A homogenization heat treatment method for high temperature alloy containing Nb

Abstract

The present invention relates to a homogenization heat treatment method for a Nb-containing high-temperature alloy, which comprises the following steps: S1. preheating a Nb-containing high-temperature alloy ingot to a first predetermined temperature range in a heat treatment furnace; S2. performing a multi-stage homogenization heat treatment on the preheated Nb-containing high-temperature alloy ingot; and S3. cooling the Nb-containing high-temperature alloy ingot after the multi-stage homogenization heat treatment, wherein the preheating time in step S1 satisfies a first functional relationship with the length or mass of the Nb-containing high-temperature alloy ingot. The homogenization heat treatment method for a Nb-containing high-temperature alloy of the present invention establishes a relationship between the length, mass and heat treatment time of the Nb-containing high-temperature alloy material and adopts a three-stage homogenization process, which can reduce the homogenization time, homogenize the alloy in a more efficient and energy-saving manner, improve the alloy performance, reduce the production cost and improve the production efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature alloys, and in particular to a homogenization heat treatment method for a Nb-containing high-temperature alloy. Background Art

[0002] High-temperature alloys can withstand large and complex stresses in high-temperature environments such as above 600°C, have good mechanical properties and surface stability, and are widely used in aero engines and industrial gas turbines, such as turbine blades, turbine disks, combustion chambers, etc. Nb is a refractory element commonly used in high-temperature alloys and a common precipitation strengthening element. Nb enters the γ' phase to form Ni3 (Al, Ti, Nb), changes the lattice constant of γ', and then increases the mismatch between γ and γ', increases the coherent strain around the γ' phase, and plays a precipitation strengthening role. At the same time, as the main element of the γ' phase, adding Nb can increase the number and size of the γ' phase, enhance the precipitation strengthening effect of the γ' phase, and thus improve the mechanical properties of the alloy such as yield strength and creep resistance. However, a high content of Nb will cause severe segregation during the solidification process of the alloy, forming a large number of Nb-rich Laves precipitation phases, and even causing macroscopic defects. The Laves phase consumes a large amount of Nb elements, reducing the precipitation strengthening effect. At the same time, its own brittleness and low melting point seriously affect the mechanical properties of the alloy. Therefore, it is usually necessary to keep the Nb-containing high-temperature alloy at an appropriate temperature for a long time to allow the Laves phase to melt back into the matrix, and then further increase the temperature to accelerate the diffusion of segregated elements until overall homogenization is achieved.

[0003] At present, for this type of Nb-containing high-temperature alloy, the existing technology usually adopts a two-stage homogenization heat treatment process, which is relatively simple. First, homogenization is carried out at a lower temperature to melt all the Laves phases back, and then the temperature is increased for a long time to keep the heat to achieve a uniform distribution of segregated elements. However, the two-stage homogenization heat treatment process is prone to cause local overburning and overall non-uniformity, which reduces the mechanical properties of the material and affects subsequent processing. In addition, long-term high-temperature homogenization heat treatment will cause abnormal grain growth, increase in oxide layer, increase in material loss rate, and increase in production costs. At the same time, affected by the heat transfer efficiency of the material, a fixed homogenization heat treatment method cannot be fully applicable to high-temperature alloy materials of different sizes. At present, the existing technology does not have a relatively complete and universal homogenization heat treatment process for Nb-containing high-temperature alloys of different ingot shapes and grades.

[0004] Therefore, the existing technology still needs to be improved. It is necessary to develop a homogenization heat treatment method for Nb-containing high-temperature alloys suitable for different ingot types to eliminate the low melting point and brittle precipitation phase Laves phase of the cast high-temperature alloy and homogenize the segregated elements, which is important for obtaining Nb-containing high-temperature alloys with excellent performance. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes a homogenization heat treatment method for Nb-containing high-temperature alloys suitable for different ingot shapes. The method can effectively homogenize high-temperature alloy materials of different sizes, effectively eliminate the uneven composition and structure in the alloy, and avoid overburning phenomena such as local melting and holes in the matrix, thereby avoiding affecting the subsequent processing and mechanical properties of the high-temperature alloy.

