K465 high-temperature alloy and preparation method thereof

Abstract

The invention provides a K465 high-temperature alloy and a preparation method thereof, and relates to the technical field of precision casting, and the preparation method comprises the following steps: smelting: performing smelting treatment on raw materials of the K465 high-temperature alloy, and performing ultrasonic oscillation treatment at the same time to obtain alloy liquid after the raw materials are molten; wherein the ultrasonic oscillation treatment enables WC in the K465 high-temperature alloy to be dispersed and distributed in alloy liquid, and WC particles are mutually rubbed and collided; and pouring is conducted, specifically, the alloy liquid is subjected to pouring treatment, and the K465 high-temperature alloy is obtained. According to the invention, ultrasonic oscillation treatment is carried out during smelting, and a driving force formed in a melt promotes carbide to move, so that WC is ensured to be uniformly dispersed and distributed in the melt (alloy liquid); meanwhile, mutual friction and collision of WC particles are promoted, coarse WC with sharp edge angles is converted into fine spherical phases or nearly spherical phases, and the feeding space between dendrites can be reduced, namely microporosity is reduced, so that the density of the K465 high-temperature alloy is improved, and the properties such as strength and plasticity of the K465 high-temperature alloy are ensured.

Description

Technical Field

[0001] This invention belongs to the field of precision casting technology, specifically relating to a K465 high-temperature alloy and its preparation method. Background Technology

[0002] Because K465 high-temperature alloy has a high degree of alloying, its solidus and liquidus temperature ranges are typically wide, generally ranging from tens to hundreds of degrees Celsius. The wider the solidus-liquidity temperature range, the greater the tendency for the alloy to form micro-porosity after casting. Under typical test bar casting temperatures, differences in the test bar's assembly structure, preheating conditions, preheating temperature, and casting temperature can lead to significant variations in the alloy's mechanical property test results, making the cast test bar's mechanical property test results unable to accurately reflect the alloy's mechanical properties. The main reason for this problem is the presence of micro-porosity defects in the cast test bars. During performance testing, the test bar preferentially fractures at the micro-porosity sites, resulting in lower mechanical properties and requiring retesting.

[0003] Currently, the structure of cast high-temperature alloy test bars is generally dumbbell-shaped. The specifications for dumbbell-shaped test bars typically require a tensile section diameter of approximately 7mm. The upper pull head 4 and lower pull head 7 of the dumbbell-shaped test bar form a transition angle α with the tensile section 5 (e.g., ...). Figure 1 and 4 As shown in the diagram, a tangent line is drawn from the center point of the tensile section as the origin, tangent to the transition angle α. The angle between this tangent line and the central axis of the test bar is defined as the feeding channel angle β, which is generally around 16°. Currently, high-temperature alloy test bars are prepared by alloy casting, where the test bar shell is fixed between an upper and lower disk, and casting is performed through a pouring cup. However, current designs for the feeding channel of the test bar are too long, the upper disk of the gating system is too thin, and the test bar surface is not easy to dissipate heat. These issues result in insufficient feeding of the high-temperature alloy liquid during the casting process, which is not conducive to timely feeding of the molten liquid in the tensile section of the test bar. Consequently, microporous structures are formed inside the test bar, which cannot accurately reflect the mechanical properties of the alloy.

[0004] Existing technologies improve the casting temperature and heat dissipation of test bars by increasing the feeding channels of the high-temperature alloy molten metal during casting, reducing the rapid solidification of the test bar surface, and enhancing the feeding effect of the gating system. This ensures unobstructed feeding channels at the test bar testing area, completely introducing micro-porosity defects in the middle of the test bar into the gating system, and using a filtration system to reduce micro-porosity caused by excessive inclusions in the alloy molten metal. However, compared to other high-temperature alloys, K465 high-temperature alloy contains more WC, which easily leads to uneven WC distribution during melting and casting, resulting in micro-porosity in the K465 high-temperature alloy and affecting its strength, plasticity, and other properties. Summary of the Invention

[0005] Therefore, the present invention provides a K465 high-temperature alloy and its preparation method, which can solve the technical problem of uneven WC distribution in the K465 high-temperature alloy leading to microporous structure in the prior art.

[0006] To address the above problems, this invention provides a method for preparing K465 high-temperature alloy, comprising the following steps:

[0007] Melting: The raw materials of K465 high-temperature alloy are melted and ultrasonically vibrated simultaneously. The melted raw materials are used to obtain a liquid alloy. The ultrasonic vibration process causes WC in K465 high-temperature alloy to be dispersed in the liquid alloy and causes the WC particles to rub and collide with each other.

[0008] Casting: The alloy liquid is cast to obtain K465 high-temperature alloy.

[0009] Furthermore, in the smelting step, the smelting process includes:

[0010] The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting.

[0011] The ultrasonic oscillation treatment is performed by an ultrasonic ceramic probe installed inside the crucible.

[0012] Preferably, the parameters for ultrasonic vibration processing are set as follows: vibration frequency of 20-70Hz, amplitude of 20-70%, and ultrasonic power consumption of 1500-2000W; wherein, the set time for pausing after vibration is 5-30s, and more preferably, the set time is 1-3 seconds.

[0013] Furthermore, in the pouring step, the pouring process includes:

[0014] The mold shell and casting device are placed in a vacuum melting furnace, and then the molten alloy is injected into the mold shell through the casting device; wherein the mold shell is a dumbbell-shaped mold shell;

[0015] Preferably, the diameter of the stretching section of the dumbbell-shaped mold shell is 3-5 mm, and the length of the stretching section is 25-30 mm; the angle of the feeding channel of the dumbbell-shaped mold shell is 25°-30°.

[0016] Preferably, the alloy liquid is injected into the mold shell in multiple stages; more preferably, after injecting the alloy liquid to a height of 1 to 1.5 mm, a second pour is performed after an interval of 2 to 3 seconds.

[0017] Furthermore, the casting device includes an upper disc, a lower disc, and a pouring cup; the upper disc and the lower disc are respectively installed at the top and bottom of the mold shell, and the pouring cup is installed at the top of the upper disc;

[0018] Preferably, the thickness of the upper disk is 20-30 mm;

[0019] Preferably, the diameter of the pouring cup gradually decreases from the top to the bottom, wherein the diameter of the top is 18-22 mm and the diameter of the bottom is 8-12 mm.

[0020] Furthermore, before placing the mold shell in the vacuum melting furnace, the process includes preheating the mold shell at 950℃~1100℃ and then holding it at that temperature for 3h~4h.

[0021] Furthermore, before injecting the molten alloy into the mold shell, the process includes heating the molten alloy to 100°C–150°C above the molten alloy temperature and refining it for 3–5 minutes.

[0022] Furthermore, an oil bath treatment device is provided on the outer side of the upper disc, the oil bath treatment device being an oil bath tank, the oil bath tank being installed on the outer side of the upper disc.

