A sealing device and process for improving the hot-induced hole yield of powder high-temperature alloy

Abstract

The present application relates to a kind of sealing device and process for improving the hot induced hole rate of powder superalloy, belong to powder superalloy technical field, solve the problem that existing powder superalloy hot induced hole rate is not high.Sealing process includes hydraulic pressure pipe, laser welding, two-way pipe welding and welding protection sleeve and other steps.The present application adopts the process of hydraulic pressure flattening-laser welding-welding protection sleeve, instead of the existing induction heating and air pressure flattening combined process, ensures the sealing quality of lower powder pipe, the yield rate is improved from 95% to 100%, and the hot induced porosity is below 0.3%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of powder superalloy, and particularly relates to a sealing device and process for improving the hot-induced hole yield of powder superalloy. BACKGROUND

[0002] As one of key components of high-performance aero-engines, powder superalloy parts are mainly used in high-temperature and high-stress environments, and the preparation process is complex and has high technical difficulty. The hot-induced hole is one of main defects in the existing powder superalloy parts. When a large number of hot-induced holes exist in the organization, the fracture behavior of the alloy changes, and the cracks are more likely to be generated and expanded, so that the tensile properties of the material are reduced. In addition, with the increase of the hot-induced porosity, the impact performance of the alloy is reduced, which seriously affects the material performance. Therefore, whether the hot-induced hole is successfully controlled directly determines whether the quality of the powder superalloy part can meet the requirements of the aero-engine, and is extremely important.

[0003] The powder superalloy part is usually formed by hot isostatic pressing in the preparation process. In order to ensure the smooth progress of the hot isostatic pressing, the powder is usually vacuum packaged in a cylindrical sleeve with a powder tube. The existing sleeve sealing process adopts a pressure welding method to seal the powder tube. Generally, the powder tube is heated to 500-700 DEG C by induction heating, and then is processed by air pressure flattening. After flattening, the flattened surface is fusion welded by using instantaneous current. However, in the mass production mode, the success rate of this sealing process is not high, and problems such as tube explosion and insufficient welding often occur during sealing, and the welding stability is poor. Even if the sealing is successful, the weld strength is also prone to air leakage under the working conditions of 100-150 MPa and 1000 DEG C or more in the hot isostatic pressing, thereby resulting in that the hot-induced porosity of the powder superalloy does not meet the requirements, and the yield is low. More seriously, it leads to the scrap of the entire sleeve, waste of powder, and greatly increases the manufacturing cost of mass production.

[0004] Therefore, a 100% reliable welding process and device are needed to completely solve the problem of air leakage of the sleeve for powder superalloy, and to improve the hot-induced hole yield. SUMMARY

[0005] In view of the above analysis, the present application aims to provide a sealing device and process for improving the hot-induced hole yield of powder superalloy, so as to solve the problem of low hot-induced hole yield of the existing powder superalloy.

[0006] In one aspect, the present application provides a sealing process for improving the hot-induced hole yield of powder superalloy, comprising the following steps:

[0007] S1: Hydraulic compression: High-temperature alloy powder is loaded into the bag through the lower powder hose via a vacuum pipeline. After the powder is loaded, the lower powder hose is flattened once. The pressure is increased and the lower powder hose is flattened again to form the first indentation. The flattening position is 8 to 10 cm above the upper end of the powder in the lower powder hose.

[0008] S2: Laser welding: align the laser emission hole with the center line of the indentation, and set the laser welding start point, end point, welding speed and welding power;

[0009] S3: Two-pass compression welding: flatten the lower powder tube 3 to 5 cm above the upper end of the powder in the lower powder tube once; increase the pressure and flatten it again to form a second indentation; then perform laser welding;

[0010] S4: Welding the protective sleeve; cut the lower powder hose along the upper edge of the first indentation. After cutting, put a cylindrical protective sleeve with a diameter 8 to 10 cm larger than the lower powder hose on the outside of the lower powder hose. The lower edge of the cylindrical protective sleeve is welded by argon arc welding. After the argon arc welding is completed, high-temperature alloy powder is filled into the protective sleeve. After it is full, the sleeve cover and the sleeve are sealed by argon arc welding.

