Thermal fatigue test device

Abstract

The utility model relates to the field of material science and engineering, and discloses a thermal fatigue test device which comprises a main machine frame, a pressure regulating valve is arranged on the left side wall of the main machine frame, and the output end of the pressure regulating valve is connected with an air compressor through a pipeline. A right furnace shell and a left furnace shell are hinged to the inner wall of the main machine frame through supports respectively, a right hearth and a left hearth are arranged on the inner wall of the right furnace shell and the inner wall of the left furnace shell respectively, the inner wall of the left hearth is connected with an electrode through a resistance wire, and electrode covers are fixedly connected to the outer wall of the left furnace shell and the outer wall of the right furnace shell respectively. According to the utility model, the resistance wire is heated by using the electrode, after the heating is finished, the clamping cylinder connecting assembly loosens the nickel chrome wire, and the metal cage falls into the stainless steel barrel to be cooled by virtue of the self weight of the metal cage, so that the problem of low thermal shock speed in the actual test process is solved, and the thermal shock is more suitable for the actual working condition; and the accuracy of an experiment result is further improved.

Description

Technical Field

[0001] This utility model relates to the field of materials science and engineering, and in particular to a thermal fatigue testing device. Background Technology

[0002] Currently, the thermal fatigue performance testing environments for materials in fields such as aero-engines and controlled nuclear fusion often involve rapid, instantaneous temperature changes that generate significant thermal stress, leading to thermal fatigue cracks in the materials in service. Therefore, designing a testing apparatus that replicates the actual operating conditions is essential.

[0003] A search revealed Chinese Patent Publication No. CN110411883B, which discloses a thermal fatigue testing device for materials science and engineering. The device comprises a heating section consisting of a spirally arranged cylindrical heating coil for heating the test sample; a gas cooling section, which alternates with the heating coil along the length of the cylindrical section and has uniformly distributed air outlets on its inner side; and a sample fixing section for fixing the test sample by having it pass through the heating coil and the interior of the gas cooling section. This invention provides a simple-to-operate thermal fatigue testing device that achieves uniform sample cooling, obtains a contamination-free and oxidation-free thermal fatigue surface, facilitates subsequent characterization and testing (especially residual stress characterization), and improves the reliability of thermal fatigue performance evaluation for materials such as hot work die steel.

[0004] The above-mentioned device has the following problems: The device uses a spiral heating coil in the shape of a cylinder with a gas cooling section evenly distributed inside the cylinder. The sample is fixed and passes through the heating coil. At this time, the sample is not separated from the heating coil. Even if there is gas cooling, the cooling rate is still very slow, which cannot truly reflect the thermal fatigue condition and has very limited thermal shock to the sample. Therefore, a thermal fatigue test device is proposed to solve the above problems.

[0005] A search revealed Chinese Patent Publication No. CN118777106A, which discloses a thermal fatigue testing device for materials science and engineering. The device includes a heating furnace, a cooling water tank, and a lifting platform. The heating furnace has a vertically arranged heating chamber. A through-hole for a suspension wire is opened at the top of the heating chamber, and a connecting pipe is connected to the bottom of the heating chamber. The bottom end of the connecting pipe is immersed in the cooling water tank and connected to an inert gas source. The lifting platform is located above the heating chamber and connects to the sample via a suspension wire. The connecting end of the suspension wire for connecting the sample is located inside the heating chamber. This invention seals the top of the heating chamber and immerses the bottom of the heating chamber in the cooling water tank via the connecting pipe, thus sealing the heating chamber. Furthermore, the introduction of inert gas into the heating chamber prevents the sample from being oxidized during heating, thus avoiding the formation of an oxide layer. This not only facilitates the observation of thermal fatigue cracks but also reduces the interference of the oxide layer on the formation and propagation of fatigue cracks.

[0006] The above-mentioned device has the following problems: The device uses a sliding rail type lifting platform. The speed at which the sliding rail type lifting platform is immersed in water is limited by the platform's own moving speed, resulting in poor thermal shock effect and failing to truly reflect the thermal fatigue condition. The sample is placed in a quartz tube, and the bottom end of the quartz tube is connected to the connecting pipe through a flange and immersed in the cooling water tank. When the sample is immersed in water, water vapor evaporates into the quartz glass tube, affecting the furnace temperature and failing to truly reflect the test temperature. Utility Model Content

[0007] To overcome the above shortcomings, this utility model provides a thermal fatigue testing device, which aims to improve the problem that the existing technology cannot truly reflect thermal fatigue conditions.

