Method for improving utilization rate of alloy consumable ingot, forging device and application of forging device in preparation of GH4169 alloy

Abstract

The embodiment of the invention provides a method for improving the utilization rate of alloy consumable ingots, a forging device and application of the forging device in GH4169 alloy preparation, and belongs to the technical field of high-temperature alloy casting. The method comprises the following steps: providing an alloy consumable ingot prepared by vacuum consumable remelting; the alloy consumable ingot is heated to the preset forging temperature at the preset heating rate; the end of the alloy consumable ingot is subjected to primary forging, and a basic clamp handle structure is formed through forging and rotating; secondary forging is conducted on the basic clamp handle structure, and the basic clamp handle structure is forged into a clamp handle through forging and pressing; after primary forging and secondary forging, the defect of the central area of the end of the alloy consumable ingot is left in the clamp handle, and the pure material surrounding the central area is pressed into the qualified area of the alloy consumable ingot to be recycled. According to the method, end defects are accurately recognized, the alloy consumable ingots are locked in the cut pliers handles so as to retain qualified materials, and the effective utilization rate of the GH4169 alloy consumable ingots is increased by 10%-15%.

Description

Technical Field

[0001] This invention relates to the technical field of high-temperature alloy casting, and particularly to a method for improving the utilization rate of alloy consumable ingots, a forging apparatus, and its application in the preparation of GH4169 alloy. Background Technology

[0002] Vacuum arc remelting (VAR) technology is a key process for preparing high-end high-temperature alloys (such as GH4169 alloy). By melting consumable electrodes in a vacuum environment and solidifying them into alloy ingots in a water-cooled copper crucible, it has advantages such as the ability to melt high-melting-point, highly reactive metals and the low incidence of shrinkage cavities. However, this process also has inherent drawbacks, especially in the end (riser) region of the ingot.

[0003] In VAR smelting, especially for large ingots, the ingot ends, as the last solidification zone, are highly susceptible to defects such as concentrated shrinkage cavities and porosity due to insufficient feeding. Simultaneously, oxide impurities from the molten pool surface at the end of the smelting process are easily drawn into this area, forming slag inclusions and harmful inclusions (such as coarse TiN). Furthermore, this area also experiences "hot spots" due to the air gap between the solidified shell and the crucible, resulting in coarse localized solidification structures and severe segregation. These metallurgical defects severely impair the mechanical properties and service reliability of the alloy material.

[0004] Typically, to ensure the purity of the final product, a conservative strategy is adopted: after the ingot is formed, the ends with potential defects are directly cut off and treated as return material. While this method ensures the quality of the alloy product, it results in a significant waste of qualified material (the defect-free parts of the cut-off body), increasing not only the amount of material needed for subsequent batching but also significantly increasing energy consumption and production costs.

[0005] In view of this, a novel method for improving the utilization rate of alloy consumable ingots, a forging device, and its application in the preparation of GH4169 alloy are proposed to solve all or part of the above problems. Summary of the Invention

[0006] To address at least one of the aforementioned problems and deficiencies in the prior art, embodiments of the present invention provide a method for improving the utilization rate of alloy consumable ingots, a forging apparatus, and its application in the preparation of GH4169 alloy. By accurately identifying and defining the concentrated area of ​​end defects in the alloy consumable ingot based on a simulated resetting of the Niyama criterion, and employing a two-step forging process to lock the defects inside the ultimately removed clamp, the clean, qualified material around the end is successfully pressed into and retained within the usable ingot body, significantly improving the effective utilization rate of the alloy material. The effective utilization rate of a single GH4169 alloy consumable ingot is increased by approximately 10%-15%. The technical solution is as follows:

[0007] According to one aspect of the present invention, a method for improving the utilization rate of alloy consumable ingots is provided. The method specifically includes:

[0008] Provide alloy consumable ingots prepared by vacuum consumable remelting;

[0009] The alloy consumable ingot is heated to a preset forging temperature at a preset heating rate;

[0010] The end of the alloy consumable ingot is initially forged, and the basic clamp structure is formed by forging and rotation.

[0011] The basic clamp handle structure is forged a second time, and the basic clamp handle structure is forged into a clamp handle through forging.

[0012] After the initial forging and secondary forging, the defects in the central region of the end of the alloy consumable ingot remain in the clamp, and the pure material around the central region is pressed into its qualified area for recycling.

[0013] In some embodiments, preferably, the preset heating rate is 25-35℃ / min and the preset forging temperature is 1060-1100℃.

[0014] In some embodiments, specifically, prior to the initial forging and the secondary forging, the defect distribution area at the end center of the alloy consumable ingot is determined by finite element simulation and the Niyama criterion, respectively; the defects in the end center region of the alloy consumable ingot include at least one of shrinkage cavities, shrinkage porosity, slag inclusions, or inclusions; the threshold of the Niyama criterion is set such that the defect distribution area is located inside the clamp handle.

