Quenching temperature measurement sample and device for measuring heat exchange coefficient of quenching interface

Abstract

The invention discloses a quenching temperature measurement sample and device for measuring the heat exchange coefficient of a quenching interface, and belongs to the field of quenching tests. The sample comprises a test bar and a heat preservation layer. The test bar comprises a temperature measuring section extending in the axial direction and a quenching end formed at the end of the temperature measuring section, a circle of blocking part is arranged on the periphery of the end, close to the quenching end, of the temperature measuring section, the temperature measuring section is provided with a first temperature measuring point and a second temperature measuring point which are arranged in the axial direction of the temperature measuring section, the diameter of the test bar is D, and the distance delta x between the first temperature measuring point and the second temperature measuring point is smaller than or equal to D / 2. The sum of the height h1 of the quenching end and the thickness h2 of the blocking part is smaller than or equal to delta x; and the thermal insulation layer is coated on the outer surface of the temperature measuring section. According to the quenching temperature measurement sample and device, interference of non-quenching end face air cooling on a sample temperature field and a quenching heat exchange coefficient is eliminated through the heat preservation layer, and the measurement precision is improved; the blocking part structure of the test bar can prevent water from entering the heat preservation layer and the temperature measurement channel and can also serve as a bearing end face making contact with the supporting piece, and uniform and stable one-way heat dissipation of the test bar is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of quenching tests, and in particular relates to a quenching temperature measuring sample and a device for measuring a quenching interface heat transfer coefficient. Background Art

[0002] Aluminum alloys are widely used in the manufacture of key components in the aerospace industry due to their excellent comprehensive properties, such as high specific strength, good corrosion resistance and low density. In order to further improve the strength of aluminum alloys, they often need to be solution quenched. This heat treatment process locks the high-temperature structure inside the material by rapid cooling, thereby obtaining excellent mechanical properties. However, in practical applications, for complex structural parts and thin-walled parts, deformation of parts is likely to occur during the quenching process, and this deformation may significantly affect the dimensional accuracy and service performance of the product. Therefore, how to regulate and predict the deformation of parts during the quenching process has become an important research topic in the field of aluminum alloy heat treatment.

[0003] In the prediction of quenching deformation, the distribution of temperature field in various parts of the part is one of the key parameters. The change of temperature field directly affects the thermal stress distribution and phase change process of the material, and the accurate simulation of temperature field depends on the accurate measurement of interface heat transfer coefficient. The interface heat transfer coefficient describes the ability of heat exchange between the surface of the part and the cooling medium, and is one of the important factors affecting the distribution of temperature field. Usually, the surface of the part will experience different forms of heat transfer during the quenching process, such as direct contact heat transfer between the quenching end face and the cooling medium (such as water), and natural convection heat transfer between the non-quenching end face and the air. The difference in this heat transfer form leads to the non-uniformity of the temperature field of the part, which affects the accuracy of the simulation results.

[0004] In the prior art, the interface heat transfer coefficient measurement method has certain deficiencies in the design of the sample's temperature measurement structure. Specifically, the existing methods often ignore the interference of the non-quenched end face with the overall temperature field of the sample through natural convection or radiation cooling. Due to this interference, the measured interface heat transfer coefficient is actually the combined effect of multiple heat transfer forms, rather than the heat transfer coefficient of a single quenched end face, resulting in low data accuracy. In addition, in the simulation calculation, the interface heat transfer coefficients of the quenched end face and the non-quenched end face need to be set separately, but the existing measurement methods are difficult to effectively distinguish the contributions of the two, further increasing the uncertainty of the simulation.

[0005] Therefore, it is necessary to provide a new solution to the above technical problems. Summary of the invention

[0006] The purpose of the present invention is to provide a quenching temperature measuring sample and device for measuring the quenching interface heat transfer coefficient, which can eliminate the interference of non-quenching end face air cooling on the sample temperature field and quenching heat transfer coefficient, and improve the measurement accuracy.

[0007] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0008] In the first aspect, the present invention provides a quenching temperature measurement specimen, comprising: a test rod, comprising a temperature measuring section extending axially and a quenching end formed at the end of the temperature measuring section, a circle of blocking portion is provided on the outer periphery of the end of the temperature measuring section adjacent to the quenching end, the temperature measuring section is provided with a first temperature measuring point and a second temperature measuring point arranged at intervals along its axial direction, the diameter of the test rod is D, the distance between the first temperature measuring point and the second temperature measuring point is Δx≤D / 2, and the sum of the height h1 of the quenching end and the thickness h2 of the blocking portion is less than or equal to Δx; an insulation layer, covering the outer surface of the entire temperature measuring section.