[0008] To achieve the above objectives, this utility model adopts the following technical solution: a thermal fatigue testing device, comprising a main frame, a pressure regulating valve provided on the left side wall of the main frame, the output end of the pressure regulating valve being connected to an air compressor via a pipe, a right furnace shell and a left furnace shell being hinged to the inner wall of the main frame via a bracket, the inner walls of the right and left furnace shells being respectively configured as a right furnace chamber and a left furnace chamber, the inner wall of the left furnace chamber being connected to an electrode via a resistance wire, electrode covers being fixedly connected to the outer walls of the left and right furnace shells respectively, and a thermocouple guide post being fixedly connected to the inner wall of the right furnace shell, the inner wall of the thermocouple guide post being... The furnace is equipped with ceramic tubes. Furnace covers are fixedly connected to the top of both the left and right furnace shells. Insulating terminals are provided between the left furnace shell and the electrodes. A moving trolley is provided on the inner wall of the main frame. A stainless steel bucket is provided on the upper surface of the moving trolley. A two-position three-way solenoid valve is provided at the top of the main frame. The output end of the two-position three-way solenoid valve is connected to the clamping cylinder connecting assembly through a pipe. A positioning rod is contacted at the top of the furnace cover. A fan assembly is provided at the top of the main frame. A testing mechanism is provided at the output end of the clamping cylinder connecting assembly. A protective assembly is provided on the inner wall of the clamping cylinder connecting assembly and the upper surface of the main frame.

[0009] The testing mechanism includes a nichrome wire, the upper end of which contacts the output end of the clamping cylinder connecting assembly, and the lower end of which is fixedly connected to a metal cage. A quartz glass tube is arranged around the outer wall of the metal cage, and a sample is placed on the inner wall of the metal cage.

[0010] As a further description of the above technical solution:

[0011] The protective assembly includes a three-position five-way solenoid valve, which is disposed on the upper surface of the main frame. The output end of the three-position five-way solenoid valve is connected to the rotary cylinder assembly through a pipeline. An air baffle is rotatably connected to the upper surface of the rotary cylinder assembly.

[0012] As a further description of the above technical solution:

[0013] The right and left furnace shells are divided into left and right side-opening furnaces.

[0014] As a further description of the above technical solution:

[0015] The inner wall of the right furnace chamber is connected to the electrodes via resistance wires, and the furnace cover is divided into left and right halves, which are respectively connected to the left and right furnace shells.

[0016] As a further description of the above technical solution:

[0017] An insulating terminal is provided between the right furnace shell and the electrode.

[0018] As a further description of the above technical solution:

[0019] The bottom of the metal cage is in contact with the inner wall of the stainless steel barrel.

[0020] As a further description of the above technical solution:

[0021] The clamping cylinder connecting assembly is fixedly connected to the top of the main frame, and the positioning rod is fixedly connected to the inner wall of the main frame.

[0022] As a further description of the above technical solution:

[0023] The bottom end of the air baffle is fixedly connected to the inner wall of the main frame by a bracket.

[0024] This utility model has the following beneficial effects:

[0025] 1; In this utility model, the resistance wire is heated by electrodes. After heating, the clamping cylinder connecting assembly is released from the nickel-chromium wire. The metal cage falls into the stainless steel bucket to cool down due to its own weight. This improves the problem of slow thermal shock speed in actual testing, makes the thermal shock more in line with actual working conditions, and further improves the accuracy of experimental results.

[0026] 2; In this utility model, by setting a three-position five-way solenoid valve, a rotary cylinder assembly and a baffle plate, the opening or closing of the baffle plate can be controlled by the rotary cylinder assembly, which can prevent water vapor from rising after the sample is immersed in water, thus affecting the service life of the high-temperature atmospheric furnace and further improving the practicality of the device. Attached Figure Description

[0027] Figure 1 This invention provides a main frame diagram and sectional view of a thermal fatigue testing device.

[0028] Figure 2Here is a structural diagram and sectional view of a high-temperature atmospheric furnace for a thermal fatigue testing device proposed in this utility model;

[0029] Figure 3 This invention provides a structural diagram and sectional view of the test fixture for a thermal fatigue testing device.

