Modified GH4145 high-temperature alloy capillary tube and preparation method thereof

Abstract

The invention discloses a modified GH4145 high-temperature alloy capillary tube and a preparation method thereof, and relates to a high-temperature alloy material, and the modified GH4145 high-temperature alloy capillary tube comprises the following chemical components in percentage by weight: 15.5-16.5% of Cr, 2.4-2.5% of Ti, 7.5-8.5% of Fe, 0.7-1.0% of Nb, 0.7-0.9% of Al, 0.02-0.04% of Co, 0.02-0.05% of Mn, 0.0015-0.003% of Ta, 0.07-0.12% of C, 0.1-0.2% of Si, 0.01-0.02% of Cu, 0.004-0.005% of B, 0.01-0.02% of RE, less than or equal to 0.008% of impurity P, less than or equal to 0.005% of impurity S and the balance of Ni. By adopting the technical scheme of metal hot extrusion / cold rolling, acid pickling and annealing heat treatment, the total deformation quantity, the pass deformation quantity and the diameter-thickness ratio of a tube blank are reasonably regulated and controlled, the non-uniform deformation degree is reduced, a material structure with good uniformity and proper grain size is obtained, the high-quality precise capillary tube is prepared, and the service life of the precise capillary tube is prolonged. And the requirements on the strength and corrosion resistance of the GH4145 alloy in high-temperature, high-pressure and corrosive environments are met.

Description

Technical Field

[0001] The invention relates to the field of high-temperature alloy materials, and in particular to a modified GH4145 high-temperature alloy capillary and a preparation method thereof. Background Art

[0002] GH4145 is a commonly used deformed high temperature alloy with γ' phase (Ni 3 (Al, Ti, Nb)) is the main strengthening phase, with excellent high temperature strength, oxidation resistance and creep resistance. Its typical composition is: Ni (≥70%), Cr (14-17%), Fe (5-9%), Ti (2.25-2.75%), Al (0.4-1.0%) and a small amount of Nb, C, etc. The alloy has good fatigue resistance, corrosion resistance and oxidation resistance below 980℃, and excellent high temperature strength below 800℃. It is widely used at home and abroad, mainly used to manufacture aero-engines that work below 800℃ and require high strength and corrosion resistance of ring parts, structural parts and bolts, pipes and other parts, as well as turbine blades and other parts. my country started late in the research on this alloy. For more than 40 years, the research has mainly focused on the trial production of alloy composition, smelting, and cold processing technology of bars, wires and large-diameter pipe products. There is relatively little research on its pipe products, especially capillary pipe products with a diameter of less than 6mm.

[0003] The γ' phase in GH4145 alloy is significantly strengthened, with high strength but poor plasticity. It is easy to cause cracks during cold processing due to large deformation resistance. In addition, the hot processing process window is narrow, which makes it difficult to hot and cold process the material. At present, the minimum size of GH4145 alloy capillary on the market is φ3×0.5mm, and the yield rate of finer specifications is low. The dimensional accuracy of capillary is poor, which is mainly reflected in: creases, cracks and other defects are easy to appear on the surface during the preparation stage of the tube blank, the hardening rate is fast, and it is difficult to balance the processing efficiency and defect suppression of the capillary.

[0004] With the development of miniaturized high-temperature devices, the market requirements for GH4145 alloy capillaries have tended to outer diameter ≤1mm and wall thickness ≤0.2mm, but the existing technology cannot meet this requirement. The main problems are: the material structure-process performance integrated technology control of GH4145 alloy is difficult, the capillary forming process lacks systematic research, and the quality reliability is low.

[0005] In summary, GH4145 alloy capillaries are mainly used for high temperature and high pressure resistant seals. However, in certain specific high temperature, high pressure and corrosive environments, the manufacture of GH4145 alloy capillaries is limited by the intrinsic properties of the material and the defects of traditional processes, resulting in problems such as high processing difficulty, poor dimensional accuracy, corrosion resistance to be improved, and unstable performance in the preparation method. It is urgent to break through the existing technical bottleneck to meet the demand for ultrafine capillaries in high-end equipment. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a modified GH4145 superalloy capillary tube and its preparation method.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] <First aspect>

[0009] The present invention provides a modified GH4145 superalloy capillary tube. By mass percentage, its chemical composition is as follows: Cr 15.5 - 16.5, Ti 2.4 - 2.5, Fe 7.5 - 8.5, Nb 0.7 - 1.0, Al 0.7 - 0.9, Co 0.02 - 0.04, Mn 0.02 - 0.05, Ta 0.0015 - 0.003, C 0.07 - 0.12, Si 0.1 - 0.2, Cu 0.01 - 0.02, B 0.004 - 0.005, RE: 0.01 - 0.02, impurity P ≤ 0.006, impurity S ≤ 0.003, and the balance is Ni.