[0015] In some embodiments, after primary forging and secondary forging, the material utilization rate of each alloy consumable ingot used for vacuum consumable remelting is increased by 10%-15%.

[0016] In some embodiments, specifically, the alloy consumable ingot is a GH4169 alloy consumable ingot; the GH4169 alloy consumable ingot has a diameter of 500-520mm, a length of 1700-1900mm, and a defect distribution area at the center of its end with a diameter of less than or equal to 200mm and a depth of less than or equal to 250mm; the basic clamp handle structure obtained after the first forging has a diameter of 250-350mm and a height of 40-60mm; the clamp handle obtained after the second forging has a diameter of 150-250mm.

[0017] In some embodiments, specifically, the threshold of the Niyama criterion is set to be less than or equal to 20 × (K·sec). 0.5 / cm.

[0018] According to another aspect of the present invention, a forging apparatus for improving the utilization rate of alloy consumable ingots is provided. This forging apparatus is used to forge alloy consumable ingots according to the method described above. The forging apparatus includes:

[0019] The upper anvil is set above the end of the alloy consumable ingot and is used to forge the end of the alloy consumable ingot to obtain a clamp.

[0020] The lower anvil section has a metal rotating disk fixedly installed above it, and the other end of the alloy consumable ingot is fixedly placed on the metal rotating disk.

[0021] A first pressure head for initial forging and a second pressure head for secondary forging are movably connected to the end face of the upper anvil near the alloy consumable ingot.

[0022] In some embodiments, specifically, the first indenter includes two alloy inserts arranged parallel to each other on the surface of the upper anvil; the alloy inserts have a preset spacing of 250-350 mm; and the width of the forging surface of each alloy insert is 80-120 mm.

[0023] In some embodiments, specifically, the second pressure head is a ring structure with a height of 150-250 mm; the center of the ring structure has a truncated conical cavity penetrating the ring structure; the truncated conical cavity includes an upper section near the upper anvil and a lower section away from the upper anvil; wherein the diameter of the upper section is 150-250 mm, the diameter of the lower section is 250-350 mm, and the edge of the lower section has a rounded corner with a radius of 80-120 mm.

[0024] According to another aspect of the present invention, a method for improving the utilization rate of alloy consumable ingots is provided and its application in the preparation of GH4169 alloy. Its characteristic is that...

[0025] Specifically, GH4169 alloy consumable ingots are forged using the method and / or forging apparatus described above for improving the utilization rate of alloy consumable ingots. The central region of the end of the GH4169 alloy consumable ingot has a clamp, in which defects of the GH4169 alloy consumable ingot are concentrated. Pure material surrounding the central region is pressed into its qualified area for subsequent melting and processing.

[0026] The method for improving the utilization rate of alloy consumable ingots, the forging apparatus, and their application in the preparation of GH4169 alloy provided by the embodiments of the present invention have at least one or a portion of the following advantages:

[0027] (1) By accurately identifying and defining the concentrated area of ​​end defects of the alloy consumable ingot, and using two-step forging to lock the defects inside the final cut-off clamp, the clean and qualified material around the end is successfully pressed into and retained in the usable ingot body, greatly improving the effective utilization rate of alloy material.

[0028] (2) The method of improving the utilization rate of alloy consumable ingots of the present invention can increase the effective utilization rate of a single GH4169 alloy consumable ingot by about 10%-15%, increase the weight of a single qualified smelting product, reduce the consumption of alloy materials, and improve economic benefits.

[0029] (3) Based on finite element simulation and the adjusted Niyama criterion, the distribution range of defects corresponding to the actual alloy consumable ingot is determined in advance, ensuring that the forging process design can completely keep the defect area inside the clamp, thereby ensuring the metallurgical quality and high purity of the main ingot material.

[0030] (4) By using two-step forging (primary forging and secondary forging) and matching the design of forging equipment, alloy inserts with spacing are used for pre-forming in the primary forging, which effectively solves the problem of edge material warping that may be caused by directly using a circular pressure head, provides a foundation for the smooth implementation of secondary forging, avoids secondary defects, and ensures the stability of the forming process and the controllability of material flow.

[0031] (5) The method of improving the utilization rate of alloy consumable ingots by the present invention, especially the two-step forging method, significantly reduces the excessive consumption of return material caused by directly cutting off the integral end. This not only reduces the cost of raw materials, but also simplifies the batching management of the smelting process and reduces the repeated consumption of energy, providing a feasible path for achieving green, sustainable and efficient production. Attached Figure Description

[0032] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:

[0033] Figure 1 A flowchart illustrating the steps of a method for improving the utilization rate of alloy consumable ingots according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the principle and structure of a common vacuum arc furnace;

[0035] Figure 3 This is a schematic diagram illustrating the principle structure of a forging apparatus according to an embodiment of the present invention and its two-step forging process;

[0036] Figure 4 for Figure 3 A schematic diagram of the structure of the first pressure head of an embodiment of the forging apparatus and its pressing process on the ingot;

[0037] Figure 5 for Figure 3 A schematic diagram of the structure of the second pressure head in one embodiment of the forging apparatus shown;