[0030] Legend:

[0031] 1.1 Air compressor; 1.2 Pressure regulating valve; 1.3 Main frame; 1.4 Stainless steel barrel; 1.5 Three-position five-way solenoid valve; 1.6 Moving trolley; 1.7 Nichrome wire; 1.8 Rotary cylinder assembly; 1.9 Air baffle; 1.10 Positioning rod; 1.11 Two-position three-way solenoid valve; 1.12 Fan assembly; 1.13 Clamping cylinder connection assembly; 2.1 Furnace cover; 2.2 Right furnace shell; 2.3 Electrode cover; 2.4 Left furnace chamber; 2.5 Left furnace shell; 2.6 Electrode; 2.7 Insulating terminal; 2.8 Right furnace chamber; 2.9 Thermocouple guide post; 2.10 Ceramic tube; 3.1 Quartz glass tube; 3.2 Metal cage; 3.3 Sample. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0033] Reference Figures 1-3This utility model provides an embodiment of a thermal fatigue testing device, comprising a main frame 1.3. The main frame 1.3 is supported by foundation feet and adopts a steel frame structure, which is less affected by heat, stable and reliable during long-term operation, and provides support for the entire testing device. A pressure regulating valve 1.2 is provided on the left side wall of the main frame 1.3. The output end of the pressure regulating valve 1.2 is connected to an air compressor 1.1 through a pipe. The pressure is adjusted by regulating the air compressor 1.1. The output compressed air pressure can provide stable power for subsequent pneumatic components. The inner wall of the main frame 1.3 is hinged to the right furnace shell 2.2 and the left furnace shell 2.5 via brackets. The right furnace shell 2.2 and the left furnace shell 2.5 are closed using existing technology. The inner walls of the right furnace shell 2.2 and the left furnace shell 2.5 are respectively configured as the right furnace chamber 2.8 and the left furnace chamber 2.4. The inner wall of the left furnace chamber 2.4 is connected to the electrode 2.6 via a resistance wire. The outer walls of the left furnace shell 2.5 and the right furnace shell 2.2 are respectively fixedly connected to electrode covers 2.3. Electrode cover seats are provided on the electrode covers 2.3, and the electrode cover seats are connected to both the electrode covers and the furnace shells to prevent accidental contact. In terms of electrical configuration, a thermocouple guide post 2.9 is fixedly connected to the inner wall of the right furnace shell 2.2. A ceramic tube 2.10 is installed on the inner wall of the thermocouple guide post 2.9, through which the thermocouple passes into the furnace to measure and control the temperature of the high-temperature atmospheric furnace. Furnace covers 2.1 are fixedly connected to the top of both the left furnace shell 2.5 and the right furnace shell 2.2. An insulating terminal 2.7 is installed between the left furnace shell 2.5 and the electrode 2.6. A moving trolley 1.6 is installed on the inner wall of the main frame 1.3. A stainless steel bucket 1.4 filled with cold water is installed on the upper surface of the moving trolley 1.6 for rapid cooling of the sample. The main frame 1.3... A two-position three-way solenoid valve 1.11 is installed at the top. This valve controls the clamping cylinder to tighten or loosen the nichrome wire 1.7. The output of the two-position three-way solenoid valve 1.11 is connected to the clamping cylinder connecting assembly 1.13 via a pipe. A positioning rod 1.10 contacts the top of the furnace cover 2.1. A fan assembly 1.12 is installed at the top of the main frame 1.3. This fan assembly 1.12 dissipates heat from the clamping cylinder connecting assembly 1.13 to prevent overheating and weakening of the clamping force. A testing mechanism is installed at the output of the clamping cylinder connecting assembly 1.13. The inner wall of the clamping cylinder connecting assembly 1.13 is located on the upper surface of the main frame 1.3. The testing mechanism is equipped with protective components and includes a nichrome wire 1.7. The upper end of the nichrome wire 1.7 contacts the output end of the clamping cylinder connecting assembly 1.13. The clamping cylinder connecting assembly 1.13 uses a finger cylinder for clamping, which has a fast response and can quickly clamp the nichrome wire 1.7. The lower end of the nichrome wire 1.7 is fixedly connected to a metal cage 3.2. The outer wall of the metal cage 3.2 is surrounded by a quartz glass tube 3.1, which can reduce the corrosion of water vapor on the resistance wire of the high-temperature atmospheric furnace. The inner wall of the metal cage 3.2 holds a sample 3.3. The metal cage is made of high-temperature alloy material and can hold 5-6 samples.

