Preparation process of nickel-based superalloy plate

Abstract

This application relates to the field of nickel-based alloy preparation technology, specifically to a preparation process for a nickel-based high-temperature alloy plate. The process includes: determining raw materials according to the composition requirements of the nickel-based high-temperature alloy plate; melting the raw materials in a vacuum induction furnace; acquiring thermal imaging images of the furnace at various times during the melting process, as well as the power of the vacuum pump at various times; determining a first adjustment coefficient and a second adjustment coefficient for controlling the melting speed of the vacuum induction furnace; using the first and second adjustment coefficients to control the melting speed of the vacuum induction furnace during the melting process, obtaining a melted alloy ingot; sequentially performing electroslag remelting, diffusion annealing, forging, hot rolling, finished hot rolling, plate straightening, and cutting, followed by surface treatment to obtain the nickel-based high-temperature alloy plate. This application improves the ability to control the melting speed of the vacuum induction furnace.

Description

Technical Field

[0001] This application relates to the field of nickel-based alloy preparation technology, specifically to a preparation process for a nickel-based high-temperature alloy plate. Background Technology

[0002] Nickel-based superalloys are metallic materials that can maintain excellent performance under extreme working conditions of stress above 600°C. They possess good resistance to hot corrosion and oxidation and are widely used in high-temperature, strong acid and alkali, and strong oxidizing environments. However, the presence of inclusions and harmful elements in nickel-based alloys can disrupt the uniformity of the alloy structure, thereby reducing the stability, mechanical properties, and corrosion resistance of the final nickel-based superalloy sheet. Therefore, before preparing nickel-based superalloy sheets, it is necessary to smelt the raw materials to improve the purity of the nickel-based superalloy in the finished sheet, thus improving the performance of the final product.

[0003] Dual-melting processes are commonly used in the existing preparation of nickel-based superalloy plates. Examples include VIM (vacuum induction melting) combined with PESR (electroslag remelting). In this process, gaseous elements, non-metallic inclusions, and harmful substances in the nickel-based superalloy plate are primarily removed during the VIM melting stage. However, when using a vacuum induction furnace to melt the alloy raw materials for nickel-based superalloy plates, oxygen in the molten alloy is mainly removed by reacting chemically with carbon in the charge to generate carbon monoxide gas, which then precipitates from the molten alloy. Adding the charge too quickly can lead to a violent carbon-oxygen reaction, causing intense boiling and splashing of the molten alloy. This makes bridging a common phenomenon during the melting process, leading to inhomogeneity in the alloy composition and reducing the performance of the final nickel-based superalloy plate.

[0004] Therefore, existing technologies typically use a smaller melting rate to slow down the rate at which the charge is added to the vacuum induction furnace, thereby suppressing bridging during the smelting of nickel-based superalloy plates. However, the determination of the melting rate currently relies heavily on historical experiments, which cannot adapt to the actual dynamic smelting process of nickel-based superalloy plates. This results in poor adaptability of the melting rate determination throughout the smelting process. Furthermore, an excessively small melting rate not only leads to low production efficiency but also high losses, making it difficult to balance the production quality, efficiency, and losses of nickel-based superalloy plates. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a process for preparing a nickel-based high-temperature alloy plate, thereby resolving the existing issues.

[0006] The preparation process of a nickel-based high-temperature alloy plate in this application adopts the following technical solution:

[0007] One embodiment of this application provides a process for preparing a nickel-based high-temperature alloy plate, the process comprising:

[0008] S1. Determine the raw materials according to the composition requirements of the nickel-based high-temperature alloy plate, use a vacuum induction furnace to melt the raw materials, and collect thermal imaging images of the furnace at various times during the melting process, as well as the power of the vacuum pump at various times.

[0009] S2. Extract the power change trend characteristics at all times within the adjustment cycle, and determine the first adjustment coefficient used to control the melting rate of the vacuum induction furnace;

[0010] S3. Segment the thermal imaging images at each time point, analyze the temperature fluctuation of the image area at the same location in the thermal imaging images over time within the adjustment period, and obtain the second adjustment coefficient used to control the melting rate of the vacuum induction furnace.

[0011] S4. Using the first adjustment coefficient and the second adjustment coefficient, the melting speed of the vacuum induction furnace during the melting process is controlled to obtain the alloy ingot after melting treatment.

[0012] S5. The alloy ingot is subjected to electroslag remelting, diffusion annealing, forging, hot rolling, finished hot rolling, plate straightening, and cutting in sequence, and then surface treatment is performed to obtain nickel-based high-temperature alloy plate.

[0013] In one embodiment, the nickel-based superalloy plate comprises the following components by weight percentage:

[0014] C≤0.1%, Mn≤0.50%, Si≤0.50%, P≤0.015%, S≤0.015%, Cr: 20.0~23.0%, Nb: 1~1.5%, Ta: 1.65~3.15%, Mo: 8.0~10.0%, Fe≤5.0%, Al≤0.4%, Ti≤0.4%, Co≤0.08%, balance is Ni, Ni≥58%.

[0015] In one embodiment, the melting process of the raw materials using a vacuum induction furnace includes:

[0016] Ni and Mo are loaded into a vacuum induction furnace, vacuumed and melted for refining. Then Cr and Nb are added, and a second refining is performed after melting. After refining, Al and Ti are added, and argon gas is used for refining. Samples are taken to fine-tune the composition until it is qualified. The temperature is measured and the steel is tapped to obtain an alloy ingot with a diameter of Φ430~Φ550mm.