[0038] Figure 6 This is a schematic diagram of the finite element simulation results of the defect distribution at the end of a common alloy consumable ingot;

[0039] Figure 7 This is a schematic diagram showing the simulation results of the forging displacement from the initial forging to the completion of forging according to Embodiment 1 of the present invention;

[0040] Figure 8 This is a schematic diagram showing the simulation results of strain and stress at the rear end of the secondary forging process according to Embodiment 1 of the present invention;

[0041] Figure 9 This is a schematic diagram of the simulation results of the forging displacement at the rear end of the secondary forging according to Embodiment 1 of the present invention;

[0042] Figure 10 This is a schematic diagram of the simulation results of the equivalent stress at the end of the ingot after one-time molding according to Embodiment 2 of the present invention;

[0043] Figure 11 This is a schematic diagram of the simulation results of the forging displacement in the Z direction at the end of the ingot after one-time forming according to Embodiment 2 of the present invention;

[0044] Figure 12 This is a schematic diagram of the simulation results of the forging displacement in the X direction at the end of the ingot after the first forging according to Embodiment 3 of the present invention;

[0045] Figure 13 This is a schematic diagram of a simulated structure of the end of an ingot obtained by secondary forging according to Embodiment 1 of the present invention;

[0046] Figure 14 This is a schematic diagram of a simulated structure of the end of an ingot obtained by secondary forging according to Comparative Example 2 of the present invention. Detailed Implementation

[0047] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.

[0048] It should also be understood that although the terms "first," "second," "third," etc., may be used in the following embodiments of the present invention to describe a component comprising two or more of the same component, these components should not be limited to these terms, which are only used to distinguish each component from one another. Furthermore, descriptions indicating orientation such as "upper," "lower," "left," and "right" are merely illustrative of the relative positions of components and should not be construed as a limitation of the present invention.

[0049] This invention provides a method for improving the utilization rate of alloy consumable ingots, particularly for the preparation of GH4169 alloy. This method accurately identifies and defines the concentrated area of ​​end defects in the alloy consumable ingot by resetting the Niyama criterion based on simulation. Then, it employs a two-step forging process (an initial forging to separate the acceptable and defective areas, and a secondary forging to form the clamp) to lock the defects inside the finally removed clamp. This successfully presses and retains the clean, acceptable material around the end within the usable ingot body, significantly improving the effective utilization rate of the alloy material. The effective utilization rate of a single GH4169 alloy consumable ingot is increased by approximately 10%-15%.

[0050] See Figure 1 This invention illustrates a method for improving the utilization rate of alloy consumable ingots according to an embodiment of the present invention. The method specifically includes:

[0051] Step S110: Provide an alloy consumable ingot prepared by vacuum consumable remelting;

[0052] Step S120: Heat the alloy consumable ingot to a preset forging temperature at a preset heating rate;

[0053] Step S130: The end of the alloy consumable ingot is initially forged to form a basic clamp structure through forging and rotation;

[0054] Step S140: The basic clamp handle structure is forged a second time to form the clamp handle through forging.

[0055] After the initial forging and secondary forging, the defects in the central region of the end of the alloy consumable ingot remain in the clamp, and the pure material around the central region is pressed into its qualified area for recycling.

[0056] See Figure 2This diagram illustrates the principle and structure of a common vacuum arc remelting furnace. Vacuum arc remelting operates under vacuum, using the material to be melted as the base material for the arc remelting electrode, and a water-cooled copper crucible as the other electrode. An electric arc is ignited and maintained between the two electrodes. The base material is melted by the high temperature of the arc and drips into the crucible, gradually melting and solidifying into a metal ingot under forced cooling conditions. A complete vacuum arc remelting furnace mainly consists of a furnace body, a vacuum device, a chemical observation device, a control system, and a DC power supply. Vacuum arc remelting furnaces have the advantages of dissolving high-melting-point, highly reactive metals and avoiding defects such as shrinkage cavities. Simultaneously, the liquid metal drips and accumulates in a mold, where it cools and solidifies into an ingot, i.e., an alloy arc remelting ingot.

[0057] When entering the casting stage of vacuum arc remelting, especially in the smelting of large-sized ingots, it is difficult to obtain all ingots that meet technical requirements through control of casting process parameters. Particularly when the hot capping is complete, the top molten pool cools rapidly, forming a closed liquid metal region within the ingot. At this point, solidification shrinkage cannot be effectively compensated, leading to shrinkage cavities. In addition, shrinkage cavities, hot cracks, and reactive porosity are prone to occur at this location. If the vacuum level of the equipment is low, elements such as nitrogen and oxygen present inside the equipment react with elements such as titanium and niobium within the material to form oxynitric compounds, which are difficult to remove. Large primary TiN inclusions are particularly difficult to eliminate in subsequent processes, severely affecting the material's mechanical properties.

