling off, and graded control commands are generated by combining the first and second critical sizes determined in real time, which can realize targeted handling of falling off of different sizes. Afterwards, power adjustment is performed according to the process characteristics of the initial melting stage, steady-state melting stage and melting end stage. The melting power of the corresponding time period is adjusted without changing the original melting power change trend, so as to promote the full melting of medium-sized falling off and reduce the generation of white spot defects from the source. At the same time, the defect locations that may be generated by ultra-large falling off are marked, providing an accurate basis for the directional detection and directional treatment of subsequent ingots. This method improves the control accuracy of the vacuum consumable remelting process, ensures the uniformity of the ingot structure, stabilizes the melting process and improves the finished quality of the metal ingot.

[0032] Furthermore, as Figure 1 For specific implementation of the method, this application provides a vacuum arc remelting device, see [link to relevant documentation]. Figure 2 As shown, the device includes a weighing sensor 1, a voltage acquisition unit 2, a current acquisition unit 3, a smelting power supply 4, and a controller 5. The weighing sensor 1 is used to acquire real-time weight data of the consumable electrode 11. The voltage acquisition unit 2 is connected in parallel across the smelting arc load and is used to acquire real-time voltage data of the smelting arc. The current acquisition unit 3 is connected in series in the smelting power supply circuit and is used to acquire real-time current data of the smelting arc. The smelting power supply 4 is used to output the power required for smelting and adjusts the smelting power under the control of the controller 5. The controller 5 is electrically connected to the weighing sensor 1, the voltage acquisition unit 2, the current acquisition unit 3, and the smelting power supply 4 respectively, and is used to execute any of the above-mentioned white spot defect control methods.

[0033] Among them, the weighing sensor 1 can be a tension sensor, which is installed at the suspension connection of the self-consuming electrode 11. Specifically, it can be installed between the electrode lifting rod 7 and the electrode connecting rod 8, and rise and fall synchronously with the self-consuming electrode 11 to ensure the real-time and accuracy of the collected data. Its sampling frequency is set to 120Hz, which can accurately capture the instantaneous change in the weight of the self-consuming electrode 11, and provide high-frequency and reliable basic data support for the identification of falling blocks.

[0034] Among them, the voltage acquisition unit 2 can be a differential voltage acquisition module, which is connected in parallel to both ends of the molten arc load. Specifically, it can be connected in parallel to both ends of the arc between the self-consumable electrode 11 and the molten pool. In order to ensure data synchronization, its sampling frequency is consistent with that of the weighing sensor 1, which is 120Hz. It can acquire the voltage signal of the molten arc in real time and avoid misjudgment of block drop recognition due to asynchronous sampling.

[0035] Among them, the current acquisition unit 3 can be a through-hole current transformer connected in series in the smelting power supply circuit. Specifically, it can be connected in series in the power supply line between the smelting power supply 4 and the vacuum furnace body 10 to collect the current data flowing through the electric arc in real time. Its sampling frequency is set to 120Hz, and it is sampled synchronously with the weighing sensor 1 and the voltage acquisition unit 2. The current acquisition can be achieved without disconnecting the line, which effectively avoids affecting the stability of the power supply and ensures the real-time and continuous current data.

[0036] Among them, the smelting power supply 4 can be a high-frequency switching power supply with continuously adjustable output power to adapt to the different power requirements of the initial smelting stage, steady-state smelting stage and smelting end stage; at the same time, its built-in PLC control interface can receive power adjustment commands issued by the controller 5 to achieve rapid power response. In conjunction with the 120Hz sampling frequency of the weighing sensor 1, voltage acquisition unit 2 and current acquisition unit 3, it ensures real-time linkage between power adjustment and block drop identification and working condition judgment, thereby improving the control accuracy.

[0037] The controller 5 can be a PLC controller with multi-channel analog and digital input / output interfaces. It is electrically connected to the weighing sensor 1, voltage acquisition unit 2, current acquisition unit 3, and smelting power supply 4, respectively. It can synchronously receive real-time data transmitted by the weighing sensor 1, voltage acquisition unit 2, and current acquisition unit 3 at a frequency of 120Hz, realizing full-process automation of data acquisition, logic judgment, and command output. At the same time, the controller 5 has a built-in preset program that stores the standard parameters for each stage, the equivalent size calculation model of the falling block, the critical size calculation model, and the power adjustment strategy. Based on the data acquired at a high frequency of 120Hz, it can process and analyze in real time, identify falling blocks, calculate relevant dimensions, compare critical values, and then output corresponding control commands. Here, the standard parameters refer to the aforementioned preset smelting parameters that are preset according to the smelting process and match the actual working conditions at each time period or moment. These include, but are not limited to: the preset standard value of the weight change slope, the preset voltage setting value at the corresponding moment, the preset current setting value at the corresponding moment, and the preset power value corresponding to different moments / periods.

