Preparation method for metallurgical defects of high-temperature alloy cast ingot

Abstract

The invention relates to the technical field of alloys, in particular to a preparation method for metallurgical defects of a high-temperature alloy ingot. The preparation method for the metallurgical defects of the high-temperature alloy cast ingot comprises a preparation method for the black spot defects of the high-temperature alloy cast ingot and a preparation method for the white spot defects of the high-temperature alloy cast ingot. By adjusting smelting process parameters in the high-temperature alloy smelting process, the black spot defect and the white spot defect can be effectively preset in the high-temperature alloy cast ingot; by presetting the black spot defect and the white spot defect in the high-temperature alloy cast ingot, the microstructure of the alloy can be changed, so that the final performance of the material is influenced, and the special alloy components and the microstructure can meet some special application requirements and provide an important basis for researching constitutive parameters of defects and optimizing inspection and detection means.

Description

Technical Field

[0001] The invention relates to the technical field of alloys, and in particular to a method for preparing metallurgical defects of high-temperature alloy ingots. Background Art

[0002] High-temperature alloys are a type of high-performance alloy material that can work for a long time in a high-temperature environment. They are widely used in aerospace, nuclear industry, petrochemical industry and other fields. These alloy materials are usually composed of elements such as nickel, chromium, titanium, aluminum, and molybdenum, and have good oxidation resistance, corrosion resistance and high-temperature mechanical properties. Due to its important industrial application value, the preparation technology of high-temperature alloy materials has always received widespread attention. In the preparation process of high-temperature alloy materials, ingot metallurgy is a key link. By controlling the process parameters in the ingot metallurgical process, the microstructure of the alloy can be adjusted, thereby affecting the final performance of the material. However, due to the complex composition and special organizational structure of high-temperature alloy materials, various metallurgical defects such as segregation, grain boundary embrittlement, thermal cracking, etc. are prone to occur during the ingot metallurgical process, which will affect the mechanical properties and service life of the material.

[0003] Existing high-temperature alloy ingot preparation technologies mainly include vacuum induction melting, vacuum arc remelting, vacuum consumable electrode melting and other methods. These methods can reduce the impurities and gas content in the alloy and improve the purity and performance of the material through vacuum environment and high-temperature melting. In terms of controlling the process parameters in the ingot metallurgical process, the existing technology mainly adjusts the alloy composition and microstructure by adjusting parameters such as melting temperature, holding time, and cooling rate. For example, by lowering the melting temperature and extending the holding time, the full diffusion and homogenization of the alloy elements can be promoted, thereby reducing the segregation phenomenon. Through rapid cooling, the coarsening of the grain boundaries can be suppressed and the toughness of the material can be improved.

[0004] However, based on the research direction of materials science, preparing high-temperature alloy samples containing certain defects can effectively help R&D personnel understand the formation mechanism of defects and form effective detection and inspection technical means, providing guidance for the subsequent production of high-quality alloy ingots and improving the qualified rate of finished parts.

[0005] In view of this, this invention is proposed. Summary of the invention

[0006] The object of the present invention is to provide a method for preparing metallurgical defects of high-temperature alloy ingots, and to preset black spot defects and white spot defects in high-temperature alloy ingots by adjusting smelting process parameters during the smelting process.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0008] The present invention provides a method for preparing metallurgical defects of high-temperature alloy ingots, including a method for preparing black spot defects of high-temperature alloy ingots and a method for preparing white spot defects of high-temperature alloy ingots;

[0009] The method for preparing black spot defects of high temperature alloy ingots comprises the following steps:

[0010] The high-temperature alloy raw material is subjected to vacuum induction melting to obtain a vacuum induction melting ingot; the vacuum induction melting ingot is subjected to protective atmosphere electroslag remelting to obtain an electrode rod; the electrode rod is subjected to vacuum consumable remelting to obtain a high-temperature alloy ingot containing black spot defects;

[0011] Wherein, during the protective atmosphere electroslag remelting process, the slag resistance swing and the voltage swing are independently 0.2-1 mOhm; the melting rate is 2.5-8 kg / min;

[0012] In the smelting stage of the vacuum consumable remelting, the melting rate from the beginning of smelting to 1 / 3 of the length of the electrode rod is 3.5-7 kg / min, the melting rate from 1 / 3 of the length of the electrode rod to 2 / 3 of the length of the electrode rod is 3-6.5 kg / min, and the melting rate from 2 / 3 of the length of the electrode rod to the end of smelting is 2.5-6 kg / min; the droplet size in the smelting stage is 1-12 mm; helium is introduced in the smelting stage, and the pressure of the helium is 300-1000 Pa;

[0013] The method for preparing white spot defects of high temperature alloy ingots comprises the following steps:

[0014] The high temperature alloy raw material is subjected to vacuum induction melting to obtain a vacuum induction melting ingot; the vacuum induction melting ingot is subjected to vacuum consumable remelting to obtain a high temperature alloy ingot containing white spot defects;

[0015] The vacuum consumable remelting includes an arc starting stage and a melting stage; the melting rate in the arc starting stage is 2.2 to 5 kg / min; in the melting stage, the melting rate from the beginning of melting to 1 / 3 of the length of the electrode rod is 1.5 to 3.5 kg / min, the melting rate from 1 / 3 of the length of the electrode rod to 2 / 3 of the length of the electrode rod is 2 to 5.5 kg / min, and the melting rate from 2 / 3 of the length of the electrode rod to the end of melting is 3 to 6 kg / min; the droplet size in the melting stage is 2 to 9 mm.

[0016] Furthermore, the high temperature alloy includes GH4169 alloy.

[0017] Furthermore, the method for preparing black spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (3);

[0018] (1) The protective gas for the protective atmosphere electroslag remelting includes argon;

[0019] (2) The flow rate of the argon gas is 20 to 120 L / min;

[0020] (3) The amount of slag in the protective atmosphere electroslag remelting is 20 to 70 kg.

[0021] Furthermore, the method for preparing black spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (3);

[0022] (1) The filling time of the protective atmosphere electroslag remelting is 10 to 70 minutes;

[0023] (2) The cooling time of the protective atmosphere electroslag remelting is 20 to 80 minutes;

[0024] (3) The diameter of the electrode rod is 350-450 mm.

[0025] Furthermore, the method for preparing black spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (3);

[0026] (1) During the arc starting stage of the vacuum consumable remelting, the arc starting weight is 120-220 kg, and the arc starting melting speed is 2.2-8 kg / min;

[0027] (2) In the vacuum consumable remelting process, the smelting is followed by furnace cooling for 1 to 4 hours, vacuum breaking, demoulding and air cooling;

[0028] (3) The diameter of the high-temperature alloy ingot containing black spot defects is 400 to 550 mm.

[0029] Furthermore, in the preparation method for white spot defects of high-temperature alloy ingots, in the arc starting stage of the vacuum consumable remelting, the arc starting weight is 120 to 220 kg, and the arc starting melting rate is 2.2 to 5 kg / min.