[0017] In one embodiment, the temperature of the melting and refining process is 1470~1570℃ and the time is ≥20min; the temperature of the secondary refining process after melting and refining is 1480~1580℃ and the time is ≥25min; the pressure of the argon gas is 7000~10000Pa; and the temperature of the tapped steel is 1440~1500℃.

[0018] In one embodiment, determining the first adjustment coefficient includes:

[0019] The trend term of the power at each time point within the adjustment period is obtained by using a time series decomposition algorithm. The trend term at all times within the adjustment period is linearly fitted in time sequence to obtain the slope of the fitted line.

[0020] The slope is normalized after being mapped by negative correlation to obtain the first adjustment coefficient.

[0021] In one embodiment, determining the second adjustment coefficient includes:

[0022] Within the adjustment period, the moving standard deviation sequence of the time-series temperature sequence of the same location in the thermal imaging image is determined, the mean of all elements in the moving standard deviation sequence is calculated, and the fusion result of the mean corresponding to all the same locations in the thermal imaging image is obtained.

[0023] Using the fusion result, a second adjustment coefficient is determined, wherein the second adjustment coefficient is negatively correlated with the fusion result.

[0024] In one embodiment, the melting rate of the vacuum induction furnace during the controlled melting process is expressed as:

[0025] ; The melting rate of the vacuum induction furnace after adjustment for the next adjustment cycle of each adjustment cycle. , These are the maximum and minimum melting rates of the vacuum induction furnace during the smelting of raw materials, respectively. S is the average of the first and second adjustment coefficients for each adjustment cycle, and round[] is the rounding function.

[0026] In one embodiment, the electroslag remelting is carried out by quaternary premelted slag remelting to obtain an electroslag ingot with a diameter of Φ530~Φ660mm, and the diffusion annealing temperature is 1170~1220℃.

[0027] In one embodiment, the electroslag ingot, after high-temperature diffusion annealing, is held at 1160~1180℃ for 6~8 hours, then forged into a slab with a thickness of 150mm~200mm and a width of 1100mm~1400mm. The slab surface is then completely white-ground, ultrasonically inspected to remove the ends, and then hot-rolled. It is held at 1160~1180℃ for 3~5 hours, then rotated 90° and rolled into a slab with a width of 1900mm~2300mm and a thickness of 80mm~100mm. It is then rolled in two separate heats to a slab with a thickness of 6mm~9mm and a width of 1900mm~2300mm. Finally, it is heated at 1060~1080℃ for 15min~25min and then rolled into a plate with a thickness of 3.5mm~5.5mm, a width of 1900mm~2300mm, and a length of 2m~15m. The final rolling temperature is ≥900℃.

[0028] In one embodiment, the final finished board is subjected to solution treatment and water cooling straightening and cutting, wherein the solution treatment temperature is 1100~1140℃ and the holding time is 8min; the surface treatment is any one of sanding, sandblasting, and pickling.

[0029] This application has at least the following beneficial effects:

[0030] This application dynamically adjusts the melting rate of the alloy smelting raw materials for nickel-based superalloy plates during vacuum induction melting based on calculated first and second adjustment coefficients. This significantly enhances the flexibility of the melting process. This adjustment mechanism can quickly respond to changes in melting conditions based on real-time monitored temperature and power changes, avoiding overheating or uneven cooling of materials that may result from a fixed melting rate. This ensures the stability of alloy melting, effectively suppresses bridging, and thus improves the consistency and reliability of the final product. Compared to the traditional method of relying on historical experiments to determine a fixed melting rate for alloy smelting raw materials, this method can dynamically adjust the melting rate of alloy smelting raw materials to improve melting efficiency while effectively suppressing bridging during the melting process. This allows for a better balance between the production quality, production efficiency, and losses of nickel-based superalloy plates. Attached Figure Description

[0031] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1A flowchart illustrating the manufacturing process of a nickel-based high-temperature alloy plate provided in this application;

[0033] Figure 2 This is a flowchart of the preparation process for nickel-based high-temperature alloy plates. Detailed Implementation

[0034] To further illustrate the technical means and effects adopted by this application to achieve the intended purpose of the invention, the following, in conjunction with the accompanying drawings and preferred embodiments, details the preparation process, specific implementation methods, structure, features, and effects of a nickel-based high-temperature alloy plate according to this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0036] The following describes in detail, with reference to the accompanying drawings, a specific scheme for the preparation process of a nickel-based high-temperature alloy plate provided in this application.

[0037] Example 1

[0038] Please see Figure 1 It shows a flowchart of the preparation process of a nickel-based high-temperature alloy plate provided in Embodiment 1 of this application, the process including:

[0039] S1. Determine the raw materials according to the composition requirements of the nickel-based high-temperature alloy plate, use a vacuum induction furnace to melt the raw materials, and collect thermal imaging images of the furnace at various times during the melting process, as well as the power of the vacuum pump at various times.

[0040] The raw material composition of nickel-based superalloy plates, by mass percentage, includes: C≤0.1%, Mn≤0.50%, Si≤0.50%, P≤0.015%, S≤0.015%, Cr: 20.0 23.0%, Nb: 1~1.5%, Ta: 1.65~3.15%, Mo: 8.0 The composition is 10.0%, Fe≤5.0%, Al≤0.4%, Ti≤0.4%, Co≤0.08%, with the balance being Ni, Ni≥58%. Metallic Ni, Mo, Cr, Nb, Al, and Ti from the raw material composition are used as smelting feedstocks for subsequent smelting processes. The remaining raw material composition is used as furnace charge for auxiliary smelting. Before use, the metallic raw materials must be cleaned to remove surface impurities and dried to ensure cleanliness and dryness.

