A high-W high-temperature alloy seamless tube and its manufacturing method

Abstract

This invention discloses a high-W high-temperature alloy seamless tube and its manufacturing method, comprising: Step 1, sequentially melting and forging the high-W high-temperature alloy seamless tube material to obtain a tube blank; Step 2, hot-working the tube blank to obtain a rough tube; Step 3, sequentially heat-treating and finishing the rough tube to obtain a preliminary alloy tube; the heat treatment is a stepped heat treatment, including a first solution heat treatment, a second solution heat treatment, and a cooling treatment; wherein the temperature of the first solution heat treatment is lower than the temperature of the second solution heat treatment; Step 4, cold-working the preliminary alloy tube to obtain a finished tube. The beneficial effects of this invention are: it possesses both ultra-high strength and good ductility and toughness; it can obtain a stable microstructure during heat treatment while reducing the residue of precipitates; it effectively improves the material elongation and cold-working plasticity; and it increases the deformation amount per pass in cold rolling to avoid mixed crystal phenomena.

Description

Technical Field

[0001] This invention belongs to the field of pipe processing and relates to a high W high temperature resistant alloy seamless pipe and its manufacturing method. In particular, it relates to a manufacturing method of a high W high temperature resistant alloy seamless pipe that can adapt to extreme working conditions of high temperature and high pressure and effectively reduce the precipitation of W-containing carbides to improve processing plasticity. The alloy seamless pipe is used to manufacture high temperature resistant components. Background Technology

[0002] Traditional alloy pipes are mainly solid solution strengthened alloys with low levels of W, Al, and Ti. In the field of nickel-based age-hardening alloys, there is a lack of experience in cold working and heat treatment techniques. To improve the strength of high-temperature alloys, W, Al, and Ti are typically added to high-temperature alloy pipes. These three elements produce a synergistic effect; for example, Al and Ti jointly optimize the γ' phase size distribution and improve the microstructure stability at 800-1000℃; TiC and W2C composite carbides synergistically strengthen grain boundaries; and Al2O3 film and W solid solution jointly enhance oxidation resistance and strength. However, age-hardening high-temperature alloys with high Al, Ti, and W content... Excessive strength, especially in high-W alloy pipes, presents several challenges during manufacturing: First, the heat treatment process easily leads to the precipitation of large amounts of W-rich phases. Due to the high strength of these precipitates, the material's plasticity deteriorates, with matrix elongation typically ≤40%. Furthermore, traditional intermediate heat treatment processes, which only involve holding at the final heat treatment temperature, result in mixed grain structures if the holding time is too long, making it difficult to guarantee the stability of the microstructure and properties. Conversely, holding for too short a time fails to achieve the desired solution treatment effect. Second, cold working is challenging. The minimal strength reduction after conventional heat treatment affects subsequent cold working, making the pipe prone to cracking under stress. Therefore, the fabrication of many age-hardened seamless pipes primarily relies on mechanical drilling followed by small-deformation cold working, resulting in low yield, small batch sizes, unstable heat treatment temperature ranges, and poor microstructure uniformity. For cold working of small- and medium-diameter aging-sensitive high-temperature alloy seamless tubes, Chinese patent CN113102546B discloses a GH4202 nickel-based high-temperature alloy tube and its preparation method. This invention controls the Al and Ti element content of the GH4202 nickel-based high-temperature alloy tube under certain conditions, fully utilizes the hot working plasticity of the material and reduces the hot deformation resistance of the alloy. Combined with hot extrusion and cold rolling processes, it can achieve the preparation of GH4202 seamless tubes with high yield, high production efficiency and high quality stability. However, in order to avoid cracking during the preparation process, the deformation amount in each pass of cold rolling is within 40%. But small deformation cold working inevitably leads to mixed crystal phenomenon in terms of microstructure control, and the production cycle is long and the processing cost is high.

[0003] Therefore, there is an urgent need for a high-temperature alloy seamless tube that combines ultra-high strength and good ductility, can effectively improve the elongation and cold working plasticity of the material, and prevent large deformation cold working cracking, as well as its manufacturing method. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention provides a high-W high-temperature alloy seamless tube and its manufacturing method. The high-W high-temperature alloy seamless tube manufactured by the present invention has both ultra-high strength and good plasticity and toughness, and can effectively improve the elongation and cold working plasticity of the material and prevent large deformation cold working cracks.