[0034] Reference Figures 1-3 The protective components include a three-position five-way solenoid valve 1.5, which is located on the upper surface of the main frame 1.3. The three-position five-way solenoid valve 1.5 can control the opening or closing of the rotary cylinder assembly 1.8. The output end of the three-position five-way solenoid valve 1.5 is connected to the rotary cylinder assembly 1.8 through a pipeline. A baffle plate 1.9 is rotatably connected to the upper surface of the rotary cylinder assembly 1.8. By rotating the baffle plate 1.9, water vapor can be prevented from rising after the sample enters water, thus affecting the service life of the high-temperature atmospheric furnace. The bottom end of the baffle plate 1.9 is fixedly connected to the inner wall of the main frame 1.3 through a bracket.

[0035] Reference Figures 1-3 The right furnace shell 2.2 and the left furnace shell 2.5 are divided into left and right side-opening furnaces. The left furnace shell 2.5 and the right furnace shell 2.2 are located on the left and right sides of the furnace body, respectively. The inner wall of the right furnace chamber 2.8 is connected to the electrode 2.6 through a resistance wire. The furnace cover 2.1 is divided into left and right halves and is connected to the left furnace shell 2.5 and the right furnace shell 2.2, respectively. The furnace cover 2.1 of the high-temperature atmospheric furnace is made of stainless steel plate. An insulating terminal 2.7 is set between the right furnace shell 2.2 and the electrode 2.6 to ensure that the electrode 2.6 is in an insulated state from the furnace body. The bottom end of the metal cage 3.2 is in contact with the inner wall of the stainless steel barrel 1.4. The clamping cylinder connecting assembly 1.13 is fixedly connected to the top of the main frame 1.3. The positioning rod 1.10 is fixedly connected to the inner wall of the main frame 1.3. The positioning rod 1.10 is used to fix the position of the high-temperature atmospheric furnace and prevent the rotation of the high-temperature atmospheric furnace from affecting the temperature uniformity of the sample.

[0036] Working Principle: During the test preparation stage, the operator places the sample 3.3 inside the metal cage 3.2. Then, using the finger cylinder in the clamping cylinder connecting assembly 1.13, the upper end of the nichrome wire 1.7 is quickly clamped. The nichrome wire 1.7, the metal cage 3.2 fixed at its lower end, and the sample 3.3 inside are thus positioned in the high-temperature atmospheric furnace. At the start of the test, the compressed air pressure output by the air compressor 1.1 is adjusted through the pressure regulating valve 1.2 to provide stable power for subsequent pneumatic components. Then, the left furnace shell 2.5 and the right furnace shell 2.2 are closed. At this time, the resistance wires in the left furnace chamber 2.4 and the right furnace chamber 2.8 are energized through the electrode 2.6, causing them to heat up. The temperature inside the furnace begins to rise, heating the sample. Thermocouples are inserted into the furnace through ceramic tubes 2.10, and the temperature of the high-temperature atmospheric furnace is monitored in real time via thermocouple guide posts 2.9 to ensure temperature control. Within the required testing range, once the high-temperature atmospheric furnace reaches the set temperature, the insulation cover on the high-temperature atmospheric furnace is closed. After insulation, timing begins, and the sample enters the heating timing period. Sample 3.3 undergoes thermal cycling in a high-temperature environment. After the heating timing period ends, the baffle plate 1.9 is rotated by controlling the rotating cylinder assembly 1.8 below the high-temperature atmospheric furnace to ensure unobstructed access to the furnace. Timing begins at this time. After 5 seconds, the clamping cylinder connecting assembly 1.13 is controlled by the two-position three-way solenoid valve 1.11 to release the nichrome wire 1.7. Sample 3.3, along with the metal cage 3.2, falls into the cold water in the stainless steel bucket 1.4 for rapid cooling, realizing the alternating hot and cold process in the thermal fatigue test. Timing begins at this time. After 10 seconds, the rotating cylinder assembly 1.8 below the high-temperature atmospheric furnace is activated, and the baffle plate 1.9 is closed. If the test needs to continue, simply repeat the above operating steps.