[0023] Furthermore, by mass percentage, the raw materials of the K465 high-temperature alloy include: C: 0.05–0.08 wt.%, S: 0.004–0.008 wt.%, P: 0.08–0.12 wt.%, Si: 0.2–0.5 wt.%, Mn: 0.2–0.5 wt.%, Cr: 15–20 wt.%, Ti: 2.2–2.5 wt.%, Mo: 2.8–3.2 wt.%, Al: 1–1.5 wt.%, Fe: 3.3–3.8 wt.%, W: 5.0–5.5 wt.%, with the balance being Ni.

[0024] On the other hand, the present invention provides a K465 high-temperature alloy, the K465 high-temperature alloy comprising a matrix phase and a WC phase, the WC phase being dispersedly distributed in the matrix phase, the grain size of the matrix phase being 1.0-1.5 μm, the volume fraction of the WC phase being 10-12%, and the size of the WC phase being approximately 1.5-3 μm.

[0025] Furthermore, the properties of the K465 high-temperature alloy are as follows: tensile strength σ b Greater than 900MPa, elongation after fracture A greater than 6%, reduction of area Z greater than 10%, and creep life exceeding 70h when impact strength is 296MPa at 975℃.

[0026] Preferably, the K465 high-temperature alloy is obtained by any of the above-described methods for preparing K465 high-temperature alloy.

[0027] The K465 high-temperature alloy and its preparation method provided by this invention have the following beneficial effects:

[0028] 1. This invention utilizes ultrasonic oscillation during the smelting of K465 high-temperature alloy raw materials. This process helps to refine and uniformly distribute WC in the K465 high-temperature alloy. On one hand, ultrasonic oscillation during smelting causes the local pressure in the molten metal to drop below the saturated vapor pressure, resulting in the formation and bursting of bubbles, i.e., cavitation. The driving force of cavitation in the molten metal promotes the movement of carbides, thereby ensuring that WC is uniformly dispersed in the melt (alloy liquid). On the other hand, the driving force of cavitation causes WC particles to rub and collide with each other, transforming coarse WC with sharp edges into fine spherical or near-spherical phases. The uniform distribution of fine, dispersed WC phases between dendrites reduces the interdendritic feeding space, i.e., reduces microporousness, thereby increasing the density of the K465 high-temperature alloy and ensuring its strength and plasticity.

[0029] 2. Furthermore, after ultrasonic vibration treatment, during the solidification process of the alloy liquid, the gas that fails to escape is prone to remain inside the metal and form pore defects. By pouring the alloy liquid in multiple stages, it is beneficial to remove the gas formed by ultrasonic vibration treatment, solve the problem of high porosity caused by ultrasonic melting, and thus ensure the density and strength of the alloy.

[0030] 3. Furthermore, the present invention sets the thickness of the upper disc to 20-30 mm and gradually reduces the diameter of the pouring cup from 20 mm to 10 mm to improve the feeding effect on K465 high-temperature alloy; specifically, increasing the thickness of the upper disc in the pouring device can ensure that the high-temperature alloy liquid has a large heat storage capacity in the upper disc, so as to achieve sufficient feeding of the middle part of the test bar after pouring; adjusting the diameter of the pouring cup is beneficial to improving the driving force of the alloy liquid flow, ensuring better fluidity of the alloy liquid, and further reducing the micro porosity defects of the alloy.

[0031] 4. On the other hand, the present invention provides a K465 high-temperature alloy, which is prepared by the above method. The K465 high-temperature alloy of the present invention includes a matrix phase and a WC phase. The WC phase is dispersed in the matrix phase, the grain size of the matrix phase is 1.0-1.5 μm, the volume fraction of the WC phase is 10-12%, and the WC phase size is about 1.5-3 μm. Its properties are as follows: room temperature tensile strength σ b It has a strength greater than 900 MPa, an elongation at break (A) greater than 6%, a reduction of area (Z) greater than 10%, and a creep rupture life exceeding 60 hours at a stress of 230 MPa at 975℃. Fine WC phases are dispersed throughout the matrix phase, which helps to compensate for shrinkage cavities during the solidification of the molten alloy, thereby increasing the density of the K465 high-temperature alloy and ensuring its strength and plasticity. Attached Figure Description

[0032] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the dumbbell-shaped high-temperature alloy test bar of the present invention;

[0034] Figure 2 This is a metallographic diagram of the high-temperature alloy test bar obtained in Example 1 of the present invention;

[0035] Figure 3 The image shows the metallographic structure of a high-temperature alloy test bar obtained using conventional methods.

[0036] Figure 4 This is a schematic diagram of the casting device of the present invention;

[0037] Figure 5 This is a schematic diagram of the oil bath cooling on the outer surface of the dumbbell-shaped high-temperature alloy test bar shell according to the present invention;

[0038] Figure 6 Comparative diagrams show the morphology and microstructure of carbides obtained in Comparative Example 4 and Example 1.

[0039] Figure 7 This is a comparison chart of WC and grain size in Comparative Example 4 and Example 1;

[0040] Figure 8 This is a metallographic diagram of the high-temperature alloy test bar obtained in Comparative Example 5 of the present invention;

[0041] Figure 9 This is a metallographic diagram of the high-temperature alloy test bar obtained in Comparative Example 6 of the present invention.

[0042] Figure 10 This is a metallographic diagram of the high-temperature alloy test bar obtained in Comparative Example 8 of the present invention;

[0043] The attached diagram is labeled as follows: a-transition angle, b-feeding channel angle, 1-sprue cup, 2-oil bath treatment equipment, 3-upper disc, 4-upper pull head, 5-stretching section, 6-middle injection pipe, 7-lower pull head, 8-lower disc. Detailed Implementation

[0044] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0045] This invention provides a method for preparing K465 high-temperature alloy, comprising the following steps:

[0046] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting and ultrasonic vibration treatment. After the raw material is melted, the alloy liquid is obtained. The ultrasonic vibration treatment causes the WC in K465 high-temperature alloy to be dispersed in the alloy liquid.

[0047] Due to the high melting temperature of high-temperature alloys, ultrasonic vibration treatment is achieved by using an ultrasonic ceramic probe installed inside the crucible; the vibration frequency is 20-70Hz, the amplitude is 20-70%, the pause time is 1-3s, and the ultrasonic power consumption is 1500-2000W.