[0010] As an embodiment, the rare earth element RE is one or several of lanthanum, cerium, and yttrium.

[0011] As an embodiment, the size of the capillary tube is such that the outer diameter is between 0.4 ± 0.01 mm and 0.83 mm ± 0.01 mm, and the wall thickness is between 0.02 ± 0.005 mm and 0.12 mm ± 0.005 mm.

[0012] As an embodiment, the size of the capillary tube is such that the outer diameter is between 0.4 ± 0.01 mm and 0.8 mm ± 0.01 mm, and the wall thickness is between 0.02 ± 0.005 mm and 0.1 mm ± 0.005 mm.

[0013] As an embodiment, the size of the polished capillary tube is such that the outer diameter is between 0.4 ± 0.01 mm and 0.63 mm ± 0.01 mm, and the wall thickness is between 0.02 ± 0.005 mm and 0.055 mm ± 0.005 mm.

[0014] As an embodiment, the size of the polished capillary tube is such that the outer diameter is between 0.4 ± 0.01 mm and 0.61 mm ± 0.01 mm, and the wall thickness is between 0.02 ± 0.005 mm and 0.052 mm ± 0.005 mm.

[0015] As an embodiment, the polished capillary has an outer diameter ranging from 0.4 ± 0.01 mm to 0.53 mm ± 0.01 mm and a wall thickness ranging from 0.02 ± 0.005 mm to 0.042 mm ± 0.005 mm.

[0016] As an embodiment, the polished capillary has an outer diameter ranging from 0.4 ± 0.01 mm to 0.51 mm ± 0.01 mm and a wall thickness ranging from 0.02 ± 0.005 mm to 0.04 mm ± 0.005 mm.

[0017] As an embodiment, the polished capillary has an outer diameter ranging from 0.4 ± 0.01 mm to 0.42 mm ± 0.01 mm and a wall thickness ranging from 0.02 ± 0.005 mm to 0.021 mm ± 0.005 mm.

[0018] <Second aspect>

[0019] The present invention provides a method for preparing a modified GH4145 superalloy capillary, comprising the following steps:

[0020] S1. Twin vacuum melting

[0021] The GH4145 alloy raw material is subjected to vacuum induction melting at 1450 - 1600 °C for 2 - 3 h, where the refining is static for 15 - 20 min, and then poured to obtain an ingot. Then, the ingot is remelted by the vacuum consumable process, with a melting current of 2000 - 3500 A, to obtain an ingot blank. After cutting off the shrinkage cavity, a first annealing treatment is carried out at 1100 - 1150 °C for 6 - 8 h, and then it is turned to obtain a finished ingot;

[0022] S2. Hot working

[0023] The finished ingot is heated to 1150 - 1250 °C and held for 3 - 4 h, then forged into a bar at 1050 - 1100 °C, with a single deformation amount of 20 - 30%. Then, the bar is turned, put into the furnace at 800 - 900 °C, heated to 1000 - 1100 °C along with the furnace, and after holding for 1 - 2 h, it is hot extruded and pierced to form a tube blank, and then pickled and finished to obtain a rough tube;

[0024] S3. Annealing and cold rolling

[0025] The rough tube is subjected to multi-pass cold rolling and inter-pass annealing treatment to obtain a capillary. Among them,

[0026] During the cold rolling process, when the wall thickness of the capillary > 2 mm, the diameter-thickness ratio of the multi-pass cold rolling is controlled at 5 - 8, the inter-pass annealing deformation amount is 20 - 25%, and the method of atmospheric annealing plus pickling is adopted;

[0027] During the cold rolling process, when the wall thickness of the capillary is ≤ 2 mm, the diameter-thickness ratio controlled in each cold rolling pass is 10 - 15, the annealing deformation amount between passes is 12 - 15%, vacuum annealing is adopted, and the vacuum degree is 10 -1 ~10 -2 Pa;

[0028] The parameters of the atmospheric annealing or vacuum annealing treatment are an annealing temperature of 1000 - 1050 °C, a time of 0.5 - 1 h, and furnace cooling.