[0005] To solve the above problems, the technical solution adopted in this application is: The present invention discloses a method for manufacturing a high-W high-temperature alloy seamless tube, comprising the following steps: Step 1: The high-W high-temperature alloy seamless tube material is melted and forged sequentially to obtain a tube blank; Step 2: The tube blank is processed into a rough tube by hot working to obtain a rough tube; Step 3: The rough tube is subjected to heat treatment and finishing in sequence to obtain the initial alloy tube; the heat treatment is a stepped heat treatment, including a first solution heat treatment, a second solution heat treatment and a cooling treatment; wherein, the temperature of the first solution heat treatment is lower than the temperature of the second solution heat treatment. Step 4: The initial alloy tube is processed using a cold working process to obtain the finished tube.

[0006] Solution heat treatment in this application is a heat treatment process for metallic materials, mainly used to improve the properties of alloys (such as stainless steel and aluminum alloys). It involves heating the alloy to a high temperature (causing the second phase to dissolve into the matrix), holding it at that temperature, and then rapidly cooling it (e.g., water quenching) to form a supersaturated solid solution. The purpose is to: dissolve and precipitate the phase, ensuring uniform element distribution; improve the material's ductility and corrosion resistance; and prepare for subsequent age hardening (e.g., in aluminum alloys). Therefore, solution heat treatment of metallic materials is very important. This application improves the heat treatment of rough tubes. The heat treatment in this application is a stepped heat treatment, including a primary solution heat treatment, a secondary solution heat treatment, and a cooling treatment, which can significantly improve the product's performance.

[0007] As a preferred embodiment of this application, the high-W high-temperature alloy seamless tube material comprises, by weight percentage: C≤0.08%, Mn≤0.50%, 4.0%≤W≤6.0%, 1.0%≤Al≤2.5%, 2.0%≤Ti≤3.0%, Si≤0.60%, 17.0%≤Cr≤20.0%, 4.0%≤Mo≤5.0%, Fe≤4.0%, with the balance being Ni and unavoidable impurities.

[0008] As a preferred embodiment of this application, the purity of the components C, Mn, W, Al, Si, Cr, Mo, Fe and Ni in the material is ≥99.99%.

[0009] As a preferred embodiment of this application, the temperature T1 of the first solution heat treatment is 20-50°C lower than the temperature T2 of the second solution heat treatment.

[0010] As a preferred scope of this application, in step 2, the heating temperature for hot working is 1150~1250℃; the heating time is 1~3min.

[0011] As a preferred embodiment of this application, in step 2, the heating temperature for hot processing is 1180°C, and the heating time is 2 minutes.

[0012] As a preferred scope of this application, in step 3, the temperature T1 of the first solution heat treatment is in the range of 1050~1180℃, the heating rate is ≤10℃ / min, and the holding time at T1 is 30~90min; the temperature T2 of the second solution heat treatment is in the range of 1100~1200℃, the heating rate is ≤8℃ / min, and the holding time at T2 is 30~60min.

[0013] As a preferred embodiment of this application, in step 3, the temperature T1 of the first solution heat treatment is 1120℃, the heating rate is 8℃ / min, and the holding time at T1 is 30min; the temperature T2 of the second solution heat treatment is 1160℃, the heating rate is 5℃ / min, and the holding time at T2 is 30min.

[0014] As a preferred scope of this application, in step 3, the cooling treatment is water cooling treatment, the temperature after the cooling treatment is room temperature, and the cooling rate is in the range of 200~500℃ / min above 200℃.

[0015] As a preferred embodiment of this application, in step 3, the average cooling rate for cooling to room temperature above 200°C is approximately 350°C / min.

[0016] As a preferred embodiment of this application, the cold working process in step 4 includes: The intermediate tube is prepared by cold rolling a primary alloy tube in multiple passes using a cold rolling mill. The intermediate tube undergoes heat treatment between passes; and The process involves using a cold rolling mill to perform multiple passes of cold rolling to produce finished tubes. Among them, the deformation amount of a single cold rolling pass of the heat-treated intermediate tube is 30~60%, and the cold deformation amount of a single cold rolling pass of the finished tube is 40~60%.