[0006] Specifically, the present invention provides a homogenization heat treatment method for a Nb-containing high-temperature alloy, which comprises the following steps: S1. preheating a Nb-containing high-temperature alloy ingot to a first predetermined temperature range in a heat treatment furnace; S2. performing a multi-stage homogenization heat treatment on the preheated Nb-containing high-temperature alloy ingot; and S3. cooling the Nb-containing high-temperature alloy ingot after the multi-stage homogenization heat treatment, wherein the preheating time in step S1 satisfies a first functional relationship with the length or mass of the Nb-containing high-temperature alloy ingot.

[0007] In some embodiments, the first predetermined temperature range is 700° C. to 900° C., and when the mass of the Nb-containing high-temperature alloy ingot is less than 200 kg or the length is less than 300 mm, the first functional relationship is the following equation 1; when the mass of the Nb-containing high-temperature alloy ingot is greater than 200 kg and less than 500 kg or the length is greater than 300 mm, the first functional relationship is the following equation 2; when the mass of the Nb-containing high-temperature alloy ingot is greater than 500 kg, the first functional relationship is the following equation 3:

[0008] t1=2+(0.013~0.023)*L Equation 1

[0009] t1=2+(0.013~0.023)*L+(1.5~2)*10 -5 *L 2 Equation 2

[0010] t1=2+(0.013~0.023)*L+(1.5~2)*10 -5 *L 2 +(1.7~4.2)*10 -3 W Equation 3

[0011] Wherein, t1 represents the preheating time, L represents the length of the Nb-containing high-temperature alloy ingot, and W represents the mass of the Nb-containing high-temperature alloy ingot.

[0012] In some embodiments, the multi-stage homogenization heat treatment includes a first-stage homogenization heat treatment, a first-stage homogenization temperature of the first-stage homogenization heat treatment is within a second predetermined temperature range, and a first holding time of the first-stage homogenization heat treatment satisfies a second functional relationship with the first-stage homogenization temperature.

[0013] In some embodiments, the second functional relationship is the following equation 4:

[0014] t2=(1.5~4)+(0.8~3.10)*10 10 exp(-0.0186*T)Equation 4

[0015] Wherein, t2 is the first insulation time, and T is the first stage homogenization temperature.

[0016] In some embodiments, the second predetermined temperature range is 1100°C to 1140°C, and the multi-stage homogenization heat treatment further includes a second-stage homogenization heat treatment and a third-stage homogenization heat treatment, wherein the second-stage homogenization temperature of the second-stage homogenization heat treatment is 1160°C, and the second holding time of the second-stage homogenization heat treatment is 15 to 25 hours, the third-stage homogenization temperature of the third-stage homogenization heat treatment is 1190°C, and the third holding time of the third-stage homogenization heat treatment is 25 to 60 hours.

[0017] In some embodiments, the heating rates in step S1 and step S2 are respectively 200° C. / h to 450° C. / h.

[0018] In some embodiments, step S3 includes cooling the Nb-containing high-temperature alloy ingot after the multi-stage homogenization heat treatment in the furnace and outside the furnace, and the furnace is cooled to 900° C. to 1120° C., and the outside of the furnace is cooled to room temperature.

[0019] In some embodiments, step S3 further includes performing a thermal deformation treatment on the Nb-containing high-temperature alloy ingot when the ingot is cooled to 1000° C. to 1120° C. in the furnace.

[0020] In some embodiments, the hot deformation process includes hot forging or hot rolling.

[0021] In some embodiments, the Nb-containing high temperature alloy casting is one of GH4169, GH3625, GH2903, GH2907, and GH2909.

[0022] The homogenization heat treatment method of the Nb-containing high-temperature alloy of the present invention can adopt different preheating systems for high-temperature alloy materials of different sizes, so that the Nb-containing high-temperature alloy can be uniformly heated from the edge to the center; for the Laves phase containing a low melting point in the Nb-containing high-temperature alloy, a method of first performing a first-stage homogenization heat treatment at a relatively low temperature is adopted; after the first-stage homogenization heat treatment is completed, the temperature is raised to a relatively high temperature to perform a second-stage homogenization heat treatment, and after a period of homogenization, the safe temperature of the alloy homogenization is increased, and the homogenization temperature is increased again to avoid overburning of the high-temperature alloy material, and at the same time, homogenization is quickly achieved; the grain growth and oxidation caused by the high-temperature alloy being in a high-temperature environment for a long time are significantly reduced, the alloy yield is improved, and the production income is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic flow chart of a homogenization heat treatment method for a Nb-containing high-temperature alloy provided by the present invention is shown;

