Smelting process of high-carbon-content high-temperature alloy cast ingot with dispersed and distributed carbides

Abstract

The invention discloses a smelting process of a high-carbon-content superalloy cast ingot with dispersively distributed carbides, which specifically comprises the following steps: weighing nickel-based superalloy raw materials including an electrode C, a metal Cr, a Co plate, a Mo strip, an Al bean, a sponge Ti, a NiB intermediate alloy and a Ni plate; the nickel-based high-temperature alloy raw material is subjected to vacuum induction melting, and a vacuum induction cast ingot is obtained; sawing the head of the vacuum induction cast ingot, grinding the surface of the vacuum induction cast ingot, and remelting and refining the vacuum induction cast ingot as an electroslag remelting electrode to obtain an electroslag remelting cast ingot; and carrying out vacuum consumable remelting to finally obtain the high-carbon-content high-temperature alloy cast ingot. According to the smelting technology, in the vacuum consumable remelting process, large remelting current is adopted, a narrower pasty area is created, the local cooling time of the alloy is shortened, and the fine dispersivity of carbide is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature alloy smelting, and in particular relates to a smelting process of a high-carbon content high-temperature alloy ingot with dispersed carbides. Background Art

[0002] The role of carbides in high-temperature alloys is two-sided. On the one hand, carbides on grain boundaries can pin grain boundaries, inhibit grain growth, hinder grain boundary migration and slip, and improve the deformation resistance of the matrix; on the other hand, high-melting point carbides will precipitate prematurely and adhere to the formed dendrites or grain boundaries, which not only hinders the replenishment of liquid phase to shrinkage cavities during solidification, but also because of the high hardness of carbides, the formed liquid film is easily torn by these carbides. Carbides in high-temperature alloys are generally in block, grid, strip and granular forms. When the smelting process is not suitable, the carbides in the alloy are segregated or distributed in a chain shape, making the carbides the crack source and expansion path during the service process of the alloy, seriously reducing the mechanical properties of the alloy.

[0003] At present, the distribution control of carbides in high-temperature alloys is mainly achieved by changing the homogenization annealing and forging deformation process during forging. A Chinese patent (application number: 202310835823.5, publication number: CN117051341A, publication date: 2023-07-10) discloses a method for improving the distribution of carbides in Ni-Fe-based high-temperature alloys for ultra-supercritical thermal power units. The distribution of carbides in Ni-Fe-based high-temperature alloy bars is improved by optimizing the billet forging process, thereby improving the grain size and uniformity of the bar billet. However, for the primary carbides produced during the smelting process of high-carbon content (C ≥ 0.05wt.%) high-temperature alloys, they will not dissolve back during the homogenization process and will be directly inherited into the bars. Therefore, the dispersion distribution control of carbides in the ingot has become a key link in the preparation of high-carbon content high-temperature alloys. Summary of the invention

[0004] The purpose of the present invention is to provide a smelting process for a high-carbon high-temperature alloy ingot with dispersed carbides, thereby improving the dispersity and uniformity of carbide distribution in the alloy ingot.

[0005] The technical solution adopted by the present invention is a smelting process of a high-carbon high-temperature alloy ingot with dispersed carbides, which is specifically implemented according to the following steps: Step 1, weighing nickel-based high-temperature alloy raw materials, including electrode C, metal Cr, Co plate, Mo bar, Al bean, sponge Ti, NiB master alloy and Ni plate; Step 2, performing vacuum induction melting on the nickel-based high-temperature alloy raw material in step 1 to obtain a vacuum induction ingot; Step 3, electroslag remelting: sawing the head of the vacuum induction ingot obtained in step 2, grinding the surface and remelting and refining it as an electroslag remelting electrode to obtain an electroslag remelting ingot; Step 4: vacuum consumable remelting to finally obtain a high-carbon content high-temperature alloy ingot.

[0006] The present invention is also characterized in that: In step 1, the raw material of the nickel-based high-temperature alloy includes the following components in weight percentage: electrode C: 0.06-0.12%, metal Cr: 18.00-20.00%, Co plate: 10.00-12.00%, Mo rod: 9.00-10.50%, Al bean: 1.40-1.80%, sponge Ti: 3.00-3.50%, NiB master alloy: 0.003-0.010%, and the remainder is Ni plate and unavoidable inclusions. The sum of the mass percentages of the above components is 100%.