[0017] As a preferred embodiment of this application, the heat treatment between passes in step 4 is a stepped heat treatment, including: The intermediate tube is subjected to primary solution heat treatment to obtain the intermediate product; the heating temperature of the primary solution heat treatment is T3, the heating rate is ≤10℃ / min, and the temperature is held at T3 for 3×L~5×L min. The intermediate product is subjected to a secondary solution heat treatment to obtain the primary product. The heating temperature of the secondary solution heat treatment, T4, is in the range of 1100~1200℃, the heating rate is ≤8℃ / min, and the holding time is 1×L~3×Lmin. L is the wall thickness of the pipe. The heating temperature of the primary solution heat treatment, T3, is 20~50℃ lower than the heating temperature of the secondary solution heat treatment, T4. After the heat preservation is completed, the initial product is cooled at a cooling rate of 200~500℃ / min to obtain the finished pipe.

[0018] As a preferred embodiment of this application, the heating temperature of the secondary solution heat treatment is 1160℃ for T4, the heating rate is 5℃ / min, and the holding time is 30min.

[0019] As a preferred embodiment of this application, the heating temperature of the primary solution heat treatment is 1120℃ for T3, the heating rate is 8℃ / min, and the holding time is 30min.

[0020] As a preferred embodiment of this application, the deformation amount of a single cold rolling pass of the heat-treated intermediate tube is 58%, and the cold deformation amount of a single cold rolling pass of the finished tube is 50%.

[0021] The present invention also provides a high-W high-temperature alloy seamless tube, which is prepared by the manufacturing method described above.

[0022] As a preferred embodiment of this application, the components of the high-W high-temperature alloy seamless tube, by weight percentage, include: C≤0.08%, Mn≤0.50%, 4.0%≤W≤6.0%, 1.0%≤Al≤2.5%, 2.0%≤Ti≤3.0%, Si≤0.60%, 17.0%≤Cr≤20.0%, 4.0%≤Mo≤5.0%, Fe≤4.0%, with the balance being Ni and unavoidable impurities.

[0023] The high-W high-temperature alloy seamless tube described in this invention is used in the manufacture of high-temperature resistant engine components.

[0024] Compared with the prior art, the beneficial effects of this application are: 1. By setting a holding step before the final solution temperature, the set temperature is generally 20-50℃ below the final solution temperature before the grains have fully grown. Below 1100℃, the grain size is relatively fine and the growth is not obvious. Holding the temperature in this range allows the W-rich phase to diffuse effectively. At the same time, the growth of the structure is not obvious in this temperature range. This avoids the uneven structure caused by high-temperature heat treatment while uniformly diffusing W and other precipitated elements.

[0025] 2. Subsequently, the temperature is raised to the solution temperature range and held for a relatively short time. Within this temperature range, significant microstructure growth effectively achieves a solution effect, reducing the overall plasticity of the material. At the same time, reducing the holding time in the high-temperature range can avoid mixed crystal phenomena caused by excessively rapid growth of individual microstructures, thus ensuring microstructure uniformity.

[0026] 3. Rapid cooling after high-temperature holding allows the uniformly diffused precipitates to dissolve quickly, thereby improving the material's plasticity. Heat treatment experiments at different cooling rates revealed that at a cooling rate of 100℃ / min, the content of precipitates at the grain boundaries was relatively high. When the cooling rate reached 200℃ / min, the content of dissolved precipitates at the grain boundaries decreased. Within the range of 200-500℃, there was no significant change in the precipitate content.

[0027] 4. The present invention achieves uniform diffusion and re-dissolution of precipitated elements by setting a stepped heat treatment and rapid cooling, thereby obtaining good microstructure uniformity and processing plasticity. Using this method, the elongation of the initial alloy tube can be effectively increased from 30-40% to 50-60% in the early stage of high W alloy production, effectively solving the problem of large deformation cold working cracking of the alloy. Moreover, the production process is shortened, production efficiency is improved, and costs are saved. Attached Figure Description

[0028] Figure 1 This is a site showing the early-stage cold rolling cracking of GH4202 pipe, a traditional alloy material.

[0029] Figure 2 Grain growth curve of the high-W high-temperature alloy seamless tube manufactured in Example 1 of the present invention.