[0029] As an embodiment, in the GH4145 alloy raw material, the B element is introduced in the form of FeB master alloy, and the rare earth element RE is added in one or more forms of La-Ni, Al-Ce, and Al-Y master alloys.

[0030] In some embodiments, the rare earth La is added in the form of La-Ni master alloy.

[0031] In some embodiments, the rare earths La and Ce are added in the forms of La-Ni and Al-Ce.

[0032] In some embodiments, the rare earth Y is added in the form of Al-Y.

[0033] In some embodiments, the rare earths Ce and Y are added in the forms of Al-Ce and Al-Y.

[0034] As an embodiment, in step S1, during the vacuum induction melting process, the raw materials are divided into four groups and added sequentially for melting. The addition timing of the second group and the third group of raw materials is: after the previous group of raw materials is completely melted, the next group of raw materials is added. After the third group of raw materials is completely melted, refining and standing for 15 - 20 min, and then the fourth group of raw materials is added for melting.

[0035] In some embodiments, in step S1, the four groups of raw materials are respectively: the first group of Fe, Ni, Co, Nb, Ta, and Cr; the second group of Al and Ti; the third group of C, Si, and Cu; the fourth group of FeB, rare earth master alloy, and Mn.

[0036] As an embodiment, in step S1, the vacuum degree during the vacuum induction melting process is 0.3 - 0.6 Pa.

[0037] In some embodiments, the vacuum degree during the vacuum induction melting process is 0.3 Pa.

[0038] As an embodiment, in step S1, the vacuum degree during the secondary melting is 0.02 - 0.4 Pa.

[0039] In some embodiments, the vacuum degree during the secondary melting is 0.2 - 0.4 Pa.

[0040] As an embodiment, in step S1, the diameter of the master ingot is The diameter of the ingot is 120 - 230 mm, and the diameter of the finished ingot is

[0041] As an embodiment, in step S2, the diameter of the bar is 60 - 70 mm, the outer diameter of the shell is 30 - 40 mm, and the wall thickness is 5 - 10 mm.

[0042] As an embodiment, in the method for preparing the superalloy capillary tube, after step S3, it further includes step S4, finishing: pickling the capillary tube to remove oil and dirt and polishing and finishing it.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1) The method for preparing a modified GH4145 superalloy capillary tube provided by the present invention adopts the technical solutions of hot extrusion / cold rolling of metal, pickling, and annealing heat treatment, reasonably controls the total deformation amount of the tube blank, the deformation amount per pass, and the diameter-thickness ratio of the tube blank, reduces the non-uniform deformation degree, obtains a material structure with good uniformity and appropriate grain size, and prepares high-quality precision capillary tubes to meet the requirements for the strength and corrosion resistance of the GH4145 alloy under high temperature, high pressure, and corrosive environments.

[0045] 2) Through the optimized design of the composition, the modified GH4145 superalloy capillary tube improves its strength and corrosion resistance in high temperature, high pressure, and corrosive environments by adding an appropriate amount of rare earth elements. By combining the metal hot extrusion / cold plastic forming technology and the heat treatment process, it breaks through the technical bottleneck of difficult room temperature plastic deformation of superalloys, greatly reduces the wall thickness of the capillary tube, improves the dimensional accuracy of the capillary tube, and obtains a capillary tube with uniform microstructure and performance. The method for preparing the modified GH4145 superalloy capillary tube provided by the present invention has the advantages of low cost, high efficiency, and good performance, and effectively realizes the integrated control preparation of the microstructure and performance of the superalloy capillary tube.