[0048] Casting: Preheat the mold shell and hold it at that temperature for 3-4 hours; heat the molten alloy to 100-150°C above the liquidus temperature and refine it for 3-5 minutes; then place the mold shell and casting device in a vacuum melting furnace and pour the molten alloy into the mold shell through the casting device; after the molten alloy solidifies, remove the mold shell to obtain K465 high-temperature alloy (test bar);

[0049] The mold shell is dumbbell-shaped; the preheating temperature of the mold shell is gradient-distributed; the stretching section is 950℃, the feeding channel is 1000℃, and the pouring cup is 1050℃; preferably, the diameter of the stretching section of the dumbbell-shaped mold shell is 3-5mm, and the length of the stretching section is 25-30mm; the angle of the feeding channel of the dumbbell-shaped mold shell is 25°-30°; preferably, the alloy liquid is injected into the mold shell in multiple stages; more preferably, after injecting alloy liquid to a height of 1-1.5mm, a second pour is performed after an interval of 2-3 seconds until the alloy liquid fills the mold shell;

[0050] The liquidus temperature of an alloy refers to the temperature at which the alloy completely melts. For K465 high-temperature alloy, its liquidus temperature is 1250℃. Refining at a temperature 100℃ to 150℃ above the alloy's liquidus temperature helps remove inclusions and gases from the alloy, thereby inhibiting grain growth during cooling and achieving grain refinement. Refined grains have higher strength and hardness. High-temperature refining also helps remove non-metallic inclusions, harmful elements such as sulfur and phosphorus from the solution, improving the alloy's purity and enhancing its properties.

[0051] The slag on the surface of the high-temperature alloy liquid is made to adhere to the crucible wall through refining, and the slag is removed by gas blowing.

[0052] Based on the above method, by simultaneously performing ultrasonic vibration treatment on the raw materials of K465 superalloy during smelting, it is helpful to refine and uniformly distribute WC in K465 superalloy. On the one hand, ultrasonic vibration treatment during smelting causes the local pressure in the molten metal to drop below the saturated vapor pressure, resulting in the formation and bursting of bubbles in the molten metal, i.e., the formation of cavitation effect. The driving force of the cavitation effect in the molten metal promotes the movement of carbides in the molten metal, thereby ensuring that WC is uniformly dispersed in the melt (alloy liquid). On the other hand, the driving force of the cavitation effect causes WC particles to rub and collide with each other, transforming the coarse WC with sharp edges into fine spherical or near-spherical phases. The uniform distribution of fine dispersed WC phases between dendrites can reduce the interdendritic feeding space, i.e., reduce micro-porosity, thereby improving the density of K465 superalloy and ensuring its strength and plasticity properties.

[0053] Ultrasonic oscillation treatment may cause gas that fails to escape during metal solidification to remain inside the metal, forming porosity defects. By pouring in multiple stages, the gas formed by ultrasonic oscillation treatment can be expelled, solving the problem of high porosity caused by ultrasonic melting, thus ensuring the performance of K465 high-temperature alloy. Therefore, the synergistic effect of ultrasonic waves and multiple pouring can synergistically improve the density of K465 high-temperature alloy, ensuring its strength and plasticity.

[0054] In some embodiments, the casting device includes an upper disc 3, a lower disc 8, and a pouring cup 1; the upper disc 3 and the lower disc 8 are respectively installed on the top and bottom of the mold shell, and the pouring cup 1 is installed on the top of the upper disc 3.

[0055] Preferably, the thickness of the upper disc 3 is 20-30 mm;

[0056] Preferably, the diameter of the pouring cup gradually decreases from the top to the bottom, wherein the diameter of the top is 18-22 mm and the diameter of the bottom is 8-12 mm.

[0057] The thickness of the upper disc is set to 20-30 mm, and the diameter of the pouring cup is gradually reduced from 20 mm to 10 mm to improve the feeding effect on K465 high-temperature alloy. Specifically, increasing the thickness of the upper disc in the pouring device can ensure that the high-temperature alloy liquid has a large heat storage capacity in the upper disc, so as to achieve sufficient feeding of the middle part of the test bar after pouring. Adjusting the diameter of the pouring cup is beneficial to increasing the driving force of the alloy liquid flow, ensuring better fluidity of the alloy liquid, and further reducing the micro porosity defects of the alloy.

[0058] In some embodiments, an oil bath treatment device 2 is provided on the outer side of the upper disk. The oil bath treatment device 2 is an oil bath tank installed on the outer side of the upper disk. The oil bath treatment can reduce the temperature drop of the high-temperature alloy liquid in the casting equipment and realize the sequential solidification of the local high-temperature alloy liquid during casting. Specifically, the solidification sequence of the high-temperature alloy liquid in the oil bath is as follows: after the test bar is cast, the high-temperature alloy liquid on the upper disk remains in a liquid state for a long time. The thinnest part in the middle of the test bar solidifies first, followed by the upper pull head 4 part of the test bar, and finally the upper disk part of the test bar. The high-temperature alloy liquid forms a smooth feeding channel in the shell, effectively reducing the micro-porosity defects in the middle of the test bar.

[0059] The oil bath is fixed to the outer circumferential side of the upper disc (not the bottom or top), forming a ring-shaped heating sleeve structure. The heat transfer path is as follows: hot oil passes through the metal tank wall → directly contacts the outer wall of the upper disc → heat is conducted to the interior of the upper disc → only the alloy melt flowing through the sprue cup is heated. Traditional oil baths immerse the workpiece in oil for heating, resulting in overall heating with high temperature uniformity, but also making the workpiece susceptible to contamination. This invention, however, uses an oil bath attached to the outer wall of the upper disc for indirect heat conduction, providing localized, directional heating with a controllable temperature gradient, ensuring zero contact with the melt and eliminating the risk of contamination. Therefore, this application achieves the following effects through a triple design of "external oil bath + upper disc heat conduction + structural insulation": precise localized heating: high temperature only in the sprue cup area, ensuring alloy fluidity; zero contamination: the melt does not contact the oil; heat-affected zone isolation: the mold shell body maintains low-temperature solidification conditions.

[0060] Furthermore, by mass percentage, the raw materials of K465 high-temperature alloy include: C: 0.05–0.08 wt.%, S: 0.004–0.008 wt.%, P: 0.08–0.12 wt.%, Si: 0.2–0.5 wt.%, Mn: 0.2–0.5 wt.%, Cr: 15–20 wt.%, Ti: 2.2–2.5 wt.%, Mo: 2.8–3.2 wt.%, Al: 1–1.5 wt.%, Fe: 3.3–3.8 wt.%, W: 5.0–5.5 wt.%, with the balance being Ni. The alloy contains high levels of sparingly soluble elements such as W and Mo (5-5.5% W, 2.8-3.2% Mo), which easily form segregated clusters or coarse primary carbides (such as M6C). The cavitation effect generated by the high-frequency mechanical oscillation (20-70Hz) of ultrasound can break up the clusters in the melt. At the same time, the shear force controlled by the amplitude (20-70%) can refine the size of the primary phase (primary carbides), preventing the continuous distribution of brittle phases at grain boundaries, thereby improving the toughness of the alloy. On the other hand, Al and Ti are the main elements for forming the γ' phase, and the γ' phase (Ni3(Al,Ti)) is the main strengthening phase, but its size is affected by the solidification cooling rate. Intermittent oscillation treatment promotes short-range diffusion of solute atoms (Al / Ti) through periodic thermal disturbance, forming more uniform nanoscale γ' phase pre-precipitated clusters. This provides uniform nucleation sites for subsequent aging. Furthermore, intermittent ultrasonic treatment allows the melt to relax local compositional fluctuations during the pause in sound waves, avoiding excessive stirring of solute atoms caused by continuous ultrasonication. This "oscillation-relaxation" cycle is more conducive to forming a gradient-distributed γ / γ' coherent interface, increasing the resistance to dislocation slip at the interface and thus improving the alloy's strength. However, excessive stirring, which creates strong convection from continuous ultrasonication, disrupts local compositional fluctuations, reducing γ' phase nucleation sites and decreasing the volume fraction and size uniformity of the precipitated phase. Additionally, excessive stirring accelerates long-range diffusion of solute atoms, causing pre-precipitated clusters to coalesce prematurely in the high-temperature melt, forming coarse γ' phases and weakening the aging strengthening effect. Moreover, continuous shear force may disrupt the already formed γ / γ' coherent interface, introducing interface defects and reducing dislocation slip resistance.

