In-situ strength evaluation device and method for turbine blade after service

Abstract

The invention provides an in-situ strength evaluation device and method for a turbine blade after service. The in-situ strength evaluation device comprises a loading mechanism, a circulating cooling system, a high-temperature environment system and a deformation measurement system, the loading mechanism is used for clamping an evaluated sample and carrying out tension loading on the sample; the loading mechanism comprises a high-temperature pull rod, the high-temperature pull rod comprises an upper pull rod and a lower pull rod, an adjusting clamping plate is installed between the upper pull rod and the lower pull rod, a positioning block is slidably connected in the adjusting clamping plate, the positioning block can move in the horizontal direction along the adjusting clamping plate, and the positioning block is used for positioning a sample. Adjusting the coaxiality between the sample and the high-temperature pull rod; the circulating cooling system is used for cooling the high-temperature pull rod; the high-temperature environment system is used for providing a high-temperature environment for the position of the sample; and the deformation measuring system is used for monitoring the deformation condition of the stressed sample. The invention relates to an in-situ strength evaluation device for a turbine blade after service, which is suitable for special-shaped samples such as torsion samples, arc samples and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of static tensile performance detection of metal materials, and in particular to an in-situ strength evaluation device and method for turbine blades after service. Background Art

[0002] Turbine blades are important components of the turbine section of gas turbine engines. The high-speed rotating blades are responsible for sucking high-temperature and high-pressure airflow into the burner to maintain the operation of the engine. In order to ensure stable and long-term operation under extreme conditions of high temperature and high pressure, turbine blades are often forged with high-temperature alloys. Metal fatigue of blades is the main cause of engine failure, and metal fatigue will greatly reduce the mechanical properties of turbine blades during service. At present, turbine blades after service are often no longer used because it is impossible to determine their continued service life or accurately test their remaining mechanical properties, resulting in a waste of resources. For such complex structure blades, conventional standard size samples cannot be sampled, and the testing is extremely difficult. At the same time, the mechanical test results of conventional size specimens, such as conventional tensile and compression testing techniques, can usually only reflect the elastic limit, elongation, elastic modulus, tensile strength, yield strength and other performance indicators of larger-sized overall samples, and cannot give the mechanical properties of the local or each tiny area of ​​the tested sample. The above factors make it difficult for conventional size testing methods to meet the sampling of mechanical properties of complex materials and high-throughput, multi-parameter, and cross-scale testing requirements in the development and service of new materials. The small sample testing method uses micro-specimens cut from turbine blades after service for testing, which can nearly meet the requirements of "micro-destructive" testing of the mechanical properties of materials, and can accurately reflect the changes in the performance of a certain part of the structure before and after service, thereby guiding the process design of structural parts and the monitoring and research of service performance. Summary of the invention

[0003] The purpose of the present invention is to provide an in-situ strength evaluation device and method for turbine blades after service.

[0004] The technical solution adopted by the present invention to solve its technical problem is: An in-situ strength evaluation device for a turbine blade after service, comprising a loading mechanism, a circulating cooling system, a high temperature environment system and a deformation measurement system; The loading mechanism is used to clamp the sample to be evaluated and to apply tensile force to the sample; The force measurement system should be calibrated in accordance with GB / T 16825.1 and its accuracy should be Class 1 or better. The loading mechanism includes a high-temperature tie rod, which includes an upper tie rod and a lower tie rod. An adjustment clamp is installed between the upper tie rod and the lower tie rod. A positioning block is slidably connected in the adjustment clamp. The positioning block can move in the horizontal direction along the adjustment clamp. The positioning block is used to position the sample. The coaxiality between the sample and the high-temperature tie rod is adjusted by sliding on the adjustment clamp. The circulating cooling system is used to cool the high-temperature tie rods; The high temperature environment system is used to provide a high temperature environment for the location where the specimen is located; The sample can be heated to the specified temperature, and the tolerance between the measured temperature and the specified temperature and the temperature gradient meet the following requirements: when the specified temperature T≤1000℃, the tolerance between the measured temperature and the specified temperature is ±3℃; when 1000<T≤1100, the tolerance between the measured temperature and the specified temperature is ±6℃.

[0005] The minimum resolution of the temperature measuring device is 1°C, and the allowable error should be within ±0.4% or ±2°C (whichever is greater).

[0006] The deformation measurement system is used to monitor the deformation of the specimen after being stressed to avoid airflow interference and the introduction of lateral forces.

[0007] Furthermore, an I-shaped through groove is provided on the side end surface of the adjustment clamping plate, and the positioning block is in an inverted T-shaped structure, which is accommodated in the I-shaped through groove and is slidably connected with the I-shaped through groove.