[0030] Furthermore, the method for preparing white spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (3);

[0031] (1) During the vacuum consumable remelting process, helium is introduced into the smelting stage, and the pressure of the helium is 300 to 1000 Pa;

[0032] (2) In the vacuum consumable remelting process, the smelting is followed by furnace cooling for 1 to 4 hours, vacuum breaking, demoulding and air cooling;

[0033] (3) The diameter of the high-temperature alloy ingot containing white spot defects is 400 to 550 mm.

[0034] Furthermore, the method for preparing black spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (3);

[0035] (1) The vacuum induction melting includes: melting, pouring, furnace cooling, vacuum breaking, slow cooling with mold and demolding in sequence;

[0036] (2) The power of the vacuum induction melting is 700-1000KW;

[0037] (3) The refining temperature of the smelting is 1450-1700°C.

[0038] Furthermore, the method for preparing black spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (4);

[0039] (1) The diameter of the pouring nozzle is 20 to 35 mm

[0040] (2) The furnace cooling time is 60 to 120 minutes;

[0041] (3) The time for slow cooling of the strip mold is 16 to 36 hours;

[0042] (4) The diameter of the vacuum induction melting ingot is 300 to 400 mm.

[0043] Furthermore, the method for preparing white spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (7);

[0044] (1) The vacuum induction melting comprises: melting, pouring, furnace cooling, vacuum breaking, furnace cooling, slow cooling with mold and demolding in sequence;

[0045] (2) The power of the vacuum induction melting is 700-1000KW;

[0046] (3) The refining temperature of the smelting is 1450-1700° C.;

[0047] (4) The diameter of the pouring nozzle is 20 to 35 mm;

[0048] (5) After the pouring, the casting is sequentially cooled with the furnace for 15 to 60 minutes, broken, and cooled with the furnace for 60 to 120 minutes;

[0049] (6) The time for slow cooling of the strip mold is 1 to 4 hours;

[0050] (7) The diameter of the vacuum induction melting ingot is 350 to 500 mm.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] The present invention can effectively preset black spot defects and white spot defects in the high-temperature alloy ingot by adjusting the smelting process parameters during the smelting process of the high-temperature alloy, such as the GH4169 alloy; by presetting the black spot defects and white spot defects in the high-temperature alloy ingot, the alloy microstructure can be changed, thereby affecting the final performance of the material. This special alloy composition and organizational structure can meet some special application requirements and provide an important basis for studying the constitutive parameters of defects and optimizing inspection and detection methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 This is a low-magnification photograph of the high-temperature alloy ingot containing black spot defects in Example 1 of the present invention.

[0055] Figure 2 This is a SEM image of black spot defects in the high-temperature alloy ingot containing black spot defects in Example 1 of the present invention.

[0056] Figure 3 This is a SEM image of the matrix in the high-temperature alloy ingot containing black spot defects in Example 1 of the present invention.

[0057] Figure 4 This is an EDS image of black spot defects in a high-temperature alloy ingot containing black spot defects according to Example 1 of the present invention.

[0058] Figure 5 This is an EDS image of the matrix in the high-temperature alloy ingot containing black spot defects in Example 1 of the present invention.

[0059] Figure 6 This is a low-magnification photograph of a high-temperature alloy ingot containing white spot defects according to Example 4 of the present invention.

[0060] Figure 7 This is a SEM image of white spot defects in a high-temperature alloy ingot containing white spot defects according to Example 4 of the present invention.

[0061] Figure 8 This is a SEM image of the matrix in the high-temperature alloy ingot containing white spot defects in Example 4 of the present invention.

[0062] Fig. 9 This is an EDS image of white spot defects in a high-temperature alloy ingot containing white spot defects according to Example 4 of the present invention.

[0063] Fig.10 This is an EDS image of the matrix in the high-temperature alloy ingot containing white spot defects in Example 4 of the present invention. DETAILED DESCRIPTION

[0064] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0065] The following is a detailed description of a method for preparing metallurgical defects of a high-temperature alloy ingot according to the present invention.

[0066] In some embodiments of the present invention, a method for preparing metallurgical defects of high-temperature alloy ingots is provided, including a method for preparing black spot defects of high-temperature alloy ingots and a method for preparing white spot defects of high-temperature alloy ingots;

[0067] A method for preparing black spot defects in high temperature alloy ingots comprises the following steps:

[0068] The high-temperature alloy raw material is subjected to vacuum induction melting to obtain a vacuum induction melting ingot; the vacuum induction melting ingot is subjected to protective atmosphere electroslag remelting to obtain an electrode rod; the electrode rod is subjected to vacuum consumable remelting to obtain a high-temperature alloy ingot containing black spot defects;

[0069] In the process of electroslag remelting in protective atmosphere, the slag resistance swing and voltage swing are independently 0.2-1mOhm; the melting rate is 2.5-8kg / min;

[0070] During the melting stage of vacuum consumable remelting, the melting rate from the beginning of melting to 1 / 3 of the length of the electrode rod is 3.5-7 kg / min, the melting rate from 1 / 3 of the length of the electrode rod to 2 / 3 of the length of the electrode rod is 3-6.5 kg / min, and the melting rate from 2 / 3 of the length of the electrode rod to the end of melting is 2.5-6 kg / min; the droplet size during the melting stage is 1-12 mm; helium is introduced during the melting stage, and the pressure of the helium is 300-1000 Pa;

[0071] A method for preparing white spot defects of high temperature alloy ingots comprises the following steps:

[0072] The high temperature alloy raw material is subjected to vacuum induction melting to obtain a vacuum induction melting ingot; the vacuum induction melting ingot is subjected to vacuum consumable remelting to obtain a high temperature alloy ingot containing white spot defects;

[0073] Vacuum consumable remelting includes an arc starting stage and a melting stage; the melting rate in the arc starting stage is 2.2 to 5 kg / min; in the melting stage, the melting rate from the beginning of melting to 1 / 3 of the length of the melting electrode rod is 1.5 to 3.5 kg / min, the melting rate from 1 / 3 of the length of the melting electrode rod to 2 / 3 of the length of the melting electrode rod is 2 to 5.5 kg / min, and the melting rate from 2 / 3 of the length of the melting electrode rod to the end of melting is 3 to 6 kg / min; the droplet size in the melting stage is 2 to 9 mm.

[0074] The present invention can effectively preset black spot defects and white spot defects in the high-temperature alloy ingot by adjusting the smelting process parameters during the high-temperature alloy smelting process.

[0075] By pre-setting black spot defects and white spot defects in high-temperature alloy ingots, the alloy microstructure can be changed, thereby affecting the final performance of the material; this special alloy composition and organizational structure can meet some special application requirements and provide an important basis for studying the constitutive parameters of defects and optimizing inspection and detection methods.