[0061] During ultrasonic oscillation treatment, the vibration lasts 5–30 seconds followed by a 1–3 second pause. This aims to ensure melt homogenization and grain refinement, while simultaneously protecting the ultrasonic probe from overheating damage. This employs an "oscillation-relaxation" method. The cavitation effect of the ultrasound refines primary carbides and eliminates continuous grain boundary distribution; the pause period allows solute relaxation, creating a compositional gradient. After aging, a high volume fraction (≥60%) and low mismatch (≤0.5%) nano-γ' phase (size deviation ≤15%) are obtained, strengthening the γ / γ' coherent interface. If continuous ultrasound exceeds 30 seconds, excessive stirring will lead to a reduction in γ' nucleation sites, coarsening of pre-precipitated clusters (>200 nm), and an increase in interface defects, resulting in a strength decrease of over 20%. Simultaneous control of the casting temperature is necessary to lock in the nanostructure.

[0062] Gradient temperature control is employed during the casting process, with different preheating temperatures set for different parts of the mold shell (such as the stretching section, feeding channel, and pouring cup): 950℃ for the stretching section, 1000℃ for the feeding channel, and 1050℃ for the pouring cup, creating a temperature gradient. The synergistic effect lies in the fact that the WC particles in the melt, after ultrasonic treatment, are refined and evenly distributed, and gradient temperature casting further optimizes the feeding path. The melt in the high-temperature region (pouring cup) remains liquid for a longer period, and the microflow generated by ultrasonic cavitation promotes interdendritic melt filling, reducing microporous porosity. The low-temperature region (stretching section) solidifies preferentially; the grain refinement effect of ultrasound (grain size 1.0–1.5 μm) synergizes with gradient solidification to avoid the formation of coarse columnar crystals, improving mechanical properties.

[0063] On the other hand, the present invention provides a K465 high-temperature alloy, which includes a matrix phase and a WC phase. The WC phase is dispersed in the matrix phase, the grain size of the matrix phase is 1.0-1.5 μm, the volume fraction of the WC phase is 10-12%, and the size of the WC phase is about 1.5-3 μm.

[0064] Furthermore, the properties of K465 high-temperature alloy are as follows: room temperature tensile strength σ b The stress is greater than 900 MPa, the elongation after fracture (A) is greater than 6%, the reduction of area (Z) is greater than 10%, and the creep rupture life at 975℃ with a stress of 230 MPa exceeds 60 hours.

[0065] Preferably, the K465 high-temperature alloy is obtained by any of the above-mentioned methods for preparing K465 high-temperature alloy.

[0066] The present invention will be further described below with reference to specific embodiments and comparative examples.

[0067] Example 1

[0068] This embodiment provides a method for preparing K465 high-temperature alloy, wherein the mold shell used is a dumbbell-shaped mold shell. The diameter of the stretching section of the dumbbell-shaped high-temperature alloy test rod wax mold is 4 mm, and the length of the stretching section is 26 mm, so that the angle of the feeding channel is 22°, thus obtaining a dumbbell-shaped mold shell. Figure 1 As shown;

[0069] The mold shell is installed between the upper and lower discs, wherein the upper disc is 25mm thick. A sprue cup is installed above the upper disc, with its diameter gradually decreasing from top to bottom, specifically 20mm at the top and 10mm at the bottom. An oil bath treatment device is installed on the outer surface of the mold shell. Figure 4 and 5 As shown;

[0070] Specifically, the following steps are included:

[0071] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting treatment, and ultrasonic vibration treatment is performed at the same time. After the raw material is melted, an alloy liquid is obtained. Among them, the ultrasonic vibration treatment causes WC in K465 high-temperature alloy to be dispersed in the alloy liquid. During melting, the temperature of the high-temperature alloy liquid is adjusted to 200°C above the alloy liquidus temperature and refined for 2 minutes, and then the power is turned off to cool down.

[0072] The ultrasonic oscillation treatment employs an ultrasonic ceramic probe installed inside the crucible; the vibration frequency is 50Hz, the amplitude is 50%, the pause time is 2s, and the ultrasonic power consumption is 1700W.

[0073] Casting: Preheat the mold shell at 950℃ and then hold it at that temperature for 3.5 hours; heat the alloy liquid to 120℃ above the alloy liquidus temperature and refine it for 3 to 5 minutes; adhere the slag on the surface of the high-temperature alloy liquid to the crucible wall and remove the slag by blowing it off with gas; then pour the high-temperature alloy liquid into the mold shell through the pouring cup.

[0074] The mold and casting device are then placed in a vacuum melting furnace, and the alloy liquid is poured into the mold through the casting device. The casting time is 2 seconds. After the alloy liquid solidifies, the mold is removed to obtain K465 high-temperature alloy (test bar). When pouring the alloy liquid into the mold, after pouring the alloy liquid to a height of 1 mm, a second pour is performed after an interval of 2 seconds.

[0075] The metallographic structure of the K465 high-temperature alloy (test bar) obtained in this embodiment is shown in the figure below. Figure 2 The image shows the metallographic structure of a high-temperature alloy test bar prepared using conventional methods. Figure 3 In comparison, the microporous structure was significantly reduced. Subsequent mechanical property tests were conducted, and the results are shown in Table 1.

[0076] Example 2

[0077] This embodiment provides a method for preparing K465 high-temperature alloy, wherein the mold shell used is a dumbbell-shaped mold shell, the diameter of the stretching section of the dumbbell-shaped high-temperature alloy test rod wax mold is 4mm, the length of the stretching section is 26mm, and the angle of the compensation channel is 22° to obtain a dumbbell-shaped mold shell.

[0078] The mold shell is installed between the upper and lower discs, wherein the thickness of the upper disc is 25mm, the sprue cup is installed above the upper disc, and the diameter of the sprue cup gradually decreases from the top to the bottom, wherein the diameter of the top is 20mm and the diameter of the bottom is 10mm. An oil bath treatment device is installed on the outer surface of the mold shell.