[0011] Furthermore, the pressure of the first flattening is 8 to 10 tons, and the pressure of the second flattening is 10 to 15 tons.

[0012] Furthermore, in step S2, the welding speed is 30-80 mm / s, and the welding power is 1-1.5 kW.

[0013] Furthermore, in step S3, the welding speed is 40-80 mm / s, and the welding power is 1.2-1.5 kW.

[0014] Furthermore, in step S2, the laser welding PWM frequency is 10000-30000 Hz, and the PWM pulse width is 50-70 ms.

[0015] Furthermore, in step S3, the laser welding PWM frequency is 10000-20000 Hz, and the PWM pulse width is 50-60 ms.

[0016] Furthermore, in steps S2 and S3, the starting point and the end point of laser welding are 1 to 1.5 mm away from the edge of the powder tube, and the starting point and the end point need to rise and fall slowly, with the rising and falling distances being 3 to 4 mm respectively.

[0017] Furthermore, after hot isostatic pressing, the heat-induced porosity of the powder high-temperature alloy is below 0.3%, and the yield is 100%. The hot isostatic pressing pressure is 100-150 MPa and the temperature is above 1000°C.

[0018] In another aspect, the present application provides a sealing device for implementing the sealing process of the present application, which is composed of a laser welding assembly 1, a hydraulic press assembly 2 and a workbench running assembly 3, and the laser welding assembly 1 and the hydraulic press assembly 2 are jointly connected on a workbench surface 4.

[0019] Further, the upper part of the workbench surface 4 is connected with an X motion shaft 6, and the workbench surface 4 is driven by an X shaft servo motor 7 to move along an X direction sliding rail 5 and the X motion shaft 6 to realize the movement of the laser welding assembly 1 and the hydraulic press assembly 2 in the X direction.

[0020] The X motion shaft 6 and the lower part of the workbench surface 4 are connected with two Z motion shafts 9 and two Y direction sliding rails 11, the Z motion shafts are driven to move in the Z direction by air cylinders 8, the lower part of the Y direction sliding rail 11 is connected on a base 12, the Y direction sliding rail is fixed by a fixed module 10, and the X motion shaft 6 ensures the back-and-forth movement of the screw rod by a fixed shaft sleeve 14.

[0021] Compared with the prior art, the present application can achieve at least one of the following beneficial effects:

[0022] 1. The present application adopts the process of combining hydraulic flattening, laser welding and welding protective sleeve, which replaces the existing process of combining induction heating and air pressure flattening. On the one hand, the process reduces the operation complexity by reducing the induction heating process, and the stable hydraulic output ensures the uniformity of the thickness of the flattened surface of the lower powder tube, thereby providing stable working conditions for the subsequent welding. On the other hand, the laser welding has high energy density, large welding process depth and small deformation, and has good fault tolerance for the thickness of the flattened assembly. At the same time, the laser welding starting point and the end point are provided with a slow rise and a slow drop, which solves the defect that the edges of the pressure welding are prone to burst, greatly improves the success rate and reliability of the welding, and finally ensures the sealing quality of the lower powder tube, the hot induced porosity of the powder high-temperature alloy is kept below 0.3%, and the yield is improved from 95% to 100%.

[0023] 2. Since the diameter difference between the lower powder tube and the sleeve is large, the present application adopts the welding protective sleeve mode, which reduces the problem of stress concentration at the root of the lower powder tube during the hot isostatic pressing process, and further reduces the possibility of hot isostatic pressing air leakage.