[0008] Furthermore, positioning scale lines are arranged on the surface of the positioning block.

[0009] Furthermore, the loading mechanism also includes an upper crossbeam and a lower base, the upper crossbeam is used to install the upper pull rod, and the lower base is used to install the lower pull rod.

[0010] Furthermore, the circulating cooling system includes a circulating cooling water pipe, and the circulating cooling water pipe is connected to the inner cavity of the high-temperature pull rod.

[0011] Furthermore, the high temperature environment system includes a high temperature furnace, the bottom of which is fixedly connected to the lower base of the loading system through a bracket, a thermocouple is installed at the rear of the high temperature furnace, the thermocouple is fixed to the furnace body of the high temperature furnace by bolts, and is directly inserted into the inner cavity of the high temperature furnace, and the front end face of the high temperature furnace is provided with high temperature resistant glass.

[0012] Furthermore, the high temperature furnace can be adjusted in front and back as well as in height by means of a bracket.

[0013] Furthermore, the deformation measurement system includes a video extensometer and a fill light green light. One end of the mounting frame is fixed on the high-temperature pull rod, the video extensometer is fixed on the side of the mounting frame, and the fill light green light and the video extensometer are located on the front side of the high-temperature resistant glass.

[0014] Furthermore, a leveling device is installed at the bottom of the video extensometer, and the leveling device is slidably installed on a slide rail. The bottom of the slide rail is fixedly connected to the mounting frame. The lateral position of the video extensometer can be adjusted through the slide rail, and the mounting frame is fixed to the lower base of the equipment through a locking device.

[0015] The present application also proposes a method for in-situ strength evaluation of a turbine blade after service, which is characterized in that the method adopts the above-mentioned in-situ strength evaluation device for a turbine blade after service, and comprises the following steps: Prepare the sample and collect the “I-shaped” sample; Use the adjusting clamp (14) to adjust the coaxiality of the upper pull rod and the lower pull rod: adjust the clamp (14) The connection position of the upper and lower parts is fixed in the grooves corresponding to the upper pull rod and the lower pull rod. When the connection of the adjustment clamp (14) is located in the grooves corresponding to each other, the upper pull rod and the lower pull rod are in a coaxial state. Use the positioning block (13) to adjust the coaxiality between the sample and the high-temperature pull rod (12), and place the sample on the upper pull rod. Two positioning blocks (13) are provided in the I-shaped grooves formed between the upper and lower pull rods, and are respectively placed against two sides of the sample. By referring to the scales on the positioning blocks (13), it is determined whether the sample is coaxial with the upper and lower pull rods in the middle of the upper and lower pull rods. After completing the above steps, remove the positioning block (13) and the adjustment clamp (14); The upper crossbeam (11) provides a tensile force to load the sample between the upper tie rod and the lower tie rod, and a high temperature environment is provided by a high temperature environment system (3); The deformation of the specimen is measured by the deformation measurement system (4) to obtain test feedback.

[0016] Beneficial effects of the present invention: The present invention designs an in-situ strength evaluation device for turbine blades after service, which is suitable for twisted, arc-shaped and other special-shaped specimens, and has strong tooling adaptability.

[0017] It is suitable for tiny specimens with parallel section length less than 10mm. Traditional contact high-temperature extensometers will cause additional force to the specimen, affecting the test accuracy and cannot meet the strain measurement requirements in high-temperature environments.

[0018] The video extensometer is used to monitor the deformation of small specimens during the test, which can achieve full-field strain measurement and measure the deformation of specimens under high temperature conditions (up to 1000°C).

[0019] The present invention will be described in more detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 It is a schematic diagram of the circulating cooling system of the present invention; Figure 3 It is a structural schematic diagram of the deformation measurement system of the present invention; Figure 4 This is a schematic diagram of the combined structure of the adjusting clamp plate and the positioning block of the present invention; Figure 5 This is a schematic diagram of the positioning block structure of the present invention; Figure 6 This is a schematic diagram of adjusting the splint structure of the present invention; Figure 7 This is a schematic diagram of the high temperature environment system structure of the present invention; Figure 8 It is a structural schematic diagram of the joint of the upper and lower pull rods of the present invention; Fig. 9 This is a schematic diagram of the sample installation structure of the present invention. DETAILED DESCRIPTION