[0009] In one or more embodiments, a distance between the first temperature measuring point and the end surface of the quenching end is equal to Δx.

[0010] In one or more embodiments, the height H of the test bar is ≥ 3D; and / or the height h1 of the quenched end is > Δx / 2.

[0011] In one or more embodiments, the thickness T of the thermal insulation layer is ≥4 mm.

[0012] In one or more embodiments, the width of the barrier portion is L, and T<L≤D / 2.

[0013] In one or more embodiments, temperature measuring thermocouples are provided at the first temperature measuring point and the second temperature measuring point.

[0014] In one or more embodiments, the thermal insulation layer includes thermal insulation cotton coated on the outer surface of the temperature measuring section and aluminum foil coated on the outer surface of the thermal insulation cotton.

[0015] In the second aspect, the present invention provides a quenching temperature measuring device for measuring the temperature of the aforementioned quenching temperature measuring sample, which comprises: a bracket, on which is mounted a clamp for clamping the quenching temperature measuring sample; a container for accommodating a quenching medium, arranged below the clamp so that the quenching end of the quenching temperature measuring sample clamped on the clamp can be immersed in the quenching medium in the container; a support member, arranged in the container, the support member comprising a plurality of support portions for supporting a blocking portion of the quenching temperature measuring sample.

[0016] In one or more embodiments, the contact area between each support portion and the blocking portion does not exceed 0.5 mm 2 .

[0017] In one or more embodiments, a heating unit for maintaining the quenching medium at a predetermined temperature is disposed in the container, and the heating unit is connected to a temperature control unit.

[0018] Compared with the prior art, the quenching temperature measuring specimen and device for measuring the heat transfer coefficient of the quenching interface provided by the present invention eliminate the interference of air cooling of the non-quenching end face on the specimen temperature field and the quenching heat transfer coefficient through the insulation layer, thereby improving the measurement accuracy; the blocking structure of the test rod can not only prevent water from entering the insulation layer and the temperature measurement channel, but also serve as the load-bearing end face in contact with the support member, thereby ensuring uniform and stable unidirectional heat dissipation of the test rod; the positioning of the test rod by the bracket and the support member of the quenching temperature measuring device enables the test rod to stably and continuously measure the temperature changes of the test rod in the boiling stage during the quenching process, thereby greatly improving the accuracy of measuring the quenching heat transfer coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a cross-sectional view of a quenching temperature measurement sample in one embodiment of the present invention;

[0021] Figure 2 It is a structural schematic diagram of a quenching temperature measuring device in one embodiment of the present invention;

[0022] Figure 3 It is a temperature drop curve diagram of the quenching temperature measurement result in Example 1 of the present invention;

[0023] Figure 4 This is a schematic diagram of the quenching temperature measurement scenario in Example 2 of the present invention;

[0024] Figure 5 This is a schematic diagram of the quenching temperature measurement scene in Comparative Example 1 of the present invention.

[0025] Description of main reference numerals:

[0026] 100-quenching temperature measuring sample, 101-test rod, 102-temperature measuring section, 103-quenching end, 104-blocking part, 105-first temperature measuring point, 106-second temperature measuring point, 107-insulation layer, 108-temperature measuring thermocouple, 109-insulation cotton, 110-aluminum foil, 200-quenching temperature measuring device, 201-bracket, 202-clamp, 203-container, 204-quenching medium, 205-support, 206-support part, 207-heating unit, 208-temperature control unit. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0028] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0029] In the solution quenching treatment of aluminum alloys, accurate measurement of the interface heat transfer coefficient plays a vital role in predicting and controlling the deformation of complex structural parts and thin-walled parts during the quenching process. However, the existing quenching heat transfer coefficient measurement method has exposed significant deficiencies in practical applications, mainly manifested in the inability to effectively suppress the multi-directional heat transfer interference caused by natural convection and radiation on the non-quenched end face, resulting in a significant reduction in the accuracy and reliability of the measurement data. Specifically, the existing technology fails to fully consider the heat dissipation effect of the non-quenched end face in the design of the temperature measurement structure of the sample, so that the measurement results are mixed with multiple heat transfer mechanisms, making it difficult to reflect the actual heat transfer situation of a single quenched end face.