[0024] In the present application, the above technical solutions can be combined with each other to realize more preferred combination schemes. Other features and advantages of the present application will be described in the subsequent specification, and some advantages will become apparent from the specification or will be understood by implementing the present application. The purpose and other advantages of the present application can be achieved and obtained from the specific indications in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and are not intended to limit the scope of the application, and the same reference numerals designate the same elements throughout the accompanying drawings.

[0026] Figure 1 A schematic view of the structure of the sealing device of the present application is shown in the figure.

[0027] Figure 2 A schematic view of the sleeve and the powder pipe in the present application is shown in the figure.

[0028] Figure 3 A schematic view of the welding track in the present application is shown in the figure.

[0029] Reference signs:

[0030] 1, laser welding assembly; 2, hydraulic press assembly; 3, workbench running assembly; 4, workbench surface; 5, X direction slide rail; 6, X movement shaft; 7, X shaft servo motor; 8, air cylinder; 9, Z movement shaft; 10, fixed module; 11, Y direction slide rail; 12, base; 13, pressure head; 14, fixed shaft sleeve; 15, powder pipe; 16, sleeve; 17, sleeve. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings form a part of the present application and are used to explain the principles of the embodiments of the present application, but are not intended to limit the scope of the present application.

[0032] The powder high-temperature alloy part is one of the key components of high-performance aeroengines, mainly serving in a high-temperature and high-stress environment, and the preparation process is complex and technically difficult. The powder high-temperature alloy part is usually formed by hot isostatic pressing in the preparation process, and in order to ensure the smooth progress of the hot isostatic pressing, the powder is usually vacuum-sealed in a cylindrical sleeve with a powder pipe. The existing sleeve sealing process adopts a press welding method to seal the powder pipe.

[0033] The existing sealing process adopts a combination of induction heating and air pressure flattening. The powder pipe is heated to 500-700℃ by induction heating, and then is processed by air pressure flattening. The flattened surface is then welded by using a transient current. However, in the mass production mode, the success rate of this sealing process is not high, and problems such as pipe explosion and insufficient welding often occur during sealing, and the welding stability is poor. Even if the sealing is successful, the weld strength is extremely prone to air leakage under the working conditions of hot isostatic pressing of 100-150 MPa and above 1000℃, thereby resulting in unqualified hot-induced porosity of the powder high-temperature alloy and low yield.

[0034] Therefore, the present application provides a sealing process for improving the yield of hot-induced holes of powder high-temperature alloy, which comprises the following steps:

[0035] S1: hydraulic tube pressing; the high-temperature alloy powder is filled in the package through the vacuum pipeline via the lower powder tube, after the powder filling is completed, the lower powder tube is pressed once, the pressure is increased and the lower powder tube is pressed twice again to form the first indentation, and the pressing position is 8-10 cm from the upper end of the powder in the lower powder tube;

[0036] S2: laser welding; the laser emission hole is aligned with the center line of the indentation, and the starting point, the ending point, the welding speed and the welding power of the laser welding are set;

[0037] S3: two-way tube welding; the lower powder tube at the upper end of 3-5 cm of the powder in the lower powder tube is pressed once; the pressure is increased and the second indentation is formed by pressing twice; and then laser welding is performed again;

[0038] S4: welding protection sleeve; the lower powder tube is cut along the upper edge of the first tube indentation, after the cutting is completed, a cylindrical protection sleeve with a diameter of 8-10 cm larger than the lower powder tube is sleeved outside the lower powder tube, the lower edge of the cylindrical protection sleeve is welded by argon arc welding, after the argon arc welding is completed, the high-temperature alloy powder is filled in the protection sleeve, and after being filled, the sleeve cover and the sleeve are completed by argon arc welding.