[0079] Specifically, the following steps are included:

[0080] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting treatment, and ultrasonic vibration treatment is performed at the same time. After the raw material is melted, an alloy liquid is obtained. Among them, the ultrasonic vibration treatment causes WC in K465 high-temperature alloy to be dispersed in the alloy liquid. During melting, the temperature of the high-temperature alloy liquid is adjusted to 200°C above the alloy liquidus temperature and refined for 2 minutes, and then the power is turned off to cool down.

[0081] The ultrasonic vibration treatment employs an ultrasonic ceramic probe installed inside the crucible; the vibration frequency is 50Hz, the amplitude is 60%, the pause time is 1.5s, and the ultrasonic power consumption is 1750W.

[0082] Casting: Preheat the mold shell at 950℃ and then hold it at that temperature for 3.5 hours; heat the alloy liquid to 120℃ above the alloy liquidus temperature and refine it for 3 to 5 minutes; adhere the slag on the surface of the high-temperature alloy liquid to the crucible wall and remove the slag by blowing it off with gas; then pour the high-temperature alloy liquid into the mold shell through the pouring cup.

[0083] The mold and casting device are then placed in a vacuum melting furnace, and the alloy liquid is poured into the mold through the casting device. The casting time is 2 seconds. After the alloy liquid solidifies, the mold is removed to obtain K465 high-temperature alloy (test bar). When pouring the alloy liquid into the mold, after pouring the alloy liquid to a height of 1.5 mm, a second pour is performed after an interval of 3 seconds.

[0084] The metallographic structure of the K465 high-temperature alloy (test bar) obtained in this embodiment is shown in the figure below. Figure 6 As shown, subsequent mechanical property tests were conducted, and the results are shown in Table 1. The results indicate that high-performance K465 alloys with fine grain structures can be prepared within the electromagnetic vibration parameter range specified in this invention.

[0085] Comparative Example 1

[0086] This comparative example provides a method for preparing K465 high-temperature alloy, wherein the mold shell used is a dumbbell-shaped mold shell, the diameter of the stretching section of the dumbbell-shaped high-temperature alloy test rod wax mold is 4mm, the length of the stretching section is 26mm, and the angle of the feeding channel is 15° to obtain a dumbbell-shaped mold shell.

[0087] The mold shell is installed between the upper and lower discs, wherein the thickness of the upper disc is 25mm, the sprue cup is installed above the upper disc, and the diameter of the sprue cup gradually decreases from the top to the bottom, wherein the diameter of the top is 20mm and the diameter of the bottom is 10mm. An oil bath treatment device is installed on the outer surface of the mold shell.

[0088] Specifically, the following steps are included:

[0089] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting treatment, and ultrasonic vibration treatment is performed at the same time. After the raw material is melted, an alloy liquid is obtained. Among them, the ultrasonic vibration treatment causes WC in K465 high-temperature alloy to be dispersed in the alloy liquid. During melting, the temperature of the high-temperature alloy liquid is adjusted to 200°C above the alloy liquidus temperature and refined for 2 minutes, and then the power is turned off to cool down.

[0090] The ultrasonic oscillation treatment employs an ultrasonic ceramic probe installed inside the crucible; the vibration frequency is 50Hz, the amplitude is 50%, the pause time is 2s, and the ultrasonic power consumption is 1700W.

[0091] Casting: Preheat the mold shell at 780℃ and then hold it for 3.5 hours; heat the alloy liquid to 60℃ above the alloy liquidus temperature and refine it for 3 to 5 minutes; adhere the slag on the surface of the high-temperature alloy liquid to the crucible wall and remove the slag by gas blowing; pour the high-temperature alloy liquid into the mold shell through the pouring cup.

[0092] The mold and casting device are then placed in a vacuum melting furnace, and the alloy liquid is poured into the mold through the casting device. The casting time is 2 seconds. After the alloy liquid solidifies, the mold is removed to obtain K465 high-temperature alloy (test bar). When pouring the alloy liquid into the mold, after pouring the alloy liquid to a height of 1 mm, a second pour is performed after an interval of 2 seconds.

[0093] The mechanical properties of the K465 high-temperature alloy (test bar) obtained in this comparative example were tested, and the performance results are shown in Table 1. It can be seen that the mechanical properties of the K465 high-temperature alloy in this comparative example are lower than those in Example 1. This is because the angle of the feeding channel in this comparative example is small, which is not conducive to the fluidity of the alloy melt, resulting in the formation of micro-porosity during its melting process, thus affecting its performance.

[0094] Comparative Example 2

[0095] This comparative example provides a method for preparing K465 high-temperature alloy, wherein the mold shell used is a dumbbell-shaped mold shell, the diameter of the stretching section of the dumbbell-shaped high-temperature alloy test rod wax mold is 4mm, the length of the stretching section is 26mm, and the angle of the compensation channel is 22° to obtain a dumbbell-shaped mold shell.

[0096] The mold shell is installed between the upper and lower discs, wherein the thickness of the upper disc is 10mm, the pouring cup is installed above the upper disc, and a foam ceramic pouring cup is placed at the bottom of the pouring cup, which is reduced from 20mm to 10mm and has a height of 9cm. An oil bath treatment device is set on the outer surface of the mold shell.

[0097] Specifically, the following steps are included:

[0098] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting treatment, and ultrasonic vibration treatment is performed at the same time. After the raw material is melted, an alloy liquid is obtained. Among them, the ultrasonic vibration treatment causes WC in K465 high-temperature alloy to be dispersed in the alloy liquid. During melting, the temperature of the high-temperature alloy liquid is adjusted to 200°C above the alloy liquidus temperature and refined for 2 minutes, and then the power is turned off to cool down.

[0099] The ultrasonic oscillation treatment employs an ultrasonic ceramic probe installed inside the crucible; the vibration frequency is 50Hz, the amplitude is 50%, the pause time is 2s, and the ultrasonic power consumption is 1700W.

[0100] Casting: Preheat the mold shell at 780℃ and then hold it for 3.5 hours; heat the alloy liquid to 60℃ above the alloy liquidus temperature and refine it for 3 to 5 minutes; adhere the slag on the surface of the high-temperature alloy liquid to the crucible wall and remove the slag by gas blowing; pour the high-temperature alloy liquid into the mold shell through the pouring cup.

[0101] The mold and casting device are then placed in a vacuum melting furnace, and the alloy liquid is poured into the mold through the casting device. The casting time is 2 seconds. After the alloy liquid solidifies, the mold is removed to obtain K465 high-temperature alloy (test bar). When pouring the alloy liquid into the mold, after pouring the alloy liquid to a height of 1 mm, a second pour is performed after an interval of 2 seconds.

[0102] The mechanical properties of the K465 high-temperature alloy (test bar) obtained in this comparative example were tested, and the performance results are shown in Table 1. It can be seen that the mechanical properties of the K465 high-temperature alloy in this comparative example are lower than those in Example 1. This is because the thickness of the upper disk in this comparative example is small, which is not conducive to sufficient heat storage of the alloy melt, resulting in insufficient driving force for the flow of the alloy melt, which cannot fully fill the space of the melt pool between dendrites, and aggravates the formation of micro-porosity during its melting process, thereby affecting its performance.