[0030] In view of the above problems, the present invention proposes an optimized quenching temperature measurement sample design, the core of which is to effectively isolate and control different heat transfer paths by improving the structural layout of the sample, thereby achieving more accurate interface heat transfer coefficient measurement. First, through in-depth analysis of the prior art, the inventors realized that the temperature field distribution of the sample is complex and difficult to accurately simulate due to the multi-directional heat transfer of the non-quenching end face during the quenching process. Therefore, the inventors envision enhancing the unidirectional heat transfer characteristics of the sample and reducing the interference of the non-quenching end face on the overall temperature field, thereby improving the accuracy of the measurement data.

[0031] To achieve this goal, the present invention introduces a heat-insulating structure into the sample design, aiming to significantly reduce the heat loss of the non-quenched end face. By selecting materials with good thermal insulation properties, the non-quenched side of the sample can be approximately insulated, so that the heat is mainly conducted in one direction along the axial direction, simulating the one-way heat transfer conditions under ideal conditions. In addition, the inventors have also optimized the layout of the temperature measurement points to ensure that the temperature measurement can focus on reflecting the heat transfer characteristics of the quenched end face, further improving the representativeness and reliability of the data.

[0032] At the same time, in order to solve the problem of water seepage failure caused by boiling in the insulation layer during high-temperature quenching, the inventors designed an effective physical barrier structure to block the water splashes and steam in the quenching medium to ensure the integrity and functional stability of the insulation layer. This structural optimization not only enhances the durability of the sample in actual operation, but also ensures the continuity and accuracy of temperature measurement.

[0033] Please refer to Figure 1 As shown, a quenching temperature measurement sample 100 for measuring the heat transfer coefficient of the quenching interface in an embodiment of the present invention includes a test rod 101 and a thermal insulation layer 107. The test rod 101 includes a temperature measurement section 102 extending in the axial direction and a quenching end 103 formed at the end of the temperature measurement section 102. A circle of blocking parts 104 are provided on the outer periphery of the end of the temperature measurement section 102 adjacent to the quenching end 103. The temperature measurement section 102 is provided with a first temperature measurement point 105 and a second temperature measurement point 106 arranged at intervals along its axial direction. The diameter of the test rod 101 is D, and the spacing Δx between the first temperature measurement point 105 and the second temperature measurement point 106 is ≤D / 2. The sum of the height h1 of the quenching end 103 and the thickness h2 of the blocking part 104 is less than or equal to Δx. The thermal insulation layer 107 covers the outer surface of the entire temperature measurement section 102.

[0034] The test rod 101 is the core component of the quenching temperature measurement specimen 100, which is composed of a temperature measurement section 102 extending in the axial direction and a quenching end 103 located at the end to form an integral structure. A barrier 104 is provided on the outer periphery of the end of the temperature measurement section 102 to form an annular structure, which is intended to limit the direct intrusion of the quenching medium 204 (such as water) into the insulation layer 107 during the quenching process. This design not only effectively prevents the quenching medium 204 from penetrating the insulation layer 107, but also ensures through geometric constraints that the sum of the height h2 of the barrier 104 and the height h1 of the quenching end 103 does not exceed the temperature measurement point spacing Δx, thereby maintaining the stability of the heat transfer path.

[0035] On the temperature measuring section 102, the first temperature measuring point 105 and the second temperature measuring point 106 are arranged at intervals along the axial direction, and the spacing Δx does not exceed D / 2 (half the diameter of the test rod 101). This compact layout of temperature measuring points ensures that the distance between the farthest temperature measuring point and the quenching end 103 surface is controlled within 50% of the diameter of the test rod 101, greatly reducing the interference of the size effect on the axial heat transfer, making the distribution of the temperature field more concentrated and uniform, and improving the accuracy of the measurement data.

[0036] The entire temperature measuring section 102 is coated with a thermal insulation layer 107, which is preferably composed of thermal insulation cotton 109 and aluminum foil 110. The thermal insulation cotton 109 is mainly responsible for slowing down the loss of heat to the outside through conduction and convection, while the outer aluminum foil 110 further blocks the thermal radiation of the temperature measuring section 102 and reduces the loss of heat. This multi-layer thermal insulation structure forms a near-insulating effect on the non-quenching surface, so that the heat is mainly conducted in one direction along the axial direction, simulating the one-way heat transfer conditions under the ideal state, thereby effectively eliminating the influence of air cooling of the non-quenching surface on the temperature field of the sample.