[0039] Compared with the prior art, the process combining hydraulic pressing, laser welding and welding protection sleeve is adopted instead of the existing process combining induction heating and gas pressure pressing. On the one hand, the induction heating process is reduced, the operation complexity is reduced, the stable hydraulic output ensures the uniformity of the thickness of the pressed surface of the lower powder tube, and stable working conditions are provided for subsequent welding. On the other hand, the laser welding has high energy density, large welding process depth and small deformation, has good fault tolerance to the thickness of the pressed assembly, and the starting point and the ending point of the laser welding are provided with slow rising and slow falling, which solves the defect that the pressed and welded edge is easy to burst, greatly improves the success rate and reliability of welding, and finally ensures the welding quality of the lower powder tube, the thermal induced porosity of the powder high-temperature alloy is kept below 0.3%, and the yield is improved from 95% to 100%.

[0040] Specifically, the pressure of the first pressing is 8-10 tons, and the pressure of the second pressing is 10-15 tons.

[0041] It should be noted that in the present application, the hydraulic process is used to press different positions of the outer peripheral surface of the lower powder tube, which moves from the outer peripheral surface to the center and forms two indentations. The position of the first indentation is 8-10 cm from the upper end of the high-temperature alloy powder in the lower powder tube, and the position of the second indentation is 3-5 cm from the upper end of the high-temperature alloy powder in the lower powder tube. The two indentations further ensure the reliability of the welding, prevent the problem of gas leakage caused by abnormal conditions. The pressing sequence of the two indentations cannot be reversed, so as to ensure the welding quality and the quality of the subsequent powder high-temperature alloy parts.

[0042] In the process of forming each indentation by crushing the lower powder tube, secondary crushing is needed, the first crushing pressure is 8-10 tons, and the second crushing pressure is 10-15 tons. The purpose of the first crushing is to provide a pre-pressing plane for the second crushing, to avoid defects such as wrinkles formed by one-time pressing, and to ensure the uniformity of the thickness of the pressing surface after pressing. The second crushing pressure must be greater than the first crushing pressure, so as to ensure that the hot-induced porosity after welding meets the requirements.

[0043] It should be noted that the purpose of filling the powder high-temperature alloy in the welding protective sleeve is to reduce the stress concentration at the root of the lower powder tube and avoid the cracking of the weld due to excessive tensile stress during hot isostatic pressing.

[0044] Specifically, the welding speed is 30-80 mm / s, and the welding power is 1-1.5 KW.

[0045] Preferably, the welding speed is 40-80 mm / s, and the welding power is 1.2-1.5 KW.

[0046] It should be noted that during the welding process, the welding speed and the welding power determine the quality of the welding. When the welding speed is less than 30 mm / s and / or the welding power is greater than 1.5 KW, it may cause the heat-affected zone of the welding to become larger, reducing the welding strength of the lower powder tube; when the welding speed is higher than 80 mm / s and / or the welding power is less than 1.2 KW, it will cause the defect of insufficient welding, which will also reduce the welding strength.

[0047] Specifically, in step S2, the laser welding PWM frequency is 10000-30000 Hz, and the PWM pulse width is 50-70 ms.

[0048] Preferably, in step S2, the laser welding PWM frequency is 10000-20000 Hz, and the PWM pulse width is 50-60 ms.

[0049] It should be noted that in the present application, a higher PWM frequency, for example, greater than 30000 Hz, can improve the welding speed, but it reduces the quality of the welding points of the lower powder tube, and a larger PWM pulse width increases defects such as weld slag and pores, reducing the welding strength of the lower powder tube and the hot-induced porosity.

[0050] Specifically, in step 2, the starting point and the ending point of the laser welding are 1-1.5 mm away from the edge of the powder tube, and the starting point and the ending point need to be raised and lowered slowly, and the distance of the slow raising and lowering is 3-4 mm.

[0051] It should be noted that in the present application, the welding start and end points cannot be set on the flattened surface of the lower powder tube. If the welding start and end points are set on the flattened surface of the powder tube, the probability of pipe explosion at the edge of the lower powder tube will be increased, and the heat-induced hole rate will also be reduced, thereby affecting the quality of the final powder superalloy part.