[0007] The gas content of metal Cr is not less than 100 ppm; the gas content of sponge Ti is not less than 80 ppm.

[0008] In step 2, specifically: First, add the Ni plate, Co plate and electrode C in the raw materials into the vacuum induction furnace, evacuate and power on to increase the induction melting power, so that the power is kept in the range of 1095~1150kW, then add Mo bars and metal Cr, heat to complete melting, reduce the melting power to 850~1950kW, control the melt temperature between 1450~1500℃, keep it for 7~13min, then enter the refining stage, add sponge Ti, Al beans and NiB master alloy in turn, increase the melting power to 1250~1350kW, keep the refining temperature at 1510~1530℃, keep electromagnetic stirring during the refining process, and the stirring time is 5~10min; The refined molten steel is then poured, and argon is continuously filled during the casting process. The casting temperature is 1450~1470℃. After the casting is completed, the ingot is cooled in the ingot mold chamber and demolded and taken out after keeping it for 55~65 minutes to obtain a vacuum induction ingot.

[0009] In step 3, during electroslag remelting, the electroslag selected includes the following components in mass percentage: 62-70% CaF2, 16-20% CaO, 12-16% Al2O3, 4-6% CeO, and the sum of the mass percentages of the above components is 100%.

[0010] In step 3, before adding slag, the electroslag is baked at 490-510°C for more than 2h; the melting rate and slag swing are controlled during the electroslag remelting process, the melting rate in the stable smelting stage is 220-240kg / h, and the slag swing is 0.2-0.4mohm; when the electrode weight is ≤100kg, the hot capping stage is entered, and after the hot capping is completed, the furnace is cooled for 60min and then demolded to obtain an electroslag remelting ingot.

[0011] In step 4, specifically: The electroslag remelting ingot is sawed at the head, with the sawing height greater than 50mm from the head end face, and the surface is peeled with a peeling depth of 5-9mm. After peeling, the surface oil is wiped dry and dried in an oven. The dried smooth ingot is used as a vacuum consumable remelting electrode. During the vacuum consumable remelting process, high current density melting is adopted to ensure that the molten pool depth is within the range of 90-120mm. Droplet control is adopted during the melting process, and the melting speed is set to 3-15 droplets / s. When the electrode weight is ≤80kg, the hot capping stage is entered. After the hot capping, the furnace is cooled for 50min, and the high-temperature alloy ingot with high carbon content is demolded.

[0012] The current density is calculated according to the following formula:

[0013] In the formula, i is the current density, in A / cm 2 ; d is the electrode diameter, in mm.

[0014] The beneficial effects of the present invention are: (1) The smelting process of the present invention uses a gas content of not less than 100 ppm of metallic Cr and a gas element content of not less than 80 ppm of sponge Ti, so that there is enough N element in the alloy to combine with elements such as Ti with a lower Gibbs free energy to form compounds such as TiN. These compounds are dispersed and serve as nucleation centers for carbides, thereby making the distribution of carbides more dispersed; (2) The smelting process of the present invention adopts a pre-melted slag system containing CeO, so that the alloy contains more CeO as a heterogeneous nucleation center of carbides, thereby improving the dispersity of carbide distribution; (3) The smelting process of the present invention uses a larger remelting current during the vacuum consumable remelting process, thereby creating a narrower mushy zone, reducing the local cooling time of the alloy, and improving the fine dispersion of carbides. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a simplified flow chart of the smelting process of a high-carbon content high-temperature alloy ingot with dispersed carbides of the present invention; Figure 2It is a scan of the dispersed carbides in the ingot; Figure 3 is a scan of a massive carbide with a nitride core in an ingot (a); Figure 4 This is a scan of massive carbides with nitride cores in an ingot (ii). DETAILED DESCRIPTION

[0016] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Example 1 The smelting process of the high-carbon content high-temperature alloy ingot with dispersed carbides of the present invention is as follows: Figure 1 As shown, the specific implementation steps are as follows: Step 1, weighing a nickel-based high-temperature alloy raw material; The raw material of the nickel-based high-temperature alloy includes the following components in weight percentage: electrode C: 0.06~0.12%, metal Cr: 18.00~20.00%, Co plate: 10.00~12.00%, Mo bar: 9.00~10.50%, Al bean: 1.40~1.80%, sponge Ti: 3.00~3.50%, NiB master alloy: 0.003~0.010%, the balance is Ni plate and unavoidable inclusions, and the sum of the above components by weight percentage is 100%; The gas content of metal Cr is not less than 100 ppm; the gas content of sponge Ti is not less than 80 ppm.