[0024] Figure 2 The as-cast structure of a high-temperature alloy containing Nb according to an embodiment of the present invention is shown;

[0025] Figure 3 Shows Figure 2 The microstructure of the Nb-containing high-temperature alloy after homogenization is shown;

[0026] Figure 4 shows the microstructure of the homogenized Nb-containing high-temperature alloy in the comparative example; and

[0027] Figure 5 The microstructure of a homogenized Nb-containing high-temperature alloy in another comparative example is shown. DETAILED DESCRIPTION

[0028] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are only illustrative. Although only a few embodiments are described in detail in the present invention, it is easy for those skilled in the art to appreciate that multiple modifications are feasible without actually departing from the teaching of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Without departing from the gist of the present invention, other replacements, modifications, changes and deletions may be made to the design, operating conditions and parameters of the following exemplary embodiments.

[0029] According to the present invention, a homogenization heat treatment method of a Nb-containing high-temperature alloy is provided, such as Figure 1 As shown, the method comprises the following steps:

[0030] S1. Preheating the Nb-containing high-temperature alloy ingot to a first predetermined temperature range in a heat treatment furnace;

[0031] S2. The preheated Nb-containing high-temperature alloy ingot is subjected to a multi-stage homogenization heat treatment; and

[0032] S3. Cooling the Nb-containing high-temperature alloy ingot after the multi-stage homogenization heat treatment.

[0033] Wherein, in step S1, the Nb-containing high temperature alloy ingot (hereinafter referred to as the Nb-containing high temperature alloy ingot) is placed in a heat treatment furnace for preheating, and the preheating time can satisfy a first functional relationship with the length or mass of the Nb-containing high temperature alloy ingot. The technical solution of the present invention establishes a relationship between the length, mass and heat treatment time of the Nb-containing high temperature alloy, and can more specifically establish a heat treatment process that meets the requirements of Nb-containing high temperature alloys of different sizes, thereby reducing production costs and improving production efficiency.

[0034] In some embodiments, the first predetermined temperature in step S1 may be in the range of 700° C. to 900° C.

[0035] In some embodiments, for a Nb-containing high temperature alloy of conventional size, such as a Nb-containing high temperature alloy ingot with a mass of less than 200 kg or a length of less than 300 mm, the first functional relationship is embodied by the following equation 1:

[0036] t1=2+(0.013~0.023)*LEquation 1

[0037] Wherein, t1 represents the preheating time, L represents the length of the Nb-containing high-temperature alloy ingot, wherein the unit of the preheating time is h, and the unit of the length is mm.

[0038] In some embodiments, for large-sized Nb-containing high-temperature alloys, the preheating time in step S1 can be extended. For example, when the mass of the Nb-containing high-temperature alloy ingot is greater than 200 kg and less than 500 kg or the length is greater than 300 mm, the first functional relationship is embodied in the following equation 2:

[0039] t1=2+(0.013~0.023)*L+(1.5~2)*10 -5 *L 2 Equation 2

[0040] When the mass of the Nb-containing high-temperature alloy ingot is greater than 500 kg, the first functional relationship is expressed as the following equation 3:

[0041] t1=2+(0.013~0.023)*L+(1.5~2)*10 -5 *L 2 +(1.7~4.2)*10 -3 W equation three

[0042] Wherein, W represents the mass of the Nb-containing high-temperature alloy ingot, in kg.

[0043] In some embodiments, the multi-stage homogenization heat treatment in step S2 may include a first-stage homogenization heat treatment, wherein the first-stage homogenization temperature of the first-stage homogenization heat treatment is within a second predetermined temperature range and the first-stage homogenization temperature is lower than the homogenization temperatures of the other stages of the homogenization heat treatment. The second predetermined temperature range may be 1100° C. to 1140° C.