[0052] Specifically, the diameter of the lower powder tube is 15-20 mm, and the wall thickness is 2-4 mm.

[0053] Specifically, the diameter of the sleeve is 500-800 mm, and the height is 800-1200 mm.

[0054] Specifically, after hot isostatic pressing at 100-150 MPa and above 1000℃, the heat-induced porosity of the powder superalloy is below 0.3%, and the yield is 100%.

[0055] It should be noted that in the present application, after flattening, laser sealing and welding of the sleeve, the powder superalloy part is produced by hot isostatic pressing process. During the hot isostatic pressing process, the pressure is 100-150 MPa, and the temperature is above 1000℃. After batch production by the sealing process provided by the present application, there will be no problems such as pipe explosion, insufficient welding, etc., and there will be no air leakage problem under hot isostatic pressing. The heat-induced porosity is below 0.3%, and the yield can reach 100%.

[0056] In order to realize the sealing process described in the present application, the present application provides a sealing device, which is composed of a laser welding assembly 1, a hydraulic press assembly 2 and a workbench running assembly 3. The laser welding assembly 1 and the hydraulic press assembly 2 are jointly connected on the workbench surface 4.

[0057] It should be noted that through the cooperation of the hydraulic press assembly 2 and the laser welding assembly 1, the flattening and welding of the lower powder tube can be completed, the quality after welding is guaranteed, and there will be no air leakage problem after hot isostatic pressing. The laser welding assembly 1 is used for welding the sleeve lower powder tube for powder superalloy, and the hydraulic press assembly 2 is used for flattening the sleeve lower powder tube.

[0058] Specifically, the upper part of the workbench surface 4 is connected with the X motion shaft 6, and the workbench surface 4 is driven by the X shaft servo motor 7 to slide along the X direction sliding rail 5 to realize the movement of the laser welding assembly 1 and the hydraulic press assembly 2 in the X direction.

[0059] The X movement shaft 6 is connected with the lower part of the workbench surface 4 through two Z movement shafts 9 and two Y direction slide rails 11, the Z movement shaft is driven to move in Z direction by the air cylinder 8; the lower part of the Y direction slide rail 11 is connected on the base 12; the Y direction slide rail is fixed by the fixed module 10, and the X movement shaft 6 ensures the screw rod to move back and forth by the fixed shaft sleeve 14.

[0060] Specifically, the hydraulic assembly 2 can provide 20 tons of pressure, the pressure head 13 is made of Cr12 steel, and the pressure head pressure surface size is 5cm-10cm.

[0061] Specifically, the hydraulic assembly 2 pressure head center line is on the same horizontal line with the laser hole of the laser welding assembly 1.

[0062] In order to more clearly describe the present application, the following examples and comparative examples are further illustrated.

[0063] Example 1

[0064] The present application provides a sealing device for improving the hot induced hole rate of powder high-temperature alloy, referring to Figure 1 , the sealing device is composed of a laser welding assembly 1, a hydraulic press assembly 2 and a workbench running assembly 3, wherein the laser welding assembly 1 and the hydraulic press assembly 2 are jointly connected on the workbench surface 4.

[0065] The upper part of the workbench surface 4 is connected with the X movement shaft 6, the workbench surface 4 is driven by the X shaft servo motor 7 to move along the X direction slide rail 5 and the X movement shaft 6 to realize the movement in X direction. The lower part of the workbench surface is connected with the X movement shaft 6 through two Z movement shafts 9 and two Y direction slide rails 11, the Z movement shaft is driven to move in Z direction by the air cylinder 8. The lower part of the Y direction slide rail 11 is connected on the base 12. The Y direction slide rail is fixed by the fixed module 10, and the X movement shaft 6 ensures the screw rod to move back and forth by the fixed shaft sleeve 14. The hydraulic assembly 2 pressure head center line is on the same horizontal line with the laser hole of the laser welding assembly 1.