[0018] Step 2, vacuum induction melting; First, add the Ni plate, Co plate and electrode C in the raw materials into the vacuum induction furnace, evacuate and power on to increase the induction melting power, so that the power is kept in the range of 1095~1150kW, then add Mo bars and metal Cr, heat to complete melting, reduce the melting power to 850~1950kW, control the melt temperature between 1450~1500℃, keep it for 7~13min, then enter the refining stage, add sponge Ti, Al beans and NiB master alloy in turn, increase the melting power to 1250~1350kW, keep the refining temperature at 1510~1530℃, keep electromagnetic stirring during the refining process, and the stirring time is 5~10min; Then, the refined molten steel is poured, and argon is continuously charged during the casting process. The casting temperature is 1450-1470°C. After the casting is completed, the ingot is cooled in the ingot mold room, and the ingot is demolded and taken out after being kept for 55-65 minutes to obtain a vacuum induction ingot with a weight of 2600-2800kg. Before casting, samples were taken with a sample bucket and composition tests were performed. The main components of the alloy were within the composition control range, the O element content was 8ppm~15ppm, and the N element content was 40ppm~60ppm.

[0019] Step 3, electroslag remelting; The vacuum induction ingot obtained in step 2 is sawn at the head, with the sawing height being greater than 80 mm from the head end face, and after surface grinding, it is used as an electroslag remelting electrode for remelting and refining; During electroslag remelting, the electroslag is selected to include the following components by mass percentage: 62~70% CaF2, 16~20% CaO, 12~16% Al2O3, 4~6% CeO, and the sum of the mass percentages of the above components is 100%; before adding slag, the electroslag is baked at 490~510℃ for more than 2h; The slag quantity is 68kg according to 25kg pre-melted slag per 1000kg alloy; The melting rate and slag swing are controlled during the electroslag remelting process. The melting rate in the stable smelting stage is 220~240kg / h, and the slag swing is 0.2~0.4mohm. When the electrode weight is ≤100kg, it enters the hot capping stage. After the hot capping is completed, the furnace is cooled for 60 minutes and then demolded to obtain the electroslag remelting ingot. Step 4, vacuum consumable remelting; The electroslag remelting ingot is sawed at the head, and the sawing height is greater than 50mm from the head end face. The surface is peeled, and the peeling depth is 5~9mm. After peeling, the surface oil is wiped with a scouring pad and dried in an oven. The dried smooth ingot is used as a vacuum consumable remelting electrode. During the vacuum consumable remelting process, high current density melting is used to ensure that the molten pool depth is within the range of 90~120mm, and the conditions for full stirring are met. The purpose is to narrow the width of the paste zone, increase the local cooling time of the alloy, and promote the fine dispersion of carbides. Droplet control is used during the smelting process, and the melting speed is set to 3~15 droplets / s. When the electrode weight is ≤80kg, it enters the hot capping stage. After the hot capping is completed, the furnace is cooled for 50min, and the high-carbon content high-temperature alloy ingot is demolded.

[0020] The current density is calculated according to the following formula:

[0021] In the formula, i is the current density, in A / cm 2 ; d is the electrode diameter, in mm.

[0022] The smelting process of the high-carbon content high-temperature alloy ingot with dispersed carbide distribution of the present invention includes raw material preparation, vacuum induction melting, electroslag remelting and vacuum consumable remelting, which fundamentally improves the dispersity and uniformity of carbide distribution in the alloy ingot, which will provide a good raw material basis for the dispersed distribution of carbides in subsequent processed materials.