[0038] Specifically, in use, firstly, the weighing sensor 1, voltage acquisition unit 2, and current acquisition unit 3 synchronously acquire real-time weight data of the consumable electrode 11, real-time voltage data of the melting arc, and real-time current data at a sampling frequency of 120Hz, and transmit the acquired high-frequency data to the controller 5 in real time. The controller 5 executes the above-mentioned white spot defect control method, performs real-time analysis and processing on the 120Hz high-frequency acquired data, completes the identification of missing blocks, calculation of the equivalent size of missing blocks, and calculation of the first and second critical sizes, compares the size relationship between the equivalent size of missing blocks and the first and second critical sizes, and generates corresponding control commands. Subsequently, the controller 5 sends the control commands to the melting power supply 4 to adjust the melting power. Throughout the melting process, the controller 5 continuously receives real-time data transmitted by the weighing sensor 1, voltage acquisition unit 2, and current acquisition unit 3 at a frequency of 120Hz, and repeats the above control process cyclically until the melting process ends, obtaining a high-quality metal ingot without white spot defects.

[0039] In some possible implementations disclosed in this application, see [link to relevant documentation]. Figure 3 As shown, the vacuum consumable remelting device also includes an electrode feed transmission device 6, an electrode lifting rod 7, an electrode connecting rod 8, a shielding protective sleeve 9, and a vacuum furnace body 10. The electrode feed transmission device 6 is connected to the upper end of the electrode lifting rod 7 and is used to drive the electrode lifting rod 7 to move up and down according to the melting process, achieving stable feeding of the consumable electrode 11. The lower end of the electrode lifting rod 7 is connected to the consumable electrode 11 through the electrode connecting rod 8. The weighing sensor 1 is fixed between the electrode lifting rod 7 and the electrode connecting rod 8 by bolts, ensuring that the weighing sensor 1 can reliably bear the entire weight of the consumable electrode 11, guaranteeing the stability and accuracy of weight acquisition. The lower end of the electrode connecting rod 8 is fixed to the consumable electrode 11 by welding, ensuring that the consumable electrode 11 will not loosen or fall off during lifting and melting, improving the overall structural robustness. The shielding protective sleeve 9 is fitted over the weighing sensor 1 to block the high-temperature heat radiation and complex electromagnetic interference generated during the melting process, preventing the external environment from affecting the detection accuracy of the weighing sensor 1. The lower structure of the consumable electrode 11 and the electrode connecting rod 8 is arranged inside the vacuum furnace body 10 by means of sliding seal. The vacuum consumable remelting process is completed in the closed vacuum environment provided by the vacuum furnace body 10, ensuring a pure smelting atmosphere and reducing internal defects of the ingot.

[0040] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0041] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A method for controlling vitiligo defects, characterized in that, include: Obtain parameters for the vacuum arc remelting process; Based on the process parameters, identify the missing blocks and determine their equivalent size; Based on the correspondence between the equivalent size of the dropped block and at least two determined critical sizes, control commands are generated; In response to the control command, the melting power of the vacuum consumable remelting device is adjusted; Wherein, the at least two determined critical dimensions include a first critical dimension and a second critical dimension; The first critical dimension and the second critical dimension are dynamic dimensions determined based on the smelting current, smelting voltage and molten pool depth before the block drop event occurs; The step of generating control commands based on the correspondence between the equivalent size of the dropped block and at least two determined critical sizes includes: When the equivalent size of the dropped block is less than the first critical size, a first control command is generated; When the equivalent size of the dropped block is greater than or equal to the first critical size and less than or equal to the second critical size, a second control command is generated. When the equivalent size of the dropped block is greater than the second critical size, a third control command is generated.

2. The method according to claim 1, characterized in that, The process parameters include real-time weight data of the consumable electrode, real-time voltage data of the melting arc, and real-time current data. The step of identifying missing blocks and determining their equivalent size based on the process parameters includes: When the slope of the change in the real-time weight data is abnormal, and the fluctuations in the real-time voltage data and the real-time current data are both abnormal, a block drop event is identified. The equivalent size of the dropped block is determined based on the quality of the dropped block corresponding to the identified dropped block event.