[0041] Ni and Mo are loaded into a vacuum induction furnace, and the furnace is evacuated for melting and refining. Then, Cr and Nb are added after melting and refining, followed by a second refining process. After this second refining, Al and Ti are added, and the furnace is purged with argon gas for further refining. Samples are taken and the composition is fine-tuned until it meets the requirements. The steel is then tapped at a temperature of Φ430~Φ550mm to obtain alloy ingots. Specifically, the melting and refining temperature is 1470~1570℃, and the time is ≥20min; the second refining temperature after melting and refining is 1480~1580℃, and the time is ≥25min; the argon gas pressure is 7000~10000Pa; and the tapping temperature is 1440~1500℃. In this embodiment, the alloy ingot with a diameter of Φ430mm is obtained by tapping at a temperature of 1470℃ and 40min for melting and refining; the second refining temperature after melting and refining is 1480℃ and 28min; the argon gas pressure is 7000Pa; and the tapping temperature is 1440℃.

[0042] To control the melting rate during the melting of nickel-based superalloys from raw materials, this embodiment uses an in-furnace endoscopic high-temperature camera to observe the crucible when the metal in the crucible begins to melt in a vacuum induction furnace. Once the alloy liquid level in the crucible exceeds the level of the solid metal, a high-temperature infrared thermal imager is used to photograph the surface of the crucible. Simultaneously, a power meter is used to collect the power of the vacuum pump in the vacuum induction furnace. The frame rate of the high-temperature infrared thermal imager and the sampling frequency of the power meter are both 100Hz, which can be set by the implementer according to actual conditions.

[0043] To facilitate real-time control of the melting rate of the vacuum induction furnace during smelting, this embodiment sets adjustment cycles. The melting rate of the vacuum induction furnace is adjusted once every adjustment cycle. In this embodiment, the duration of the adjustment cycle is set to 1 second, but the implementer can set it according to actual conditions.

[0044] Taking any adjustment cycle as an example, within that adjustment cycle, all frames of thermal imaging images and all power data of the vacuum pump are acquired, and all acquired data are preprocessed.

[0045] Specifically, the median filtering algorithm is used to denoise each frame of the acquired thermal imaging image to reduce the noise impact on the thermal imaging image during image acquisition and transmission. The median filtering algorithm is a well-known existing technology, and implementers can choose other feasible filtering algorithms, such as Gaussian filtering.

[0046] Secondly, the temperature value of each pixel in each frame of the denoised thermal imaging image is normalized to eliminate the influence of dimensions. Specifically, the ratio between the temperature value of each pixel and the upper limit of the temperature acquisition of the high-temperature infrared thermal imager is calculated as the result of the normalization process for the temperature value of each pixel. Simultaneously, the acquired power data of the vacuum pump are replaced with the ratio between the power data and the upper limit of the power meter's data acquisition to eliminate the influence of data dimensions in the acquired data, thus achieving preprocessing of the thermal imaging image and the power data of the vacuum pump.

[0047] S2. Extract the power change trend characteristics at all times within the adjustment cycle, and determine the first adjustment coefficient used to control the melting rate of the vacuum induction furnace.

[0048] During the melting of nickel-based superalloys in a vacuum induction furnace, oxygen in the molten alloy reacts with carbon in the charge to produce carbon monoxide gas, which is then released from the molten alloy. If excessive carbon monoxide is generated and not promptly removed by the vacuum pump, the vacuum level inside the furnace will decrease. The vacuum control system in the induction furnace maintains a stable vacuum by increasing the power of the vacuum pump. Therefore, if the power of the vacuum pump increases over a certain period, the rate of carbon monoxide generation in the molten alloy is likely to be too rapid during that time. To prevent severe splashing of the molten alloy due to rapid carbon monoxide release and subsequent bridging, the induction furnace should use a lower melting rate to slow down the charge addition. This slows the carbon-oxygen reaction between carbon in the charge and oxygen in the molten alloy, thus preventing bridging during subsequent alloy melting.

[0049] Based on the above analysis, all power data of the vacuum pump within the adjustment period are arranged in ascending order according to the acquisition time. The resulting sequence is recorded as the vacuum pump power time series of the adjustment period, which is used to characterize the change of vacuum pump power of the vacuum induction furnace used for smelting raw materials over time during the adjustment period.

[0050] To reduce the noise data introduced by environmental interference in the collected vacuum pump power data and its impact on subsequent evaluation of the changing trend of vacuum pump power during the adjustment period, the STL (Seasonal and Trend Decomposition using Loess) time series decomposition algorithm is used to extract the trend terms of each power in the vacuum pump power time series, and the corresponding trend term time series is formed. The STL time series decomposition algorithm is a well-known existing technology, and its specific process will not be elaborated further.

[0051] The least squares method is used to linearly fit the time series of the trend term. In the fitting process, the horizontal axis represents the position of the trend term in the series, and the vertical axis represents the trend term of each power. The slope of the resulting fitted line is recorded as the power trend characteristic value of the adjustment period. This value is used to evaluate the data change trend of the vacuum pump power of the vacuum induction furnace within the adjustment period during the smelting process. The larger the power trend characteristic value, the more significant the increase in vacuum pump power. The least squares method is a known existing technique; implementers can choose other feasible linear fitting algorithms.

