Rapid compression experimental device and experimental method

Abstract

The invention relates to the technical field of steel and iron material detection, in particular to a rapid compression experiment device which comprises an experiment box body, a movable shaft and a fixed shaft are coaxially arranged in the experiment box body, the movable shaft is driven by a main hydraulic cylinder outside the experiment box body to move, and the fixed shaft is fixedly connected to the inner wall of the experiment box body. The movable shaft and the fixed shaft are connected with anvil heads respectively, the movable shaft is fixedly sleeved with a baffle, an upper top plate is arranged above the fixed shaft, a lower top plate is arranged below the fixed shaft, the upper top plate and the lower top plate are in sliding connection with a guide rail fixed to the side wall of the experiment box body, and an upper push block attached to the inner side wall of the experiment box body is arranged above the fixed shaft. A lower pushing block attached to the inner side wall of the experiment box body is arranged below the fixing shaft, the outer surfaces of the upper pushing block and the lower pushing block are symmetrical inclined planes, the upper pushing block and the lower pushing block are driven by pushing block hydraulic cylinders to move, the upper pushing block can be tightly attached to the upper top plate, the lower pushing block can be tightly attached to the lower top plate, and pressure sensors are arranged on the two anvil heads.

Description

Technical Field

[0001] This invention belongs to the field of steel material testing technology, and specifically relates to a rapid compression test device and test method. Background Technology

[0002] High-temperature compression tests on metallic materials can reveal the influence of heat treatment parameters, such as deformation temperature, strain rate, and deformation amount, on the microstructure and properties of metallic materials. Therefore, in order to obtain products with good performance, a series of high-temperature compression tests are required to find out the relationship between heat treatment parameters and material microstructure.

[0003] Because different materials exhibit varying sensitivities to heat treatment parameters, accurate experimental results require testing machines capable of precisely controlling high-temperature compression test parameters, such as deformation, strain rate, and deformation temperature. Typically, a thermodynamic simulation testing machine is used for high-temperature compression experiments, with a PID closed-loop control system controlling the deformation. This method effectively controls deformation at lower strain rates; however, at higher strain rates, the obtained deformation often exceeds the preset value, and the higher the strain rate, the greater the deviation between the actual and preset deformation. The thermodynamic simulation testing machine manufactured by DSI (Dual Steering Systems) in the United States is equipped with a hydraulic wedge unit, which can effectively address the issue of actual deformation exceeding the preset value. However, using this unit for high-temperature experiments requires system unit conversion, which is complex and costly. Furthermore, the experimental functions achievable after conversion to the hydraulic wedge unit are relatively limited.

[0004] To achieve precise control of deformation in rapid compression experiments without replacing system units, it is also necessary to develop experimental methods suitable for rapid compression experimental devices and their supporting methods. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a rapid compression test device and test method, which accurately controls the deformation in high-temperature rapid compression tests, thereby improving the accuracy and efficiency of the experiment.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A rapid compression experimental device includes an experimental chamber. A movable shaft and a fixed shaft are coaxially arranged inside the experimental chamber. The movable shaft is driven to move by a main hydraulic cylinder outside the experimental chamber. The fixed shaft is fixedly connected to the inner wall of the experimental chamber. Anvils are connected to both the movable and fixed shafts. A baffle is fixedly sleeved on the outside of the movable shaft. An upper top plate is located above the fixed shaft, and a lower top plate is located below the fixed shaft. The upper and lower top plates are slidably connected to guide rails fixed to the side wall of the experimental chamber. An upper push block is located above the fixed shaft and fits against the inner side wall of the experimental chamber, and a lower push block is located below the fixed shaft and fits against the inner side wall of the experimental chamber. The outer surfaces of the upper and lower push blocks are symmetrical inclined planes. The upper and lower push blocks are driven to move by push block hydraulic cylinders. The upper push block can fit tightly against the upper top plate, and the lower push block can fit tightly against the lower top plate. Pressure sensors are provided on both anvils.

[0008] The upper and lower top plates are symmetrical structures, with a groove on one side of each plate. The groove on the upper top plate engages with the outer inclined surface of the upper push block, and the groove on the lower top plate engages with the outer inclined surface of the lower push block.

[0009] The guide rail is a round rod, and it is slidably connected to the round holes provided inside the upper and lower top plates.

[0010] The compression test method using a rapid compression test apparatus includes the following specific steps:

[0011] 1) Place the steel sample between the two anvils. The main hydraulic cylinder drives the moving shaft to clamp the steel sample. At this time, the baffle is in contact with one side of the upper and lower top plates, and the other side of the upper and lower top plates is in contact with the upper and lower push blocks.

