Device system and method for testing cooling speed of quenching liquid

Abstract

The invention provides a quenching liquid cooling speed testing device system and a quenching liquid cooling speed testing method. The quenching liquid cooling speed testing device system comprises a cooling speed testing device, a stirring device, a temperature measuring device, a fixing device and a cooling speed testing and collecting device. The cooling speed testing device is a hollow box body with an opening in the upper end; a U-shaped pipe with an opening in the upper end is fixed in the hollow box body; the heights of the two ends of the U-shaped pipe are different, the higher end is a first branch pipe, and the lower end is a second branch pipe; a temperature measuring device is arranged in the first branch pipe; a stirring device is arranged in the second branch pipe; and a fixing device is connected above the cooling speed testing device. By improving the cooling speed testing device, the temperature drop curve and the cooling speed in the quenching process can be conveniently and quickly tested, the actual working condition of a site can be better simulated, it is ensured that quenching liquid is in a stable state in the testing process, and then the accuracy and the reliability of a quenching testing result are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of metal heat treatment, and relates to a cooling rate testing device system and a testing method for a quenching liquid. Background Art

[0002] Quenching usually refers to a heat treatment process in which a metal material is heated to above a critical temperature, maintained for a period of time, and then rapidly cooled at a cooling rate greater than the critical temperature to form martensite or other hardened phases. In addition, as a key medium in the metal heat treatment process, the cooling performance of the quenching liquid directly affects the microstructure and macroscopic properties of the metal after quenching. The cooling rate of the quenching liquid, usually referred to as the cooling rate, is an important parameter for evaluating the performance of the quenching liquid.

[0003] However, there are several limitations in the existing quenching liquid cooling rate test methods and devices, which limit the precise control and optimization of the quenching process on site. First, the first limitation is the complexity of the operation: the existing test methods and devices usually require complex equipment settings and operation procedures, which not only increases the test cost, but also increases the difficulty of operation, which is not conducive to quickly and accurately obtaining test data. In addition, the second limitation is the consistency of the data. Since the test conditions are difficult to standardize, the test results obtained by different laboratories or different operators may vary greatly, affecting the consistency and comparability of the data. The third limitation is the impact of the environment. Some test methods are sensitive to environmental conditions. For example, changes in temperature and humidity may affect the test results, reducing the reliability of the test results. Finally, the fourth limitation is the diversity of quenching media. There are many types of quenching liquids on the market, including water-based, oil-based and other different media. The existing test methods are difficult to fully adapt to the characteristics of various quenching liquids.

[0004] In summary, there is an urgent need to provide an improved quenching liquid cooling rate testing device and method to improve test accuracy, simplify the operating process, enhance the consistency and reliability of test results, and be able to simulate more actual working conditions, overcome the shortcomings of the existing technology, and provide a more scientific and effective means for the performance evaluation of quenching liquid. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a cooling rate testing device system and a testing method for quenching liquid. By improving the cooling rate testing device and combining it with a fixing device for adding a temperature measuring device, it is not only possible to conveniently and quickly test the temperature drop curve and cooling rate of the quenching process and better simulate the actual working conditions on site, but also to ensure that the quenching liquid flow is in a stable advection state during the test, thereby improving the accuracy and reliability of the quenching test results.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a cooling rate test device system for a quenching liquid, the cooling rate test device system comprising a cooling rate test device, a stirring device, a temperature measuring device, a fixing device and a cooling rate test collection device;

[0008] The cooling rate test device is a hollow box with an open top; a U-shaped tube with an open top is fixed in the hollow box;

[0009] The two ends of the U-shaped tube have different heights, wherein the end with a higher height is the first branch tube, and the end with a lower height is the second branch tube;

[0010] A temperature measuring device is placed inside the first branch pipe;

[0011] A stirring device is placed inside the second branch pipe;

[0012] A fixing device is connected above the cooling rate testing device; the fixing device is used to fix the temperature measuring device;

[0013] The temperature measuring device is connected to the cooling rate test collection device.