[0052] After normalizing the slope using a negative correlation mapping, a first adjustment coefficient for controlling the melting rate of the vacuum induction furnace is obtained. The negative correlation mapping represents a mathematical relationship where an increase in one variable leads to a decrease in another, reflecting the negative correlation between the first adjustment coefficient and the slope. In this embodiment, the negative correlation mapping method involves obtaining the negative value of the slope and using this negative value as the result of the negative correlation mapping. After normalizing this negative value, the first adjustment coefficient is obtained, meaning the first adjustment coefficient ranges from 0 to 1. In this embodiment, the normalization of the negative value is performed using a function... The result of substituting the opposite number as the independent variable x into the function to obtain f(x) is used as the normalized result. In another embodiment, the negative correlation mapping can be performed by taking the reciprocal.

[0053] The smaller the negative number, the more obvious the increase in the power of the vacuum pump of the vacuum induction furnace used for smelting raw materials is within the adjustment period. In other words, the smaller the obtained first adjustment coefficient, the lower the melting rate of the vacuum induction furnace should be, so as to slow down the rate of charge addition in the vacuum induction furnace in the next time period, thereby slowing down the carbon-oxygen reaction rate between carbon in the charge of the vacuum induction furnace and oxygen in the alloy liquid in the crucible, so as to avoid bridging phenomenon of the smelting raw materials during subsequent melting.

[0054] S3. Segment the thermal imaging images at each time point, analyze the temperature fluctuation of the image area at the same location in the thermal imaging image over time within the adjustment period, and obtain the second adjustment coefficient used to control the melting rate of the vacuum induction furnace.

[0055] If the melting rate of a vacuum induction furnace is too slow, it will result in low working efficiency, high losses, and difficulty in reducing costs. Therefore, when the surface temperature of the alloy liquid in the crucible of the vacuum induction furnace does not change drastically over a certain period of time, it means that the melting process of the alloy liquid is relatively stable during this period of time and there is no serious splashing of the alloy liquid. This indicates that the smelting raw materials are less likely to experience bridging in the subsequent melting process of the vacuum induction furnace. In this case, the vacuum induction furnace can use a larger melting rate to improve the working efficiency of the vacuum induction furnace and reduce losses.

[0056] Based on the above analysis, taking any frame of thermal imaging image C within the adjustment period as an example, thermal imaging image C is divided into multiple image regions, and the average temperature value of all pixels in each image region is recorded as the region temperature value of each image region, which is used to characterize the average temperature of the alloy liquid surface region corresponding to the image region at the time of image acquisition of thermal imaging image C. In this embodiment, the number of image regions in each frame of thermal imaging image is set to 16, but the implementer can set it according to the actual situation.

[0057] Taking any image region c within thermal imaging image C as an example, obtain each image region at the same position as image region c in all other frames of thermal imaging images except thermal imaging image C within the adjustment period. Arrange the region temperature values ​​of the image region in ascending order according to the corresponding acquisition time of the image region. The resulting sequence is recorded as the region temperature time series of image region c, which is used to characterize the data change of the average temperature of the alloy liquid surface region corresponding to image region c over time within the adjustment period.

[0058] The moving standard deviation method is used to obtain the moving standard deviation sequence of the regional temperature time series, which is used to characterize the local fluctuation of the data in the regional temperature time series. In this embodiment, the window width in the moving standard deviation method is set to 5, and the mean of all data in the moving standard deviation sequence is recorded as the temporal drastic feature value of image region c. It is used to evaluate whether the average temperature of the alloy liquid surface region corresponding to image region c has changed drastically over time during the adjustment period. The larger the temporal drastic feature value, the more drastic the change in the regional temperature value over time during the adjustment period. The moving standard deviation method in the time series is a well-known existing technology, and the specific process will not be described in detail.

[0059] The fusion result of the temporal drastic feature values ​​of all image regions in thermal imaging image C is denoted as the temperature temporal feature value of the adjustment period. This value is used to evaluate whether the temperature of the entire alloy liquid surface in the crucible of the vacuum induction furnace used for smelting raw materials has changed drastically over time within the adjustment period. The larger the temperature temporal feature value, the more drastic the temperature change of the entire alloy liquid surface over time within the adjustment period. Fusion refers to combining multiple variables, which can be calculated using methods such as addition, multiplication, or averaging. In this embodiment, the average of the temporal drastic feature values ​​of all image regions in thermal imaging image C is denoted as the temperature temporal feature value of the adjustment period.

[0060] The temperature time-series characteristic value of the adjustment cycle is mapped to the range (0, 1) using the same normalization function as the opposite number. The difference between the natural number 1 and the mapping result of the temperature time-series characteristic value is calculated as a second adjustment coefficient for controlling the melting rate of the vacuum induction furnace. This coefficient is used to adjust the melting rate of the vacuum induction furnace in the time period of the next adjustment cycle. The larger the second adjustment coefficient, the larger the melting rate of the vacuum induction furnace should be, so as to improve the working efficiency of the vacuum induction furnace and reduce losses.

[0061] S4. Using the first adjustment coefficient and the second adjustment coefficient, the melting speed of the vacuum induction furnace during the melting process is controlled to obtain the alloy ingot after melting treatment.