[0037] In order to further ensure the stability of the insulation layer 107 in actual operation, especially to prevent the insulation layer 107 from being invaded by water splashes caused by boiling during high-temperature quenching, a barrier portion 104 with a moderate width is added below the temperature measurement point of the sample to block the water splashes caused by the boiling medium during the quenching process, prevent the water splashes from entering the insulation layer 107, and maintain the integrity and function of the insulation layer 107. In addition, the immersion depth of the quenching end 103 during the quenching process is optimized and precisely controlled to ensure that the immersion depth of the quenching end 103 is within the range of 2mm to h1-1mm, which can further prevent the splashing of water splashes and the failure of the insulation layer 107 due to water seepage.

[0038] In an exemplary embodiment, the distance between the first temperature measuring point 105 and the end surface of the quenching end 103 is equal to Δx. By arranging the first temperature measuring point 105 at a distance Δx from the quenching end 103 surface, not only can the early changes in the heat transfer of the quenching end 103 surface be captured, but also the interference of the end surface edge effect on the temperature measurement data can be effectively avoided.

[0039] Specifically, the quenching end 103 is the area where the sample is in direct contact with the quenching medium 204, and is also the starting point of heat transfer. Due to the intense heat exchange phenomenon that occurs when the end face contacts the medium, the heat is gradually transferred to other parts through the axial direction of the test rod 101. If the first temperature measurement point 105 is too close to the end face, the measured temperature may be affected by the local temperature fluctuation of the end face and the instability of the boundary layer, resulting in data deviation. If the temperature measurement point is too far from the end face, it may not be able to reflect the dynamic changes of the heat exchange on the quenching end 103 surface in a timely manner, reducing the timeliness and accuracy of the measurement.

[0040] Therefore, setting the first temperature measurement point 105 at a distance Δx from the quenching end 103 is an optimized design solution that comprehensively considers the heat exchange dynamics and temperature measurement stability. This distance is strictly controlled based on the proportional relationship of the diameter D of the test rod 101, satisfying Δx≤D / 2, to ensure that the temperature measurement point can accurately capture the initial changes in axial unidirectional heat transfer, while keeping the temperature field at the location of the temperature measurement point relatively stable. In addition, such an arrangement enables the first temperature measurement point 105 to serve as a reference point for the temperature change of the sample, and cooperate with other temperature measurement points (such as the second temperature measurement point 106) to jointly record the temperature change curve, providing an accurate data basis for the subsequent calculation of the heat transfer coefficient.

[0041] In an exemplary embodiment, the height H of the test rod 101 is ≥ 3D; and / or the height h1 of the quenching end 103 is > Δx / 2. This design aims to improve the stability of the heat transfer path and the accuracy of the temperature measurement data by optimizing the geometric proportions of the test rod 101, while overcoming the temperature field distortion problem caused by the unreasonable size proportions of traditional specimens.

[0042] The height H of the test rod 101 is an important factor affecting the length of the heat transfer path. The design requires H ≥ 3D to ensure that the test rod 101 has sufficient extension length in the axial direction to form a stable unidirectional heat transfer condition. If the height is too low, the heat transfer in the test rod 101 is easily affected by the boundary effect, resulting in an uneven distribution of the temperature field along the axial direction, which has an adverse effect on the accuracy of the temperature measurement data. By setting the ratio of height to diameter to at least 3 times, not only the heat transfer path is extended, but also the interference of radial heat conduction on the axial temperature gradient is reduced, so that the temperature change can more clearly reflect the characteristics of unidirectional heat transfer.

[0043] On the other hand, the height h1 of the quenching end 103 is a key parameter that determines the axial transfer of heat from the test rod 101 to the temperature measuring section 102. Designing h1 to be greater than Δx / 2 ensures that the quenching end 103 has sufficient volume to contact the quenching medium 204 to achieve effective heat exchange, and avoids the problem of insufficient heat exchange caused by the quenching end 103 being too short. If the height of the quenching end 103 is insufficient, the initial heat transfer path of the test rod 101 will be too concentrated, resulting in distortion of the temperature data recorded at the temperature measuring point.