[0076] In some embodiments of the present invention, the high temperature alloy includes GH4169 alloy.

[0077] In some embodiments of the present invention, the GH4169 alloy comprises the following components by mass percentage:

[0078] C≤0.08%, Cr 17.00%~21.00%, Ni 50.00%~55.00%, Co≤1.00%, Mo2.80%~3.30%, Al 0.20%~0.80%, Ti 0.65%~1.15%, Nb 4.75%~5.50%, B≤0.006%, Mg≤0.010%, Mn≤0.35%, Si≤0.35%, P≤0.015%, S≤0.015%, Cu≤0.300%, and the balance is Fe.

[0079] In terms of controlling the process parameters in the ingot metallurgical process, the high-temperature alloy ingot preparation technology is mainly based on experience-based exploration and experimental adjustment, lacking precise control methods and theoretical guidance, resulting in low production efficiency and unstable product quality. The present invention adjusts the smelting process parameters in the GH4169 alloy smelting process, adopts the ingot metallurgical process with the above process parameters, and accurately controls the process parameters, thereby achieving the presetting of black spot defects and white spot defects in the GH4169 alloy ingot, and provides a method for accurately and effectively presetting black spot defects and white spot defects in the GH4169 alloy ingot.

[0080] High-temperature alloy ingot preparation technology When preparing high-temperature alloy ingots, the alloy microstructure is mainly adjusted by adjusting process parameters, but this method is limited by alloy composition and structure to a certain extent, and it is difficult to meet some special application requirements. The present invention adjusts the smelting process parameters during the smelting process of GH4169 alloy to pre-set black spot and white spot defects in the GH4169 alloy ingot, providing a method and idea for studying the special application requirements of metallurgical defects of high-temperature alloy materials.

[0081] The preparation method of the black spot defect of the high-temperature alloy ingot adopts a triple smelting process, which includes vacuum induction melting, protective atmosphere electroslag remelting and vacuum consumable remelting in sequence.

[0082] In some embodiments of the present invention, the parameters of the protective atmosphere electroslag remelting in the method for preparing black spot defects in high-temperature alloy ingots are as follows:

[0083] Protective atmosphere electroslag remelting includes: peeling or tumbling the surface of the vacuum induction melting ingot to reveal the original color of the metal, clean the surface, and remove oil and paint. At the same time, the shrinkage end is cut off by more than 50 to 300 mm, and then loaded into the electroslag remelting furnace for smelting. Protective gas is introduced throughout the smelting process. After smelting, it is cooled with the furnace;

[0084] Shielding gases include argon;

[0085] The flow rate of argon gas is 20 to 120 L / min; typically but not limiting, for example, the flow rate of argon gas can be 20 L / min, 40 L / min, 60 L / min, 80 L / min, 100 L / min, 120 L / min or a range of any two thereof; preferably 20 to 100 L / min;

[0086] The amount of slag is 20-70Kg; typically but not limiting, for example, the amount of slag can be 20Kg, 30Kg, 40Kg, 50Kg, 60Kg, 70Kg or a range of any two thereof; preferably 30-60Kg;

[0087] The slag resistance swing and the voltage swing are each independently 0.2-1 mOhm; typically but not limiting, for example, the slag resistance swing and the voltage swing can each independently be 0.2 mOhm, 0.3 mOhm, 0.4 mOhm, 0.5 mOhm, 0.6 mOhm, 0.7 mOhm, 0.8 mOhm, 0.9 mOhm, 1 mOhm or a range of any two thereof; preferably 0.4-0.9 mOhm;

[0088] The melting rate is 2.5 to 8 kg / min; typically but not limiting, for example, the melting rate can be 2.5 kg / min, 3 kg / min, 3.5 kg / min, 4 kg / min, 4.5 kg / min, 5 kg / min, 5.5 kg / min, 6 kg / min, 6.5 kg / min, 7 kg / min, 7.5 kg / min, 8 kg / min or a range of any two thereof; preferably 3 to 7 kg / min;

[0089] The filling time is 10 to 70 minutes; typically but not limiting, for example, the filling time can be 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes or a range of any two thereof; preferably 20 to 60 minutes; the filling time refers to the time required for the consumable electrode to be continuously melted and filled into the molten pool during the electroslag remelting process until a steel ingot of a predetermined size and shape is formed;

[0090] The time of cooling with the furnace is 20 to 80 minutes; typically but not limiting, for example, the time of cooling with the furnace can be 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes or a range of any two thereof; preferably 25 to 65 minutes;

[0091] The diameter of the electrode rod is 350-450 mm; typically but not limiting, for example, the diameter of the electrode rod can be 350 mm, 360 mm, 370 mm, 380 mm, 390 mm, 400 mm, 410 mm, 420 mm, 430 mm, 440 mm, 450 mm or a range consisting of any two of them.

[0092] In some embodiments of the present invention, the parameters of vacuum consumable remelting in the method for preparing black spot defects in high temperature alloy ingots are as follows:

[0093] Vacuum consumable remelting includes: using a polishing method to completely peel the electrode rod to ensure that there is no black skin on the surface, and using electric spark cutting to cut the head of the electrode rod flat, and then vacuum consumable remelting; vacuum consumable remelting includes arc starting stage and melting stage in sequence;

[0094] The arc starting weight in the arc starting stage is 120-220Kg; typically but not limiting, for example, the arc starting weight can be 120Kg, 130Kg, 140Kg, 150Kg, 160Kg, 170Kg, 180Kg, 190Kg, 200Kg, 210Kg, 220Kg or a range of any two thereof; preferably 140-200Kg;

[0095] The arc starting melting speed in the arc starting stage is 2.2-8 kg / min; typically but not limiting, for example, the arc starting melting speed can be 2.2 kg / min, 3 kg / min, 4 kg / min, 5 kg / min, 6 kg / min, 7 kg / min, 8 kg / min or a range of any two thereof; preferably 2.5-6.5 kg / min; the arc starting melting speed is controlled by current plus voltage;

[0096] In the smelting stage, the melting rate from the beginning of smelting to 1 / 3 of the length of the electrode rod is 3.5-7kg / min (for example, 3.5kg / min, 4kg / min, 4.5kg / min, 5kg / min, 5.5kg / min, 6kg / min, 6.5kg / min, 7kg / min, etc.), the melting rate from 1 / 3 of the length of the electrode rod to 2 / 3 of the length of the electrode rod is 3-6.5kg / min (for example, 3kg / min, 3.5kg / min, 4kg / min, 4.5kg / min, 5kg / min, 5.5kg / min, 6kg / min, 6.5kg / min, etc.), and the melting rate from 2 / 3 of the length of the electrode rod to the end of smelting is 2 .5~6kg / min (for example, it can be 2.5kg / min, 3kg / min, 3.5kg / min, 4kg / min, 4.5kg / min, 5kg / min, 5.5kg / min, 6kg / min, etc.); in the smelting stage, the melting speed of the electrode rod at the beginning of smelting is controlled to be between 3.5 and 7kg / min, the melting speed of the middle 1 / 3 length is controlled to be 3-6.5kg / min, and the melting speed of the remaining 1 / 3 length is controlled to be 2.5-6kg / min; preferably, the melting speed of the electrode rod at the beginning of smelting is controlled to be between 4 and 6.5kg / min, the melting speed of the middle 1 / 3 length is controlled to be 3-6kg / min, and the melting speed of the remaining 1 / 3 length is controlled to be 2.5-5.5kg / min;