[0066] The maximum pressure of the hydraulic assembly 2 is 20 tons, the pressure head 13 is made of Cr12 steel, and the pressure head pressure surface size is between 5cm-10cm.

[0067] Example 2

[0068] Example 2 provides a sealing process for improving the hot induced hole rate of powder high-temperature alloy, and the sealing is completed by using the sealing device in example 1, referring to Figures 1-3 .

[0069] The diameter of the sleeve 17 is 600 mm, and the height is 1200 mm; the diameter of the lower powder pipe 15 is 15 mm, and the wall thickness of the lower powder pipe 15 is 3 mm.

[0070] The lower powder pipe 15 and the sleeve 17 are sealed and welded, including the following steps:

[0071] S1: Hydraulic pipe pressing

[0072] The high-temperature alloy powder is filled into the sleeve 17 along the lower powder pipe 15 through the vacuum pipeline. After the powder is filled and vibrated, the approximate position of the powder is first determined, and then the press head is wiped with alcohol to ensure that the press head is free of foreign matter and oil stains. The hydraulic press assembly is adjusted to the lower powder pipe 15 by adjusting the X, Y, and Z movement axes of the sealing and welding device, so that the lower powder pipe 15 is just in the middle of the press head. The press head is 8-10 cm away from the upper end of the powder in the pipe, and the lower edge of the press head is perpendicular to the powder pipe. The hydraulic system is started, the pressure is adjusted to 8 tons, the lower powder pipe 15 is pressed once, and then the pressure is adjusted to 11 tons, the lower powder pipe 15 is pressed again, and the first indentation is formed.

[0073] S2: Laser welding

[0074] The laser welding machine assembly is adjusted to the pressed pipe by adjusting the X, Y, and Z movement axes of the sealing and welding device, so that the laser emission hole is on the center line of the indentation. The starting point and the ending point of the laser welding are set, and the starting point and the ending point are 1 mm away from the edge of the powder pipe. The starting point and the ending point are each 3 mm away from the starting point and the ending point. The welding speed is set to 40 mm / s, the welding power is 1.0 KW, the laser welding PWM frequency is 10000 Hz, and the PWM pulse width is 50 ms.

[0075] S3: Second pipe pressing and welding

[0076] According to the operation procedures of steps S1 and S2, the press head in the hydraulic press assembly is adjusted to be 3-5 cm away from the upper end of the powder in the pipe, the pipe is pressed and laser welded, and after the welding is completed, the ball valve for vacuumizing the upper part of the lower powder pipe 15 is closed.

[0077] S4: Welding protective sleeve

[0078] The lower powder pipe 15 is cut along the upper edge of the first pipe pressing indentation. After cutting is completed, a cylindrical protective sleeve 16 with a diameter of 8-10 cm larger than the lower powder pipe 15 is sleeved outside the lower powder pipe 15. The lower edge of the cylindrical protective sleeve 16 is welded by argon arc welding. After the argon arc welding is completed, the sleeve 16 is filled with high-temperature alloy powder, and after being filled, the sleeve 16 is sealed and welded with the cover of the sleeve 16.

[0079] Example 3

[0080] Example 3 is prepared in substantially the same manner as Example 2, except that in Example 3, the pressure of the first flattening is 10 tons, and the pressure of the second flattening is 15 tons.

[0081] Example 4

[0082] Example 4 is prepared in substantially the same manner as Example 2, except that in Example 4, the welding speed is set to 80 mm / s, the welding power is 1.5 KW, the laser welding PWM frequency is 20000 Hz, and the PWM pulse width is 60 ms.

[0083] Example 5

[0084] Example 5 is prepared in substantially the same manner as Example 2, except that in Example 5, the welding speed is set to 60 mm / s, the welding power is 1.2 KW, the laser welding PWM frequency is 30000 Hz, and the PWM pulse width is 70 ms.