[0030] Figure 3 This is a schematic diagram of the initial cold rolling process of the high-W high-temperature alloy seamless tube manufactured according to Embodiment 1 of the present invention.

[0031] Figure 4 The precipitation content of the high-W high-temperature alloy seamless tube of the present invention is measured at a cooling rate of 100℃ / min.

[0032] Figure 5 The precipitation content of the high-W high-temperature alloy seamless tube of the present invention is measured at a cooling rate of 200℃ / min.

[0033] Figure 6 The precipitation content of the high-W high-temperature alloy seamless tube of the present invention is measured at a cooling rate of 500℃ / min. Detailed Implementation

[0034] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0035] It should be noted that the process equipment or apparatus not specifically mentioned in the following embodiments are all conventional equipment or apparatus in the art.

[0036] Furthermore, it should be understood that the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps, does not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise stated. It should also be understood that the combined connection relationship between one or more devices / apparatus mentioned in this invention does not preclude the existence of other devices / apparatus before or after the combined devices / apparatus, or the insertion of other devices / apparatus between these explicitly mentioned devices / apparatus, unless otherwise stated. Moreover, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or limiting the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0037] The present application will be further described below with reference to specific embodiments, but the scope of protection of the present application is not limited thereto.

[0038] The high-W high-temperature alloy seamless tube of the present invention is a high-temperature alloy GH4202. The composition of the material by weight percentage includes: C≤0.08%, Mn≤0.50%, 4.0%≤W≤6.0%, 1.0%≤Al≤2.5%, 2.0%≤Ti≤3.0%, Si≤0.60%, 17.0%≤Cr≤20.0%, 4.0%≤Mo≤5.0%, Fe≤4.0%, with the balance being Ni and unavoidable impurities.

[0039] Example 1 This embodiment provides a method for manufacturing a high-W high-temperature alloy seamless tube with a specification of 53×3.5mm.

[0040] I. Raw Material Formula The present invention discloses a high-W high-temperature alloy seamless tube, wherein the material of the high-W high-temperature alloy seamless tube comprises the following components by weight percentage: C=0.05%, Mn=0.07%, W=4.42%, Al=1.28%, Ti=2.54%, Si=0.08%, Cr=18.38%, Mo=4.44%, Fe=0.62%, with the balance being Ni and unavoidable impurities.

[0041] II. The manufacturing method of high-W high-temperature alloy seamless tube includes the following steps: Step 1: The high-W high-temperature alloy seamless tube material is melted and forged sequentially to obtain a tube blank; The specific steps are as follows: The raw materials used in smelting undergo strict element control to ensure that the stability and purity requirements of the alloy composition are met. The raw material formula is smelted in an electroslag remelting furnace and then forged using a multi-directional forging press. The smelting composition is controlled as required, and the specific control parameters are shown in Table 1.

[0042] Table 1 Electroslag Remelting Parameters parameter Control range Function Description Slag composition <![CDATA[CaF2:Al2O3:CaO:MgO:TiO2 50:20:20:5:5]]> Deoxidation and desulfurization improve the purity of raw materials. Melting current density 0.8-1.2A / cm² Ensure stable molten pool depth Crystallizer diameter Φ400-450mm Matching subsequent forging billet specifications Cooling water flow rate 25-30m³ / h Prevent local overheating Multi-directional forging process conditions: Forging of billets: Initial forging temperature: 1180±10℃ (upper limit of β phase region); Final forging temperature: ≥950℃ (to avoid low-temperature brittleness); Equipment requirements: Use a high-speed forging machine with a capacity of 2000T or more, and a strain rate of 0.1-1s⁻¹; Die preheating temperature: 300-350℃ (to prevent thermal shock); Process monitoring: Infrared thermal imager monitors the temperature field in real time, with a gradient difference ≤30℃.

[0043] Step 2: The tube blank is processed into a rough tube by hot working to obtain a rough tube; Specifically, the steps include the following: The raw materials are fed and extruded to form rough tubes, wherein the extrusion heating temperature is 1180℃ and the heating time is 2min.