[0012] 2) The steel sample is heated by electricity, and the temperature is raised to 1000℃-1100℃ at a rate of 10-15℃ / s, held for 180s-200s, and then cooled to 900-920℃ at a rate of 10-15℃ / s.

[0013] 3) The moving shaft clamps the steel sample. The distance that the upper and lower push blocks move towards the center is calculated according to the preset deformation of the steel sample. The hydraulic cylinder of the push block is started to move the upper and lower push blocks towards the center in a synchronous manner. The upper and lower top plates are manually adjusted to make close contact with the upper and lower push blocks respectively.

[0014] 4) Start the main hydraulic cylinder to drive the moving shaft to move laterally and compress the steel sample at the preset strain rate. When the baffle contacts and presses against the upper and lower top plates, the moving shaft stops. At this time, the deformation of the steel sample is the preset deformation.

[0015] Compared with existing technologies, the beneficial effects of this invention are:

[0016] This invention fully considers the entire process of compressing and deforming the sample in a rapid compression test device. By utilizing the shape characteristics of the upper and lower push blocks, the distance between the upper and lower top plates and the baffle is adjusted. During deformation, the baffle is quickly stopped by the limiting effect of the upper and lower top plates, which can achieve precise control of the deformation amount. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] Figure 2 This is a structural schematic diagram of the top plate.

[0019] In the diagram: 1. Experimental chamber; 2. Moving shaft; 3. Fixed shaft; 4. Main hydraulic cylinder; 5. Anvil; 6. Baffle; 7. Upper top plate; 8. Lower top plate; 9. Guide rail; 10. Upper push block; 11. Lower push block; 12. Push block hydraulic cylinder; 13. Pressure sensor. Detailed Implementation

[0020] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0021] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of these terms in this invention based on the specific circumstances.

[0022] like Figures 1-2A rapid compression experimental device includes an experimental chamber 1. A movable shaft 2 and a fixed shaft 3 are coaxially arranged inside the experimental chamber 1. The movable shaft 2 is driven to move by a main hydraulic cylinder 4 outside the experimental chamber 1. The fixed shaft 3 is fixedly connected to the inner wall of the experimental chamber 1. Anvils 5 are respectively connected to the movable shaft 2 and the fixed shaft 3. A baffle 6 is fixedly sleeved outside the movable shaft 2. An upper top plate 7 is provided above the fixed shaft 3, and a lower top plate 8 is provided below the fixed shaft 3. The upper top plate 7 and the lower top plate 8 are fixed to the side of the experimental chamber 1. The guide rail 9 on the wall is slidably connected. Above the fixed shaft 3, there is an upper push block 10 that fits against the inner wall of the experimental chamber 1. Below the fixed shaft 3, there is a lower push block 11 that fits against the inner wall of the experimental chamber 1. The outer surfaces of the upper push block 10 and the lower push block 11 are symmetrical inclined surfaces. The upper push block 10 and the lower push block 11 are driven to move by the push block hydraulic cylinder 12 respectively. The upper push block 10 can fit tightly against the upper top plate 7, and the lower push block 11 can fit tightly against the lower top plate 8. Pressure sensors 14 are provided on the two anvils 5.

[0023] The upper top plate 7 and the lower top plate 8 are symmetrical structures. Each of the upper top plate 7 and the lower top plate 8 has a groove on one side. The groove of the upper top plate 7 is in contact with the outer inclined surface of the upper push block 10, and the groove of the lower top plate 8 is in contact with the outer inclined surface of the lower push block 11.

[0024] The guide rail 9 is a round rod, and the guide rail 9 is slidably connected to the round holes provided inside the upper top plate 7 and the lower top plate 8.

[0025] The compression test method using a rapid compression test apparatus includes the following specific steps:

[0026] 1) Place the steel sample between the two anvils 5. The main hydraulic cylinder 4 drives the moving shaft 2 to clamp the steel sample 15. At this time, the baffle 6 is in contact with one side of the upper top plate 7 and the lower top plate 8, and the other side of the upper top plate 7 and the lower top plate 8 is in contact with the upper push block 7 and the lower push block 8.

[0027] 2) The steel sample is heated by electricity, and the temperature is raised to 1000℃-1100℃ at a rate of 10-15℃ / s, held for 180s-200s, and then cooled to 900-920℃ at a rate of 10-15℃ / s.

[0028] 3) Calculate the distance that the upper push block 10 and the lower push block 11 will move toward the center according to the preset deformation amount of the steel sample. Start the hydraulic cylinder 12 of the push block to move the upper push block 10 and the lower push block 11 toward the center in a synchronous manner. Manually adjust the upper top plate 7 and the lower top plate 8 to make close contact with the upper push block 10 and the lower push block 11 respectively.