[0085] Comparative Example 1

[0086] In Comparative Example 1, the induction heating-gas pressure flattening device is used to seal the lower powder tube and the sleeve, the diameter of the sleeve is 600 mm, the height is 1200 mm; the diameter of the lower powder tube is 15 mm, and the wall thickness of the lower powder tube is 3 mm.

[0087] The steps include:

[0088] S1: Induction heating

[0089] The sleeve is filled with high-temperature alloy powder through a vacuum pipeline. After the powder is vibrated and compacted, the approximate position of the powder is first determined, and a portable induction heater is used to heat at a distance of 8-10 cm from the upper end of the powder in the tube, with a heating power of 10 KW and a heating time of 15 s.

[0090] S2: Gas pressure tube

[0091] The press head is wiped with alcohol to ensure that there is no foreign matter and oil on the press head. By adjusting the X, Y, and Z movement axes, the gas pressure press assembly is adjusted to the lower powder tube, so that the lower powder tube is just in the middle of the press head, the press head is at a distance of 8-10 cm from the upper end of the powder in the tube, and the lower edge of the press head is perpendicular to the powder tube. Start the gas pressure system and adjust the pressure to 2 tons to flatten the lower powder tube once, and ensure that the pressure is 2 tons to flatten the lower powder tube twice.

[0092] S3: Pressure welding

[0093] By adjusting the X, Y, and Z movement axes, the pressure welding machine assembly is adjusted to the flattened powder tube, so that the pressure welding machine press head is on the center line of the gas pressure indentation. The power is set to 50 KW and the current is 150 A to perform pressure welding.

[0094] S4: Second pressure tube welding

[0095] According to the above operation process, the pneumatic press head is adjusted to be 3-5 cm away from the upper end of the powder in the tube, the tube is pressed and the welding is welded, and after the welding is completed, the ball valve for vacuumizing the upper part of the lower powder tube is closed.

[0096] S5: welding protective sleeve

[0097] Cut the lower powder tube along the upper edge of the first tube pressing mark, after cutting, transfer the package to an open place with a special device, place a cylindrical protective sleeve with a diameter of 8 cm larger than the lower powder tube outside the lower powder tube, the lower edge of the sleeve just fits the lower powder tube base and the upper surface of the package, the lower edge is welded by argon arc welding, fill the high-temperature alloy powder into the protective sleeve, after the first filling, knock and shake with a special knocking hammer until the powder cannot be poured, then cover the sleeve cover on the top of the sleeve, and complete the sealing of the sleeve cover and the sleeve by argon arc welding.

[0098] Comparative Example 2

[0099] Comparative Example 2 and Example 2 have basically the same preparation process, except that in Comparative Example 2, the welding speed is 100 mm / s, the welding power is 2 KW, the laser welding PWM frequency is 20000 Hz, and the PWM pulse width is 60 ms.

[0100] Comparative Example 3

[0101] Comparative Example 3 and Example 2 have basically the same preparation process, except that in Comparative Example 3, the pressure of the first flattening is 11 tons, and the pressure of the second flattening is 8 tons.

[0102] Performance detection

[0103] After the sealing of the above Examples 2-5 and Comparative Examples 1-3, the powder high-temperature alloy parts are produced by hot isostatic pressing process, the pressure is 100-150 MPa, and the temperature is 1000℃, then the thermal induced porosity is detected, and the detection results are shown in Table 1.

[0104] Porosity detection method, cut the sample from the alloy, heat it to 1200℃±10℃ for 4h, and the decrease of room temperature density compared with before treatment is generally greater than 0.3% is unqualified.

[0105] Table 1 performance detection results

[0106]

[0107] *The yield is the statistical result, 5 powder high-temperature alloy parts are produced for each example or comparative example.