[0044] Step 3: The rough tube is subjected to heat treatment and finishing in sequence to obtain the intermediate tube; the heat treatment is a stepped heat treatment, including a first preheating heat treatment, a second solution heat treatment and a cooling treatment; wherein, the temperature of the first preheating heat treatment is lower than the temperature of the second solution heat treatment. Heat treatment specifically includes the following steps: First, the raw pipe is subjected to a preheating heat treatment. The temperature of the preheating heat treatment is T1, which is 1120℃, the heating rate is 8℃ / min, and the holding time is 30min. Subsequently, a second solution heat treatment is performed, with a temperature T2 of 1160℃, a heating rate of 5℃ / min, and a holding time of 30min. After the heat preservation is completed, a cooling process is carried out to cool to room temperature. The average cooling rate of the cooling process is about 350℃ / min.

[0045] Step 4: The intermediate tube is processed using a cold working process to obtain the finished tube; Specifically, the steps include the following: The intermediate tube is prepared by using a cold rolling mill to perform multiple cold rolling processes. The intermediate tube undergoes heat treatment between passes; The process involves using a cold rolling mill to perform multiple passes of cold rolling to produce finished tubes. Among them, the deformation amount of the intermediate tube in a single cold rolling pass is 58%, and the cold deformation amount of the finished tube in a single pass is 58%.

[0046] The heat treatment between passes in step 4 is a stepped heat treatment, including: The intermediate tube was subjected to primary solution heat treatment to obtain the intermediate product. The heating temperature T3 of the primary solution heat treatment was 1120℃, the heating rate was 8℃ / min, and the temperature was held at T3 for 30min. The intermediate product is subjected to a secondary solution heat treatment to obtain the initial product. The heating temperature of the secondary solution heat treatment is within the range of 1160℃ for T4, the heating rate is 5℃ / min, and the holding time is 30min. After the holding time is completed, the initial product is cooled at a cooling rate of 350℃ / min to obtain the finished tube.

[0047] Each of the final product pipes was subjected to grain size and physicochemical tests. The physicochemical tests included room temperature yield strength, elongation at break, tensile strength, and hardness. The tensile test was conducted according to the GB / T 228.1 test standard. The test results are shown in Table 2.

[0048] Example 2 This embodiment provides a method for manufacturing a high-W high-temperature alloy seamless tube of another material, with a specification of 38×6.5mm. The material used is different from that in Embodiment 1, but the heat treatment method used is basically the same.

[0049] I. Raw Material Formula The material of the high-W high-temperature alloy seamless tube comprises the following components by weight percentage: C=0.037%, Mn=0.106%, S=0.0009%, W=12.09%, Al=0.05%, Ti=2.54%, Si=0.267%, Cr=27.57%, Mo=4.44%, Fe=2.98%, with the balance being Ni and unavoidable impurities.

[0050] II. The manufacturing method of high-W high-temperature alloy seamless tube includes the following steps: Step 1: The high-W high-temperature alloy seamless tube material is melted and forged sequentially to obtain a tube blank; The specific steps are as follows: The raw materials used in smelting undergo strict element control to ensure that the stability and purity requirements of the alloy composition are met. The raw material formula is smelted in an electroslag remelting furnace and then forged using a multi-directional forging press. The smelting composition is controlled as required, and the specific control parameters are shown in Table 1.

[0051] Table 1 Electroslag Remelting Parameters Slag composition <![CDATA[CaF2:Al2O3:CaO:MgO:TiO2 50:20:20:5:5]]> Deoxidation and desulfurization improve the purity of raw materials. Melting current density 0.8-1.2A / cm² Ensure stable molten pool depth Crystallizer diameter Φ400-450mm Matching subsequent forging billet specifications Cooling water flow rate 25-30m³ / h Prevent local overheating Multi-directional forging process conditions: Forging of billets: Initial forging temperature: 1180±10℃ (upper limit of β phase region); Final forging temperature: ≥950℃ (to avoid low-temperature brittleness); Equipment requirements: Use a high-speed forging machine with a capacity of 2000T or more, and a strain rate of 0.1-1s⁻¹; Die preheating temperature: 300-350℃ (to prevent thermal shock); Process monitoring: Infrared thermal imager monitors the temperature field in real time, with a gradient difference ≤30℃.

[0052] Step 2: The tube blank is processed into a rough tube by hot working to obtain a rough tube; Specifically, the steps include the following: The raw materials are fed and extruded to form rough tubes, wherein the extrusion heating temperature is 1180℃ and the heating time is 2min.