[0058] Therefore, during the production process, the port portion of the alloy consumable ingot often fails to meet quality requirements. To save production costs, this port portion is often completely cut off and reused as scrap material for remelting. However, using it as scrap material undoubtedly causes significant problems for subsequent batching calculations, results in a huge waste of energy and resources, and increases production costs.

[0059] The method for improving the utilization rate of alloy consumable ingots through the embodiments of the present invention can effectively solve this process problem, maximize the recycling of alloy materials, and achieve green, sustainable and highly efficient high-temperature alloy casting.

[0060] Preferably, in step S120, the preset heating rate is set to 25-35℃ / min, and the preset forging temperature is set to 1060-1100℃.

[0061] Preferably, in the two-step forging process of steps S130 and S140, before each forging step, it is necessary to determine the defect distribution area at the end center of the alloy consumable ingot through finite element simulation and Niyama criterion, respectively.

[0062] Furthermore, as mentioned in the above smelting process description, defects in the central region of the end of the alloy consumable ingot typically include at least one of shrinkage cavities, shrinkage porosity, slag entrapment, or inclusions. These defects are usually formed in combination at the end of the alloy consumable ingot.

[0063] Furthermore, in various embodiments of the present invention, the threshold of the Niyama criterion is set such that the defect distribution area is located inside the clamp handle.

[0064] In one example, specifically, before implementing the forging steps (including before the initial forging and the secondary forging), in order to accurately define the defect areas that need to be isolated or separated, finite element simulation software can be used to simulate and analyze the solidification process of the ingot, and then the Niyama criterion can be applied to predict defects.

[0065] The Niyama criterion is an empirical criterion used to predict shrinkage cavities and porosity defects in metal casting. Its general expression is: Where G is the temperature gradient of the alloy consumable ingot, T is the temperature change per unit time in the simulated calculation area, and A is the set threshold. This is used to assess defect risk; when the value is below the critical threshold, it indicates a high defect tendency. This criterion is widely used in traditional casting, but with the development of processes such as additive manufacturing with high cooling rates, the effectiveness of its empirical judgment is limited to some extent. Therefore, it is necessary to make appropriate adjustments based on it.

[0066] See Figure 3 This paper illustrates the principle structure of a forging apparatus 100 according to an embodiment of the present invention and its two-step forging process.

[0067] Combination Figure 1 and Figure 3 As shown, the forging apparatus 100 is used to forge an alloy consumable ingot 200 according to the method described above. Specifically, the forging apparatus 100 includes:

[0068] The upper anvil 10 is provided above the end of the alloy consumable ingot 200 for forging the end of the alloy consumable ingot 20 to obtain the clamp 201.

[0069] The lower anvil 20 has a metal rotating disk 21 fixedly installed above it, and the other end of the alloy consumable ingot 200 is fixedly placed on the metal rotating disk 21.

[0070] A first pressure head 11 for initial forging and a second pressure head 12 for secondary forging are movably connected to the end face of the upper anvil 10 near the alloy consumable ingot.

[0071] In one example, a metal rotating disk 21 is fixed above the lower anvil 20 to support and rotate the alloy consumable ingot 200. The upper anvil 10 has pressure heads with different structures for the two forging stages on its end face near the alloy consumable ingot 200. To switch the corresponding pressure heads between the two forging stages, the connection between the upper anvil 10 and the two pressure heads is a movable connection, such as a quick-change mechanism via bolts, slots, etc.

[0072] In one example, see Figure 4 The diagram illustrates the structure of a first pressure head 11 according to one embodiment and its pressing process on an ingot. Specifically, the first pressure head 11 includes two alloy inserts 11a and 11b arranged parallel to each other on the surface of the upper anvil 10, with a preset distance between them. The preset distance is typically adjusted according to the actual ingot, and can be set to 250-350 mm for common ingots. Furthermore, the forging surface of each alloy insert has a preset width, which also needs to be adjusted according to the actual ingot forging process, and can typically be set to 80-120 mm.

[0073] In one example, see Figure 5 The diagram illustrates the structure of a second pressure head 12 according to one embodiment. Specifically, the second pressure head 12 is an annular structure with a height of 150-250 mm. The center of the annular structure has a truncated conical cavity penetrating the annular structure. This truncated conical cavity includes an upper section near the upper anvil 10 and a lower section away from the upper anvil 10. The diameter of the upper section is 150-250 mm, the diameter of the lower section is 250-350 mm, and the edge of the lower section has a rounded corner with a radius of 80-120 mm. This structure facilitates the flow of alloy material towards its center during the pressing process, resulting in the final clamp shape that meets the desired specifications.

[0074] The specific structural parameters for the truncated conical cavity described above can be adjusted according to the actual ingot structure. This description only provides a range of parameter settings for the ingots of various embodiments of the present invention. Those skilled in the art will understand that these structural dimensional parameters can be adjusted according to the specific structure of the ingot. The present invention only provides some illustrative examples and should not be construed as a limitation of the present invention.