[0108] It can be seen from the combination of the embodiments 1-5 and the comparative examples 1-3 of the present application and Table 1 that, by using the sealing process and device provided by the present application, the lower powder tube is sealed by using the process of combining hydraulic flattening, laser welding and welding protective sleeve, and after hot isostatic pressing, the yield of the embodiments of the present application is improved from 95% to 100%, and the thermal induced porosity is below 0.3%, which meets the requirements.

[0109] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A sealing process for improving the yield of heat-induced holes in powder high-temperature alloys, characterized in that: The following steps are involved: S1: Hydraulic compression: High-temperature alloy powder is loaded into the bag through the lower powder hose via a vacuum pipeline. After the powder is loaded, the lower powder hose is flattened once. The pressure is increased and the lower powder hose is flattened again to form the first indentation. The flattening position is 8 to 10 cm above the upper end of the powder in the lower powder hose. S2: Laser welding: align the laser emission hole with the center line of the indentation, and set the laser welding start point, end point, welding speed and welding power; S3: Two-pass compression welding: flatten the lower powder tube 3 to 5 cm above the upper end of the powder in the lower powder tube once; increase the pressure and flatten it again to form a second indentation; then perform laser welding; S4: Welding the protective sleeve; cut the lower powder hose along the upper edge of the first indentation. After cutting, put a cylindrical protective sleeve with a diameter 8 to 10 cm larger than the lower powder hose on the outside of the lower powder hose. The lower edge of the cylindrical protective sleeve is welded by argon arc welding. After the argon arc welding is completed, high-temperature alloy powder is filled into the protective sleeve. After it is full, the sleeve cover and the sleeve are sealed by argon arc welding.

2. The sealing process according to claim 1, characterized in that: The pressure of the first flattening is 8 to 10 tons, and the pressure of the second flattening is 10 to 15 tons.

3. The sealing process according to claim 1, characterized in that: The welding speed is 30-80 mm / s, and the welding power is 1-1.5 KW.

4. The sealing process according to claim 3, characterized in that: The welding speed is 40-80 mm / s, and the welding power is 1.2-1.5 KW.

5. The sealing process according to claim 1, characterized in that: In step S2, the laser welding PWM frequency is 10000-30000 Hz, and the PWM pulse width is 50-70 ms.

6. The sealing process according to claim 5, characterized in that: In step S2, the laser welding PWM frequency is 10000-20000 Hz, and the PWM pulse width is 50-60 ms.

7. The sealing process according to claim 1, characterized in that: In step 2, the starting and ending points of laser welding are 1 to 1.5 mm away from the edge of the powder tube. The starting and ending points need to rise and fall slowly, with the rising and falling distances being 3 to 4 mm respectively.

8. The sealing process according to claim 1, characterized in that: After hot isostatic pressing, the heat-induced porosity of the powder high-temperature alloy is below 0.3%, and the yield is 100%. The hot isostatic pressing pressure is 100-150MPa and the temperature is above 1000℃.

9. A sealing device, characterized in that: Used to implement the sealing process described in any one of claims 1 to 8, the sealing device consists of a laser welding component (1), a hydraulic press component (2) and a workbench travel component (3), and the laser welding component (1) and the hydraulic press component (2) are jointly connected to a workbench surface (4).

10. The sealing device according to claim 9, characterized in that: The upper portion of the work table (4) is connected to the X-axis motion axis (6), and the work table (4) drives the slide rail (5) and the X-axis motion axis (6) along the X direction via the X-axis servo motor (7) to achieve the movement of the laser welding assembly (1) and the hydraulic press assembly (2) in the X-axis direction; The X-motion axis (6) is connected to the lower part of the work table (4) via two Z-motion axes (9) and two Y-direction slide rails (11), and the Z-motion axis is driven by a cylinder (8) to move in the Z direction; the lower part of the Y-direction slide rail (11) is connected to the base (12); the Y-direction slide rail is fixed with auxiliary means by a fixing module (10), and the X-motion axis (6) relies on a fixing sleeve (14) to ensure that the screw rod can move back and forth.

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