[0022] like Figure 1-7 The in-situ strength evaluation device for a turbine blade after service shown in the figure comprises a loading mechanism 1, a circulating cooling system 2, a high temperature environment system 3 and a deformation measurement system 4; The loading mechanism 1 is used to clamp the sample to be evaluated and to apply tensile force to the sample; The loading mechanism 1 includes a high temperature tie rod 12, which includes an upper tie rod and a lower tie rod, and also includes an adjustment clamp 14 and a positioning block 13. The adjustment clamp 14 is used to assist in adjusting the coaxiality of the upper and lower tie rods. Figure 4 as well as Figure 8 As shown, grooves are provided on the outer circumference of the upper and lower pull rods. The adjustment clamping plate is in a door-shaped structure as a whole, and the upper and lower inner sides of the adjustment clamping plate are fixed on the grooves 122, as shown in FIG. Figure 4 As shown, since the structure of the adjustment clamp 14 is a standard part, when installing it on the groove 122, the coaxiality of the upper and lower pull rods can be referenced. The positioning block 13 is used to locate the coaxiality of the sample and the pull rod, and a scale is set on the positioning block 13. When using, refer to Fig. 9 As shown, the joint of the upper and lower tie rods is provided with a positioning pin 121, which forms an I-shaped groove for placing the sample A (the upper and lower tie rods can apply tension to the sample A by moving toward each other). Two positioning blocks 13 are provided, which are respectively against the two sides of the sample A. By referring to the scale on the positioning block 13, it can be judged whether the sample A is coaxial with the upper and lower tie rods in the middle of the upper and lower tie rods. In addition, in order to cooperate with the work of the positioning block 13, refer to Figure 4 , an I-shaped groove is also provided on the adjusting clamping plate 14. After the coaxiality is adjusted, the positioning block 13 and the adjusting clamping plate 14 need to be removed.

[0023] Continue to refer to Figure 1As shown, the loading mechanism 1 also includes an upper crossbeam 11 and a lower base 10. The upper crossbeam 11 is used to install the upper pull rod, and the lower base 10 is used to install the lower pull rod. The upper crossbeam 11 provides an upward pulling force through a screw rod or a hydraulic drive source. A force value sensor is installed in the middle of the upper crossbeam 11. The sensor is connected to the upper pull rod, and the sensor tests the force value of the sample.

[0024] The circulating cooling system 2 is used to cool the high temperature tie rod 12; Figure 2 As shown, the circulating cooling system 2 includes a circulating cooling water pipe, which is connected to the inner cavity of the high-temperature pull rod 12 .

[0025] The high temperature environment system 3 is used to provide a high temperature environment for the location of the sample; Figure 7 As shown, the high temperature environment system 3 includes a high temperature furnace 31, the bottom of which is fixedly connected to the lower base 10 of the loading system 1 through a bracket 34, a thermocouple 32 is installed at the rear of the high temperature furnace 31, the thermocouple 32 is fixed to the furnace body of the high temperature furnace 31 by bolts, and directly inserted into the inner cavity of the high temperature furnace 31, and a high temperature resistant glass 33 is provided on the front face of the high temperature furnace 31. The high temperature furnace 31 can adjust the front and rear and height positions through the bracket 34, and the bracket 34 drives the high temperature furnace 31 to achieve position adjustment through the servo. It is worth mentioning that the high temperature furnace 31 is not a fully enclosed structure, which is equivalent to being sleeved on the pull rod, surrounding the position of the sample to provide heating.

[0026] The deformation measurement system 4 is used to monitor the deformation of the sample after being subjected to force. Figure 3 As shown, the deformation measurement system 4 includes a video extensometer 4-1 and a fill light 4-3, one end of the mounting frame 4-2 is fixed on the high temperature pull rod 12, the video extensometer 4-1 is fixed on the side of the mounting frame 4-2, and the fill light 4-3 and the video extensometer 4-1 are located in front of the high temperature resistant glass 33. A leveling device 4-5 is installed at the bottom of the video extensometer 4-1, and the leveling device 4-5 is slidably installed on the slide rail 4-4. The bottom of the slide rail 4-4 is fixedly connected to the mounting frame 4-2, and the lateral position of the video extensometer 4-1 can be adjusted through the slide rail 4-4. The mounting frame 4-2 is fixed to the lower base by a locking device 4-6.

[0027] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or they are directly applied to other occasions without improvement, they all fall within the protection scope of the present invention.