[0044] In some embodiments, the first holding time of the first stage homogenization heat treatment and the first stage homogenization temperature satisfy a second functional relationship, and the second functional relationship is the following equation 4:

[0045] t2=(1.5~4)+(0.8~3.10)*10 10 exp(-0.0186*T)Equation 4

[0046] Wherein, t2 is the first holding time, and T is the first stage homogenization temperature, the unit of the first holding time is h, and the unit of the first stage homogenization temperature is °C.

[0047] In some embodiments, the multi-stage homogenization heat treatment in step S2 may also include a second-stage homogenization heat treatment and a third-stage homogenization heat treatment, wherein the second-stage homogenization temperature of the second-stage homogenization heat treatment is 1160°C, and the second holding time of the second-stage homogenization heat treatment is 15 to 25 hours; the third-stage homogenization temperature of the third-stage homogenization heat treatment is 1190°C, and the third holding time of the third-stage homogenization heat treatment is 25 to 60 hours.

[0048] In some embodiments, the heating rates in step S1 and step S2 are respectively 200° C. / h to 450° C. / h.

[0049] In the technical solution of the present invention, the corresponding homogenization temperatures of the first stage homogenization heat treatment, the second stage homogenization heat treatment and the third stage homogenization heat treatment are increased step by step, which can effectively avoid overburning of the Nb-containing high-temperature alloy, and quickly achieve homogenization, significantly reduce the grain growth and oxidation caused by the Nb-containing high-temperature alloy being in a high-temperature environment for a long time, improve the alloy yield, and increase production benefits.

[0050] In some embodiments, step S3 includes cooling the Nb-containing high-temperature alloy ingot after the multi-stage homogenization heat treatment in the furnace and outside the furnace, and the furnace is cooled to 900° C. to 1120° C., and the outside of the furnace is cooled to room temperature. The outside of the furnace cooling can be at least one of air cooling, water cooling and oil cooling.

[0051] In some embodiments, step S3 may further include performing a hot deformation treatment on the Nb-containing high-temperature alloy ingot when the Nb-containing high-temperature alloy ingot is cooled to 1000° C. to 1120° C. in the furnace to improve the grain size of the Nb-containing high-temperature alloy. The hot deformation treatment may include hot forging or hot rolling.

[0052] In some embodiments, the Nb-containing high-temperature alloy is one of GH4169, GH3625, GH2903, GH2907, and GH2909.

[0053] The method of the present invention at least performs preheating treatment, three-stage homogenization treatment, hot working deformation and cooling on the cast high-temperature alloy. Different preheating systems are used for Nb-containing high-temperature alloys of different sizes, so that the Nb-containing high-temperature alloy can be evenly heated from the edge to the center; for the Laves phase containing a low melting point in the Nb-containing high-temperature alloy, a method of first performing a first-stage homogenization heat treatment at a lower temperature is adopted. After the first-stage homogenization is completed, the temperature is raised to a higher temperature for a second-stage homogenization heat treatment. After a period of homogenization, the safe temperature of the alloy homogenization is increased. The homogenization temperature is increased again (i.e., the third-stage homogenization heat treatment), which can avoid overburning of the Nb-containing high-temperature alloy material and quickly achieve homogenization; significantly reduce the grain growth and oxidation caused by the Nb-containing high-temperature alloy being in a high-temperature environment for a long time, improve the alloy yield, and improve production benefits.

[0054] The technical solution of the present invention is further illustrated by specific embodiments below:

[0055] Example 1

[0056] A Nb-containing high-temperature alloy ingot is placed in a heat treatment furnace. The ingot length L = 120 mm and the ingot weight W = 10 kg. The as-cast structure is as follows Figure 2 As shown. The as-cast structure has dendrite structure, a large amount of Laves phase exists between the dendrites, and the Nb element segregation coefficient is 2.67. The method of the present invention is used to heat treat the ingot, including the following steps:

[0057] S1: The Nb-containing high-temperature alloy ingot is preheated with the furnace heated to 800°C, with a heating rate of 5°C / min to 7.5°C / min. The preheating time t1=4h is calculated using the above equation 1.

[0058] S2: Three-stage homogenization heat treatment.

[0059] The homogenization temperature in the first stage is 1130° C., and the first insulation time t2=15h is calculated using the above equation 4.

[0060] The second stage homogenization temperature is 1160℃, and the temperature is kept for 15h.