[0044] In an exemplary embodiment, the thickness of the thermal insulation layer 107 is T≥4 mm. The width of the barrier portion 104 is L, and T<L≤D / 2. This design not only significantly reduces the possibility of heat loss from the non-quenching surface by coordinating the geometric relationship between the thermal insulation layer 107 and the barrier portion 104, but also further optimizes the heat transfer path and structural stability of the test rod 101.

[0045] The main function of the thermal insulation layer 107 is to reduce the heat loss caused by convection, conduction and radiation on the non-quenched surface, thereby forming a nearly insulating state on the non-quenched end face of the test rod 101. The thickness T of the thermal insulation layer 107 is designed to be no less than 4 mm, which is determined after comprehensive consideration of the thermal insulation performance and the compactness of the sample structure. A thinner thermal insulation layer 107 may cause excessive heat loss through the side, thereby interfering with the axial heat transfer process inside the test rod 101, while an overly thick thermal insulation layer 107 may increase the volume and weight of the sample, which is not conducive to the flexibility of experimental operation. By controlling the thickness within a reasonable range, the thermal insulation layer 107 can effectively isolate the heat loss of the non-quenched end face and ensure that the heat of the test rod 101 is concentrated and transferred in one direction along the axial direction.

[0046] As a part of the test rod 101, the blocking portion 104 is designed with a width L to further enhance the protective function of the insulation layer 107, while providing a stable support structure for the insulation layer 107. The width L of the blocking portion 104 satisfies T<L≤D / 2, that is, it is wide enough to cover the insulation layer 107, but not too wide to avoid excessive interference with the heat transfer path of the test rod 101. By setting L to be less than D / 2, the diffusion of radial heat transfer can be effectively limited. The blocking portion 104 and the insulation layer 107 work together to prevent the invasion of water splashes and steam on the insulation layer 107, and isolate the interference of the external environment on the heat transfer of the test rod 101 through a physical barrier.

[0047] In an exemplary embodiment, a temperature measuring thermocouple 108 is provided at the first temperature measuring point 105 and the second temperature measuring point 106. Installing the temperature measuring thermocouple 108 at these two positions further enhances the real-time and accuracy of temperature data acquisition. The first temperature measuring point 105 is close to the quenching end 103 surface, and can detect the change of the initial heat transfer in time; while the second temperature measuring point 106 is closer to the middle of the test rod 101, and by comparing the data with the first temperature measuring point 105, the attenuation law of the axial heat transfer can be intuitively reflected.

[0048] The thermocouple can be directly embedded in the location of the temperature measurement point, and through good thermal contact, it can realize real-time sensing of the local temperature of the test rod 101. This direct embedded design reduces the intermediate links in the heat transfer process and minimizes the measurement error. At the same time, the high sensitivity and fast response characteristics of the thermocouple enable it to accurately capture the transient temperature changes during the quenching process.

[0049] Please refer to Figure 2 As shown, an embodiment of the present invention provides a quenching temperature measuring device 200, which can be used to measure the temperature of the quenching temperature measuring sample 100. The quenching temperature measuring device 200 includes a bracket 201, a container 203 for accommodating a quenching medium 204, and a support member 205.

[0050] Among them, a clamp 202 for clamping the quenching and temperature measuring sample 100 is installed on the bracket 201; the container 203 is arranged below the clamp 202, so that the quenching end 103 of the quenching and temperature measuring sample 100 clamped on the clamp 202 can be immersed in the quenching medium 204 in the container 203; the support is arranged in the container 203, and the support member 205 includes a plurality of support parts 206 for supporting the blocking part 104 of the quenching and temperature measuring sample 100.

[0051] The bracket 201 is the frame structure of the entire device, on which a clamp 202 for fixing the quenching temperature measurement sample 100 is installed. The design of the clamp 202 takes into account the convenience and stability of the sample during the quenching process, and can firmly clamp the sample to avoid measurement errors caused by vibration or sample shaking. Through the cooperation of the bracket 201 and the clamp 202, the sample can be accurately maintained at a predetermined position, so that its quenching end 103 can always be in the quenching medium 204 in the container 203, thereby ensuring that the heat transfer process of the sample is not disturbed by the outside world.