[0062] Furthermore, the melting rate of the vacuum induction furnace after adjustment is obtained, which is used as the melting rate of the vacuum induction furnace as the raw material for smelting during the time period of the next adjustment cycle in the current adjustment cycle. The calculation method for the adjusted melting rate is as follows:

[0063] ; The melting rate of the vacuum induction furnace after adjustment for the next adjustment cycle of each adjustment cycle. , These are the maximum and minimum melting rates of the vacuum induction furnace during the smelting of raw materials, obtained experimentally. In this application, v1 and v2 are set to 4.0 and 1.3, respectively; S is the average of the first and second adjustment coefficients for each adjustment cycle, and round[] is the rounding function. It should be noted that during the first adjustment cycle of the smelting process, due to a lack of historical data, the vacuum induction furnace operates according to the preset initial melting rate. For example, the initial melting rate is set to... .

[0064] During the smelting process of the raw materials, the melting rate of the vacuum induction furnace is controlled using the above method. After the smelting process is completed, an alloy ingot is obtained.

[0065] S5. The alloy ingot is subjected to electroslag remelting, diffusion annealing, forging, hot rolling, finished hot rolling, plate straightening, and cutting in sequence, and then surface treatment is performed to obtain nickel-based high-temperature alloy plate.

[0066] (1) Electroslag remelting treatment

[0067] The alloy ingots obtained by smelting are subjected to electroslag remelting in a protective atmosphere electroslag furnace. Electroslag ingots with a diameter of Φ530~Φ660mm are obtained by remelting with quaternary pre-melted slag to further improve the density of the ingots and reduce the content of sulfur and non-metallic inclusions in the ingots. The surface of the electroslag ingots is then machine-polished to a full white finish. In this embodiment, the quaternary pre-melted slag is CaF2, Al2O3, CaO, and MgO. The steady-state melting rate of the electroslag process is controlled at 6kg / min, and the diameter of the electroslag ingot is Φ530mm.

[0068] (2) Annealing treatment

[0069] The obtained electroslag ingot is subjected to high-temperature diffusion annealing to further reduce element segregation in the electroslag ingot. The diffusion annealing temperature is 1170~1220℃, and in this embodiment it is 1170℃.

[0070] (3) Forging billet

[0071] After surface grinding of the electroslag ingots subjected to high-temperature diffusion annealing, the ingots are held at 1160~1180℃ for 6~8 hours, then forged into forged slabs with a thickness of 150mm~200mm and a width of 1100mm~1400mm. In this embodiment, the ingots are held at 1160℃ for 6 hours, then forged into forged slabs with a thickness of 150mm, a width of 1100mm, and a length of 1500mm.

[0072] (4) Hot rolling of billet width

[0073] The surface of the obtained forged slab is fully white-ground, ultrasonically inspected and the head and tail are removed, and then hot-rolled. It is held at 1160~1180℃ for 3~5 hours, and after being taken out of the furnace, it is rotated 90° and rolled into a slab with a width of 1900mm~2300mm and a thickness of 80mm~100mm. Then it is rolled in two separate heats to a slab with a thickness of 6mm~9mm and a width of 1900mm~2300mm.

[0074] In this embodiment, the surface of the forged slab is fully white-ground, ultrasonically inspected to remove the head and tail, and then hot-rolled. It is held at 1160℃ for 3 hours, then rotated 90° and rolled into a slab with a thickness of 80mm, a width of 1900mm, and a length of L. It is then rolled again to a slab with a thickness of 25mm, a width of 1920mm, and a length of L. According to the finished product specifications, the slab is cut to a size of 25mm×1920mm×2200mm~2500mm, held at 1160℃ for 1 hour, and then longitudinally rolled to a slab with a thickness of 7mm, a width of 1920mm, and a length of 7500mm~8000mm. The slab is then trimmed on all four sides. The heating furnace used for rolling the slab is a natural gas chamber furnace, and the rolling equipment is a 3300mm hot rolling mill. The thickness of the hot-rolled intermediate slab (80mm, 25mm) is adjusted according to the actual requirements of the rolling mill and heating furnace. The length of the intermediate slab is determined according to the required length of the finished product.

[0075] (5) Finished hot rolling

[0076] Finally, after heating and holding at 1060~1080℃ for 15min~25min, the slab is rolled into a sheet with a thickness of 3.5mm~5.5mm, a width of 1900mm~2300mm, and a length of 2m~15m, with a final rolling temperature ≥900℃. In this embodiment, the slab obtained in step (4) is heated and held at 1060℃ for 15min and then rolled into a sheet with a thickness of 3.5mm, a width of 1920mm, and a length of 10m. The heating furnace used for rolling the product is a roll bottom resistance heating furnace, and the rolling equipment is a 2400mm hot rolling mill.

[0077] (6) Straightening and cutting of sheet metal

[0078] The hot-rolled sheet obtained in step (5) is subjected to solution treatment and water cooling straightening and cutting. The solution treatment temperature is 1100~1140℃ and the holding time is 8min. In this embodiment, the solution treatment temperature is 1100℃.

[0079] (7) Surface treatment

[0080] The straightened and cut sheet material undergoes surface treatment, which may involve sanding, blasting, or pickling to obtain the finished nickel-based superalloy sheet. In this embodiment, sanding is used as the surface treatment. The process flow chart for preparing the nickel-based superalloy sheet is shown below. Figure 2 As shown.