[0037] To stop the experiment, first turn off the heating switch to cool down, then turn off the main power supply, and simultaneously pull out the moving trolley 1.6 to remove the stainless steel bucket 1.4. The staff can then retrieve the metal cage 3.2 from the stainless steel bucket 1.4 and take out the sample 3.3. After the work is completed, the main frame 3 and the metal cage 3.2 need to be wiped clean to ensure that there is no water residue on the main frame 1.3 and the metal cage 3.2.

[0038] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A thermal fatigue testing apparatus comprising a mainframe (1.3), characterized by: A pressure regulating valve (1.2) is provided on the left side wall of the main frame (1.3). The output end of the pressure regulating valve (1.2) is connected to the air compressor (1.1) through a pipe. The inner wall of the main frame (1.3) is hinged to the right furnace shell (2.2) and the left furnace shell (2.5) through a bracket. The inner walls of the right furnace shell (2.2) and the left furnace shell (2.5) are respectively set as the right furnace chamber (2.8) and the left furnace chamber (2.4). The inner wall of the left furnace chamber (2.4) is connected to the electrode (2.6) through a resistance wire. The outer walls of the left furnace shell (2.5) and the right furnace shell (2.2) are respectively fixedly connected to the electrode cover (2.3). The inner wall of the right furnace shell (2.2) is fixedly connected to the thermocouple guide post (2.9). The inner wall of the thermocouple guide post (2.9) is provided with a ceramic tube (2.10). The left furnace shell (2.5) and the right furnace shell (2.2) are respectively fixedly connected to the electrode cover (2.3). The top of each part is fixedly connected to a furnace cover (2.1). An insulating terminal (2.7) is provided between the left furnace shell (2.5) and the electrode (2.6). A moving trolley (1.6) is provided on the inner wall of the main frame (1.3). A stainless steel bucket (1.4) is provided on the upper surface of the moving trolley (1.6). A two-position three-way solenoid valve (1.11) is provided at the top of the main frame (1.3). The output end of the two-position three-way solenoid valve (1.11) is connected to the clamping cylinder connection assembly (1.13) through a pipe. A positioning rod (1.10) is in contact with the top of the furnace cover (2.1). A fan assembly (1.12) is provided at the top of the main frame (1.3). A test mechanism is provided at the output end of the clamping cylinder connection assembly (1.13). A protective assembly is provided on the inner wall of the clamping cylinder connection assembly (1.13) and the upper surface of the main frame (1.3). The testing mechanism includes a nichrome wire (1.7), the upper end of which contacts the output end of the clamping cylinder connecting assembly (1.13), and the lower end of which is fixedly connected to a metal cage (3.2). A quartz glass tube (3.1) is arranged around the outer wall of the metal cage (3.2), and a sample (3.3) is placed on the inner wall of the metal cage (3.2).

2. The thermal fatigue testing apparatus of claim 1, wherein: The protective assembly includes a three-position five-way solenoid valve (1.5), which is disposed on the upper surface of the main frame (1.3). The output end of the three-position five-way solenoid valve (1.5) is connected to the rotary cylinder assembly (1.8) through a pipeline. A baffle plate (1.9) is rotatably connected to the upper surface of the rotary cylinder assembly (1.8).

3. The thermal fatigue testing apparatus of claim 1, wherein: The right furnace shell (2.2) and the left furnace shell (2.5) are divided into left and right side open furnaces.

4. The thermal fatigue testing apparatus of claim 1, wherein: The inner wall of the right furnace chamber (2.8) is connected to the electrode (2.6) via a resistance wire. The furnace cover (2.1) is divided into left and right halves and is connected to the left furnace shell (2.5) and the right furnace shell (2.2) respectively.

5. The thermal fatigue testing apparatus of claim 1, wherein: An insulating terminal (2.7) is provided between the right furnace shell (2.2) and the electrode (2.6).

6. The thermal fatigue testing apparatus of claim 1, wherein: The bottom end of the metal cage (3.2) is in contact with the inner wall of the stainless steel barrel (1.4).

7. The thermal fatigue testing apparatus of claim 1, wherein: The clamping cylinder connecting assembly (1.13) is fixedly connected to the top of the main frame (1.3), and the positioning rod (1.10) is fixedly connected to the inner wall of the main frame (1.3).

8. The thermal fatigue testing apparatus of claim 2, wherein: The bottom end of the baffle plate (1.9) is fixedly connected to the inner wall of the main frame (1.3) by a bracket.

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