[0061] The third stage homogenization temperature is 1190℃, and the temperature is kept for 36h.

[0062] The heating rate is 5℃ / min~7.5℃ / min.

[0063] S3: Cool the furnace to 900°C, take out the sample and water cool it to room temperature.

[0064] The microstructure of the Nb-containing high-temperature alloy treated in Example 1 after homogenization was observed using a scanning electron microscope. Figure 3 The original dendrite structure was melted, and the Laves phase was completely melted back into the alloy matrix without overburning. The residual segregation coefficient of Nb element was 0.15, and the residual segregation coefficients of other segregation elements such as Ni, Si, Fe, and Ti were all less than 0.10.

[0065] Example 2

[0066] Place a Nb-containing high-temperature alloy ingot into a heat treatment furnace, the ingot length L = 500 mm, the ingot weight W = 490 kg. Perform the following steps:

[0067] S1: The Nb-containing high-temperature alloy ingot is preheated with the furnace heated to 900°C, with a heating rate of 3.5°C / min to 5°C / min. The preheating time t1=18h is calculated using equation 2 as described above.

[0068] S2: Three-stage homogenization heat treatment.

[0069] The homogenization temperature in the first stage is 1140° C., and the first holding time t2=19 h is calculated using equation 4 as described above.

[0070] The second stage homogenization temperature is 1160℃, and the temperature is kept for 24h.

[0071] The third stage homogenization temperature is 1190℃, and the temperature is kept for 36h.

[0072] The heating rate is 3.5℃ / min~5℃ / min.

[0073] S3: Cool the furnace to 1080℃, and immediately perform hot forging after exiting the furnace, with a forging temperature of 1120℃ and a deformation of 45%. After hot forging, air cool to room temperature.

[0074] The microstructure of the Nb-containing high-temperature alloy after treatment in Example 2 was observed by scanning electron microscope, optical microscope, etc. The Laves phase was completely melted back without overburning, and the residual segregation coefficient of each element was less than 0.20. The grain size of the original ingot was level 3, and the grain size after hot deformation treatment was level 7, and there was no cracking on the surface of the material.

[0075] Example 3

[0076] Place a Nb-containing high-temperature alloy ingot into a heat treatment furnace, the ingot length L = 40 mm, the ingot weight W = 0.45 kg. Perform the following steps:

[0077] S1: The Nb-containing high-temperature alloy ingot is preheated with the furnace heated to 700°C, with a heating rate of 4°C / min to 6°C / min. The preheating time t1 = 2.6h is calculated using the above equation 1.

[0078] S2: Three-stage homogenization heat treatment.

[0079] The homogenization temperature in the first stage is 1130° C., and the first insulation time t2=19h is calculated using the above equation 4.

[0080] The second stage homogenization temperature is 1160℃, and the temperature is kept for 15h.

[0081] The third stage homogenization temperature is 1190℃, and the temperature is kept for 48h.

[0082] The heating rate is 4℃ / min~6℃ / min.

[0083] S3: Cool the furnace to 900°C, take out the sample and air cool it to room temperature.

[0084] After the treatment in Example 3, the Laves phase of the Nb-containing high-temperature alloy was completely melted back without overburning, and the residual segregation coefficient of each element was less than 0.17.

[0085] Example 4

[0086] A Nb-containing high-temperature alloy ingot is placed in a heat treatment furnace, the ingot length L = 628 mm, and the ingot mass W = 660 kg.

[0087] S1: The Nb-containing high-temperature alloy ingot is preheated with the furnace heated to 850°C, with a heating rate of 5°C / min to 7°C / min. The preheating time t1=21h is calculated using the above equation 3.

[0088] S2: After preheating, the temperature is raised to 1120°C with the furnace, and the first holding time t2=26h is calculated using the above equation 4, and the first stage of homogenization heat treatment is performed.

[0089] The temperature was raised to 1160°C and kept at this temperature for 20 hours, and the second stage of homogenization heat treatment was carried out.

[0090] The temperature was raised to 1190°C and kept at that temperature for 40 hours, and the third stage of homogenization heat treatment was carried out.

[0091] Heating rate: 4℃ / min~7℃ / min.

[0092] S3: Cool the furnace to 1000°C, take out the sample and oil cool it to room temperature.