[0014] In the present invention, the cooling rate test collection device can adopt a conventional cooling characteristic tester in the prior art, which is not specifically limited here.

[0015] The cooling rate test device system provided by the present invention can conveniently and quickly test the temperature drop curve and cooling rate of the quenching process by improving the cooling rate test device and adding a fixing device of the temperature measuring device, thereby improving the test efficiency, and better simulating the actual working conditions on site, and also ensuring that the quenching liquid flows in a stable state during the test, thereby improving the accuracy and reliability of the quenching test results. The cooling rate test device system is easy to operate and can be cleaned conveniently and quickly.

[0016] It should be noted that by fixing a U-shaped tube with an upper opening and different heights at both ends in a hollow box, placing a temperature measuring device in the higher end, and placing a stirring device in the other end, the first is to improve the test accuracy. The device can make the quenching liquid circulate faster, so that the probe can contact the quenching liquid for a longer time during the test, thereby recording a more accurate temperature-time curve. The second is to better simulate the actual working conditions on site. The device can better simulate the flow state of the liquid in the quenching tank on site during quenching, so that the test results are closer to the actual production situation. The third is to discharge bubbles in the medium. The device can discharge bubbles in the heated medium to avoid the influence of bubbles on the test results, so that the measurement results are more accurate. For example, water-based polymer quenching liquid is very sensitive, and the polymer content and contaminants will affect the test results. The use of a stirrer can reduce the interference of these factors. The fourth is to improve the reproducibility and repeatability of the test. The use of this device can improve the reproducibility and repeatability of the test data.

[0017] As a preferred technical solution of the present invention, the U-shaped tube is fixed to the opposite side walls of the hollow box body through steel plates.

[0018] Preferably, the U-shaped tube is not in contact with any of the four side walls of the hollow box.

[0019] In the present invention, the distance between the U-shaped tube and the four side walls of the hollow box is not specifically limited, and those skilled in the art can determine it according to site needs.

[0020] As a preferred technical solution of the present invention, the height of the hollow box is 180-220mm, for example, it can be 182mm, 185mm, 188mm, 190mm, 192mm, 195mm, 198mm, 200mm, 202mm, 205mm, 208mm, 210mm, 212mm, 215mm or 218mm, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0021] Preferably, the length of the hollow box is 120-160 mm, for example, it can be 125 mm, 130 mm, 135 mm, 140 mm, 145 mm, 150 mm, 155 mm or 158 mm, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0022] As a preferred technical solution of the present invention, the height ratio of the first branch pipe to the hollow box body is (0.72-0.82):1, for example, it can be 0.73:1, 0.74:1, 0.75:1, 0.76:1, 0.77:1, 0.78:1, 0.79:1, 0.8:1 or 0.81:1, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0023] Preferably, the height difference between the first branch pipe and the second branch pipe is 35-45 mm, for example, it can be 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm or 44 mm, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0024] It should be noted that by further controlling the height difference of the two branches of the U-tube, the two branches are at the optimal height difference, which has the following advantages: First, the test accuracy is improved. The optimal height difference can ensure the stability of the flow rate of the quenching liquid in the U-tube, thereby improving the accuracy of the cooling rate test data. Second, the fluid flow state is improved and the heat exchange efficiency is improved. The optimal height difference can make the quenching liquid form a more ideal flow state in the U-tube, such as stable advection, so as to better simulate the actual quenching process. In addition, the appropriate height difference helps to improve the heat exchange efficiency between the quenching liquid in the U-tube and the surrounding environment. Third, the experimental stability is guaranteed. The optimal height difference helps to reduce the pulsation phenomenon in the U-tube, thereby improving the stability of the experimental system. In addition, the appropriate height difference can also maintain a stable flow of the quenching liquid and avoid the influence of flow fluctuations on the experimental results.

[0025] As a preferred technical solution of the present invention, the inner diameters of the first branch pipe and the second branch pipe are the same.

[0026] In the present invention, by keeping the inner diameters of the two branches of the U-shaped tube the same, the flow characteristics of the quenching liquid in the two branches of the U-shaped tube can be ensured to be consistent, thus avoiding affecting the uniformity of the cooling effect and the accuracy of the test results, and improving the repeatability of the test results.