[0103] Comparative Example 3

[0104] This comparative example provides a method for preparing K465 high-temperature alloy, wherein the mold shell used is a dumbbell-shaped mold shell, the diameter of the stretching section of the dumbbell-shaped high-temperature alloy test rod wax mold is 4mm, the length of the stretching section is 26mm, and the angle of the compensation channel is 22° to obtain a dumbbell-shaped mold shell.

[0105] The mold shell is installed between the upper and lower discs, wherein the thickness of the upper disc is 25mm, and the sprue cup is installed above the upper disc. The diameter of the sprue cup gradually decreases from the top to the bottom, wherein the diameter of the top is 20mm and the diameter of the bottom is 10mm.

[0106] Specifically, the following steps are included:

[0107] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting treatment, and ultrasonic vibration treatment is performed at the same time. After the raw material is melted, an alloy liquid is obtained. Among them, the ultrasonic vibration treatment causes WC in K465 high-temperature alloy to be dispersed in the alloy liquid. During melting, the temperature of the high-temperature alloy liquid is adjusted to 200°C above the alloy liquidus temperature and refined for 2 minutes, and then the power is turned off to cool down.

[0108] The ultrasonic oscillation treatment employs an ultrasonic ceramic probe installed inside the crucible; the vibration frequency is 50Hz, the amplitude is 50%, the pause time is 2s, and the ultrasonic power consumption is 1700W.

[0109] Casting: Preheat the mold shell at 780℃ and then hold it for 3.5 hours; heat the alloy liquid to 60℃ above the alloy liquidus temperature and refine it for 3 to 5 minutes; adhere the slag on the surface of the high-temperature alloy liquid to the crucible wall and remove the slag by gas blowing; pour the high-temperature alloy liquid into the mold shell through the pouring cup.

[0110] The mold and casting device are then placed in a vacuum melting furnace, and the alloy liquid is poured into the mold through the casting device. The casting time is 2 seconds. After the alloy liquid solidifies, the mold is removed to obtain K465 high-temperature alloy (test bar). When pouring the alloy liquid into the mold, after pouring the alloy liquid to a height of 1 mm, a second pour is performed after an interval of 2 seconds.

[0111] The mechanical properties of the K465 high-temperature alloy (test bar) obtained in this comparative example were tested, and the performance results are shown in Table 1. It can be seen that the mechanical properties of the K465 high-temperature alloy in this comparative example are lower than those in Example 1. This is because oil bath treatment was not used in this comparative example, so no temperature gradient was formed in the component during solidification. Therefore, the middle part, the upper pull head and the upper disk part of the test bar solidified simultaneously, resulting in insufficient solidification and feeding driving force in the middle fine part of the test bar. That is, the order of priority solidification of components was not controlled when the alloy solution cooled, which is not conducive to sufficient feeding of the alloy, thus affecting its performance.

[0112] Comparative Example 4

[0113] This comparative example provides a method for preparing K465 high-temperature alloy, wherein the mold shell used is a dumbbell-shaped mold shell, the diameter of the stretching section of the dumbbell-shaped high-temperature alloy test rod wax mold is 4mm, the length of the stretching section is 26mm, and the angle of the compensation channel is 22° to obtain a dumbbell-shaped mold shell.

[0114] The mold shell is installed between the upper and lower discs, wherein the thickness of the upper disc is 10mm, the sprue cup is installed above the upper disc, and the diameter of the sprue cup gradually decreases from the top to the bottom, wherein the diameter of the top is 20mm and the diameter of the bottom is 10mm. An oil bath treatment device is set on the outer surface of the mold shell.

[0115] Specifically, the following steps are included:

[0116] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting treatment. After the raw material is melted, the alloy liquid is obtained. During melting, the temperature of the high-temperature alloy liquid is adjusted to 200°C above the alloy liquidus temperature and refined for 2 minutes. Then the power is turned off and the temperature is lowered.

[0117] Casting: Preheat the mold shell at 780℃ and then hold it for 3.5 hours; heat the alloy liquid to 60℃ above the alloy liquidus temperature and refine it for 3 to 5 minutes; adhere the slag on the surface of the high-temperature alloy liquid to the crucible wall and remove the slag by gas blowing; pour the high-temperature alloy liquid into the mold shell through the pouring cup.

[0118] The mold and casting device are then placed in a vacuum melting furnace, and the alloy liquid is poured into the mold through the casting device. The casting time is 2 seconds. After the alloy liquid solidifies, the mold is removed to obtain K465 high-temperature alloy (test bar). When pouring the alloy liquid into the mold, after pouring the alloy liquid to a height of 1 mm, a second pour is performed after an interval of 2 seconds.

[0119] The as-cast microstructure of the K465 high-temperature alloy (test bar) obtained in this comparative example and Example 1 is compared to that in Example 1. Figure 6 As shown, the comparison of WC phase size and grain size in K465 high-temperature alloy is as follows: Figure 7 As shown, the tungsten carbide in this comparative example is large in size, so its effect on refining the matrix phase grains is not significant. At the same time, the alloy has a high content of pore defects, which leads to a significant decrease in the strength of the final alloy. The specific mechanical properties are shown in Table 1.

[0120] Comparative Example 5

[0121] This comparative example provides a method for preparing K465 high-temperature alloy, wherein the mold shell used is a dumbbell-shaped mold shell, the diameter of the stretching section of the dumbbell-shaped high-temperature alloy test rod wax mold is 4 mm, the length of the stretching section is 26 mm, and the angle of the feeding channel is 22°, thus obtaining a dumbbell-shaped mold shell, as shown. Figure 1 As shown;

[0122] The mold shell is installed between the upper and lower discs, wherein the thickness of the upper disc is 25mm, the sprue cup is installed above the upper disc, and the diameter of the sprue cup gradually decreases from the top to the bottom, wherein the diameter of the top is 20mm and the diameter of the bottom is 10mm. An oil bath treatment device is installed on the outer surface of the mold shell.

[0123] Specifically, the following steps are included:

[0124] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting treatment, and ultrasonic vibration treatment is performed at the same time. After the raw material is melted, an alloy liquid is obtained. Among them, the ultrasonic vibration treatment causes WC in K465 high-temperature alloy to be dispersed in the alloy liquid. During melting, the temperature of the high-temperature alloy liquid is adjusted to 200°C above the alloy liquidus temperature and refined for 2 minutes, and then the power is turned off to cool down.

[0125] The ultrasonic oscillation treatment employs an ultrasonic ceramic probe installed inside the crucible; the vibration frequency is 10Hz, the amplitude is 10%, the pause time is 1s, and the ultrasonic power consumption is 1000W.