[0029] 4) Start the main hydraulic cylinder 4 and drive the moving shaft 2 to move laterally to compress the steel sample 15 at a preset strain rate. When the baffle 6 contacts and presses against the upper top plate 7 and the lower top plate 8, the moving shaft 2 stops. At this time, the deformation of the steel sample 15 is the preset deformation.

[0030] Stress-strain curves were obtained through compression experiments.

[0031] To make the objectives, technical solutions, and technical effects of this invention clearer, the technical solutions in the embodiments of this invention are now described clearly and completely. However, the embodiments described below are only some embodiments of this invention, not all embodiments. All other embodiments obtained by those skilled in the art in conjunction with the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0032] Example 1:

[0033] A rapid compression experimental device includes an experimental chamber 1. Inside the experimental chamber 1, a movable shaft 2 and a fixed shaft 3 are coaxially arranged. The movable shaft 2 is driven to move by a main hydraulic cylinder 4 outside the experimental chamber 1. The fixed shaft 3 is fixedly connected to the inner wall of the experimental chamber 1. Anvils 5 are respectively connected to the movable shaft 2 and the fixed shaft 3. A baffle 6 is fixedly sleeved on the outside of the movable shaft 2. An upper top plate 7 is provided above the fixed shaft 3, and a lower top plate 8 is provided below the fixed shaft 3. The upper top plate 7 and the lower top plate 8 are symmetrical structures, and a groove is provided on one side of both the upper top plate 7 and the lower top plate 8.

[0034] The upper top plate 7 and the lower top plate 8 are slidably connected to the guide rail 9 fixed on the side wall of the experimental chamber 1. The guide rail 9 is a round rod, and the guide rail 9 is slidably connected to the round holes provided inside the upper top plate 7 and the lower top plate 8.

[0035] Above the fixed shaft 3 is an upper push block 10 that fits against the inner wall of the experimental chamber 1, and below the fixed shaft 3 is a lower push block 11 that fits against the inner wall of the experimental chamber 1. The outer surfaces of the upper push block 10 and the lower push block 11 are symmetrical inclined surfaces with an angle of 45° to the horizontal plane. The groove of the upper top plate 7 is in contact with the outer inclined surface of the upper push block 10, and the groove of the lower top plate 8 is in contact with the outer inclined surface of the lower push block 11.

[0036] The upper push block 10 and the lower push block 11 are driven to move by the push block hydraulic cylinder 12, respectively.

[0037] Pressure sensors 14 are installed on both anvil heads 5.

[0038] Example 2:

[0039] A compression test method using a rapid compression testing apparatus was employed. A cylindrical sample with a diameter of 10 mm and a height of 15 mm was used. The compression test was conducted using the apparatus described in Example 1. The specific steps included:

[0040] 1) Place the steel sample between the two anvils 5. The main hydraulic cylinder 4 drives the moving shaft 2 to clamp the steel sample 15. At this time, the baffle 6 is in contact with one side of the upper top plate 7 and the lower top plate 8, and the other side of the upper top plate 7 and the lower top plate 8 is in contact with the upper push block 7 and the lower push block 8.

[0041] 2) The steel sample was heated by electricity, and the temperature was raised to 1000℃ at a rate of 12℃ / s, held for 185s, and then lowered to 900℃ at a rate of 10℃ / s.

[0042] 3) The moving shaft presses the steel sample, so that the steel sample is subjected to a force of 150kg. The distance that the upper push block 10 and the lower push block 11 move towards the center is calculated according to the preset 30% deformation of the steel sample. The hydraulic cylinder 12 of the push block is started to move the upper push block 10 and the lower push block 11 towards the center in a synchronous manner. The upper top plate 7 and the lower top plate 8 are manually adjusted to make close contact with the upper push block 10 and the lower push block 11 respectively.

[0043] 4) Start the main hydraulic cylinder 4 and drive the moving shaft 2 to move laterally, compressing the steel sample 15 at a strain rate of 10 / s. When the baffle 6 contacts and presses against the upper top plate 7 and the lower top plate 8, the moving shaft 2 stops. At this time, the deformation of the steel sample 15 is the pre-deformation amount.

[0044] Example 3:

[0045] A compression test method using a rapid compression testing apparatus was employed. A cylindrical sample with a diameter of 10 mm and a height of 15 mm was used. The compression test was conducted using the apparatus described in Example 1. The specific steps included:

[0046] 1) Place the steel sample between the two anvils 5. The main hydraulic cylinder 4 drives the moving shaft 2 to clamp the steel sample 15. At this time, the baffle 6 is in contact with one side of the upper top plate 7 and the lower top plate 8, and the other side of the upper top plate 7 and the lower top plate 8 is in contact with the upper push block 7 and the lower push block 8.