[0052] The container 203 is located below the fixture 202 and is used to hold the quenching medium 204, such as water or other cooling liquids. It is the core of the sample quenching process. The design of the container 203 not only takes into account its matching with the sample geometry, but also ensures sufficient depth to ensure that the sample quenching end 103 can be immersed in the medium. Such a design can provide a uniform cooling environment, ensuring that the sample receives consistent heat exchange during the quenching process, thereby avoiding experimental errors caused by uneven media or liquid level changes.

[0053] The support member 205 disposed in the container 203 further optimizes the placement and operation of the sample. The support member 205 includes a plurality of support portions 206 for supporting the sample blocking portion 104. The height difference between the top of the support portion 206 and the liquid surface of the quenching medium 204 determines the immersion depth of the quenching end 103 of the test rod 101. The arrangement position of the support portion 206 matches the blocking portion 104 of the sample. By minimizing the contact area between the support portion 206 and the blocking portion 104, the heat loss on the support path can be effectively reduced, thereby ensuring the axiality of the sample heat transfer and the accuracy of the measurement. In addition, the heat resistance and corrosion resistance of the material of the support portion 206 ensure that it can be used for a long time in a high temperature and medium environment without interfering with the quenching process of the sample.

[0054] Specifically, the contact area between each support portion 206 and the blocking portion 104 does not exceed 0.5 mm 2 By strictly controlling the contact area, the support portion 206 not only effectively supports the stable placement of the sample, but also minimizes the heat loss of the sample during the quenching process.

[0055] The blocking portion 104 is a part of the test rod 101, which can form a contact interface with the support 205 during the quenching process to fix and stabilize the position of the sample. The support 206 is a supporting structure in the container 203, which contacts the blocking portion 104 to provide physical support for the sample while minimizing interference with the axial heat transfer of the test rod 101. By limiting the contact area between the two to 0.5mm 2 Hereinafter, the possibility of heat diffusion through the contact points to the support path is greatly reduced, ensuring that the heat transfer of the specimen is mainly concentrated in the axial direction.

[0056] In an exemplary embodiment, a heating unit 207 for maintaining the quenching medium 204 at a predetermined temperature is provided in the container 203, and the heating unit 207 is connected to the temperature control unit 208. The coordinated work of the heating unit 207 and the temperature control unit 208 ensures that the quenching medium 204 can always be maintained within a preset temperature range, providing a basis for the temperature measurement accuracy of the sample and the repeatability of the experiment.

[0057] The heating unit 207 may be located at the bottom or inner wall of the container 203. As a core component that directly affects the temperature of the quenching medium 204, the heating unit 207 can uniformly heat the medium in the container 203 to avoid uneven heat transfer caused by local temperature fluctuations.

[0058] The temperature control unit 208, as the control center of the heating unit 207, is responsible for real-time monitoring of the temperature change of the quenching medium 204 and adjusting the heating unit 207 through a feedback mechanism. This closed-loop control system can accurately maintain the temperature of the quenching medium 204 near the set value.

[0059] The heating unit 207 and the temperature control unit 208 provide a controllable quenching environment for the experiment. The temperature of the quenching medium 204 has a direct impact on the heat transfer characteristics of the sample, and different medium temperatures will lead to significant changes in the interface heat transfer coefficient. Therefore, the introduction of the heating unit 207 and the temperature control unit 208 enables the device to conduct experiments under different temperature conditions, expanding the scope of application of the research.

[0060] The present invention will be further described below in conjunction with specific embodiments.

[0061] Example 1

[0062] Use machining to obtain Figure 1The quenching temperature measurement sample 100 shown has a test rod 101 with an overall length of 115 mm. The diameter of the rest of the test rod 101 is 30 mm except for the blocking portion 104. Two temperature measurement holes with a diameter of 1 mm and a depth of 15 mm are drilled along the radial direction near a circular end face (the end face of the quenching end 103). The axis of the first temperature measurement hole (the first temperature measurement point 105) is 6 mm away from the end face, and the axis of the second temperature measurement hole (the second temperature measurement point 106) is 12 mm away from the end face. The blocking portion 104 has a width of 7 mm and a thickness of 2 mm, and the bottom surface of the blocking portion 104 is 4 mm away from the quenching end face.