[0081] The mechanical properties of the finished nickel-based superalloy plate prepared in Example 1 of this application were tested at room temperature and high temperature. The test results are shown in Table 1.

[0082] Table 1. Test results of room temperature and high temperature mechanical properties of finished nickel-based superalloy plates

[0083]

[0084] As can be seen from the test results in Table 1, the room temperature and high temperature mechanical values ​​of the nickel-based high-temperature alloy plate prepared in this application are higher than the standard values, which can enhance the mechanical properties of the alloy material.

[0085] Example 2

[0086] Please see Figure 1 It shows a flowchart of the preparation process of a nickel-based high-temperature alloy plate provided in Embodiment 2 of this application, the process including:

[0087] S1. Determine the raw materials according to the composition requirements of the nickel-based high-temperature alloy plate, use a vacuum induction furnace to melt the raw materials, and collect thermal imaging images of the furnace at various times during the melting process, as well as the power of the vacuum pump at various times.

[0088] The raw material composition of nickel-based superalloy plates, by mass percentage, includes: C≤0.1%, Mn≤0.50%, Si≤0.50%, P≤0.015%, S≤0.015%, Cr: 20.0 23.0%, Nb: 1~1.5%, Ta: 1.65~3.15%, Mo: 8.0 The composition is 10.0%, Fe≤5.0%, Al≤0.4%, Ti≤0.4%, Co≤0.08%, with the balance being Ni, Ni≥58%. Metallic Ni, Mo, Cr, Nb, Al, and Ti from the raw material composition are used as smelting feedstocks for subsequent smelting processes. The remaining raw material composition is used as furnace charge for auxiliary smelting. Before use, the metallic raw materials must be cleaned to remove surface impurities and dried to ensure cleanliness and dryness.

[0089] Ni and Mo were loaded into a vacuum induction furnace and refined under vacuum. Then, Cr and Nb were added after the initial refining, followed by a second refining process. After this second refining, Al and Ti were added, and the furnace was purged with argon gas for further refining. Samples were taken and the composition was fine-tuned until it met the specifications. The steel was then tapped at a temperature of Φ500mm to obtain an alloy ingot. The initial refining temperature was 1520℃ for 50 minutes, the second refining temperature after purification was 1530℃ for 30 minutes, the argon gas pressure was 9000Pa, and the tapping temperature was 1470℃.

[0090] During the smelting process of the raw materials, the melting speed of the vacuum induction furnace was controlled using the same processing method as in Example 1 of this application. After the smelting process was completed, an alloy ingot was obtained.

[0091] S5. The alloy ingot is subjected to electroslag remelting, diffusion annealing, forging, hot rolling, finished hot rolling, plate straightening, and cutting in sequence, and then surface treatment is performed to obtain nickel-based high-temperature alloy plate.

[0092] (1) Electroslag remelting treatment

[0093] The alloy ingot obtained by smelting is electroslag remelted in a protective atmosphere electroslag furnace. The electroslag ingot with a diameter of Φ600mm is obtained by remelting with quaternary pre-melted slag to further improve the density of the ingot and reduce the content of sulfur and non-metallic inclusions in the ingot. The surface of the electroslag ingot is then machine-ground to achieve a completely white finish. In this embodiment, the quaternary pre-melted slag is CaF2, Al2O3, CaO, and MgO, and the steady-state melting rate of the electroslag process is controlled at 6 kg / min.

[0094] (2) Annealing treatment

[0095] The obtained electroslag ingot was subjected to high-temperature diffusion annealing to further reduce element segregation in the electroslag ingot. The diffusion annealing temperature was 1200℃.

[0096] (3) Forging billet

[0097] After the surface of the electroslag ingot that has undergone high-temperature diffusion annealing is ground, it is held at 1170℃ for 7 hours and then forged into a forged slab with a thickness of 170mm, a width of 1300mm, and a length of 1500mm.

[0098] (4) Hot rolling of billet width

[0099] In this embodiment, the surface of the forged slab is fully white-ground, ultrasonically inspected to remove the head and tail, and then hot-rolled. It is held at 1170℃ for 4 hours, then rotated 90° after removal from the furnace and rolled into a slab with a thickness of 90mm, a width of 2100mm, and a length of L. It is then rolled again to a slab with a thickness of 25mm, a width of 2000mm, and a length of L. According to the finished product specifications, the slab is cut to a size of 25mm×2000mm×2200mm~2500mm, held at 1170℃ for 1 hour, and then longitudinally rolled to a slab with a thickness of 8mm, a width of 2000mm, and a length of 7500mm~8000mm. The slab is then trimmed on all four sides. The heating furnace used for rolling the slab is a natural gas chamber furnace, and the rolling equipment is a 3300mm hot rolling mill. The thickness of the hot-rolled intermediate slab (80mm, 25mm) is adjusted according to the actual requirements of the rolling mill and heating furnace. The length of the intermediate slab is determined according to the required length of the finished product.

[0100] (5) Finished hot rolling

[0101] Finally, after heating and holding at 1070℃ for 20 minutes, the rolled product is a plate with a thickness of 4.5mm, a width of 2000mm, and a length of 13m. The final rolling temperature is ≥900℃. The heating furnace used for rolling the product is a roll-bottom resistance heating furnace, and the rolling equipment is a 2400mm hot rolling mill.

[0102] (6) Straightening and cutting of sheet metal

[0103] The hot-rolled sheet obtained in step (5) is subjected to solution treatment and water cooling straightening and cutting, wherein the solution treatment temperature is 1120℃ and the holding time is 8min.