[0097] The droplet size during the smelting stage (the whole process) is 1 to 12 mm; typically but not limiting, for example, the droplet size can be 1 mm, 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm or any range of two values; preferably 1.5 to 11 mm;

[0098] Helium is introduced during the smelting stage, and the pressure of helium is 300-1000Pa; typically but not restrictively, for example, the pressure of helium can be 300Pa, 400Pa, 500Pa, 600Pa, 700Pa, 800Pa, 900Pa, 1000Pa or a range of any two thereof; preferably 300-700Pa; helium is introduced throughout the smelting process for cooling; the introduction of helium during the smelting stage means that after the smelting process reaches a stable state and various parameters such as current, voltage, melting rate, etc. remain relatively stable, helium is introduced. The role of introducing helium is to adjust the temperature of the consumable electrode to prevent the electrode from overheating; overheated electrodes may cause problems such as decreased material performance and excessive electrode consumption, and the introduction of helium can effectively take away part of the heat, maintain the electrode within a suitable temperature range, extend the service life of the electrode, and also help to improve the smelting efficiency;

[0099] After smelting, the furnace is cooled for 1 to 4 hours, broken, demolded and air-cooled in sequence; typically but not limiting, for example, the furnace cooling time can be 1 hour, 2 hours, 3 hours, 4 hours or a range of any two thereof; preferably 1.5 to 3.5 hours;

[0100] The diameter of the high-temperature alloy ingot containing black spot defects is 400-550 mm; typically but not restrictively, for example, the diameter of the high-temperature alloy ingot containing black spot defects can be 400 mm, 420 mm, 440 mm, 460 mm, 480 mm, 500 mm, 520 mm, 540 mm, 550 mm or a range of any two thereof.

[0101] The main factors that affect the generation of black spot defects include the melting rate in the electroslag remelting process and the vacuum consumable remelting process and the cooling rate of the formed ingot. The present invention controls the generation of black spot defects by controlling the melting rate of the vacuum consumable remelting, the cooling rate of the ingot and coordinating other parameter settings; wherein, a high melting rate means high productivity, and also means that the corresponding mushy zone is deeper and the fluid flow between the dendrites will become stronger, which will lead to the formation of black spots; when the cooling rate of the ingot decreases, the local solidification time increases, the depth of the mushy zone of the ingot will become deeper, the density reversal phenomenon between the dendrites will be enhanced, and more black spot defects will be generated.

[0102] In some embodiments of the present invention, the parameters of vacuum induction melting in the method for preparing black spot defects in high temperature alloy ingots are as follows:

[0103] Vacuum induction melting includes: melting, pouring, furnace cooling, breaking, slow cooling with mold and demoulding in sequence; preferably, pouring is carried out in a vacuum environment;

[0104] The power of vacuum induction melting is 700-1000KW; typically but not limiting, for example, the power of vacuum induction melting can be 700KW, 750KW, 800KW, 850KW, 900KW, 950KW, 1000KW or a range of any two thereof; preferably 800-950KW;

[0105] The refining temperature of the smelting is 1450-1700°C; typically but not limiting, for example, the refining temperature of the smelting can be 1450°C, 1500°C, 1550°C, 1600°C, 1650°C, 1700°C or a range of any two thereof; preferably 1450-1600°C;

[0106] The diameter of the pouring nozzle for pouring is 20 to 35 mm; typically but not limiting, for example, the diameter of the pouring nozzle for pouring can be 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, 32 mm, 35 mm or a range of any two thereof; preferably 23 to 33 mm;

[0107] The time of cooling with the furnace is 60 to 120 minutes; typically but not limiting, for example, the time of cooling with the furnace can be 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes, 120 minutes or a range of any two thereof; preferably 75 to 110 minutes;

[0108] The time for slow cooling with a mold is 16 to 36 hours; typically but not limiting, for example, the time for slow cooling with a mold can be 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, 26 hours, 28 hours, 30 hours, 32 hours, 34 hours, 36 hours or a range of any two thereof; preferably 18 to 30 hours;

[0109] The diameter of the vacuum induction melting ingot is 300-400 mm; typically but not limiting, for example, the diameter of the vacuum induction melting ingot can be 300 mm, 320 mm, 340 mm, 360 mm, 380 mm, 400 mm or a range of any two thereof.

[0110] The preparation method of the white spot defect of the high-temperature alloy ingot adopts a double smelting process, which includes vacuum induction melting and vacuum consumable remelting in sequence.

[0111] In some embodiments of the present invention, the parameters of vacuum consumable remelting in the method for preparing white spot defects in high temperature alloy ingots are as follows:

[0112] Vacuum consumable remelting includes: using a polishing method to completely peel the vacuum induction melting ingot to ensure that there is no black skin on the surface, cutting off 50 to 300 mm of the riser end of the vacuum induction melting ingot by sawing or wire cutting, and then performing vacuum consumable remelting; vacuum consumable remelting includes an arc starting stage and a melting stage in sequence;

[0113] The arc starting weight in the arc starting stage is 120-220Kg, typically but not limiting, for example, the arc starting weight can be 120Kg, 130Kg, 140Kg, 150Kg, 160Kg, 170Kg, 180Kg, 190Kg, 200Kg, 210Kg, 220Kg or a range of any two thereof; preferably 130-200Kg;

[0114] The arc starting melting speed in the arc starting stage is 2.5-5 kg / min; typically but not limiting, for example, the arc starting melting speed can be 2.5 kg / min, 3 kg / min, 3.5 kg / min, 4 kg / min, 4.5 kg / min, 5 kg / min or a range of any two thereof; preferably 2.5-4.5 kg / min; the arc starting melting speed is controlled by current plus voltage;