[0063] like Figure 2 As shown, the thermocouple 108 uses a 0.5 mm K-type thermocouple, and the temperature change curve inside the test rod 101 during the quenching process is obtained through the Hioki LR8400-21 data acquisition instrument 209, the sampling frequency is 10 Hz, and the test rod 101 connected to the thermocouple 108 is placed in a resistance furnace and heated to 535° C. and kept warm for three hours.

[0064] The quenching medium 204 (water) in the container 203 of the quenching temperature measuring device 200 is heated and kept warm to 46°C. During the experiment, the sample 100 is taken out of the insulation furnace and placed on the support 205 with the height difference adjusted to the liquid surface of the quenching medium 204 within 10 seconds, and the sample 100 is clamped and fixed by the clamp 202 on the bracket 201. The support 205 consists of six support pins (support part 206) and a base. The tip of the support pin (support part 206) is directly in contact with the blocking part 104, and the quenching water immersion depth is 3 mm.

[0065] During the quenching process, the boiling water at the bottom of the sample 100 was blocked by the blocking portion 104. After the test, there was no sign of water entering the insulation layer 107, and the temperature measurement experiment was successful. Figure 3 shown.

[0066] Example 2

[0067] Use machining to obtain Figure 1 The quenching temperature measurement sample 100 shown has a test rod 101 with an overall length of 115 mm. The diameter of the rest of the test rod 101 is 30 mm except for the blocking portion 104. Two temperature measurement holes with a diameter of 1 mm and a depth of 15 mm are drilled along the radial direction near a circular end face (the end face of the quenching end 103). The axis of the first temperature measurement hole (the first temperature measurement point 105) is 6 mm away from the end face, and the axis of the second temperature measurement hole (the second temperature measurement point 106) is 12 mm away from the end face. The blocking portion 104 has a width of 7 mm and a thickness of 2 mm, and the bottom surface of the blocking portion 104 is 4 mm away from the quenching end face.

[0068] like Figure 4As shown, the thermocouple 108 adopts a 0.5 mm K-type thermocouple, and the temperature change curve inside the test rod during the quenching process is obtained by the Hioki LR8400-21 data acquisition instrument 401, and the sampling frequency is 10 Hz. First, the thermocouple 108 is inserted into the bottom of the temperature measuring hole, and then fixed to the surface of the test rod 101 with aluminum foil tape, and then the side surface and top surface of the test rod 101 are wrapped with 5 mm thick insulation cotton 109, and the outside is wrapped and fixed with aluminum foil 110.

[0069] Thermocouple 108 uses a 0.5 mm K-type thermocouple, and uses Hioki LR8400-21 data acquisition instrument 401 to obtain the temperature change curve inside the test rod 101 during the quenching process. The sampling frequency is 10 Hz. The test rod 101 connected to the thermocouple 108 is placed in a resistance furnace and heated to 535°C for three hours.

[0070] The quenching medium 403 (water) in the container 402 is heated and kept warm to 35°C. During the experiment, the sample 100 is taken out of the insulation furnace and placed on the support 404 with the height difference adjusted to the liquid surface of the quenching medium 403 within 10 seconds. The support 404 consists of six support pins 405 and a base. The tip of the support pin 405 is directly in contact with the blocking part 104, and the quenching water depth is 3 mm.

[0071] During the quenching process, boiling water droplets are blocked by the blocking part 104, and the heat insulation cotton 109 and the temperature measurement channel are not flooded. However, the structure is top-heavy, and the center of gravity is too high, which can easily cause the sample to shake and fall, and the experimental success rate is low.

[0072] Comparative Example 1

[0073] like Figure 5 As shown, a test rod 501 with a diameter of 30 mm and a height of 115 mm is obtained by machining. Two temperature measuring holes with a diameter of 1 mm and a depth of 15 mm are drilled along the radial direction near a circular end face (quenching end 512 end face). The axis of the first temperature measuring hole 502 is 6 mm from the end face, and the axis of the second temperature measuring hole 503 is 12 mm from the end face. The thermocouple 504 uses a 0.5 mm K-type thermocouple, and the temperature change curve inside the test rod during the quenching process is obtained by using the Hioki LR8400-21 data acquisition instrument 505. The sampling frequency is 10 Hz. The thermocouple 504 is first inserted into the bottom of the temperature measuring hole, and then fixed to the surface of the test rod 501 with aluminum foil tape. Then, the side surface and the top surface are wrapped with 5 mm thick insulation cotton 506, and the outside is wrapped and fixed with aluminum foil 507, leaving 5 mm of the side surface of the sample above the bottom quenching end face.