[0075] The processing of alloy consumable ingots can be completed by using the forging apparatus 100 described above in conjunction with the method of the present invention for improving the utilization rate of alloy consumable ingots. The following describes this process in further detail using a specific GH4169 alloy consumable ingot as an example.

[0076] In one example, specifically, the GH4169 alloy consumable ingot has a diameter of 500-520mm and a length of 1700-1900mm, with a defect distribution area at the center of its end having a diameter of less than or equal to 200mm and a depth of less than or equal to 250mm; the basic clamp handle structure obtained after the first forging has a diameter of 250-350mm and a height of 40-60mm; the clamp handle obtained after the second forging has a diameter of 150-250mm.

[0077] The specific processing steps are as follows:

[0078] First, GH4169 alloy consumable ingots prepared by vacuum arc remelting process are provided. The typical dimensions of the ingot are 508 mm in diameter (within the range of 500-520 mm) and 1800 mm in length (within the range of 1700-1900 mm).

[0079] Next, after removing the ingot from the mold, it is heated to 1080°C (adjustable within the range of 1060-1100°C) at a rate of 30°C / min (adjustable within the range of 25-35°C / min). By setting this heating parameter, the ingot is brought to a suitable austenitic state for forging while avoiding overheating.

[0080] Then, the end of the ingot is forged into a clamp shape, combined with... Figure 4 and Figure 5 As shown, this process is divided into two stages:

[0081] Initial forging: A first pressure head 11 is installed on the upper anvil 10 of the forging device 100. This first pressure head 11 includes two parallel alloy inserts 11a and 11b, with a distance of 300mm between them (adjustable within the range of 250-350mm). The width of the forging surface of each alloy insert is 100mm (adjustable within the range of 80-120mm). A metal rotating disk 21 with a diameter of approximately 700mm is installed on the lower anvil 20. The ingot is placed vertically with its end aligned with the upper anvil 10. Through the pressing down of the upper anvil 10 and the intermittent rotation of the metal rotating disk 21, the end of the ingot is forged, gradually forming a disc-shaped basic clamp structure with a diameter of approximately 300mm (adjustable within the range of 250-350mm) and a height of approximately 50mm (adjustable within the range of 40-60mm).

[0082] Secondary forging: Replace the pressure head of the upper anvil 10 and use the second pressure head 12 to perform final forging on the basic clamp handle formed during the initial forging process. The second pressure head 12 is a ring structure with a height of 200mm (adjustable within the range of 150-250mm). Its lower bottom surface (forging surface) has a diameter of 300mm (adjustable within the range of 250-350mm), and its upper bottom surface has a diameter of 200mm (adjustable within the range of 150-250mm). The lower bottom surface edge has a rounded corner with a radius of 100mm (adjustable within the range of 80-120mm). Under the pressure of the second pressure head 12, the basic clamp handle structure is further compressed and shaped, ultimately forming a clamp handle with a diameter of approximately 200mm (adjustable within the range of 150-250mm based on simulation results and the preset threshold of the Niyama criterion).

[0083] After the two forging processes described above, defects (such as shrinkage cavities, porosity, slag inclusions, and inclusions) in the central region of the GH4169 alloy consumable ingot are successfully confined and retained within the final shaped clamp handle. Meanwhile, the alloy material that originally surrounded the central region (defect area) and met the required purity is squeezed out and incorporated into the main qualified area of ​​the GH4169 alloy consumable ingot during the forging process, thus enabling its recycling and reuse.

[0084] Furthermore, taking into account the alloy material characteristics of GH4169 alloy consumable ingots, a detailed explanation is given on how to obtain the above-mentioned appropriate structural dimension parameters and processing parameter range limits.

[0085] See Figure 6 The results show finite element simulations of the defect distribution in common alloy consumable ingots, particularly at their ends.

[0086] The Niyama criterion shows that its value generally decreases from the outer edge of the ingot towards the interior. The commonly used Niyama criterion value is less than or equal to 7.7 × (K·sec). 0.5 / cm, which is 1×(℃·min) 0.5 / cm is used to determine the shrinkage porosity area inside the ingot. However, in the high-temperature alloy forging process, due to the influence of other processes or process parameters (for example), the threshold of the Niyama criterion needs to be appropriately adjusted for GH4169 alloy consumable ingots to adapt to and guide the two-step forging method adopted in this invention, so as to obtain a result that can fully isolate the qualified material area at the end of the ingot from the defect accumulation area and limit the defect accumulation area to the inside of the clamp formed by the final forging.

[0087] Taking the forging of GH4169 alloy as an example, the threshold of the Niyama criterion was set to be less than or equal to 20 × (K·sec) through simulation and experimental verification. 0.5 Areas with a value of / cm (which can be adjusted around this value) are identified as areas prone to defects (shrinkage porosity, shrinkage cavity) or areas where defects accumulate.