[0023] Example 2 Step 1, ingredients. According to the composition requirements of nickel-based high-temperature alloy: C: 0.085%, metal Cr: 19.50%, Co plate: 10.80%, Mo bar: 9.80%, Al bean: 1.65%, sponge Ti: 3.32%, NiB master alloy: 0.006%, the balance is Ni and unavoidable inclusions, the sum of the above components by mass percentage is 100%; Step 2, vacuum induction melting. The order of adding raw materials during the feeding period is Ni plate, Co plate and electrode C. Evacuate and power on to increase the induction melting power, keep the power at 1100kW, then add Mo bars and metal Cr, heat to complete melting and reduce the melting power to 1050kW, control the melt temperature at 1478℃. After keeping for 8min, enter the refining stage, add sponge Ti, Al beans and NiB intermediate alloy in turn, increase the melting power to 1250kW, keep the refining temperature at 1510℃, keep electromagnetic stirring during the refining process, and the stirring time is 5min. The refined molten steel is poured. Before casting, the sample bucket is used for sampling and the composition test is carried out. The main components of the alloy are within the composition control range, the O element content is 12 ppm, and the N element content is 54ppm. During the casting process, argon is continuously charged and the casting temperature is 1465℃. After the casting is completed, the ingot is cooled in the ingot mold room and demolded and taken out after keeping it for 60 minutes. The weight of the ingot is 2600kg.

[0024] Step 3, electroslag remelting. The vacuum induction ingot obtained in step 2 is sawn at the head, and the sawing height is greater than 80mm from the head end face. After surface grinding, it is used as an electroslag remelting electrode for remelting and refining. Electroslag remelting uses 65% CaF2, 18% CaO, 12% Al2O3, and 5% CeO by mass percentage. The pre-melted slag is baked at 500°C for more than 2 hours before adding slag. The slag amount is 68kg according to 25kg pre-melted slag for every 1000kg alloy. The melting rate and slag swing are controlled during electroslag remelting. The melting rate in the stable smelting stage is 230kg / h, and the slag swing is 0.2mohm. When the electrode weight is ≤100kg, it enters the hot capping stage. After the hot capping is completed, the furnace is cooled for 60min and then demolded.

[0025] Step 4: Vacuum consumable remelting. The electroslag remelting ingot is sawn at the head, with the sawing height greater than 50mm from the head end face, and the surface is peeled to a depth of 8mm. After surface cleaning, it is used as a vacuum consumable remelting electrode with an electrode diameter of 430mm. During the vacuum consumable remelting process, 9.1A / cm 2 During smelting, the position of the electrode rod is automatically adjusted by droplet control to control the remelting rate of the alloy. The droplet setting range is 7 / s. When the electrode weight is ≤80kg, the hot capping stage is entered. After the hot capping is completed, the furnace is cooled for 50 minutes and then demolded to obtain an alloy ingot.

[0026] Figure 2 This is a scan of the carbides in the ingot obtained by smelting using this method. It can be seen that the carbides are dispersed and evenly distributed. Figure 3 and Figure 4 The following are scans of carbides with oxide and nitride cores in the ingot obtained by this method. Figure 3 and Figure 4 It can be seen that during the alloying process, carbides are formed at a lower Gibbs free energy with nitrides and oxides as the core, making the distribution of carbides more uniform.

[0027] Table 1 shows the O and N contents and carbide distribution in the ingots melted by this method. It can be seen that in the ingots melted by this method, the carbides are fine, with an average size of 7.6 μm, and the distance between carbides is large, reaching 20.9 μm.

[0028] Table 1 O, N content and carbide distribution in alloy ingots

[0029] Example 3 Step 1, ingredients. According to the composition requirements of nickel-based high-temperature alloy, electrode: C: 0.065%, metal Cr: 19.75%, Co plate: 10.60%, Mo bar: 9.79%, Al bean: 1.60%, sponge Ti: 3.42%, NiB master alloy: 0.003%, the balance is Ni plate and unavoidable inclusions, the sum of the above components by mass is 100%; Step 2, vacuum induction melting. The order of adding raw materials during the feeding period is Ni plate, Co plate and electrode C. Evacuate and power on to increase the induction melting power, keep the power at 1100kW, then add Mo bars and metal Cr, heat to complete melting and reduce the melting power to 1050kW, control the melt temperature at 1478℃. After keeping for 8 minutes, enter the refining stage, add sponge Ti, Al beans, NiB intermediate alloy, increase the melting power to 1350kW, keep the refining temperature at 1530℃, maintain electromagnetic stirring during the refining process, and the stirring time is 5min. The refined molten steel is poured. Before casting, the sample bucket is used for sampling and the composition test is carried out. The main components of the alloy are within the composition control range, the O element content is 12ppm, and the N element content is 54ppm. During the casting process, argon is continuously charged and the casting temperature is 1465℃. After the casting is completed, the ingot is cooled in the ingot mold room and demolded and taken out after keeping it for 60 minutes. The weight of the ingot is 2600kg.