[0027] Preferably, the ratio of the inner diameter of the first branch pipe to the length of the hollow box is (0.35-0.4):1, for example, it can be 0.36:1, 0.37:1, 0.38:1 or 0.39:1, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0028] Preferably, the distance between the walls of the first branch pipe and the second branch pipe is 25-35 mm, for example, it can be 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm or 34 mm, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0029] In the present invention, the tube wall spacing between the first branch tube and the second branch tube refers to the distance between adjacent tube walls in the U-shaped tube.

[0030] It should be noted that by controlling the distance between the tube walls of the first branch tube and the second branch tube within a certain range, it is ensured that the flow of the quenching liquid in the tube is more uniform and stable, and the pulsation of the quenching liquid in the tube is avoided.

[0031] As a preferred technical solution of the present invention, the height ratio of the quenching liquid surface to the hollow box is (0.85-0.92):1, for example, it can be 0.86:1, 0.87:1, 0.88:1, 0.89:1, 0.9:1 or 0.91:1, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0032] Preferably, the temperature measuring device is placed in the first branch pipe to a depth of 70-80 mm, for example, 71 mm, 72 mm, 73 mm, 74 mm, 75 mm, 76 mm, 77 mm, 78 mm or 79 mm, etc., but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0033] In the present invention, by controlling the temperature measuring device to be placed at the optimal depth in the U-tube, the following advantages are achieved: First, the measurement error can be reduced. The placement at an appropriate depth can avoid the measurement error caused by the probe being too deep or too shallow. For example, if the probe is too deep, it may contact the bottom, and if it is too shallow, it may be affected by the surface temperature fluctuation. Second, data acquisition can be optimized. The placement at the optimal depth helps stabilize the probe in the U-tube, ensuring the continuity and stability of data acquisition, thereby obtaining a more reliable cooling curve. Third, the probe and equipment can be protected. Reasonable control of the probe depth can avoid the collision of the probe with the bottom of the U-tube or other components, thereby extending the service life of the probe and equipment.

[0034] Preferably, the top of the temperature measuring device is higher than the quenching liquid level.

[0035] Preferably, the temperature measuring device comprises a probe.

[0036] As a preferred technical solution of the present invention, the side wall of the cooling rate testing device is provided with a plurality of slots.

[0037] Preferably, the slot is used to fix the connecting rod.

[0038] In the present invention, the side wall of the cooling rate test device is provided with a plurality of fixing slots for fixing the connecting rods; wherein the number of the fixing slots corresponds to the number of the connecting rods.

[0039] Preferably, the fixing device is connected to the top of the cooling rate testing device through a plurality of connecting rods.

[0040] Preferably, the fixing device comprises a cylinder and a fixing and placing component arranged in the cylinder.

[0041] In the present invention, the barrel can be a hollow cylindrical structure.

[0042] Preferably, the fixed placement component is an inverted hollow frustum structure.

[0043] Preferably, a fixing sleeve is provided at the bottom end of the fixing and placing component.

[0044] It should be noted that the present invention not only fixes the temperature measuring device but also ensures that the temperature measuring device is in an optimal position during the test by adding a fixing device with a specific structure.

[0045] As a preferred technical solution of the present invention, the stirring device includes a stirring device body and a base, and the stirring device body is located on the top of the base.

[0046] Preferably, the stirring device body comprises a motor, a stirring rod and a stirring head.

[0047] Preferably, a motor is provided at the top of the stirring device body, a stirring rod is connected to the output end of the motor, and a stirring head is fixedly provided at the bottom end of the stirring rod.

[0048] Preferably, the stirring head is a petal-shaped structure.

[0049] Preferably, the stirring rod is placed in the second branch at a depth of 30-40 mm, for example, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm or 39 mm, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0050] In the present invention, by controlling the depth range of the stirring rod in the U-shaped tube, a uniform stirring effect is ensured and pulsation during the stirring process is reduced. The cooling environment of the actual workpiece in the quenching liquid can also be better simulated, thereby improving the repeatability and reliability of the test results.