[0053] Step 3: The rough tube is subjected to heat treatment and finishing in sequence to obtain the intermediate tube; the heat treatment is a stepped heat treatment, including a first preheating treatment, a second solution heat treatment and a cooling treatment; wherein, the temperature of the first preheating treatment is lower than the temperature of the second solution heat treatment. Heat treatment specifically includes the following steps: First, the raw pipe is preheated. The temperature T1 of the preheating treatment is 1120℃, the heating rate is 8℃ / min, and the holding time is 30min. Subsequently, a second solution heat treatment is performed, with a temperature T2 of 1160℃, a heating rate of 5℃ / min, and a holding time of 30min. After the heat preservation is completed, a cooling process is carried out to cool to room temperature. The average cooling rate of the cooling process is about 350℃ / min.

[0054] Step 4: The intermediate tube is processed using a cold working process to obtain the finished tube; Specifically, the steps include the following: The intermediate tube is prepared by using a cold rolling mill to perform multiple cold rolling processes. The intermediate tube undergoes heat treatment between passes; The process involves using a cold rolling mill to perform multiple passes of cold rolling to produce finished tubes. Among them, the deformation amount of a single cold rolling pass for intermediate tubes is 57%, and the cold deformation amount of a single cold rolling pass for finished tubes is 53%.

[0055] The heat treatment between passes in step 4 is a stepped heat treatment, including: The intermediate tube is preheated once, with a heating temperature T3 of 1120℃ and a heating rate of 8℃ / min. The tube is then held at T3 for 30min. The intermediate product is subjected to a second solution heat treatment. The heating temperature for the second solution heat treatment is within the range of 1160℃ (T4), the heating rate is 5℃ / min, and the holding time is 30min. After the holding time, the product is cooled at a cooling rate of 350℃ / min to obtain the finished tube.

[0056] Each of the final product pipes was subjected to physical and chemical tests, including room temperature yield strength, elongation at break, and tensile strength. The tensile test was conducted according to the GB / T 228.1 test standard. The test results are shown in Table 2.

[0057] Comparative Example 1 The difference between this comparative example and Example 1 is that the high-W high-temperature alloy seamless tube is made of UNS N06022 alloy, comprising the following components by weight percentage: Ni=58.2%, C=0.006%, Mn=0.3%, W=3.2%, Si=0.04%, Cr=21.7%, Mo=13.1%, P=0.005%, S=0.0007%, Co=0.03%, Fe=3.1%, with the balance being Ni and unavoidable impurities. All other processes are the same.

[0058] Comparative Example 2 The difference between this comparative example and Example 1 is that the high-W high-temperature alloy seamless tube is made of Hastelloy C-276, comprising the following components by weight percentage: Ni=58.0%, C=0.008%, Mn=0.5%, W=3.6%, Si=0.03%, Cr=16.10%, Mo=15.45%, P=0.0024%, S=0.001%, Co=0.05%, Fe=6.2%, with the balance being Ni and unavoidable impurities. All other processes are the same.

[0059] Table 2 Tensile strength (MPa) Room temperature yield strength (MPa) Elongation at break (%) Example 1 730 321 69.5 Example 2 775 310 59 Comparative Example 1 795 375 72 Comparative Example 2 790 414 57.5 In summary, this invention optimizes the heat treatment process for high-W high-temperature alloy seamless tubes. The manufactured high-W high-temperature alloy seamless tubes exhibit excellent performance. The specifications, surface finish, and various properties of the finished tubes produced by the above method meet the high requirements of high-temperature engines. Moreover, the entire manufacturing method is simple. By setting up stepped heat treatment and rapid cooling, the precipitated elements are uniformly diffused and dissolved back, while the cooling rate is increased to obtain good microstructure uniformity and processing plasticity. Using this method, the cold working deformation of the intermediate tube in the early stage of high-W alloy production is increased from 30-40% to 50-60%, which not only effectively solves the problem of large deformation cold working cracking of this alloy, but also greatly reduces costs and improves the yield of finished products, providing a solution for the manufacturing and production of high-W high-temperature alloy seamless tubes.