[0030] Then the refined molten steel is poured, and argon is continuously charged during the casting process. The casting temperature is 1450-1470°C. After the casting is completed, the ingot is cooled in the ingot mold room, and the ingot is demolded and taken out after being kept for 55-65 minutes to obtain a vacuum induction ingot with an ingot weight of 2800kg. Before casting, samples were taken with a sample bucket and composition tests were performed. The main components of the alloy were within the composition control range, the O element content was 8ppm~15ppm, and the N element content was 40ppm~60ppm.

[0031] Step 3, electroslag remelting. The vacuum induction ingot obtained in step 2 is sawn at the head, and the sawing height is greater than 80mm from the head end face. After surface grinding, it is used as an electroslag remelting electrode for remelting and refining. Electroslag remelting uses 65% CaF2, 18% CaO, 12% Al2O3, and 5% CeO by mass percentage. The pre-melted slag is baked at 500°C for more than 2 hours before adding slag. The slag amount is 68kg according to 25kg pre-melted slag for every 1000kg alloy. The melting rate and slag swing are controlled during electroslag remelting. The melting rate in the stable smelting stage is 230kg / h, and the slag swing is 0.2mohm. When the electrode weight is ≤100kg, it enters the hot capping stage. After the hot capping is completed, the furnace is cooled for 60min and then demolded.

[0032] Step 4: Vacuum consumable remelting. The electroslag remelting ingot is sawn at the head, with the sawing height greater than 50mm from the head end face, and the surface is peeled to a depth of 8mm. After surface cleaning, it is used as a vacuum consumable remelting electrode with an electrode diameter of 430mm. During the vacuum consumable remelting process, 9.1A / cm 2During smelting, the position of the electrode rod is automatically adjusted by droplet control to control the remelting rate of the alloy. The droplet setting range is 7 / s. When the electrode weight is ≤80kg, the hot capping stage is entered. After the hot capping is completed, the furnace is cooled for 50 minutes and then demolded to obtain an alloy ingot.

[0033] Table 2 shows the content of O and N and the distribution of carbides in the ingot obtained by this method. It can be seen that, consistent with Example 2, the ingot obtained by smelting using this method has fine carbides with an average size of 7.7 μm, and the distance between carbides is relatively large, reaching 24.9 μm.

[0034] Table 2 O, N content and carbide distribution in alloy ingots

[0035] Comparative Example 1 A high-temperature alloy with the same nominal composition as in Example 2 was prepared by batching → vacuum induction melting → electroslag remelting → vacuum consumable remelting. The method of this comparative example is basically the same as that of Example 2, except that degassed Cr and pure Ti blocks are used as raw materials. Table 3 shows the distribution of O, N content and carbides in the ingot obtained by conventional smelting method.

[0036] Table 3 O, N content and carbide distribution in ingots prepared by conventional smelting method

[0037] It can be seen that compared with Example 2, the carbide size in the ingot smelted by the conventional method (i.e., not using metal Cr with a gas content of not less than 100 ppm and sponge Ti with a gas element of not less than 80 ppm) is comparable to the carbide size in Implementation 2, which is 7.9 μm, but the average distance between carbides is much smaller than the distance in Example 2, which is only 14.9 μm, indicating that the process of the present invention is effective in achieving dispersed distribution of carbides and has promotion value.

[0038] Comparative Example 2 The high-temperature alloy with the same nominal composition as in Example 2 was prepared by batching → vacuum induction melting → electroslag remelting → vacuum consumable remelting. The method of this comparative example is basically the same as that of Example 2, except that 65% CaF2, 18% CaO, and 17% Al2O3 are selected in electroslag remelting by mass percentage. Table 4 shows the distribution of O and N contents and carbides in the ingot obtained by conventional smelting.

[0039] Table 4 O, N content and carbide distribution in ingots prepared by conventional smelting method

[0040] It can be seen that compared with Example 2, the carbide size in the ingot smelted by the conventional method (i.e., the pre-melted slag system without CeO) is comparable to the carbide size in Example 2, which is 7.5 μm, but the average distance between carbides is much smaller than that in Example 2, which is only 14.9 μm, indicating that the process of the present invention is effective in achieving dispersed distribution of carbides and has promotion value.