[0046] 3) Using the method for preparing the modified GH4145 superalloy capillary tube provided by the present invention, capillary tubes with an outer diameter of 0.4 ± 0.01 mm - 0.83 ± 0.01 mm and a wall thickness of 0.02 ± 0.005 mm - 0.12 ± 0.005 mm can be prepared. Description of the Drawings

[0047] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, purposes, and advantages of the present invention will become more obvious:

[0048] Figure 1 It is a photo of the shell obtained in step S2 of Embodiment 2 of the present invention;

[0049] Figure 2 This is a photograph of the capillary tube obtained in step S4 of Embodiment 2 of the present invention. Detailed implementation manners

[0050] The present invention will be described in detail below in conjunction with embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several adjustments and improvements can still be made. These all belong to the protection scope of the present invention.

[0051] For easy understanding, the raw materials mentioned below are first explained:

[0052] The rare earth element RE is added using intermediate alloys of La-Ni, Al-Ce, and Al-Y, and the element B is added using an Fe-B alloy. These alloys have different content types. For the present invention, choosing alloys with different contents only makes a difference in the weights required in the batching calculation process, but does not affect the subsequent preparation process and preparation effect.

[0053] Embodiment 1

[0054] This embodiment provides a method for preparing a modified GH4145 superalloy capillary tube with a size of Φ0.8mm×0.1mm.

[0055] First, prepare the raw materials according to the following mass percentages (unit: wt.%):

[0056] Cr 15.5, Ti 2.4, Fe 8.0, Nb 0.7, Al 0.8, Co 0.02, Mn 0.04, Ta 0.0015, C 0.09, Si 0.1, Cu 0.01, B 0.005, La: 0.01, and the balance is Ni.

[0057] Divide the raw materials into four groups,

[0058] Group A1: Fe, Ni, Co, Nb, Ta, and Cr;

[0059] Group A2: Al and Ti;

[0060] Group A3: C, Si, and Cu;

[0061] Group A4: Fe-B, La-Ni, and Mn.

[0062] The preparation steps are as follows:

[0063] S1. Double vacuum melting

[0064] In the vacuum induction melting process, the raw materials in Group A1 are loaded into the crucible in the order of Fe, Ni, Co, Nb, Ta, and Cr. Subsequently, the raw materials in Group A2 and Group A3 are respectively loaded into the corresponding alloy feeding boxes. During the melting process, the vacuum degree is 0.3 Pa, and the furnace temperature is raised to 1450 °C. After the raw materials in Group A1 are completely melted, the raw materials in Group A2 and Group A3 are added in sequence for melting. After the furnace charge is melted, it is refined and left standing for 15 min. Subsequently, the raw materials in Group A4 are added. After all the raw materials are melted, the molten alloy is stirred for 1 - 2 min to ensure uniform composition. Finally, it is cast into the master ingot, and the entire induction melting process is controlled within 2 - 3 h;

[0065] Subsequently, the master ingot is transferred to a vacuum consumable arc furnace for secondary melting. The melting current is set at 2000 A, the melting voltage is 20 V, the melting time is 50 min, the working vacuum degree is 0.3 Pa, and the leak rate is 0.1 Pa / min. Through this process, the modified GH4145 superalloy ingot is prepared. Then, the shrinkage cavity part of the ingot is cut off, and homogenization annealing treatment is carried out at 1100 °C for 8 h. After turning, the finished ingot is obtained.

[0066] S2. Hot working

[0067] After the finished ingot obtained in step S1 is charged into the furnace at room temperature, it is gradually heated to 1150 °C at a speed of 5 °C / min and held for 3 h, then cogging forging is carried out, forging at 1050 °C, with a single deformation amount of 20%, and finally forged into bar;

[0068] Then the forged bar is turned into a bright bar. After being charged into the furnace at 800 °C, it is heated to 1050 °C at a speed of 5 °C / min and held for 1 h;

[0069] Then, through a 2000T extrusion press, it is pierced into a tube blank at a speed of 60 mm / s. After pickling and finishing, the rough tube is obtained for cold rolling.