[0088] like Figure 6 As shown, for the aforementioned GH4169 alloy consumable ingot (e.g., a typical size of 508 mm in diameter and length), the defects at its ends are roughly concentrated within an approximately cylindrical body with a diameter of about 160 mm to 200 mm and a depth of about 200 mm to 250 mm, centered at the end face center. This analysis guides the design of the subsequent two-step forging process parameters (e.g., the spacing between the two alloy inserts 11a and 11b of the first pressure head 11 used in the initial forging, and the diameter of the final clamp 201 obtained in the second forging). The aim is to ensure that the defect concentration area is completely enclosed within the final formed clamp 201 without contaminating the main material.

[0089] Embodiments of the present invention also illustrate the application of the method of improving the utilization rate of alloy consumable ingots by using the forging apparatus 100 described above in the preparation of GH4169 alloy. Detailed descriptions are provided below through specific embodiments and comparative examples.

[0090] GH4169 high-temperature alloy possesses superior performance and fatigue resistance, making it commonly used in aerospace and nuclear energy fields. It is primarily produced using the vacuum arc remelting (VAR) process. However, defects such as floating spots, white spots, and large inclusions significantly degrade the quality of its alloy ingots. Since these defects cannot be removed during forging, they are inherent in the final product. Therefore, the removal of inclusions and various defects is particularly important for alloy arc remelting ingots.

[0091] GH4169 alloy consumable ingots are forged using the method and / or forging apparatus described above for improving the utilization rate of alloy consumable ingots. The central region of the end of the GH4169 alloy consumable ingot has a clamp, in which defects of the GH4169 alloy consumable ingot are concentrated. Pure material surrounding the central region is pressed into its qualified area for subsequent melting and processing.

[0092] The method and forging apparatus of this invention are particularly suitable for the preparation of GH4169 alloy consumable ingots. By applying this method, the prepared GH4169 alloy consumable ingot has a forged clamp at its end. This clamp concentrates most of the metallurgical defects at the center of the ingot end, while ensuring the material purity of the ingot body and the surrounding area at the end. This allows it to be directly used in subsequent smelting and processing steps, achieving high material utilization while maintaining high quality.

[0093] Example 1

[0094] The structural parameters of the GH4169 alloy consumable ingot are a diameter of 508 mm and a length of 1800 mm, heated to 1080 °C at a heating rate of 30 °C / min.

[0095] A two-step forging process is performed using forging apparatus 100. First, a first forging is performed using a first pressure head 11. The two alloy inserts 11a and 11b of the first pressure head 11 are spaced 300 mm apart, and each alloy insert has a width of 100 mm on the forging surface. After the first forging, a frustum with a diameter of 300 mm and a height of 50 mm is formed at the end of the GH4169 alloy consumable ingot. Then, a second forging is performed using a second pressure head 12. This second pressure head is a ring-shaped structure with a bottom diameter of 300 mm, a top diameter of 200 mm, a height of 200 mm, and a bottom corner radius of 100 mm. After the second forging, the frustum formed in the first forging is further forged into a 200 mm diameter clamp handle.

[0096] See Figure 7The simulation results of the forging displacement from the initial forging to the completion of forging are shown.

[0097] In the initial forging stage, the first pressure head 11 forges the end of the ingot, extruding external material to the intended clamping position, preparing for the secondary forging. This effectively solves the edge warping problem caused by the direct pressing of the circular forging surface structure of the second pressure head 12. Process testing shows that this stage can add 244 kg of smeltable material (qualified material) to the ingot, improving the effective utilization rate of alloy material by approximately 8%.

[0098] Furthermore, finite element simulation results show that during the initial forging of the ingot at this stage, the ends exhibit significant displacement in the edge material, while the center shows no significant displacement, proving that the defect location remains unchanged. Subsequent forging operations result in a 50mm high frustum, but the defect concentration area remains undeformed, indicating that the internal defects have not moved, providing a basis for subsequent secondary forging. The central portion, unaffected by pressure, shows no significant deformation, while the forging edge exhibits the greatest displacement, gradually decreasing inwards. Finally, continuous downward forging forms the basic clamp structure, trapping the defects within it.

[0099] See Figure 8 The simulation results of strain and stress at the end of the ingot after secondary forging are shown.

[0100] See Figure 9 The simulation results of the forging displacement at the end of the ingot after secondary forging are shown.

[0101] In the secondary forging stage, the first pressure head 11 is replaced with the second pressure head 12. The circular structure of the second pressure head 12 is used to finalize the basic clamp handle structure, further forging the basic clamp handle and the end alloy material, leaving the defects in the middle at the clamp handle area. Process testing shows that this stage can increase the amount of smeltable material by approximately 66 kg and improve the effective utilization rate of alloy material by approximately 2.2%.

[0102] Furthermore, finite element simulation results show that during the secondary forging process, pressing the edge of the ingot end can force the surface material (qualified material) into the smeltable region. The flow direction of the alloy material during forging is as follows... Figure 8 As shown.