[0041] Comparative Example 3 The high-temperature alloy with the same nominal composition as in Example 2 was prepared by batching → vacuum induction melting → electroslag remelting → vacuum consumable remelting. The method of this comparative example is basically the same as that of Example 2, except that 7.8A / cm 2 Table 5 shows the content of O and N and the distribution of carbides in the ingot obtained by smelting.

[0042] Table 5 O, N content and carbide distribution in ingots prepared by conventional smelting method

[0043] It can be seen that compared with Example 2, the carbide size in the ingot obtained by smelting using the conventional method (i.e., without using a large current) is comparable to the carbide size in Example 2, which is 7.4 μm, but the average distance between carbides is much smaller than that in Example 2, which is only 12.9 μm, indicating that the process of the present invention is effective in achieving dispersed distribution of carbides and has promotion value.

[0044] Example 4 The smelting process of the high-carbon content high-temperature alloy ingot with dispersed carbides of the present invention is specifically implemented according to the following steps: Step 1, weighing a nickel-based high-temperature alloy raw material; The raw material of the nickel-based high-temperature alloy includes the following components in weight percentage: electrode C: 0.10%, metal Cr: 18.50%, Co plate: 11.10%, Mo bar: 9.50%, Al bean: 1.50%, sponge Ti: 3.25%, NiB master alloy: 0.009%, the balance is Ni plate and unavoidable inclusions, and the sum of the above components by weight percentage is 100%; The gas content of metal Cr is not less than 100 ppm; the gas content of sponge Ti is not less than 80 ppm.

[0045] Step 2, vacuum induction melting; First, Ni plate, Co plate and electrode C in the raw materials are added into a vacuum induction furnace, vacuumed and powered on to increase the induction melting power, and the power is kept at 1150kW. Then, Mo bars and metal Cr are added, and the melting power is reduced to 1050kW after the temperature is raised to complete melting. The melt temperature is controlled at 1450℃, and after maintaining for 7 minutes, it enters the refining stage, and sponge Ti, Al beans and NiB master alloy are added in turn, and the melting power is increased to 1250kW, and the refining temperature is maintained at 1510℃. Electromagnetic stirring is maintained during the refining process, and the stirring time is 5 minutes; Then the refined molten steel was poured, and argon was continuously charged during the casting process. The casting temperature was 1450°C. After the casting was completed, the ingot was cooled in the ingot mold room and demolded after 55 minutes to obtain a vacuum induction ingot with an ingot weight of 2600kg. Before casting, samples were taken with a sample bucket and composition tests were performed. The main components of the alloy were within the composition control range, with the O element content being 8 ppm and the N element content being 40 ppm.

[0046] Step 3, electroslag remelting; The vacuum induction ingot obtained in step 2 is sawn at the head, with the sawing height being greater than 80 mm from the head end face, and after surface grinding, it is used as an electroslag remelting electrode for remelting and refining; The melting rate and slag swing are controlled during the electroslag remelting process. The melting rate in the stable smelting stage is 220kg / h and the slag swing is 0.2mohm. When the electrode weight is ≤100kg, the hot capping stage is entered. After the hot capping, the furnace is cooled for 60 minutes and then demolded to obtain the electroslag remelting ingot. Step 4, vacuum consumable remelting; The electroslag remelting ingot is sawed at the head, and the sawing height is greater than 50mm from the head end face. The surface is peeled, and the peeling depth is 5mm. After peeling, the surface oil is wiped with a scouring pad and dried in an oven. The dried smooth ingot is used as a vacuum consumable remelting electrode. During the vacuum consumable remelting process, high current density melting is used to ensure that the molten pool depth is within 90mm and has the conditions for full stirring. The purpose is to narrow the width of the paste zone, increase the local cooling time of the alloy, and promote the fine dispersion of carbides. Droplet control is used during the smelting process, and the melting speed is set to 3 drops / s. When the electrode weight is ≤80kg, the hot capping stage is entered. After the hot capping is completed, the furnace is cooled for 50 minutes, and the high-carbon content high-temperature alloy ingot is demolded.