[0115] In the smelting stage, the melting rate from the beginning of smelting to the melting of 1 / 3 of the length of the electrode rod is 2.2-5 kg / min (for example, 2.2 kg / min, 2.5 kg / min, 3 kg / min, 3.5 kg / min, 4 kg / min, 4.5 kg / min, 5 kg / min, etc.), the melting rate from 1 / 3 of the length of the electrode rod to the melting of 2 / 3 of the length of the electrode rod is 1.5-3.5 kg / min (for example, 1.5 kg / min, 2 kg / min, 2.5 kg / min, 3 kg / min, etc.), and the melting rate from 2 / 3 of the length of the electrode rod to the end of smelting is 3-6 kg / min (for example, 3 kg / min). g / min, 3.5kg / min, 4kg / min, 4.5kg / min, 5kg / min, 5.5kg / min, 6kg / min, etc.); in the smelting stage, the melting rate of the first 1 / 3 of the electrode rod is controlled to be between 2.2 and 5kg / min, the melting rate of the middle 1 / 3 of the electrode rod is controlled to be between 1.5 and 3.5kg / min, and the melting rate of the remaining 1 / 3 of the electrode rod is controlled to be between 3 and 6kg / min; preferably, the melting rate of the first 1 / 3 of the electrode rod is controlled to be between 1.75 and 3.5kg / min, the melting rate of the middle 1 / 3 of the electrode rod is controlled to be between 2.5 and 5kg / min, and the melting rate of the remaining 1 / 3 of the electrode rod is controlled to be between 3.5 and 5.5kg / min;

[0116] The droplet size during the smelting stage (the entire process) is 2 to 9 mm; typically but not limiting, for example, the droplet size can be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or any range of two values;

[0117] Helium is introduced during the smelting stage, and the pressure of the helium is 300-1000Pa; typically but not limitingly, for example, the pressure of the helium can be 300Pa, 400Pa, 500Pa, 600Pa, 700Pa, 800Pa, 900Pa, 1000Pa or a range of any two thereof; preferably 400-800Pa; helium is introduced throughout the smelting process for cooling; the introduction of helium during the smelting stage means that the smelting process reaches a stable state, and various parameters such as current, voltage, melting rate, etc. remain relatively stable, and then helium is introduced;

[0118] After smelting, the furnace is cooled for 1 to 4 hours, broken, demolded and air-cooled in sequence; typically but not limiting, for example, the furnace cooling time can be 1 hour, 2 hours, 3 hours, 4 hours or a range of any two thereof; preferably 1.5 to 3.5 hours;

[0119] The diameter of the high-temperature alloy ingot containing white spot defects is 400-550 mm; typically but not restrictively, for example, the diameter of the high-temperature alloy ingot containing white spot defects can be 400 mm, 420 mm, 440 mm, 460 mm, 480 mm, 500 mm, 520 mm, 540 mm, 550 mm or a range of any two thereof.

[0120] The main factors that affect the generation of white spot defects include the quality of the electrode during vacuum consumable remelting, the unstable voltage caused by the melting conditions that causes fluctuations in the melting rate, and the amount of helium charged. When there are shrinkage cavities in the electrode, the melting process will cause arc instability, affecting the normal melting of the electrode and causing the electrode's easily detached materials to fall into the molten pool, forming dendrite-like white spots. Therefore, in order to adjust the quality of the electrode rod, the parameters of the vacuum induction melting process are regulated; when the melting rate fluctuates, the depth of the ingot's molten pool will be reduced, and exogenous materials will fall into the molten pool, making it more difficult to melt and prone to white spots. Therefore, the arc starting melting rate and the melting rate in the melting stage during vacuum consumable remelting are regulated.

[0121] In some embodiments of the present invention, the parameters of vacuum induction melting in the method for preparing white spot defects in high temperature alloy ingots are as follows;

[0122] Vacuum induction melting includes: melting, pouring, furnace cooling, breaking, furnace cooling, slow cooling with mold and demoulding in sequence; preferably, pouring is carried out in a vacuum environment;

[0123] The power of vacuum induction melting is 700-1000KW; typically but not limiting, for example, the power of vacuum induction melting can be 700KW, 750KW, 800KW, 850KW, 900KW, 950KW, 1000KW or a range of any two thereof; preferably 800-950KW;

[0124] The refining temperature of the smelting is 1450-1700°C; typically but not limiting, for example, the refining temperature of the smelting can be 1450°C, 1500°C, 1550°C, 1600°C, 1650°C, 1700°C or a range of any two thereof; preferably 1450-1600°C;

[0125] The diameter of the pouring nozzle for pouring is 20 to 35 mm; but not limited to, for example, the diameter of the pouring nozzle for pouring can be 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, 32 mm, 35 mm or a range of any two thereof; preferably 23 to 33 mm;

[0126] Breaking the air means breaking the vacuum environment and reducing the vacuum degree;

[0127] The time of cooling in the furnace before breaking the air is 15 to 60 minutes; typically but not limiting, for example, the time of cooling in the furnace before breaking the air can be 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes or a range of any two thereof; preferably 20 to 50 minutes;

[0128] The time for cooling in the furnace after breaking the air is 60 to 120 minutes; typically but not limiting, for example, the time for cooling in the furnace after breaking the air can be 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes, 120 minutes or a range of any two thereof; preferably 80 to 100 minutes;

[0129] The time for slow cooling with the mold is 1 to 4 hours; typically but not limiting, for example, the time for slow cooling with the mold can be 1 hour, 2 hours, 3 hours, 4 hours or a range of any two thereof; preferably 1.5 to 3.5 hours;

[0130] The diameter of the vacuum induction melting ingot is 350-500 mm; typically but not limiting, for example, the diameter of the vacuum induction melting ingot can be 350 mm, 380 mm, 400 mm, 420 mm, 440 mm, 460 mm, 480 mm, 500 mm or a range of any two thereof.

[0131] The present invention can successfully preset black spot defects and white spot defects in the GH4169 alloy ingot by adjusting the smelting process parameters during the smelting process of the GH4169 alloy. This purposeful metallurgical defect preset can provide more data support and theoretical basis for subsequent research and application. For example, in the field of aerospace, by systematically studying the preset defects in high-temperature alloy ingots, the failure mechanism of high-temperature alloy materials can be deeply understood, thereby providing guidance for the development and application of high-temperature alloy materials.

[0132] Example 1

[0133] The preparation method of black spot defects of GH4169 alloy ingot provided in this embodiment comprises the following steps:

[0134] S1. Vacuum induction melting of GH4169 alloy raw materials to obtain vacuum induction melting ingots; vacuum induction melting includes: after adding GH4169 alloy raw materials, power is turned on for melting, the power is 1000KW, and the refining temperature is 1550°C; then casting is performed under vacuum environment, the casting nozzle diameter Φ is 27mm, after casting, the casting is cooled with the furnace for 25min and then broken, after breaking, the mold is slowly cooled for 3.5h and then demolded to obtain a vacuum induction melting ingot with a diameter of Φ360mm;

[0135] S2. The vacuum induction melting ingot is subjected to protective atmosphere electroslag remelting to obtain an electrode rod; the protective atmosphere electroslag remelting includes: peeling or tumbling the surface of the vacuum induction melting ingot to reveal the original color of the metal, making the surface clean, free of oil stains and paint, and cutting off more than 70 to 200 mm of the shrinkage cavity end, and then loading it into an electroslag remelting furnace for melting, and the whole melting process is filled with argon gas, the argon gas flow rate is 60L / min, the slag amount is 45Kg, the slag resistance swing and voltage swing are both 0.6mOhm, the melting rate is 3kg / min, the filling time is 20 to 60min, and the furnace is cooled for 45min after melting to obtain an electrode rod with a diameter of Φ430mm;