[0047] 2) The steel sample was heated by electricity, and the temperature was increased to 1100℃ at a rate of 12℃ / s, held for 180s, and then decreased to 1000℃ at a rate of 10℃ / s.

[0048] 3) Move the shaft 2 to press the steel sample 15 so that the steel sample is subjected to a force of 160kg. Calculate the distance that the upper push block 10 and the lower push block 11 will move towards the center based on the 20% deformation of the steel sample. Start the hydraulic cylinder 12 of the push block to move the upper push block 10 and the lower push block 11 towards the center in a synchronous manner. Manually adjust the upper top plate 7 and the lower top plate 8 to make close contact with the upper push block 10 and the lower push block 11 respectively.

[0049] 4) Start the main hydraulic cylinder 4 and drive the moving shaft 2 to move laterally, compressing the steel sample 15 at a preset strain rate of 10 / s. When the baffle 6 contacts and presses against the upper top plate 7 and the lower top plate 8, the moving shaft 2 stops. At this time, the deformation of the steel sample 15 is the preset deformation.

[0050] 5) Then cool down to 900℃ at a rate of 10℃ / s;

[0051] 6) Calculate the distance that the upper push block 10 and the lower push block 11 move towards the center based on the 20% deformation of the steel sample. Start the hydraulic cylinder 12 of the push block to move the upper push block 10 and the lower push block 11 towards the center in a synchronous manner. Manually adjust the upper top plate 7 and the lower top plate 8 to make close contact with the upper push block 10 and the lower push block 11 respectively.

[0052] 7) Start the main hydraulic cylinder 4 and drive the moving shaft 2 to move laterally, compressing the steel sample 15 at a preset strain rate of 10 / s. When the baffle 6 contacts and presses against the upper top plate 7 and the lower top plate 8, the moving shaft 2 stops. At this time, the deformation of the steel sample 15 is the preset deformation.

[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A rapid compression experimental apparatus, characterized in that, The experimental box is internally coaxially provided with a moving shaft and a fixed shaft, the moving shaft is driven to move by a main hydraulic cylinder outside the experimental box, the fixed shaft is fixedly connected to the inner wall of the experimental box, anvil heads are respectively connected to the moving shaft and the fixed shaft, a baffle is fixedly sleeved outside the moving shaft, an upper top plate is arranged above the fixed shaft, a lower top plate is arranged below the fixed shaft, the upper top plate and the lower top plate are slidingly connected to guide rails fixed to the side wall of the experimental box, an upper push block is arranged above the fixed shaft and abuts against the inner side wall of the experimental box, a lower push block is arranged below the fixed shaft and abuts against the inner side wall of the experimental box, the outer surfaces of the upper push block and the lower push block are symmetrical inclined surfaces, the upper push block and the lower push block are respectively driven to move by push block hydraulic cylinders, the upper push block can abut against the upper top plate, and the lower push block can abut against the lower top plate, and pressure sensors are arranged on the two anvil heads.

2. The rapid compression device of claim 1, wherein, The upper top plate and the lower top plate are symmetrical structures, recesses are arranged on one side of the upper top plate and the lower top plate, the recess of the upper top plate is in contact with the outer inclined surface of the upper push block, and the recess of the lower top plate is in contact with the outer inclined surface of the lower push block.

3. The rapid compression device of claim 1, wherein, The guide rails are round rods, and the guide rails are slidingly connected to the round holes arranged in the upper top plate and the lower top plate.

4. A compression test method using the rapid compression test apparatus according to claim 1, characterized by, The specific steps include: 1) placing a steel sample between the two anvil heads, driving the moving shaft to clamp the steel sample by the main hydraulic cylinder, at this time, the baffle abuts against one side of the upper top plate and the lower top plate, and the other side of the upper top plate and the lower top plate abut against the upper push block and the lower push block; 2) heating the steel sample by electricity, heating at a rate of 10-15 ℃ / s to 1000-1100 ℃, maintaining for 180-200 s, and then decreasing at a rate of 10-15 ℃ / s to 900-920 ℃; 3) clamping the steel sample by the moving shaft, calculating the moving distance of the upper push block and the lower push block to the middle part according to the preset deformation of the steel sample, starting the push block hydraulic cylinder to synchronously move the upper push block and the lower push block to the middle part, and manually adjusting the upper top plate and the lower top plate to tightly contact the upper push block and the lower push block respectively; 4) starting the main hydraulic cylinder to drive the moving shaft to move horizontally, compressing the steel sample at a preset strain rate, and stopping the moving shaft when the baffle abuts against and tightly abuts against the upper top plate and the lower top plate, at this time, the deformation of the steel sample is the preset deformation.

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