[0070] S3. Annealing and cold rolling

[0071] The rough tube obtained in step S2 is processed by multi-pass cold rolling at room temperature to obtain capillary tubes with dimensions Specifically:

[0072] During the cold rolling process, annealing treatment is carried out in the middle of each pass. The parameters of each annealing treatment are: temperature 1000 °C, holding time 1 h, cooling in the furnace;

[0073] When the wall thickness of the cold-rolled rough tube > 2 mm, the diameter-thickness ratio is controlled at 6, and the annealing deformation amount per pass is 20%. The method of atmospheric annealing plus pickling is adopted;

[0074] When the wall thickness of the cold-rolled blank tube is ≤ 2 mm, control the diameter-thickness ratio to be 10, the annealing deformation per pass is 12%, and use vacuum annealing with a vacuum degree of 10 -1 Pa.

[0075] S4. Finishing

[0076] The cold-rolled capillary tube obtained in step S3 is pickled to remove oil and dirt, and then polished and finished to obtain a Φ0.8 mm × 0.1 mm capillary tube finished product with a clean appearance and high dimensional accuracy, where the outer diameter accuracy is 0.01 mm and the wall thickness accuracy is 0.005 mm.

[0077] After testing, the content of impurity element P in the prepared capillary tube finished product is 0.006 wt.%, and the content of impurity element S is 0.003 wt.%.

[0078] Example 2

[0079] This example provides a preparation method for a modified GH4145 superalloy capillary tube with Φ0.61 mm × 0.052 mm.

[0080] First, prepare raw materials according to the following mass percentages (unit: wt.%):

[0081] Cr 16.5, Ti 2.5, Fe 8.5, Nb 1.0, Al 0.8, Co 0.03, Mn 0.05, Ta 0.002, C 0.10, Si 0.15, Cu 0.02, B 0.0045, La 0.008, Ce 0.007, and the balance is Ni.

[0082] The preparation steps are as follows:

[0083] S1. Double vacuum melting

[0084] Refer to Example 1 and sequentially add four groups of raw materials into a vacuum induction melting equipment for melting. The melting temperature is 1500 °C. After the melting of the first three groups of raw materials, perform refining and standing for 16 min, then add the A4 group of raw materials. After all the raw materials are melted, stir the molten alloy for 1 - 2 min to ensure uniform composition. Finally, cast it into an ingot, and the entire induction melting process is controlled within 2 - 3 h;

[0085] Subsequently, transfer the ingot to a vacuum consumable arc furnace for secondary melting. Set the melting current to 2500 A, the melting voltage to 25 V, the melting time to 55 min, the working vacuum degree to 0.4 Pa, and the air leakage rate to 0.2 Pa / min. Through this process, Modified GH4145 superalloy ingot. Then, the shrinkage cavity part of the ingot was cut off, and homogenization annealing treatment was carried out at 1150 °C for 6 h. After turning, the finished ingot was obtained.

[0086] S2. Hot working

[0087] After the finished ingot obtained in step S1 was charged into the furnace at room temperature, it was gradually heated to 1180 °C at a speed of 8 °C / min and held for 4 h, then cogging forging was carried out, forging at 1080 °C, with a single deformation amount of 25%, and finally forged into bar;

[0088] Then the forged bar was turned into bright bar. After being charged into the furnace at 850 °C, it was heated to 1100 °C at a speed of 10 °C / min and held for 1.5 h;

[0089] Then, through a 2000T extruder, it was pierced at a speed of 60 mm / s to make a tube blank. After pickling and finishing, the raw tube (as Figure 1 shown) was obtained for cold rolling.

[0090] S3. Annealing and cold rolling

[0091] The raw tube obtained in step S2 was cold-rolled at room temperature through multiple passes to obtain capillary tubes with dimensions specifically:

[0092] During the cold rolling process, annealing treatment was carried out in the middle of each pass. The parameters of each annealing treatment were: temperature 1020 °C, holding time 0.8 h, cooling in the furnace;

[0093] When the wall thickness of the cold-rolled raw tube > 2 mm, the diameter-thickness ratio was controlled to be 5, and the annealing deformation amount per pass was 25%. The method of atmospheric annealing plus pickling was adopted;

[0094] When the wall thickness of the cold-rolled raw tube ≤ 2 mm, the diameter-thickness ratio was controlled to be 12, and the annealing deformation amount per pass was 15%. Vacuum annealing was adopted, and the vacuum degree was 10 -2 Pa.