[0060] The above embodiments are for illustrating the implementation schemes disclosed in this application and should not be construed as limiting this application. Furthermore, various modifications listed herein, as well as variations in methods and compositions of the invention, will be apparent to those skilled in the art without departing from the scope and spirit of this application. Although this application has been specifically described in conjunction with various specific preferred embodiments, it should be understood that this application should not be limited to these specific embodiments. In fact, various modifications as described above that are obvious to those skilled in the art to obtain the invention should be included within the scope of this application.

Claims

1. A method for manufacturing a high-W high-temperature alloy seamless tube, characterized in that, Includes the following steps: Step 1: The high-W high-temperature alloy seamless tube material is melted and forged sequentially to obtain a tube blank; The components of the high-W high-temperature alloy seamless tube material, by weight percentage, include: C≤0.08%, Mn≤0.50%, 4.0%≤W≤6.0%, 1.0%≤Al≤2.5%, 2.0%≤Ti≤3.0%, Si≤0.60%, 17.0%≤Cr≤20.0%, 4.0%≤Mo≤5.0%, Fe≤4.0%, with the balance being Ni and unavoidable impurities; Step 2: The tube blank is processed into a rough tube by hot working to obtain a rough tube; Step 3: The rough tube is subjected to heat treatment and finishing in sequence to obtain a preliminary alloy tube. The heat treatment is a stepped heat treatment, including a first solution heat treatment, a second solution heat treatment, and a cooling treatment. The temperature of the first solution heat treatment is lower than that of the second solution heat treatment. The temperature T1 of the first solution heat treatment is 20-50°C lower than the temperature T2 of the second solution heat treatment. The temperature T1 of the first solution heat treatment is in the range of 1050-1180°C, with a heating rate ≤10°C / min, and is held at T1 for 30-90 minutes. The temperature T2 of the second solution heat treatment is in the range of 1100-1200°C, with a heating rate ≤8°C / min, and is held at T2 for 30-60 minutes. Step 4: The initial alloy tube is processed using a cold working process to obtain the finished tube; The cold working process includes: The intermediate tube is prepared by cold rolling a primary alloy tube in multiple passes using a cold rolling mill. The intermediate tube undergoes heat treatment between passes; and The process involves using a cold rolling mill to perform multiple passes of cold rolling to produce finished tubes. Among them, the deformation amount of a single cold rolling pass for heat-treated intermediate tubes is 30-80%, and the cold deformation amount of a single cold rolling pass for finished tubes is 40-60%. The heat treatment between passes is a stepped heat treatment, including: The intermediate tube is subjected to primary solution heat treatment to obtain the intermediate product; the heating temperature of the primary solution heat treatment is T3, the heating rate is ≤10℃ / min, and the temperature is held at T3 for 3×L~5×L min. The intermediate product is subjected to a secondary solution heat treatment to obtain the primary product. The heating temperature of the secondary solution heat treatment, T4, is in the range of 1100~1200℃, the heating rate is ≤8℃ / min, and the holding time is 1×L~3×Lmin. L is the wall thickness of the pipe. The heating temperature of the primary solution heat treatment, T3, is 20~50℃ lower than the heating temperature of the secondary solution heat treatment, T4. After the heat preservation is completed, the initial product is cooled at a cooling rate of 200~500℃ / min to obtain the finished pipe.

2. The manufacturing method according to claim 1, characterized in that, In step 2, the heating temperature for hot working is 1150~1250℃; the heating time is 1~3min.

3. The manufacturing method according to claim 1, characterized in that, In step 3, the cooling process is water cooling, and the temperature after cooling is room temperature. The cooling rate is in the range of 200~500℃ / min above 200℃.

4. A high-W high-temperature alloy seamless tube, characterized in that, It is prepared by the manufacturing method described in any one of claims 1 to 3.

5. A high-W high-temperature alloy seamless tube according to claim 4, characterized in that, The components of the high-W high-temperature alloy seamless tube, by weight percentage, include: C≤0.08%, Mn≤0.50%, 4.0%≤W≤6.0%, 1.0%≤Al≤2.5%, 2.0%≤Ti≤3.0%, Si≤0.60%, 17.0%≤Cr≤20.0%, 4.0%≤Mo≤5.0%, Fe≤4.0%, with the balance being Ni and unavoidable impurities.

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