[0126] Casting: Preheat the mold shell at 950℃ and then hold it at that temperature for 3.5 hours; heat the alloy liquid to 120℃ above the alloy liquidus temperature and refine it for 3 to 5 minutes; adhere the slag on the surface of the high-temperature alloy liquid to the crucible wall and remove the slag by blowing it off with gas; then pour the high-temperature alloy liquid into the mold shell through the pouring cup.

[0127] The mold and casting device are then placed in a vacuum melting furnace, and the alloy liquid is poured into the mold through the casting device. The casting time is 2 seconds. After the alloy liquid solidifies, the mold is removed to obtain K465 high-temperature alloy (test bar). When pouring the alloy liquid into the mold, after pouring the alloy liquid to a height of 1 mm, a second pour is performed after an interval of 2 seconds.

[0128] The metallographic structure of the K465 high-temperature alloy (test bar) obtained in this comparative example is shown in the figure below. Figure 8 As shown, since the electromagnetic stirring parameters of this comparative example are lower than the parameters set in this invention, the electromagnetic driving force on WC is insufficient and it cannot be uniformly dispersed in the melt. Therefore, the solidification and feeding ability of the interdendritic molten pool is reduced, resulting in more microporous structure and lower mechanical properties than in Example 1 of this invention. The mechanical properties are shown in Table 1.

[0129] Comparative Example 6

[0130] This comparative example provides a method for preparing K465 high-temperature alloy, wherein the mold shell used is a dumbbell-shaped mold shell, the diameter of the stretching section of the dumbbell-shaped high-temperature alloy test rod wax mold is 4mm, the length of the stretching section is 26mm, and the angle of the compensation channel is 22° to obtain a dumbbell-shaped mold shell.

[0131] The mold shell is installed between the upper and lower discs, wherein the thickness of the upper disc is 25mm, the sprue cup is installed above the upper disc, and the diameter of the sprue cup gradually decreases from the top to the bottom, wherein the diameter of the top is 20mm and the diameter of the bottom is 10mm. An oil bath treatment device is installed on the outer surface of the mold shell.

[0132] Specifically, the following steps are included:

[0133] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting treatment, and ultrasonic vibration treatment is performed at the same time. After the raw material is melted, an alloy liquid is obtained. Among them, the ultrasonic vibration treatment causes WC in K465 high-temperature alloy to be dispersed in the alloy liquid. During melting, the temperature of the high-temperature alloy liquid is adjusted to 200°C above the alloy liquidus temperature and refined for 2 minutes, and then the power is turned off to cool down.

[0134] The ultrasonic oscillation treatment employs an ultrasonic ceramic probe installed inside the crucible; the vibration frequency is 100Hz, the amplitude is 100%, the pause time is 2s, and the ultrasonic power consumption is 2500W.

[0135] Casting: Preheat the mold shell at 950℃ and then hold it at that temperature for 3.5 hours; heat the alloy liquid to 120℃ above the alloy liquidus temperature and refine it for 3 to 5 minutes; adhere the slag on the surface of the high-temperature alloy liquid to the crucible wall and remove the slag by blowing it off with gas; then pour the high-temperature alloy liquid into the mold shell through the pouring cup.

[0136] The mold and casting device are then placed in a vacuum melting furnace, and the alloy liquid is poured into the mold through the casting device. The casting time is 2 seconds. After the alloy liquid solidifies, the mold is removed to obtain K465 high-temperature alloy (test bar). When pouring the alloy liquid into the mold, after pouring the alloy liquid to a height of 1 mm, a second pour is performed after an interval of 2 seconds.

[0137] The metallographic structure of the K465 high-temperature alloy (test bar) obtained in this comparative example is shown in the figure below. Figure 9As shown, since the electromagnetic stirring parameters of this comparative example are higher than the parameters set in this invention, the electromagnetic driving force on WC is too large, which causes the small WC to collide and aggregate and grow, which will hinder the flow of molten liquid between dendrites in the molten pool. Therefore, the solidification and feeding ability of the molten pool between dendrites is reduced, resulting in more microporous structure and lower mechanical properties than in Example 1 of this invention. The mechanical properties are shown in Table 1.

[0138] Comparative Example 7

[0139] This comparative example provides a method for preparing K465 high-temperature alloy, wherein the mold shell used is a dumbbell-shaped mold shell, the diameter of the stretching section of the dumbbell-shaped high-temperature alloy test rod wax mold is 4mm, the length of the stretching section is 26mm, and the angle of the feeding channel is 15° to obtain a dumbbell-shaped mold shell.

[0140] The mold shell is installed between the upper and lower discs, wherein the thickness of the upper disc is 25mm, the sprue cup is installed above the upper disc, and the diameter of the sprue cup gradually decreases from the top to the bottom, wherein the diameter of the top is 20mm and the diameter of the bottom is 10mm. An oil bath treatment device is installed on the outer surface of the mold shell.

[0141] Specifically, the following steps are included:

[0142] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting treatment. After the raw material is melted, the alloy liquid is obtained. During melting, the temperature of the high-temperature alloy liquid is adjusted to 200°C above the alloy liquidus temperature and refined for 2 minutes. Then the power is turned off and the temperature is lowered.

[0143] Casting: Preheat the mold shell at 780℃ and then hold it for 3.5 hours; heat the alloy liquid to 60℃ above the alloy liquidus temperature and refine it for 3 to 5 minutes; adhere the slag on the surface of the high-temperature alloy liquid to the crucible wall and remove the slag by gas blowing; pour the high-temperature alloy liquid into the mold shell through the pouring cup.

[0144] The mold and casting device are then placed in a vacuum melting furnace, and the alloy liquid is poured into the mold through the casting device. The casting time is 2 seconds. After the alloy liquid solidifies, the mold is removed to obtain K465 high-temperature alloy (test bar). When pouring the alloy liquid into the mold, after pouring the alloy liquid to a height of 1 mm, a second pour is performed after an interval of 2 seconds.

[0145] The mechanical properties of the K465 high-temperature alloy (test bar) obtained in this comparative example were tested, and the performance results are shown in Table 1. It can be seen that the mechanical properties of the K465 high-temperature alloy in this comparative example are lower than those in Example 1. This is because ultrasonic vibration treatment was not used in this comparative example, the WC size is large, and there are more alloy defects, which leads to a decrease in its mechanical properties.

[0146] Comparative Example 8

[0147] This comparative example provides a method for preparing K465 high-temperature alloy, wherein the mold shell used is a dumbbell-shaped mold shell, the diameter of the stretching section of the dumbbell-shaped high-temperature alloy test rod wax mold is 4 mm, the length of the stretching section is 26 mm, and the angle of the feeding channel is 22°, thus obtaining a dumbbell-shaped mold shell, as shown. Figure 1 As shown;

[0148] The mold shell is installed between the upper and lower discs, wherein the thickness of the upper disc is 25mm, the sprue cup is installed above the upper disc, and the diameter of the sprue cup gradually decreases from the top to the bottom, wherein the diameter of the top is 20mm and the diameter of the bottom is 10mm. An oil bath treatment device is installed on the outer surface of the mold shell.