[0095] S4. Finishing

[0096] The cold-rolled capillary tubes obtained in step S3 were pickled to remove oil and dirt, and then polished and finished to obtain capillary tube products with a clean appearance and high dimensional accuracy of Φ0.61 mm × 0.052 mm, where the outer diameter accuracy was 0.01 mm and the wall thickness accuracy was 0.005 mm (as Figure 2 shown).

[0097] After testing, the content of impurity element P in the prepared capillary tube products was 0.0045 wt.%, and the content of impurity element S was 0.0022 wt.%.

[0098] Example 3

[0099] This example provides a preparation method for a modified GH4145 superalloy capillary with a size of Φ0.51mm×0.04mm.

[0100] First, prepare the raw materials according to the following mass percentages (unit: wt.%):

[0101] Cr 16.0, Ti 2.4, Fe 7.5, Nb 0.85, Al 0.9, Co 0.04, Mn 0.03, Ta 0.003, C 0.12, Si 0.2, Cu 0.015, B 0.004, Y 0.012, and the balance is Ni.

[0102] The preparation steps are as follows:

[0103] S1. Double vacuum melting

[0104] Refer to Example 1 and sequentially add four groups of raw materials into the vacuum induction melting equipment for melting. The melting temperature is 1550°C. After the first three groups of raw materials are melted, perform refining and static settling for 20 min, then add the fourth group of raw materials. After all the raw materials are melted, stir the molten alloy for 1 - 2 min to ensure uniform composition. Finally, cast it into an ingot, and the entire induction melting process is controlled within 2 - 3 h;

[0105] Subsequently, transfer the ingot to a vacuum consumable arc furnace for secondary melting. Set the melting current to 3500 A, the melting voltage to 30 V, the melting time to 75 min, the working vacuum degree to 0.2 Pa, and the air leakage rate to 0.15 Pa / min. Prepare a modified GH4145 superalloy ingot through this process. Then, cut off the shrinkage part of the ingot and perform homogenization annealing treatment at 1150°C for 7 h. After turning it smooth, obtain a finished ingot.

[0106] S2. Hot working

[0107] After loading the finished ingot obtained in step S1 into the furnace at room temperature, gradually heat it to 1250°C at a rate of 10°C / min, hold for 4 h, and perform cogging forging. Forge at 1100°C with a single deformation amount of 20%, and finally forge it into a bar;

[0108] Then turn the forged bar into a bright bar, load it into the furnace at 900°C and heat it to 1060°C at a rate of 8°C / min, and hold for 2 h;

[0109] Then, use a 2000T extruder to punch holes at a speed of 60 mm / s to make a tube blank. After pickling and finishing, obtain The capillary tube, for cold rolling.

[0110] S3. Annealing and cold rolling

[0111] The capillary tube obtained in step S2 is processed by multi-pass cold rolling at room temperature to obtain capillary tubes with dimensions Specifically:

[0112] During the cold rolling process, annealing treatment is carried out in the middle of each pass. The parameters of each annealing treatment are: temperature 1050 °C, holding time 0.5 h, cooling in the furnace;

[0113] When the wall thickness of the cold-rolled capillary tube > 2 mm, control the diameter-thickness ratio to be 8, the annealing deformation per pass is 25%, and adopt the method of atmospheric annealing plus pickling;

[0114] When the wall thickness of the cold-rolled capillary tube ≤ 2 mm, control the diameter-thickness ratio to be 15, the annealing deformation per pass is 15%, and adopt vacuum annealing with a vacuum degree of 10 -2 Pa.

[0115] S4. Finishing

[0116] The cold-rolled capillary tube obtained in step S3 is pickled to remove oil and dirt, and then polished and finished to obtain a capillary tube finished product with a clean appearance and high dimensional accuracy of Φ0.51 mm × 0.04 mm, where the outer diameter accuracy is 0.01 mm and the wall thickness accuracy is 0.005 mm.

[0117] After testing, the content of impurity element P in the prepared capillary tube finished product is 0.003 wt.%, and the content of impurity element S is 0.0012 wt.%.

[0118] Example 4

[0119] This example provides a preparation method for a modified GH4145 superalloy capillary tube with Φ0.4 mm × 0.02 mm.