[0047] Example 5 The smelting process of the high-carbon content high-temperature alloy ingot with dispersed carbides of the present invention is specifically implemented according to the following steps: Step 1, weighing a nickel-based high-temperature alloy raw material; The raw material of the nickel-based high-temperature alloy includes the following components in weight percentage: electrode C: 0.12%, metal Cr: 20.00%, Co plate: 12.00%, Mo bar: 10.50%, Al bean: 1.80%, sponge Ti: 3.50%, NiB master alloy: 0.010%, the balance is Ni plate and unavoidable inclusions, and the sum of the above components by weight percentage is 100%; The gas content of metal Cr is not less than 100 ppm; the gas content of sponge Ti is not less than 80 ppm.

[0048] Step 2, vacuum induction melting; First, Ni plate, Co plate and electrode C in the raw materials are added into a vacuum induction furnace, vacuumed and powered on to increase the induction melting power, and the power is kept at 1150kW. Then, Mo bars and metal Cr are added, and the temperature is raised to complete melting, and then the melting power is reduced to 1950kW. The melt temperature is controlled between 1500℃ and maintained for 13min before entering the refining stage. Sponge Ti, Al beans and NiB master alloy are added in turn, and the melting power is increased to 1350kW. The refining temperature is maintained at 1530℃. Electromagnetic stirring is maintained during the refining process, and the stirring time is 10min. Then the refined molten steel was poured, and argon was continuously charged during the casting process. The casting temperature was 1470°C. After the casting was completed, the ingot was cooled in the ingot mold room and demolded after 65 minutes to obtain a vacuum induction ingot with a weight of 2800kg. Before casting, samples were taken with a sample bucket and composition tests were performed. The main components of the alloy were within the composition control range, with the O element content being 15ppm and the N element content being 60ppm.

[0049] Step 3, electroslag remelting; The vacuum induction ingot obtained in step 2 is sawn at the head, with the sawing height being greater than 80 mm from the head end face, and after surface grinding, it is used as an electroslag remelting electrode for remelting and refining; The melting rate and slag swing are controlled during the electroslag remelting process. The melting rate in the stable smelting stage is 240kg / h and the slag swing is 0.4mohm. When the electrode weight is ≤100kg, the hot capping stage is entered. After the hot capping, the furnace is cooled for 60 minutes and then demolded to obtain the electroslag remelting ingot. Step 4, vacuum consumable remelting; The electroslag remelting ingot is sawn at the head, with the sawing height greater than 50mm from the head end face, and the surface is peeled to a depth of 9mm. After peeling, the surface oil is wiped dry with a scouring pad and dried in an oven. The dried smooth ingot is used as a vacuum consumable remelting electrode. During the vacuum consumable remelting process, high current density smelting is used to ensure that the molten pool depth is within the range of 120mm, and the conditions for full stirring are met. The purpose is to narrow the width of the paste zone, increase the local cooling time of the alloy, and promote the fine dispersion of carbides. Droplet control is used during the smelting process, and the melting speed is set to 15 droplets / s. When the electrode weight is ≤80kg, the hot capping stage is entered. After the hot capping is completed, the furnace is cooled for 50 minutes, and the high-carbon content high-temperature alloy ingot is demolded.

[0050] Example 6 The smelting process of dispersed carbide in high-carbon high-temperature alloy ingot of the present invention is to add metal Cr and sponge titanium with high gas content in the batching and vacuum induction melting stage, control the temperature during the induction melting and refining period, and obtain a master alloy with high gas content; the electroslag remelting process uses an alkaline slag system with 5wt.%Ce to ensure the oxygen content and heterogeneous nucleation particles in the electroslag ingot; the vacuum consumable remelting uses a large current smelting to create a larger molten pool depth and sufficient stirring conditions, narrow the width of the mushy zone, and reduce the local cooling time of the alloy. The carbides of the high-temperature alloy ingot prepared by the method of the present invention are small and dispersed, which can greatly improve the strip-shaped carbide structure defects in the subsequent thermal deformation process of the alloy.