[0093] In the high-temperature alloy material treated in Example 4, the Laves phase is completely melted back without overburning, and the residual segregation coefficient of each element is less than 0.20.

[0094] From the above examples, it can be seen that the Laves phase of the ingot obtained by the homogenization heat treatment method of a Nb-containing high-temperature alloy of the present invention is completely melted back, the segregation elements are evenly diffused, the residual segregation coefficient of each element is less than 0.20, and there is no overburning phenomenon. After the homogenized alloy is subjected to hot deformation processing, the grain size is improved.

[0095] Comparative Example 1

[0096] The method is the same as that of Example 1, except that this comparative example 1 adopts a two-stage homogenization heat treatment process, which is as follows:

[0097] S1': The Nb-containing high-temperature alloy ingot is preheated with the furnace heated to 800°C, the heating rate is 5°C / min to 7.5°C / min, and the preheating time t1 = 4h.

[0098] S2': Two-stage homogenization heat treatment.

[0099] The first stage homogenization temperature is 1160℃, and the temperature is kept for 30h.

[0100] The second stage homogenization temperature is 1190℃, and the temperature is kept for 36h.

[0101] The heating rate is 5℃ / min~7.5℃ / min.

[0102] S3': Cool the furnace to 900°C, take out the sample and water cool it to room temperature.

[0103] The microstructure of the ingot treated in Comparative Example 1 was characterized by scanning electron microscopy. Figure 4 As shown in the figure, overburning phenomena such as black holes appeared in the alloy, and the residual segregation coefficient of Nb element was 0.32.

[0104] Comparative Example 2

[0105] The method is the same as that in Example 1, except that the temperature of the third stage homogenization process in this comparative example 2 is different, as follows:

[0106] S1": The Nb-containing high-temperature alloy ingot is preheated with the furnace to 800°C, the heating rate is 5°C / min to 7.5°C / min, and the preheating time t1 = 4h.

[0107] S2”: three-stage homogenization heat treatment.

[0108] The first stage homogenization temperature is 1130°C and the holding time is 15h.

[0109] The second stage homogenization temperature is 1160℃, and the temperature is kept for 15h.

[0110] The third stage homogenization temperature is 1210℃, and the temperature is kept for 36h.

[0111] The heating rate is 5℃ / min~7.5℃ / min.

[0112] S3”: Cool the furnace to 900°C, take out the sample and water cool it to room temperature.

[0113] The microstructure of the ingot after the treatment of Comparative Example 2 was characterized by scanning electron microscopy. Figure 5 As shown in the figure, overburning phenomena such as black holes appeared in the alloy, and the residual segregation coefficient of Nb element was 0.27.

[0114] The heat treatment process of Comparative Example 1 only adopts a two-stage homogenization process. The temperature of the first stage homogenization heat treatment is too high, exceeding the dissolution temperature of the Laves phase, resulting in holes left in the matrix during the Laves phase melting back, and the segregated elements are not diffused evenly, affecting the mechanical properties of the material.

[0115] The third-stage homogenization temperature of Comparative Example 2 is too high, resulting in overburning of the material, forming black holes, and the segregated elements cannot be evenly diffused.

[0116] The method of the present invention includes preheating heat treatment, three-stage homogenization heat treatment, thermal deformation treatment and cooling treatment steps for cast high-temperature alloys of different sizes. The method adopts a process system of gradually increasing the temperature and keeping the temperature from low temperature to high temperature, and specifically realizes the elimination of dendrites and Laves phases of cast alloys of different ingot types, and realizes uniform diffusion of segregated elements. The preheating stage can make the alloy heated more evenly, avoiding overburning at the edge of the ingot during the homogenization heat treatment stage and substandard temperature in the center. The three-stage homogenization heat treatment system effectively eliminates the low-melting-point Laves phase, making the diffusion of alloy segregation elements more uniform and faster. While ensuring that the high-temperature alloy can achieve the homogenization effect, the high-temperature homogenization time is shortened as much as possible, the negative impact of excessive grain size is reduced, and the mechanical properties of the high-temperature alloy are improved. At the same time, the degree of oxidation of the alloy during homogenization is reduced, the material loss rate is reduced, the production cost is effectively reduced, and the profit is increased.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. If the present invention is modified or replaced by equivalents without departing from the spirit and scope of the present invention, it should be included in the protection scope of the claims of the present invention.