[0120] First, prepare raw materials according to the following mass percentages (unit: wt.%):

[0121] Cr 16.2, Ti 2.45, Fe 7.8, Nb 0.9, Al 0.7, Co 0.028, Mn 0.02, Ta 0.0022, C 0.07, Si 0.2, Cu 0.015, B 0.004, Ce + Y 0.02 (where Ce 0.01, Y 0.01), and the balance is Ni.

[0122] The preparation steps are as follows:

[0123] S1. Double vacuum melting

[0124] In Reference Example 1, four groups of raw materials were sequentially added to a vacuum induction melting equipment for melting. The melting temperature was 1600 °C. After the melting of the first three groups of raw materials was completed, refining and standing for 15 minutes were carried out, and then the fourth group of raw materials A was added. After all the raw materials were melted, the molten alloy was stirred for 1 - 2 minutes to ensure uniform composition. Finally, it was cast into an ingot, and the entire induction melting process was controlled within 2 - 3 hours;

[0125] Subsequently, the ingot was transferred to a vacuum consumable arc furnace for secondary melting. The melting current was set at 3000 A, the melting voltage was 25 V, the melting time was 55 minutes, the working vacuum degree was 0.22 Pa, and the air leakage rate was 0.1 Pa / min. Through this process, a modified GH4145 superalloy ingot was prepared. Then, the shrinkage cavity part of the ingot was cut off, and homogenization annealing treatment at 1120 °C for 6 hours was carried out. After turning it smooth, a finished ingot was obtained.

[0126] S2. Hot working

[0127] After the finished ingot obtained in step S1 was charged into the furnace at room temperature, it was gradually heated to 1200 °C at a speed of 5 °C / min and held for 3 hours, then cogging forging was carried out, forging at 1080 °C, with a single deformation amount of 30%, and finally forged into a bar;

[0128] Then the forged bar was turned into a bright bar. After charging into the furnace at 850 °C, it was heated to 1000 °C at a speed of 8 °C / min and held for 1 hour;

[0129] Then, through a 2000T extruder, it was pierced into a tube blank at a speed of 60 mm / s. After pickling and finishing, a rough tube was obtained for cold rolling.

[0130] S3. Annealing and cold rolling

[0131] The rough tube obtained in step S2 was processed by multi-pass cold rolling at room temperature to obtain a capillary tube with dimensions specifically:

[0132] During the cold rolling process, annealing treatment was carried out in the middle of each pass. The parameters of each annealing treatment were: temperature 1050 °C, holding for 0.5 hours, and cooling in the furnace;

[0133] When the wall thickness of the cold-rolled rough tube > 2 mm, the diameter-thickness ratio was controlled at 8, and the annealing deformation amount per pass was 25%. The method of atmospheric annealing plus pickling was adopted;

[0134] When the wall thickness of the cold-rolled rough tube ≤ 2 mm, the diameter-thickness ratio was controlled at 13, and the annealing deformation amount per pass was 15%. Vacuum annealing was adopted, and the vacuum degree was 10 -2 Pa.

[0135] S4, Finishing

[0136] The cold-rolled capillary obtained in step S3 is pickled to remove oil and dirt, and then polished and finished to obtain a Φ0.4mm×0.02mm capillary finished product with a clean appearance and high dimensional accuracy, where the outer diameter accuracy is 0.01mm and the wall thickness accuracy is 0.005mm.

[0137] After testing, the content of impurity element P in the prepared capillary finished product is 0.0013wt.%, and the content of impurity element S is 0.0011wt.%.

[0138] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various deformations or modifications within the scope of the claims, which does not affect the essence of the present invention.

Claims

1. A modified GH4145 high temperature alloy capillary, characterized in that: The chemical composition of the capillary is calculated by mass percentage: Cr 15.5-16.5, Ti 2.4-2.5, Fe 7.5-8.5, Nb 0.7-1.0, Al 0.7-0.9, Co 0.02-0.04, Mn 0.02-0.05, Ta 0.0015-0.003, C 0.07-0.12, Si 0.1-0.2, Cu 0.01-0.02, B0.004-0.005, RE: 0.01-0.02, impurity P≤0.008, impurity S≤0.005, and the balance is Ni.

2. The modified GH4145 high temperature alloy capillary according to claim 1, characterized in that: The rare earth element RE is one or more of lanthanum, cerium and yttrium.