[0149] Specifically, the following steps are included:

[0150] Melting: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting treatment, and ultrasonic vibration treatment is performed at the same time. After the raw material is melted, an alloy liquid is obtained. Among them, the ultrasonic vibration treatment causes WC in K465 high-temperature alloy to be dispersed in the alloy liquid. During melting, the temperature of the high-temperature alloy liquid is adjusted to 200°C above the alloy liquidus temperature and refined for 2 minutes, and then the power is turned off to cool down.

[0151] The ultrasonic oscillation treatment employs an ultrasonic ceramic probe installed inside the crucible; the vibration frequency is 50Hz, the amplitude is 50%, the pause time is 2s, and the ultrasonic power consumption is 1700W.

[0152] Casting: Preheat the mold shell at 950℃ and then hold it at that temperature for 3.5 hours; heat the alloy liquid to 120℃ above the alloy liquidus temperature and refine it for 3 to 5 minutes; adhere the slag on the surface of the high-temperature alloy liquid to the crucible wall and remove the slag by blowing it off with gas; then pour the high-temperature alloy liquid into the mold shell through the pouring cup.

[0153] The mold and casting device are then placed in a vacuum melting furnace, and the alloy liquid is injected into the mold through the casting device. The casting time is 2 seconds. After the alloy liquid solidifies, the mold is removed to obtain K465 high-temperature alloy (test bar). The casting method is a one-time casting.

[0154] The metallographic structures of the K465 high-temperature alloy (test bar) obtained in this comparative example and Example 1 are shown below. Figure 10 As shown in the figure, compared with Example 1, the alloy obtained in this comparative example has more pores. This is because the casting method of this comparative example is one-time casting, which cannot eliminate the gas generated by ultrasonic true vibration treatment. Therefore, the pore content of the alloy is significantly increased, which significantly reduces the mechanical properties of the alloy. The mechanical property test results of this comparative example are shown in Table 1.

[0155] Table 1. Comparison of the properties of K465 high-temperature alloy obtained from the examples and comparative examples.

[0156]

[0157]

[0158] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0159] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A method for preparing K465 high-temperature alloy, characterized in that, Includes the following steps: Melting: The raw materials of K465 high-temperature alloy are melted and ultrasonically vibrated simultaneously. The melted raw materials are used to obtain a liquid alloy. The ultrasonic vibration process causes WC in K465 high-temperature alloy to be dispersed in the liquid alloy and causes the WC particles to rub and collide with each other. Casting: The alloy liquid is cast to obtain K465 high-temperature alloy.

2. The method for preparing K465 high-temperature alloy according to claim 1, characterized in that, In the smelting step, the smelting process includes: The crucible containing the raw material of K465 high-temperature alloy is placed in a vacuum melting furnace for melting. The ultrasonic oscillation treatment is performed by an ultrasonic ceramic probe installed inside the crucible. Preferably, the parameters for ultrasonic vibration processing are set as follows: vibration frequency of 20-70Hz, amplitude of 20-70%, and ultrasonic power consumption of 1500-2000W; wherein, the set time for pausing after vibration is 5-30s, and more preferably, the set time is 1-3s.

3. The method for preparing K465 high-temperature alloy according to claim 1, characterized in that, In the pouring step, the pouring process includes: The mold shell and casting device are placed in a vacuum melting furnace, and then the molten alloy is injected into the mold shell through the casting device; wherein the mold shell is a dumbbell-shaped mold shell; Preferably, the diameter of the stretching section of the dumbbell-shaped mold shell is 3-5 mm, and the length of the stretching section is 25-30 mm; the angle of the compensation channel of the dumbbell-shaped mold shell is 25°-30°. Preferably, the alloy liquid is injected into the mold shell in multiple stages; more preferably, after injecting the alloy liquid to a height of 1 to 1.5 mm, a second pour is performed after an interval of 2 to 3 seconds.

4. The method for preparing K465 high-temperature alloy according to claim 3, characterized in that, The casting device includes an upper disc, a lower disc, and a pouring cup; the upper disc and the lower disc are respectively installed on the top and bottom of the mold shell, and the pouring cup is installed on the top of the upper disc; Preferably, the thickness of the upper disk is 20-30 mm; Preferably, the diameter of the pouring cup gradually decreases from the top to the bottom, wherein the diameter of the top is 18-22 mm and the diameter of the bottom is 8-12 mm.

5. The method for preparing K465 high-temperature alloy according to claim 3, characterized in that, Before placing the mold shell into the vacuum melting furnace, the process also includes: preheating and maintaining the temperature of the mold shell; Preferably, the preheating temperature of the mold shell is distributed in a gradient; wherein, the stretching section is 950°C, the feeding channel is 1000°C, and the sprue cup is 1050°C. Preferably, the heat preservation time is 3 to 4 hours.

6. The method for preparing K465 high-temperature alloy according to claim 3, characterized in that, Before the step of injecting the molten alloy into the mold shell, the process also includes: heating the molten alloy to 100°C to 150°C above the molten alloy temperature and refining it for 3 to 5 minutes.

7. The method for preparing K465 high-temperature alloy according to claim 4, characterized in that, An oil bath treatment device is provided on the outer side of the upper disc. The oil bath treatment device is an oil bath tank, which is installed on the outer side of the upper disc.

8. The method for preparing K465 high-temperature alloy according to any one of claims 1 to 7, characterized in that, The raw materials of the K465 high-temperature alloy, by mass percentage, include: C: 0.05-0.08 wt.%, S: 0.004-0.008 wt.%, P: 0.08-0.12 wt.%, Si: 0.2-0.5 wt.%, Mn: 0.2-0.5 wt.%, Cr: 15-20 wt.%, Ti: 2.2-2.5 wt.%, Mo: 2.8-3.2 wt.%, Al: 1-1.5 wt.%, Fe: 3.3-3.8 wt.%, W: 5.0-5.5 wt.%, with the balance being Ni.

9. A K465 high-temperature alloy, characterized in that, The K465 high-temperature alloy comprises a matrix phase and a WC phase. The WC phase is dispersed in the matrix phase, the grain size of the matrix phase is 1.0-1.5 μm, the volume fraction of the WC phase is 10-12%, and the size of the WC phase is approximately 1.5-3 μm.

10. The K465 high-temperature alloy according to claim 9, characterized in that, The properties of the K465 high-temperature alloy are as follows: room temperature tensile strength σ b The stress is greater than 900 MPa, the elongation after fracture (A) is greater than 6%, the reduction of area (Z) is greater than 10%, and the creep rupture life at 975℃ with a stress of 230 MPa exceeds 60 hours. Preferably, the K465 high-temperature alloy is obtained by the preparation method of the K465 high-temperature alloy according to any one of claims 1 to 8.

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