[0104] (7) Surface treatment

[0105] The sheet material obtained after straightening and cutting is subjected to surface treatment, namely sandblasting, to obtain the finished nickel-based high-temperature alloy sheet.

[0106] Example 3

[0107] Please see Figure 1 It shows a flowchart of the preparation process of a nickel-based high-temperature alloy plate provided in Embodiment 3 of this application, the process including:

[0108] S1. Determine the raw materials according to the composition requirements of the nickel-based high-temperature alloy plate, use a vacuum induction furnace to melt the raw materials, and collect thermal imaging images of the furnace at various times during the melting process, as well as the power of the vacuum pump at various times.

[0109] The raw material composition of nickel-based superalloy plates, by mass percentage, includes: C≤0.1%, Mn≤0.50%, Si≤0.50%, P≤0.015%, S≤0.015%, Cr: 20.0 23.0%, Nb: 1~1.5%, Ta: 1.65~3.15%, Mo: 8.0 The composition is 10.0%, Fe≤5.0%, Al≤0.4%, Ti≤0.4%, Co≤0.08%, with the balance being Ni, Ni≥58%. Metallic Ni, Mo, Cr, Nb, Al, and Ti from the raw material composition are used as smelting feedstocks for subsequent smelting processes. The remaining raw material composition is used as furnace charge for auxiliary smelting. Before use, the metallic raw materials must be cleaned to remove surface impurities and dried to ensure cleanliness and dryness.

[0110] Ni and Mo were loaded into a vacuum induction furnace and refined under vacuum. Then, Cr and Nb were added after the initial refining, followed by a second refining process. After this second refining, Al and Ti were added, and the furnace was purged with argon gas for further refining. Samples were taken and the composition was fine-tuned until it met the specifications. The steel was then tapped at a temperature of Φ550mm to obtain an alloy ingot. The initial refining temperature was 1570℃ for 60 minutes, the second refining temperature after purification was 1580℃ for 35 minutes, the argon gas pressure was 10000Pa, and the tapping temperature was 1500℃.

[0111] During the smelting process of the raw materials, the melting speed of the vacuum induction furnace was controlled using the same processing method as in Example 1 of this application. After the smelting process was completed, an alloy ingot was obtained.

[0112] S5. The alloy ingot is subjected to electroslag remelting, diffusion annealing, forging, hot rolling, finished hot rolling, plate straightening, and cutting in sequence, and then surface treatment is performed to obtain nickel-based high-temperature alloy plate.

[0113] (1) Electroslag remelting treatment

[0114] The alloy ingot obtained by smelting is electroslag remelted in a protective atmosphere electroslag furnace. The electroslag ingot with a diameter of Φ660mm is obtained by remelting with quaternary pre-melted slag to further improve the density of the ingot and reduce the content of sulfur and non-metallic inclusions in the ingot. The surface of the electroslag ingot is then machine-polished to a full white finish. In this embodiment, the quaternary pre-melted slag is CaF2, Al2O3, CaO, and MgO, and the steady-state melting rate of the electroslag process is controlled at 6kg / min.

[0115] (2) Annealing treatment

[0116] The obtained electroslag ingot was subjected to high-temperature diffusion annealing to further reduce element segregation in the electroslag ingot. The diffusion annealing temperature was 1220℃.

[0117] (3) Forging billet

[0118] After the surface of the electroslag ingot that has undergone high-temperature diffusion annealing is ground, it is held at 1180℃ for 8 hours and then forged into a forged slab with a thickness of 200mm, a width of 1400mm, and a length of 1500mm.

[0119] (4) Hot rolling of billet width

[0120] In this embodiment, the surface of the forged slab is fully white-ground, ultrasonically inspected to remove the head and tail, and then hot-rolled. It is held at 1180℃ for 5 hours, then rotated 90° after exiting the furnace and rolled into a slab with a thickness of 100mm, a width of 2300mm, and a length of L. This is then reversed and rolled into a slab with a thickness of 25mm, a width of 2300mm, and a length of L. According to the finished product specifications, the slab is cut to a size of 25mm×2300mm×2200mm~2500mm, held at 1180℃ for 2 hours, and then longitudinally rolled to a thickness of 9mm, a width of 2300mm, and a length of 7500mm~8000mm. The slab is then trimmed on all four sides. The heating furnace used for rolling the slab is a natural gas chamber furnace, and the rolling equipment is a 3300mm hot rolling mill. The thickness of the hot-rolled intermediate slab (80mm, 25mm) is adjusted according to the actual requirements of the rolling mill and heating furnace. The length of the intermediate slab is determined according to the required length of the finished product.

[0121] (5) Finished hot rolling

[0122] Finally, after heating and holding at 1080℃ for 25 minutes, the rolled product is a plate with a thickness of 5.5mm, a width of 2300mm, and a length of 15m, with a final rolling temperature of ≥900℃. The heating furnace used for rolling the product is a roll-bottom resistance heating furnace, and the rolling equipment is a 2400mm hot rolling mill.

[0123] (6) Straightening and cutting of sheet metal

[0124] The hot-rolled sheet obtained in step (5) is subjected to solution treatment and water cooling straightening and cutting, wherein the solution treatment temperature is 1140℃ and the holding time is 8min.

[0125] (7) Surface treatment

[0126] The sheet material obtained after straightening and cutting is subjected to surface treatment, namely acid pickling, to obtain the finished nickel-based high-temperature alloy sheet.