[0074] The assembled quenching temperature measuring test bar 501 is placed in a resistance furnace and subjected to solution treatment at 535°C for 3 hours. Before quenching, the temperature recorder is turned on, and the test bar is taken out with a crucible tong and placed on a support frame 509 in a container 508. The temperature of the quenching medium 511 (water) in the container 508 is kept at room temperature of 25°C. The support frame 509 is composed of seven support pins 510 and a base. The tip of the support pin 510 directly contacts the quenching surface of the test bar 501, and the quenching water depth is 3mm.

[0075] During the quenching process, boiling water droplets near the quenching surface surged up, and there was a gap between the aluminum foil under the insulation cotton and the test rod, causing water to enter the insulation cotton and the water to enter the thermocouple temperature measurement channel, resulting in temperature measurement failure.

[0076] In summary, the temperature measuring sample and device for measuring the heat transfer coefficient of the quenching interface of aluminum alloy castings provided by the present invention eliminate the interference of air cooling of the non-quenching end face on the sample temperature field and the quenching heat transfer coefficient through the insulation layer, thereby improving the measurement accuracy; the blocking structure of the test rod can not only prevent water from entering the insulation layer and the temperature measuring channel, but also serve as the load-bearing end face in contact with the support member, thereby ensuring uniform and stable unidirectional heat dissipation of the test rod; the positioning of the test rod by the bracket and the support member of the quenching temperature measuring device enables the test rod to stably and continuously measure the temperature changes of the test rod in the boiling stage during the quenching process, thereby greatly improving the accuracy of measuring the quenching heat transfer coefficient.

[0077] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0078] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A quenching temperature measuring sample for measuring the heat transfer coefficient of the quenching interface, characterized in that: include: A test rod, comprising a temperature measuring section extending in an axial direction and a quenching end formed at the end of the temperature measuring section, a circle of blocking parts is provided on the outer periphery of the end of the temperature measuring section adjacent to the quenching end, a first temperature measuring point and a second temperature measuring point are provided on the temperature measuring section and are arranged at intervals in the axial direction thereof, the diameter of the test rod is D, the distance between the first temperature measuring point and the second temperature measuring point is Δx≤D / 2, and the sum of the height h1 of the quenching end and the thickness h2 of the blocking part is less than or equal to Δx; The heat-insulating layer is coated on the outer surface of the entire temperature measuring section.

2. The quenching temperature measurement sample according to claim 1, characterized in that: The distance between the first temperature measuring point and the end surface of the quenching end is equal to Δx.

3. The quenching temperature measurement sample according to claim 1, characterized in that: The height of the test bar H≥3D; and / or the height of the quenched end h1>Δx / 2.

4. The quenching temperature measurement sample according to claim 1, characterized in that: The thickness of the thermal insulation layer is T≥4mm.

5. The quenching temperature measurement sample according to claim 4, characterized in that: The width of the blocking portion is L, and T<L≤D / 2.

6. The quenching temperature measurement sample according to claim 1, characterized in that: Temperature measuring thermocouples are provided at the first temperature measuring point and the second temperature measuring point.

7. The quenching temperature measurement sample according to claim 1, characterized in that: The heat-insulating layer comprises heat-insulating cotton wrapped on the outer surface of the temperature measuring section and aluminum foil wrapped on the outer surface of the heat-insulating cotton.

8. A quenching temperature measuring device for measuring the temperature of a quenching temperature measuring sample according to any one of claims 1 to 7, characterized in that: include: A bracket, on which a fixture for clamping a quenching temperature measurement sample is installed; A container for containing a quenching medium is provided below the fixture so that the quenching end of the quenching temperature measurement sample clamped on the fixture can be immersed in the quenching medium in the container; The support member is arranged in the container, and the support member includes a plurality of support parts for supporting the blocking part of the quenching temperature measurement sample.

9. The quenching temperature measuring device according to claim 8, characterized in that: The contact area between each supporting part and the blocking part does not exceed 0.5 mm 2 .

10. The quenching temperature measuring device according to claim 8, characterized in that: A heating unit for maintaining the quenching medium at a predetermined temperature is arranged in the container, and the heating unit is connected to the temperature control unit.

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