3. The modified GH4145 high temperature alloy capillary according to any one of claims 1 to 2, characterized in that: The dimensions of the capillary are an outer diameter ranging from 0.4±0.01 mm to 0.83 mm±0.01 mm, and a wall thickness ranging from 0.02±0.005 mm to 0.12 mm±0.005 mm.

4. The modified GH4145 high temperature alloy capillary according to claim 3, characterized in that: The dimensions of the capillary are an outer diameter ranging from 0.4±0.01 mm to 0.63 mm±0.01 mm, and a wall thickness ranging from 0.02±0.005 mm to 0.055 mm±0.005 mm.

5. The method for preparing the modified GH4145 high temperature alloy capillary according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Dual vacuum melting The raw materials of GH4145 alloy are subjected to vacuum induction melting at 1450-1600° C. for 2-3 hours, wherein the refining is allowed to stand for 15-20 minutes, and a mother ingot is cast, and then the mother ingot is subjected to secondary melting by a vacuum consumable process with a melting current of 2000-3500A to obtain an ingot blank, and after the shrinkage cavities are removed, a first annealing treatment is carried out at 1100-1150° C. for 6-8 hours, and the finished ingot is obtained by polishing; S2. Hot working The finished ingot is heated to 1150-1250° C., kept warm for 3-4 hours, and then forged into a rod at 1050-1100° C., with a single deformation of 20-30%, and then the rod is polished, put into a furnace at 800-900° C., heated to 1000-1100° C. with the furnace, kept warm for 1-2 hours, and then hot extruded and pierced to form a tube blank, and then pickled and finished to obtain a rough tube; S3, annealing and cold rolling The capillary tube is subjected to multiple cold rolling and annealing between passes to obtain a capillary tube, wherein: During the cold rolling process, when the capillary wall thickness is greater than 2 mm, the cold rolling passes are controlled to have a diameter-to-thickness ratio of 5 to 8, the annealing deformation between passes is 20 to 25%, and an atmospheric annealing plus pickling method is used; During the cold rolling process, when the capillary wall thickness is ≤2 mm, the diameter-to-thickness ratio of the cold rolling passes is controlled to be 10-15, the annealing deformation between passes is 12-15%, and vacuum annealing is adopted with a vacuum degree of 10 -1 ~10 -2 Pa; The parameters of the atmospheric annealing or vacuum annealing treatment are annealing temperature of 1000-1050° C., time of 0.5-1 h, and furnace cooling.

6. The method for preparing the modified GH4145 high temperature alloy capillary according to claim 5, characterized in that: The B element in the GH4145 alloy raw material is introduced in the form of FeB master alloy, and the rare earth element RE is added in the form of one or more of La-Ni, Al-Ce, and Al-Y master alloys.

7. The method for preparing the modified GH4145 high temperature alloy capillary according to claim 5, characterized in that: In step S1, during the vacuum induction melting process, the raw materials are divided into four groups, namely: the first group of Fe, Ni, Co, Nb, Ta and Cr; the second group of Al and Ti; the third group of C, Si and Cu; the fourth group of FeB, rare earth master alloy and Mn, and the four groups of raw materials are added in sequence for melting. The timing of adding the second and third groups of raw materials is: after the previous group of raw materials is melted, the next group of raw materials is added. After the third group of raw materials is melted, they are refined and left to stand for 15 to 20 minutes, and then the fourth group of raw materials are added for melting.

8. The method for preparing the modified GH4145 high temperature alloy capillary according to claim 5, characterized in that: In step S1, the vacuum degree during the vacuum induction melting process is 0.3-0.6Pa, and the vacuum degree during the secondary melting is 0.02-0.4Pa.

9. The method for preparing the modified GH4145 high temperature alloy capillary according to claim 5, characterized in that: In step S1, the diameter of the mother ingot is The diameter of the ingot is 120-230 mm, and the diameter of the finished ingot is 10. The method for preparing the modified GH4145 high temperature alloy capillary according to claim 5, characterized in that: In step S2, the rod has a diameter of 60 to 70 mm, the outer diameter of the capillary tube has a diameter of 30 to 40 mm, and the wall thickness has a thickness of 5 to 10 mm.

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