[0136] S3. The electrode rod is subjected to vacuum consumable remelting to obtain a high-temperature alloy ingot containing black spot defects; the vacuum consumable remelting includes: the electrode rod is completely peeled by polishing to ensure that there is no black skin on the surface, and the head of the electrode rod is cut flat by electric spark cutting, and then vacuum consumable remelting is performed; the vacuum consumable remelting includes an arc starting stage and a melting stage in sequence; in the arc starting stage, the arc starting weight is 170Kg, and the arc starting melting speed is controlled to be 6.5kg / min by using current plus voltage; in the melting stage, the electrode rod The melting rate of the first 1 / 3 of the length was 5.75 kg / min, the melting rate of the middle 1 / 3 of the length was 5.25 kg / min, and the melting rate of the remaining 1 / 3 of the length was 4.75 kg / min. The droplet size throughout the whole process was 7 mm. When a stable state was reached during the smelting process, helium was introduced for cooling, and the pressure of the helium was 600 Pa. After smelting, the alloy was cooled in the furnace for 2 hours, and then broken, demolded, and cooled in the air in turn to obtain a high-temperature alloy ingot with a diameter of Φ508 mm and containing black spot defects.

[0137] A low-power photo of a high-temperature alloy ingot containing black spot defects is shown in Figure 1. Figure 1 As shown, Figure 1 Figure a is a low-magnification photo of a high-temperature alloy ingot containing black spot defects. Figure 1 b is another low-magnification photo of a high-temperature alloy ingot containing black spot defects; Figure 1 It can be seen that there are patches of black spot defects of different sizes at the core and outer edge of the ingot. The microstructure characterization of a black spot defect and the matrix in the high-temperature alloy ingot containing black spot defects is shown in the following figure. Figure 2 , Figure 3 and Figure 4 , Figure 5 shown; from Figure 2 , Figure 3 , Figure 4 and Figure 5 It can be seen that the Nb content in the black spot defects of GH4169 alloy is 8.1wt%, which is higher than the Nb content in the GH4169 alloy matrix (5wt%). At the same time, due to the increase in Nb content, a large number of strengthening phases appear at the grain boundaries. Due to the grain boundary pinning effect of the strengthening phase, the grain size at the black spot position is significantly smaller than the grain size at the matrix position.

[0138] Example 2

[0139] The preparation method of black spot defects of GH4169 alloy ingot provided in this embodiment comprises the following steps:

[0140] S1. Vacuum induction melting of GH4169 alloy raw materials to obtain vacuum induction melting ingots; vacuum induction melting includes: after adding GH4169 alloy raw materials, power is turned on for melting, the power is 700KW, and the refining temperature is 1450°C; then casting is performed under vacuum environment, the casting nozzle diameter Φ is 23mm, after casting, the casting is cooled with the furnace for 75min and then broken, after breaking, the mold is slowly cooled for 18h and then demolded to obtain a vacuum induction melting ingot with a diameter of Φ 300mm;

[0141] S2. The vacuum induction melting ingot is subjected to protective atmosphere electroslag remelting to obtain an electrode rod; the protective atmosphere electroslag remelting includes: peeling or rolling the surface of the vacuum induction melting ingot to reveal the original color of the metal, the surface is clean, and there is no oil stain or paint, and at the same time, the shrinkage end is cut off by more than 70 to 200 mm, and then the ingot is loaded into the electroslag remelting furnace for melting. Argon is filled throughout the melting process, the argon flow rate is 20L / min, the slag amount is 30Kg, the slag resistance swing and voltage swing are both 0.4mOhm, the melting rate is 3kg / min, the filling time is 20 to 60min, and the ingot is cooled with the furnace for 25min after melting to obtain an electrode rod with a diameter of Φ400mm;

[0142] S3. The electrode rod is subjected to vacuum consumable remelting to obtain a high-temperature alloy ingot containing black spot defects; the vacuum consumable remelting includes: using a polishing method to completely peel the electrode rod to ensure that there is no black skin on the surface, and using electric spark cutting to cut the head of the electrode rod flat, and then vacuum consumable remelting; the vacuum consumable remelting includes an arc starting stage and a melting stage in sequence; in the arc starting stage, the arc starting weight is 120Kg, and the arc starting melting rate is controlled to be 2.2kg / min by using current plus voltage; in the melting stage, the melting rate of the first 1 / 3 of the electrode rod is 3.5kg / min, the melting rate of the middle 1 / 3 of the length is 3 / min, and the melting rate of the remaining 1 / 3 of the length is 2.5kg / min, the droplet size throughout the process is 1mm, and when a stable state is reached during the melting process, helium is introduced for cooling, and the pressure of the helium is 300Pa; after melting, it is cooled in the furnace for 1h and then broken, demolded, and cooled in the air are performed in sequence to obtain a high-temperature alloy ingot containing black spot defects with a diameter of Φ 400mm.

[0143] Example 3

[0144] The preparation method of black spot defects of GH4169 alloy ingot provided in this embodiment comprises the following steps:

[0145] S1. Vacuum induction melting of GH4169 alloy raw materials to obtain vacuum induction melting ingots; vacuum induction melting includes: after adding GH4169 alloy raw materials, power is turned on for melting, the power is 1000KW, and the refining temperature is 1700°C; then casting is performed under vacuum environment, the casting nozzle diameter Φ is 35mm, after casting, the furnace is cooled for 120min and then the vacuum is broken, after breaking, the mold is slowly cooled for 36h and then demolded to obtain a vacuum induction melting ingot with a diameter of Φ 400mm;

[0146] S2. The vacuum induction melting ingot is subjected to protective atmosphere electroslag remelting to obtain an electrode rod; the protective atmosphere electroslag remelting includes: peeling or tumbling the surface of the vacuum induction melting ingot to reveal the original color of the metal, making the surface clean, free of oil stains and paint, and cutting off more than 70 to 200 mm of the shrinkage cavity end, and then loading it into an electroslag remelting furnace for melting, and the whole melting process is filled with argon gas, the argon gas flow rate is 120L / min, the slag amount is 70Kg, the slag resistance swing and voltage swing are both 1mOhm, the melting rate is 3kg / min, the filling time is 20 to 60min, and the furnace is cooled for 80min after melting to obtain an electrode rod with a diameter of Φ550mm;

[0147] S3. The electrode rod is subjected to vacuum consumable remelting to obtain a high-temperature alloy ingot containing black spot defects; the vacuum consumable remelting includes: using a polishing method to completely peel the electrode rod to ensure that there is no black skin on the surface, and using electric spark cutting to cut the head of the electrode rod flat, and then vacuum consumable remelting; the vacuum consumable remelting includes an arc starting stage and a melting stage in sequence; in the arc starting stage, the arc starting weight is 220Kg, and the arc starting melting rate is controlled to be 8kg / min by using current plus voltage; in the melting stage, the melting rate of the first 1 / 3 of the electrode rod is 7kg / min, the melting rate of the middle 1 / 3 is 6.5 / min, and the melting rate of the remaining 1 / 3 is 6kg / min. The droplet size throughout the process is 12mm. When a stable state is reached during the melting process, helium is introduced for cooling, and the pressure of the helium is 1000Pa; after melting, it is cooled in the furnace for 4h and then broken, demolded, and cooled in air in sequence to obtain a high-temperature alloy ingot containing black spot defects with a diameter of Φ 550mm.