3. The method according to claim 2, characterized in that, The abnormal slope of the real-time weight data change is defined as the slope of the real-time weight data change exceeding 1.3 to 1.8 times the slope of the weight change in the corresponding time period under the set smelting conditions. The fluctuations in the real-time voltage data and the real-time current data are both abnormal, with the fluctuation range of the real-time voltage data relative to the voltage setting value at the corresponding time under the set melting conditions, and the fluctuation range of the real-time current data relative to the current setting value at the corresponding time under the set melting conditions, both reaching 3% to 5%.

4. The method according to claim 1, characterized in that, The equivalent size of the dropped block conforms to the formula: ； In the formula, The equivalent size of the dropped block. ; For the quality of the dropped blocks, ; This is the shape correction factor, with a value ranging from 0.82 to 0.92; The density of consumable electrodes, .

5. The method according to claim 1, characterized in that, The first critical dimension conforms to the formula: ； In the formula, This is the first critical size. ; This is a correction factor, with a value ranging from 0.19 to 0.22; The value of the smelting current before the aforementioned block-dropping event occurred. ; The melting voltage value prior to the occurrence of the lump-dropping event. ; The depth of the molten pool before the block drop event occurred. ; The thermal conductivity of the consumable electrode is given. ; The latent heat of fusion of the consumable electrode. ; The density of the consumable electrode, ; The specific heat capacity of the consumable electrode is given. ; The second critical dimension conforms to the formula: ； In the formula, This is the second critical dimension. ; This is a correction factor, with a value ranging from 0.28 to 0.32; The value of the smelting current before the aforementioned block-dropping event occurred. ; The melting voltage value prior to the occurrence of the lump-dropping event. ; The depth of the molten pool before the block drop event occurred. ; The thermal conductivity of the consumable electrode is given. ; The latent heat of fusion of the consumable electrode. ; The density of the consumable electrode, ; The specific heat capacity of the consumable electrode is given. .

6. The method according to claim 1, characterized in that, The adjustment of the melting power of the vacuum consumable remelting device in response to the control command includes: In response to the first control command, the vacuum self-consuming remelting device is controlled to operate according to a preset smelting process, without actively adjusting the smelting power; In response to the second control command, the vacuum consumable remelting device is controlled to increase the smelting power by 5% to 10% based on the power at the corresponding moment of the preset smelting process; In response to the third control command, the vacuum self-consuming remelting device is controlled to operate according to the preset smelting process, without actively adjusting the smelting power, and the axial height of the defect is marked according to the smelting time and the ingot growth height, so as to use the mark to directionally process the defect in the future.

7. The method according to claim 6, characterized in that, The second control command is used to increase the melting power for a duration of 30 to 60 seconds.

8. A vacuum consumable remelting device, characterized in that, include: Weighing sensor, voltage acquisition unit, current acquisition unit, smelting power supply and controller; The weighing sensor is used to collect real-time weight data of the consumable electrode; The voltage acquisition unit is connected in parallel across the two ends of the molten arc load to acquire real-time voltage data of the molten arc. The current acquisition unit is connected in series in the smelting power supply circuit and is used to acquire real-time current data of the smelting arc. The smelting power source is used to output the power required for smelting and to adjust the smelting power under the control of the controller; The controller is electrically connected to the weighing sensor, the voltage acquisition unit, the current acquisition unit and the smelting power supply respectively, and is used to execute the white spot defect control method as described in any one of claims 1 to 7.

9. The apparatus according to claim 8, characterized in that, Also includes: Electrode feed transmission device, electrode lifting rod, electrode connecting rod, shielding protective sleeve and vacuum furnace body; The electrode feed transmission device is connected to the upper end of the electrode lifting rod and is used to drive the electrode lifting rod to rise and fall. The lower end of the electrode lifting rod is connected to the consumable electrode via the electrode connecting rod; The weighing sensor is installed between the electrode lifting rod and the electrode connecting rod to detect the weight of the consumable electrode in real time. The shielding sleeve is fitted over the outside of the weighing sensor to isolate thermal radiation and electromagnetic interference during the smelting process. The consumable electrode and the lower part of the electrode connecting rod are located inside the vacuum furnace.

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