Claims

1. An in-situ strength evaluation device for turbine blades after service, characterized in that : comprising a loading mechanism (1), a circulating cooling system (2), a high temperature environment system (3) and a deformation measurement system (4); The loading mechanism (1) is used to clamp the sample to be evaluated and to apply tensile force to the sample; The loading mechanism (1) comprises a high-temperature pull rod (12), the high-temperature pull rod (12) comprises an upper pull rod and a lower pull rod, an adjustment clamping plate (14) is installed between the upper pull rod and the lower pull rod, a positioning block (13) is slidably connected to the adjustment clamping plate (14), and the positioning block (13) can move in a horizontal direction along the adjustment clamping plate (14). The positioning block (13) is used to position the sample, and the coaxiality between the sample and the high-temperature pull rod (12) is adjusted by sliding on the adjustment clamping plate (14); The circulating cooling system (2) is used to cool the high-temperature tie rod (12); The high temperature environment system (3) is used to provide a high temperature environment at the location where the sample is located; The deformation measurement system (4) is used to monitor the deformation of the specimen after being subjected to force.

2. The in-situ strength evaluation device for turbine blades after service according to claim 1 is characterized in that: An I-shaped through groove is provided on the side end surface of the adjustment clamping plate (14), and the positioning block (13) is in an inverted T-shaped structure, accommodated in the I-shaped through groove, and slidably connected to the I-shaped through groove.

3. The in-situ strength evaluation device for turbine blades after service according to claim 2 is characterized in that: The surface of the positioning block (13) is provided with positioning scale lines.

4. The in-situ strength evaluation device for turbine blades after service according to claim 3 is characterized in that: The loading mechanism (1) further comprises an upper crossbeam (11) and a lower base (10); the upper crossbeam (11) is used to install an upper pull rod, and the lower base (10) is used to install a lower pull rod.

5. The in-situ strength evaluation device for turbine blades after service according to claim 1 is characterized in that: The circulating cooling system (2) comprises a circulating cooling water pipe, and the circulating cooling water pipe is connected to the inner cavity of the high-temperature pull rod (12).

6. The in-situ strength evaluation device for turbine blades after service according to claim 1 is characterized in that: The high temperature environment system (3) comprises a high temperature furnace (31). The bottom of the high temperature furnace (31) is fixedly connected to the lower base (10) of the loading system (1) via a bracket (34). A thermocouple (32) is installed at the rear of the high temperature furnace (31). The thermocouple (32) is fixed to the furnace body of the high temperature furnace (31) via bolts and is directly inserted into the inner cavity of the high temperature furnace (31). The front end surface of the high temperature furnace (31) is provided with high temperature resistant glass (33).

7. The in-situ strength evaluation device for turbine blades after service according to claim 5 is characterized in that: The high temperature furnace (31) can be adjusted in front and back direction and in height through the bracket (34).

8. The in-situ strength evaluation device for turbine blades after service according to claim 1 is characterized in that: The measuring system (4) comprises a video extensometer (4-1) and a fill light green light (4-3); one end of the mounting frame (4-2) is fixed on the high temperature pull rod (12); the video extensometer (4-1) is fixed on the side of the mounting frame (4-2); and the fill light green light (4-3) and the video extensometer (4-1) are located on the front side of the high temperature resistant glass (33).

9. The in-situ strength evaluation device for turbine blades after service according to claim 8 is characterized in that: A leveling device (4-5) is installed at the bottom of the video extensometer (4-1). The leveling device (4-5) is slidably installed on a slide rail (4-4). The bottom of the slide rail (4-4) is fixedly connected to a mounting frame (4-2). The lateral position of the video extensometer (4-1) can be adjusted via the slide rail (4-4). The mounting frame (4-2) is fixed to a fixing rod installed on the lower base (10) via a locking device (4-6).

10. A method for in-situ strength evaluation of turbine blades after service, characterized in that: An in-situ strength evaluation device for a turbine blade after service as claimed in any one of claims 1 to 9 is used, comprising the following steps: Prepare the specimen, using an "I-shaped" specimen; Use the adjusting clamp (14) to adjust the coaxiality of the upper pull rod and the lower pull rod: adjust the clamp (14) The connection position of the upper and lower parts is fixed in the grooves corresponding to the upper pull rod and the lower pull rod. When the connection of the adjustment clamp (14) is located in the grooves corresponding to each other, the upper pull rod and the lower pull rod are in a coaxial state. Use the positioning block (13) to adjust the coaxiality between the sample and the high-temperature pull rod (12), and place the sample on the upper pull rod. Two positioning blocks (13) are provided in the I-shaped grooves formed between the upper and lower pull rods, and are respectively placed against two sides of the sample. By referring to the scales on the positioning blocks (13), it is determined whether the sample is coaxial with the upper and lower pull rods in the middle of the upper and lower pull rods. After completing the above steps, remove the positioning block (13) and the adjustment clamp (14); The upper crossbeam (11) provides a tensile force to load the sample between the upper tie rod and the lower tie rod, and a high temperature environment is provided by a high temperature environment system (3); The deformation of the specimen is measured by the deformation measurement system (4) to obtain test feedback.

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