[0103] In terms of displacement results, such as Figure 9As shown, the displacement is mainly manifested as elongation in the axial direction (Z direction). However, there is also displacement in the direction parallel to the cross-section (X and Y directions), mainly concentrated at the edge position of the initial forging. Due to the downward pressure of the die, the surrounding material is gradually pressed into the position for consumable remelting along one side. No significant displacement occurs at the center position in this location. This simulation proves that the central material does not move during the secondary forging stage and therefore does not enter the consumable ingot body.

[0104] Therefore, after two forging steps, GH4169 alloy consumable ingots with clamps are obtained, and the product purity meets the standards after testing. This process also increases the effective utilization rate of alloy materials by more than 10%, approximately 15%. Each GH4169 alloy remelting ingot can yield approximately 300 kg more product.

[0105] Example 2

[0106] Under the same GH4169 alloy consumable ingot and heating conditions as in Example 1, the final clamp handle was obtained directly using the second pressure head 12 in a single forming process without initial forging. The results showed warping at the end edges, poor surface quality, and lower alloy material utilization than in Example 1.

[0107] See Figure 10 The simulation results of the equivalent stress at the end of the ingot after one-time molding in Example 2 are shown.

[0108] See Figure 11 The simulation results of the forging displacement in the Z direction at the end of the ingot after one-time forming in Example 2 are shown.

[0109] Through finite element simulation, such as Figure 10 As shown, if the second pressure head 12 is used directly for one-time forming, a discontinuous warping deformation will be formed at the edge of the ingot end, which will undoubtedly have a serious adverse effect on the forging quality.

[0110] Furthermore, combined with the equivalent stress diagram, it can be seen that during the compressive deformation process, the edge of the ingot end experiences the greatest equivalent stress, resulting in excessive and uncontrollable deformation at the edge.

[0111] And, such as Figure 11 As shown, the material whose edge at the end of the ingot is deformed and warped is actually an ingot with a good casting state at the lower end, which will undoubtedly have a negative impact on the ingot utilization rate.

[0112] Example 3

[0113] The same GH4169 alloy consumable ingot as in Example 1 was used, and the same heating rate was set, but the heating temperature was increased to 1150°C. The potential effects of high temperature on microstructure and defect migration were observed.

[0114] See Figure 12 The simulation results of the forging displacement in the X direction at the end of the ingot after the initial forging in Example 3 are shown.

[0115] From the forging results, the impact of increased deformation temperature on forging quality is mainly concentrated in the initial forging stage. This is because as the deformation temperature increases, the deformation stress gradually decreases. During the pressing process, the relatively low deformation stress leads to significant deformation of the ingot, with obvious outward extension at the edges.

[0116] Furthermore, this outward extension not only affects the final forging quality, but the unusable surface portion also leads to low material utilization. Moreover, as the heating temperature increases, greater heat loss occurs during forging, which also has a significant negative impact on deformation processing costs.

[0117] Comparative Example 1

[0118] The same GH4169 alloy consumable ingot as in Example 1 was used and heated to 1080°C at a heating rate of 30°C / min. The ends were simply forged in one pass using a standard anvil, meaning the anvil lacked a specially structured pressure head. This method cannot effectively control the defect distribution at the center of the ingot end, and to ensure final product quality, a large area of ​​the end still needs to be removed, resulting in low material utilization.

[0119] Comparative Example 2

[0120] After obtaining steel ingots of the same size as in Example 1 by vacuum induction melting, the heating rate was increased to 1080°C based on the conditions of Example 1, for example, to 40°C / min, 45°C / min, 50°C / min, etc., and a second forging was completed.

[0121] See Figure 13 The diagram shows a simulated structure of the ingot end obtained by secondary forging in Example 1.

[0122] See Figure 14 The diagram shows a simulated structure of the ingot end obtained by secondary forging in Comparative Example 2.

[0123] contrast Figure 13 and Figure 14It is known that excessively rapid heating will lead to significant cracks during forging. This is because when the heating rate is too fast, the surface temperature of the ingot rises rapidly, accompanied by structural expansion. However, the center of the ingot remains at a relatively low temperature, and the amount of structural expansion is relatively small. This uneven expansion and subsequent contraction generate enormous thermal stress within the ingot. When this thermal stress exceeds the strength limit of the ingot material at that temperature, cracks will form on its surface and even inside. These cracks are highly likely to propagate further during subsequent forging or use, severely impacting the final forging quality.

[0124] The method for improving the utilization rate of alloy consumable ingots, the forging apparatus, and their application in the preparation of GH4169 alloy provided by the embodiments of the present invention have at least one or a portion of the following advantages:

[0125] (1) By accurately identifying and defining the concentrated area of ​​end defects of the alloy consumable ingot, and using two-step forging to lock the defects inside the final cut-off clamp, the clean and qualified material around the end is successfully pressed into and retained in the usable ingot body, greatly improving the effective utilization rate of alloy material.

[0126] (2) The method of improving the utilization rate of alloy consumable ingots of the present invention can increase the effective utilization rate of a single GH4169 alloy consumable ingot by about 10%-15%, increase the weight of a single qualified smelting product, reduce the consumption of alloy materials, and improve economic benefits.