[0127] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, specific embodiments of this specification have been described above. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0128] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0129] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them; modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions of some of the technical features, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A process for preparing a nickel-based high-temperature alloy plate, characterized in that, The process includes: S1. Determine the raw materials according to the composition requirements of the nickel-based high-temperature alloy plate, use a vacuum induction furnace to melt the raw materials, and collect thermal imaging images of the furnace at various times during the melting process, as well as the power of the vacuum pump at various times. S2. Extract the power change trend characteristics at all times within the adjustment cycle, and determine the first adjustment coefficient used to control the melting rate of the vacuum induction furnace; S3. Segment the thermal imaging images at each time point, analyze the temperature fluctuation of the image area at the same location in the thermal imaging images over time within the adjustment period, and obtain the second adjustment coefficient used to control the melting rate of the vacuum induction furnace. S4. Using the first adjustment coefficient and the second adjustment coefficient, the melting speed of the vacuum induction furnace during the melting process is controlled to obtain the alloy ingot after melting treatment. S5. The alloy ingot is sequentially subjected to electroslag remelting, diffusion annealing, forging, hot rolling, hot rolling of finished product, plate straightening, and cutting, and then surface treatment is performed to obtain nickel-based high-temperature alloy plate. The determination of the first adjustment coefficient includes: The trend term of the power at each time point within the adjustment period is obtained by using a time series decomposition algorithm. The trend term at all times within the adjustment period is linearly fitted in time sequence to obtain the slope of the fitted line. After normalizing the slope through negative correlation mapping, the first adjustment coefficient is obtained; The determination of the second adjustment factor includes: Within the adjustment period, the moving standard deviation sequence of the time-series temperature sequence of the same location in the thermal imaging image is determined, the mean of all elements in the moving standard deviation sequence is calculated, and the fusion result of the mean corresponding to all the same locations in the thermal imaging image is obtained. Using the fusion result, the second adjustment coefficient is determined, wherein the second adjustment coefficient is negatively correlated with the fusion result; The expression for regulating the melting rate of the vacuum induction furnace during the smelting process is: ; The melting rate of the vacuum induction furnace after adjustment for the next adjustment cycle of each adjustment cycle. , These are the maximum and minimum melting rates of the vacuum induction furnace during the smelting of raw materials, respectively. S is the average of the first and second adjustment coefficients for each adjustment cycle, and round[] is the rounding function.

2. The preparation process of a nickel-based high-temperature alloy plate as described in claim 1, characterized in that, The nickel-based superalloy plate comprises the following components by weight percentage: C≤0.1%, Mn≤0.50%, Si≤0.50%, P≤0.015%, S≤0.015%, Cr: 20.0~23.0%, Nb: 1~1.5%, Ta: 1.65~3.15%, Mo: 8.0~10.0%, Fe≤5.0%, Al≤0.4%, Ti≤0.4%, Co≤0.08%, balance is Ni, Ni≥58%.

3. The preparation process of a nickel-based high-temperature alloy plate as described in claim 2, characterized in that, The process of smelting raw materials using a vacuum induction furnace includes: Ni and Mo are loaded into a vacuum induction furnace, vacuumed and melted for refining. Then Cr and Nb are added, and a second refining is performed after melting. After refining, Al and Ti are added, and argon gas is used for refining. Samples are taken to fine-tune the composition until it is qualified. The temperature is measured and the steel is tapped to obtain an alloy ingot with a diameter of Φ430~Φ550mm.

4. The preparation process of a nickel-based high-temperature alloy plate as described in claim 3, characterized in that, The temperature of the melting and refining process is 1470~1570℃, and the time is ≥20min. The temperature of the secondary refining process after melting and refining is 1480~1580℃, and the time is ≥25min. The pressure of the argon gas is 7000~10000Pa, and the temperature of the tapped steel is 1440~1500℃.

5. The preparation process of a nickel-based high-temperature alloy plate as described in claim 1, characterized in that, The electroslag remelting process yields an electroslag ingot with a diameter of Φ530~Φ660mm through quaternary pre-melted slag remelting and smelting. The diffusion annealing temperature is 1170~1220℃.

6. The preparation process of a nickel-based high-temperature alloy plate as described in claim 5, characterized in that, Electroslag ingots that have undergone high-temperature diffusion annealing are held at 1160~1180℃ for 6~8 hours, then forged into slabs with a thickness of 150mm~200mm and a width of 1100mm~1400mm. The slab surface is then completely white-ground, ultrasonically inspected, and the ends are removed before hot rolling. The slabs are held at 1160~1180℃ for 3~5 hours, then rotated 90° and rolled into slabs with a width of 1900mm~2300mm and a thickness of 80mm~100mm. The slabs are then rolled in two separate heats to a thickness of 6mm~9mm and a width of 1900mm~2300mm. Finally, the slabs are heated at 1060~1080℃ for 15min~25min and rolled into plates with a thickness of 3.5mm~5.5mm, a width of 1900mm~2300mm, and a length of 2m~15m. The final rolling temperature is ≥900℃.

7. The preparation process of a nickel-based high-temperature alloy plate as described in claim 6, characterized in that, The final finished board is straightened and cut by solution treatment and water cooling. The solution treatment temperature is 1100~1140℃ and the holding time is 8min. The surface treatment is any one of sanding, sandblasting and pickling.

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