[0148] Example 4

[0149] The method for preparing white spot defects of GH4169 alloy ingot provided in this embodiment comprises the following steps:

[0150] S1. Vacuum induction melting of GH4169 alloy raw materials to obtain vacuum induction melting ingots; vacuum induction melting includes: after adding GH4169 alloy raw materials, power is turned on for melting, the power is 1000KW, and the refining temperature is 1550°C; then casting is performed under vacuum environment, the casting nozzle diameter Φ is 27mm, after casting, it is cooled with the furnace for 25min and then broken, after breaking, it is cooled with the furnace for 1.5min, and then it is slowly cooled with the mold for 2h and then demolded to obtain a vacuum induction melting ingot with a diameter of Φ360mm;

[0151] S2. The vacuum induction melting ingot is subjected to vacuum consumable remelting to obtain a high-temperature alloy ingot containing white spot defects; the vacuum consumable remelting includes: the vacuum induction melting ingot is subjected to full skinning by polishing to ensure that there is no black skin on the surface, the riser end of the vacuum induction melting ingot is cut off by 100 to 250 mm, the cutting method is a sawing machine or a wire cutting, and then the vacuum consumable remelting is performed; the vacuum consumable remelting includes an arc starting stage and a melting stage in sequence; in the arc starting stage, the arc starting weight is 170 kg, and the arc starting melting speed is controlled to 4 by the current plus voltage method. .2kg / min; in the smelting stage, the melting rate of the first 1 / 3 of the electrode rod is 3.25kg / min, the melting rate of the middle 1 / 3 is 3.75 / min, and the melting rate of the remaining 1 / 3 is 4.25kg / min. The droplet size throughout the whole process is 4. When a stable state is reached during the smelting process, helium is introduced for cooling. The pressure of helium is 600Pa. After smelting, it is cooled in the furnace for 2h, and then broken, demolded, and cooled in the air are performed in turn to obtain a high-temperature alloy ingot with a diameter of Φ440mm containing white spot defects.

[0152] A low-power photo of a high-temperature alloy ingot containing white spot defects is shown in Figure 1. Figure 6 As shown, Figure 5 Figure a is a low-magnification photo of a high-temperature alloy ingot containing white spot defects. Figure 5 b is another low-magnification photo of a high-temperature alloy ingot containing white spot defects; Figure 5 It can be seen that a single large-sized white spot appeared in the core and outer edge of the ingot, as well as white spot defects of varying sizes scattered on low-magnification films. The microstructural characterization of one of the white spot defects and the microstructural characterization of a black spot defect and the matrix in the high-temperature alloy ingot containing the white spot defect were performed, and the results are shown in Figure 2. Figure 7 , Figure 8 , Fig. 9 and Fig.10 shown; from Figure 7 , Figure 8 Fig. 9 and Fig.10It can be seen that the Nb content in the white spot defects of the GH4169 alloy is 4.3wt%, which is lower than the Nb content in the GH4169 alloy matrix (5.5wt%). Because the white spot defect area contains a lower Nb content, less strengthening phase precipitated at the grain boundary, the pinning effect is weak, and the grain size of the white spot defect area is significantly larger than that of the collective area.

[0153] Example 5

[0154] The method for preparing white spot defects of GH4169 alloy ingot provided in this embodiment comprises the following steps:

[0155] S1. Vacuum induction melting of GH4169 alloy raw material to obtain vacuum induction melting ingot; vacuum induction melting includes: after adding GH4169 alloy raw material, power is turned on for melting, power is 700KW, and refining temperature is 1550℃; then casting is carried out in a vacuum environment, the casting nozzle diameter Φ is 20mm, after casting, it is cooled with the furnace for 15min and then broken, after breaking, it is cooled with the furnace for 60min, and then it is slowly cooled with the mold for 1h and then demolded to obtain a vacuum induction melting ingot with a diameter of Φ350mm;

[0156] S2. The vacuum induction melted ingot is subjected to vacuum consumable remelting to obtain a high-temperature alloy ingot containing white spot defects; the vacuum consumable remelting includes: the vacuum induction melted ingot is subjected to full skinning by polishing to ensure that there is no black skin on the surface, the riser end of the vacuum induction melted ingot is cut off by 100 to 250 mm, the cutting method is a sawing machine or a wire cutting, and then the vacuum consumable remelting is carried out; the vacuum consumable remelting includes an arc starting stage and a melting stage in sequence; in the arc starting stage, the arc starting weight is 120 kg, and the arc starting melting is controlled by current plus voltage. The rate is 2.2kg / min; in the smelting stage, the first 1 / 3 of the electrode rod is melted at a rate of 1.5kg / min, the middle 1 / 3 is melted at a rate of 2 / min, and the remaining 1 / 3 is melted at a rate of 3kg / min. The droplet size throughout the whole process is 2. When a stable state is reached during the smelting process, helium is introduced for cooling, and the pressure of the helium is 300Pa. After smelting, the furnace is cooled for 1h, and then the furnace is broken, demolded, and cooled in the air in turn to obtain a high-temperature alloy ingot with a diameter of Φ400mm containing white spot defects.

[0157] Example 6

[0158] The method for preparing white spot defects of GH4169 alloy ingot provided in this embodiment comprises the following steps:

[0159] S1. Vacuum induction melting of GH4169 alloy raw materials to obtain vacuum induction melting ingots; vacuum induction melting includes: after adding GH4169 alloy raw materials, power is turned on for melting, the power is 1000KW, and the refining temperature is 1700°C; then casting is performed under vacuum environment, the casting nozzle diameter Φ is 35mm, after casting, it is cooled with the furnace for 60min and then broken, after breaking, it is cooled with the furnace for 120min, and then it is slowly cooled with the mold for 4h and then demolded to obtain a vacuum induction melting ingot with a diameter of Φ 500mm;

[0160] S2. The vacuum induction melting ingot is subjected to vacuum consumable remelting to obtain a high-temperature alloy ingot containing white spot defects; the vacuum consumable remelting includes: the vacuum induction melting ingot is subjected to full skinning by polishing to ensure that there is no black skin on the surface, the riser end of the vacuum induction melting ingot is cut off by 100 to 250 mm, the cutting method is a sawing machine or a wire cutting, and then the vacuum consumable remelting is performed; the vacuum consumable remelting includes an arc starting stage and a melting stage in sequence; in the arc starting stage, the arc starting weight is 220 kg, and the arc starting melting speed is controlled by a current plus voltage method. 3.5kg / min; in the smelting stage, the first 1 / 3 of the electrode rod is melted at a melting rate of 3.5kg / min, the middle 1 / 3 is melted at a melting rate of 5.5 / min, and the remaining 1 / 3 is melted at a melting rate of 6kg / min. The droplet size during the whole process is 9mm. When a stable state is reached during the smelting process, helium is introduced for cooling. The pressure of helium is 1000Pa. After smelting, it is cooled in the furnace for 4h, then broken, demolded, and cooled in the air in turn to obtain a high-temperature alloy ingot with a diameter of Φ500mm containing white spot defects.