Claims

1. A smelting process for high-carbon high-temperature alloy ingots with dispersed carbides, characterized in that: Follow the steps below to implement it: Step 1, weighing nickel-based high-temperature alloy raw materials, including electrode C, metal Cr, Co plate, Mo bar, Al bean, sponge Ti, NiB master alloy and Ni plate; Step 2, performing vacuum induction melting on the nickel-based high-temperature alloy raw material in step 1 to obtain a vacuum induction ingot; Step 3, electroslag remelting: sawing the head of the vacuum induction ingot obtained in step 2, grinding the surface and remelting and refining it as an electroslag remelting electrode to obtain an electroslag remelting ingot; Step 4: vacuum consumable remelting to finally obtain a high-carbon content high-temperature alloy ingot.

2. The smelting process of the high-carbon high-temperature alloy ingot with dispersed carbide distribution according to claim 1, characterized in that: In the step 1, the raw material of the nickel-based high-temperature alloy comprises the following components in weight percentage: electrode C: 0.06-0.12%, metal Cr: 18.00-20.00%, Co plate: 10.00-12.00%, Mo rod: 9.00-10.50%, Al bean: 1.40-1.80%, sponge Ti: 3.00-3.50%, NiB master alloy: 0.003-0.010%, and the remainder is Ni plate and unavoidable inclusions. The sum of the mass percentages of the above components is 100%.

3. The smelting process of the high-carbon high-temperature alloy ingot with dispersed carbide distribution according to claim 2, characterized in that: The gas content of metal Cr is not less than 100 ppm; the gas content of sponge Ti is not less than 80 ppm.

4. The smelting process of high-carbon high-temperature alloy ingot with dispersed carbide distribution according to claim 1, characterized in that: In the step 2, specifically: First, add the Ni plate, Co plate and electrode C in the raw materials into the vacuum induction furnace, evacuate and power on to increase the induction melting power, so that the power is kept in the range of 1095~1150kW, then add Mo bars and metal Cr, heat to complete melting, reduce the melting power to 850~1950kW, control the melt temperature between 1450~1500℃, keep it for 7~13min, then enter the refining stage, add sponge Ti, Al beans and NiB master alloy in turn, increase the melting power to 1250~1350kW, keep the refining temperature at 1510~1530℃, keep electromagnetic stirring during the refining process, and the stirring time is 5~10min; The refined molten steel is then poured, and argon is continuously filled during the casting process. The casting temperature is 1450~1470℃. After the casting is completed, the ingot is cooled in the ingot mold chamber and demolded and taken out after keeping it for 55~65 minutes to obtain a vacuum induction ingot.

5. The smelting process of high-carbon high-temperature alloy ingot with dispersed carbide distribution according to claim 1, characterized in that: In the step 3, during electroslag remelting, the electroslag selected includes the following components in mass percentage: 62-70% CaF2, 16-20% CaO, 12-16% Al2O3, 4-6% CeO, and the sum of the mass percentages of the above components is 100%.

6. The smelting process of high-carbon high-temperature alloy ingot with dispersed carbide distribution according to claim 5, characterized in that: In the step 3, before adding slag, the electroslag is baked at 490-510° C. for more than 2 hours; the melting rate and slag swing are used to control the electroslag remelting process, the melting rate in the stable smelting stage is 220-240 kg / h, and the slag swing is 0.2-0.4 mohm; when the electrode weight is ≤100 kg, the hot capping stage is entered, and after the hot capping is completed, the furnace is cooled for 60 minutes and then demolded to obtain an electroslag remelting ingot.

7. The smelting process of high-carbon high-temperature alloy ingot with dispersed carbide distribution according to claim 1, characterized in that: In the step 4, specifically: The electroslag remelting ingot is sawed at the head, with the sawing height greater than 50mm from the head end face, and the surface is peeled with a peeling depth of 5-9mm. After peeling, the surface oil is wiped dry and dried in an oven. The dried smooth ingot is used as a vacuum consumable remelting electrode. During the vacuum consumable remelting process, high current density melting is adopted to ensure that the molten pool depth is within the range of 90-120mm. Droplet control is adopted during the melting process, and the melting speed is set to 3-15 droplets / s. When the electrode weight is ≤80kg, the hot capping stage is entered. After the hot capping, the furnace is cooled for 50min, and the high-temperature alloy ingot with high carbon content is demolded.

8. The smelting process of high-carbon high-temperature alloy ingot with dispersed carbide distribution according to claim 7, characterized in that: The current density is calculated according to the following formula: In the formula, i is the current density, in A / cm 2 ; d is the electrode diameter, in mm.

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