[0127] (3) Based on finite element simulation and the adjusted Niyama criterion, the distribution range of defects corresponding to the actual alloy consumable ingot is determined in advance, ensuring that the forging process design can completely keep the defect area inside the clamp, thereby ensuring the metallurgical quality and high purity of the main ingot material.

[0128] (4) By using two-step forging (primary forging and secondary forging) and matching the design of forging equipment, alloy inserts with spacing are used for pre-forming in the primary forging, which effectively solves the problem of edge material warping that may be caused by directly using a circular pressure head, provides a foundation for the smooth implementation of secondary forging, avoids secondary defects, and ensures the stability of the forming process and the controllability of material flow.

[0129] (5) The method of improving the utilization rate of alloy consumable ingots by the present invention, especially the two-step forging method, significantly reduces the excessive consumption of return material caused by directly cutting off the integral end. This not only reduces the cost of raw materials, but also simplifies the batching management of the smelting process and reduces the repeated consumption of energy, providing a feasible path for achieving green, sustainable and efficient production.

[0130] While some embodiments of the present general inventive concept have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for improving the utilization rate of alloy consumable ingots, characterized in that, The method includes: Provide alloy consumable ingots prepared by vacuum consumable remelting; The alloy consumable ingot is heated to a preset forging temperature at a preset heating rate; The end of the alloy consumable ingot is initially forged, and a basic clamp structure is formed by forging and rotation. The basic clamp handle structure is subjected to secondary forging, and the basic clamp handle structure is forged into a clamp handle through forging pressing; wherein After the initial forging and secondary forging, the defects in the central region of the end of the alloy consumable ingot remain in the clamp, and the pure material around the central region is pressed into its qualified area for recycling.

2. The method according to claim 1, characterized in that, The preset heating rate is 25-35℃ / min. The preset forging temperature is 1060-1100℃.

3. The method according to claim 2, characterized in that, Before the initial forging and the secondary forging, the defect distribution area at the end center of the alloy consumable ingot was determined by finite element simulation and Niyama criterion, respectively. The defects in the central region of the end of the alloy consumable ingot include at least one of shrinkage cavity, shrinkage porosity, slag entrapment, or inclusions. The threshold of the Niyama criterion is set such that the defect distribution area is located inside the clamp handle.

4. The method according to claim 3, characterized in that, After the initial forging and the secondary forging, the material utilization rate of each alloy consumable ingot used for vacuum consumable remelting is increased by 10%-15%.

5. The method according to any one of claims 1-4, characterized in that, The alloy consumable ingot is a GH4169 alloy consumable ingot; The GH4169 alloy consumable ingot has a diameter of 500-520mm and a length of 1700-1900mm. The diameter of the defect distribution area at the end center of the GH4169 alloy consumable ingot is less than or equal to 200 mm and the depth is less than or equal to 250 mm. The basic clamp handle structure obtained after the initial forging has a diameter of 250-350mm and a height of 40-60mm; The diameter of the pliers handle obtained through the secondary forging process is 150-250mm.

6. The method according to claim 5, characterized in that, The threshold for the Niyama criterion is set to be less than or equal to 20 × (K·sec). 0.5 / cm.

7. A forging apparatus for improving the utilization rate of alloy consumable ingots, said forging apparatus being used to forge alloy consumable ingots according to any one of claims 1-6, characterized in that, The forging apparatus includes: An upper anvil, which is disposed above the end of the alloy consumable ingot for forging the end of the alloy consumable ingot to obtain a clamp; The lower anvil section has a metal rotating disk fixedly mounted above it, and the other end of the alloy consumable ingot is fixedly placed on the metal rotating disk; wherein... A first pressure head for initial forging and a second pressure head for secondary forging are movably connected to the end face of the upper anvil near the alloy consumable ingot.

8. The forging apparatus according to claim 7, characterized in that, The first pressure head includes two alloy inserts arranged in parallel on the surface of the upper anvil; The alloy inserts are spaced at a preset distance of 250-350 mm. The width of the forged surface of each alloy insert is 80-120 mm.

9. The forging apparatus according to claim 7, characterized in that, The second pressure head is a ring structure, and the height of the ring is 150-250mm; The center of the annular structure has a truncated conical cavity that penetrates the annular structure; The truncated conical cavity includes an upper cross section near the upper anvil and a lower cross section away from the upper anvil; wherein The diameter of the upper section is 150-250mm. The diameter of the lower section is 250-350 mm. The lower section has rounded edges with a radius of 80-120 mm.

10. The application of a method for improving the utilization rate of alloy consumable ingots in the preparation of GH4169 alloy, characterized in that, GH4169 alloy consumable ingots are obtained by forging using the method of any one of claims 1-6 or by forging using the forging apparatus of any one of claims 7-9. The central region of the end of the GH4169 alloy consumable ingot has a clamp, and the defects of the GH4169 alloy consumable ingot are concentrated in the clamp. The pure material around the central region is pressed into its qualified area for subsequent smelting and processing.

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