[0161] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing metallurgical defects of high temperature alloy ingots, characterized in that: It includes a preparation method for black spot defects of high temperature alloy ingots and a preparation method for white spot defects of high temperature alloy ingots; The method for preparing black spot defects of high temperature alloy ingots comprises the following steps: The high-temperature alloy raw material is subjected to vacuum induction melting to obtain a vacuum induction melting ingot; the vacuum induction melting ingot is subjected to protective atmosphere electroslag remelting to obtain an electrode rod; the electrode rod is subjected to vacuum consumable remelting to obtain a high-temperature alloy ingot containing black spot defects; Wherein, during the protective atmosphere electroslag remelting process, the slag resistance swing and the voltage swing are independently 0.2-1 mOhm; the melting rate is 2.5-8 kg / min; In the smelting stage of the vacuum consumable remelting, the melting rate from the beginning of smelting to 1 / 3 of the length of the electrode rod is 3.5-7 kg / min, the melting rate from 1 / 3 of the length of the electrode rod to 2 / 3 of the length of the electrode rod is 3-6.5 kg / min, and the melting rate from 2 / 3 of the length of the electrode rod to the end of smelting is 2.5-6 kg / min; the droplet size in the smelting stage is 1-12 mm; helium is introduced in the smelting stage, and the pressure of the helium is 300-1000 Pa; The method for preparing white spot defects of high temperature alloy ingots comprises the following steps: The high temperature alloy raw material is subjected to vacuum induction melting to obtain a vacuum induction melting ingot; the vacuum induction melting ingot is subjected to vacuum consumable remelting to obtain a high temperature alloy ingot containing white spot defects; The vacuum consumable remelting includes an arc starting stage and a melting stage; the melting rate in the arc starting stage is 2.2 to 5 kg / min; in the melting stage, the melting rate from the beginning of melting to 1 / 3 of the length of the electrode rod is 1.5 to 3.5 kg / min, the melting rate from 1 / 3 of the length of the electrode rod to 2 / 3 of the length of the electrode rod is 2 to 5.5 kg / min, and the melting rate from 2 / 3 of the length of the electrode rod to the end of melting is 3 to 6 kg / min; the droplet size in the melting stage is 2 to 9 mm.

2. The method for preparing metallurgical defects of high temperature alloy ingots according to claim 1, characterized in that: The high temperature alloy includes GH4169 alloy.

3. The method for preparing metallurgical defects of high temperature alloy ingots according to claim 1, characterized in that: The method for preparing black spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (3); (1) The protective gas for the protective atmosphere electroslag remelting includes argon; (2) The flow rate of the argon gas is 20 to 120 L / min; (3) The amount of slag in the protective atmosphere electroslag remelting is 20 to 70 kg.

4. The method for preparing metallurgical defects of high temperature alloy ingots according to claim 3, characterized in that: The method for preparing black spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (3); (1) The filling time of the protective atmosphere electroslag remelting is 10 to 70 minutes; (2) The cooling time of the protective atmosphere electroslag remelting is 20 to 80 minutes; (3) The diameter of the electrode rod is 350-450 mm.

5. The method for preparing metallurgical defects of high temperature alloy ingots according to claim 1, characterized in that: The method for preparing black spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (3); (1) During the arc starting stage of the vacuum consumable remelting, the arc starting weight is 120-220 kg, and the arc starting melting speed is 2.2-8 kg / min; (2) In the vacuum consumable remelting process, the smelting is followed by furnace cooling for 1 to 4 hours, vacuum breaking, demoulding and air cooling; (3) The diameter of the high-temperature alloy ingot containing black spot defects is 400 to 550 mm.

6. The method for preparing metallurgical defects of high temperature alloy ingots according to claim 1, characterized in that: In the preparation method for white spot defects in high-temperature alloy ingots, in the arc starting stage of the vacuum consumable remelting, the arc starting weight is 120 to 220 kg, and the arc starting melting rate is 2.2 to 5 kg / min.

7. The method for preparing metallurgical defects of high temperature alloy ingots according to claim 6, characterized in that: The method for preparing white spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (3); (1) During the vacuum consumable remelting process, helium is introduced into the smelting stage, and the pressure of the helium is 300 to 1000 Pa; (2) In the vacuum consumable remelting process, the smelting is followed by furnace cooling for 1 to 4 hours, vacuum breaking, demoulding and air cooling; (3) The diameter of the high-temperature alloy ingot containing white spot defects is 400 to 550 mm.

8. The method for preparing metallurgical defects of high temperature alloy ingots according to claim 1, characterized in that: The method for preparing black spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (3); (1) The vacuum induction melting includes: melting, pouring, furnace cooling, vacuum breaking, slow cooling with mold and demolding in sequence; (2) The power of the vacuum induction melting is 700-1000KW; (3) The refining temperature of the smelting is 1450-1700°C.

9. The method for preparing metallurgical defects of high temperature alloy ingots according to claim 8, characterized in that: The method for preparing black spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (4); (1) The diameter of the pouring nozzle is 20 to 35 mm; (2) The furnace cooling time is 60 to 120 minutes; (3) The time for slow cooling of the strip mold is 16 to 36 hours; (4) The diameter of the vacuum induction melting ingot is 300 to 400 mm.

10. The method for preparing metallurgical defects of high temperature alloy ingots according to claim 1, characterized in that: The method for preparing white spot defects in high temperature alloy ingots comprises at least one of the following features (1) to (7); (1) The vacuum induction melting comprises: melting, pouring, furnace cooling, vacuum breaking, furnace cooling, slow cooling with mold and demolding in sequence; (2) The power of the vacuum induction melting is 700-1000KW; (3) The refining temperature of the smelting is 1450-1700° C.; (4) The diameter of the pouring nozzle is 20 to 35 mm; (5) After the pouring, the casting is sequentially cooled with the furnace for 15 to 60 minutes, broken, and cooled with the furnace for 60 to 120 minutes; (6) The time for slow cooling of the strip mold is 1 to 4 hours; (7) The diameter of the vacuum induction melting ingot is 350 to 500 mm.

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