Claims

1. A homogenization heat treatment method for a Nb-containing high-temperature alloy, characterized in that: The following steps are involved: S1. Preheating the Nb-containing high temperature alloy ingot to 700°C to 900°C in a heat treatment furnace; S2. performing a multi-stage homogenization heat treatment on the preheated Nb-containing high-temperature alloy ingot, wherein the multi-stage homogenization heat treatment includes a first-stage homogenization heat treatment, a second-stage homogenization heat treatment and a third-stage homogenization heat treatment, wherein the first-stage homogenization temperature of the first-stage homogenization heat treatment is 1100° C. to 1140° C., and after the first-stage homogenization heat treatment is completed, the temperature is increased to perform the second-stage homogenization heat treatment for a second holding time, and then the temperature is increased again to perform the third-stage homogenization heat treatment for a third holding time, so as to avoid overburning of the Nb-containing high-temperature alloy and quickly achieve homogenization; and S3. Cooling the Nb-containing high-temperature alloy ingot after the multi-stage homogenization heat treatment, Wherein, the preheating time in step S1 satisfies a first functional relationship with the length or mass of the Nb-containing high-temperature alloy ingot. When the mass of the Nb-containing high-temperature alloy ingot is less than 200 kg or the length is less than 300 mm, the first functional relationship is the following equation 1; when the mass of the Nb-containing high-temperature alloy ingot is greater than 200 kg and less than 500 kg or the length is greater than 300 mm, the first functional relationship is the following equation 2; when the mass of the Nb-containing high-temperature alloy ingot is greater than 500 kg, the first functional relationship is the following equation 3: t1=2+(0.013~0.023)*L equation 1 t1=2+(0.013~0.023)*L+(1.5~2)*10 -5 *L 2 Equation 2 t1=2+(0.013~0.023)*L+(1.5~2)*10 -5 *L 2 +(1.7~4.2)*10 -3 W equation three Wherein, t1 represents the preheating time, L represents the length of the Nb-containing high-temperature alloy ingot, and W represents the mass of the Nb-containing high-temperature alloy ingot. The first holding time of the first stage homogenization heat treatment and the first stage homogenization temperature satisfy a second functional relationship, and the second functional relationship is the following equation 4: t2=(1.5~4)+(0.8~3.10)*10 10 exp(-0.0186*T)Equation 4 Wherein, t2 is the first insulation time, and T is the first stage homogenization temperature.

2. The homogenization heat treatment method of a Nb-containing high-temperature alloy according to claim 1, characterized in that: The second stage homogenization temperature of the second stage homogenization heat treatment is 1160°C, the second holding time of the second stage homogenization heat treatment is 15 to 25 hours, the third stage homogenization temperature of the third stage homogenization heat treatment is 1190°C, and the third holding time of the third stage homogenization heat treatment is 25 to 60 hours.

3. The homogenization heat treatment method of a Nb-containing high-temperature alloy according to claim 1, characterized in that: The heating rates in step S1 and step S2 are each in the range of 200° C. / h to 450° C. / h.

4. The homogenization heat treatment method of a Nb-containing high-temperature alloy according to claim 1, characterized in that: Step S3 includes cooling the Nb-containing high-temperature alloy ingot after the multi-stage homogenization heat treatment in the furnace and outside the furnace, and cooling in the furnace to 900° C. to 1120° C. and outside the furnace to room temperature.

5. The homogenization heat treatment method of a Nb-containing high-temperature alloy according to claim 4, characterized in that: Step S3 further includes performing a thermal deformation treatment on the Nb-containing high-temperature alloy ingot when the ingot is cooled to 1000° C. to 1120° C. in the furnace.

6. The homogenization heat treatment method of a Nb-containing high-temperature alloy according to claim 5, characterized in that: The thermal deformation treatment includes hot forging or hot rolling.

7. The homogenization heat treatment method of a Nb-containing high-temperature alloy according to claim 1, characterized in that: The Nb-containing high-temperature alloy is one of GH4169, GH3625, GH2903, GH2907, and GH2909.

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