[0051] Preferably, the top end of the stirring rod is higher than the quenching liquid level.

[0052] In the present invention, the hollow box, the U-shaped tube and the fixing device are all made of stainless steel.

[0053] In a second aspect, the present invention provides a cooling rate test method for a quenching liquid, the cooling rate test method being performed using the cooling rate test device system described in the first aspect, and comprising the following steps:

[0054] (1) performing a first heating on the temperature measuring device and a second heating on the quenching liquid;

[0055] (2) transferring the second heated quenching liquid into the hollow box, placing the first heated temperature measuring device in the first branch pipe through a fixing device, and starting stirring at the same time to perform a quenching liquid cooling rate test;

[0056] (3) Based on the data collected by the cooling rate test acquisition device, the cooling characteristic curve and cooling rate of the quenching liquid are obtained.

[0057] In the present invention, the temperature endpoint of the first heating can be determined according to the client's requirements; the temperature endpoint of the second heating can be determined according to the properties of the quenching liquid.

[0058] In the present invention, parameters such as cooling rate can be obtained after calculating the cooling characteristic curve; wherein the cooling rate refers to the time required for the quenching liquid to be rapidly cooled from a high temperature state to a low temperature state.

[0059] The test method provided by the present invention is easy to operate and can obtain test data simply and quickly. No steam film is generated during the test process, so the cooling rate test will not be affected by the steam film and cause data deviation.

[0060] As a preferred technical solution of the present invention, the stirring speed in step (2) includes the following situations:

[0061] (a) If the theoretical cooling rate of the quenching liquid is 0-65°C / s, excluding 0°C / s, the stirring speed is 550-650 rpm; or

[0062] (b) if the theoretical cooling rate of the quenching liquid is 65-120°C / s, excluding 65°C / s, the stirring speed is 750-950 rpm; or

[0063] (b) If the theoretical cooling rate of the quenching liquid is greater than 120°C / s, the stirring speed is greater than 1000 rpm.

[0064] It should be noted that the stirring speed is adjusted accordingly according to the theoretical cooling rate range of different quenching liquids to ensure that the flow state of the quenching liquid during the test is consistent with the actual working conditions, thereby more accurately reflecting the actual cooling rate of the quenching liquid and improving the accuracy and reliability of the test results.

[0065] In the present invention, if the theoretical cooling rate of the quenching liquid is 0-65°C / s, and does not include 0°C / s, for example, it can be 10°C / s, 20°C / s, 30°C / s, 40°C / s, 50°C / s or 60°C / s, etc., then the stirring speed is 550-650rpm, for example, it can be 560rpm, 570rpm, 580rpm, 590rpm, 600rpm, 610rpm, 620rpm, 630rpm or 640rpm, etc.; if the theoretical cooling rate of the quenching liquid is 65-120°C / s, and does not include 65°C / s, for example, it can be 70°C / s, 80°C / s, 90°C / s, 100°C / s, 110°C / s or 115°C / s, etc., then the stirring speed is 750-950rpm, for example, it can be The stirring speed may be 760rpm, 780rpm, 800rpm, 820rpm, 850rpm, 860rpm, 880rpm, 900rpm, 920rpm or 940rpm; if the theoretical cooling rate of the quenching liquid is greater than 120°C / s, for example, it may be 130°C / s, 140°C / s, 150°C / s, 160°C / s, 170°C / s or 180°C / s, then the stirring speed may be greater than 1000rpm, for example, it may be 1050rpm, 1100rpm, 1150rpm, 1200rpm, 1250rpm, 1300rpm, 1350rpm, 1400rpm or 1500rpm, but is not limited to the listed values, and other values ​​within the numerical range are equally applicable.

[0066] In the present invention, after the quenching liquid cooling rate test is completed, the temperature measuring device is cooled for a period of time and then cleaned with petroleum ether or alcohol.

[0067] Compared with the prior art, the present invention has the following beneficial effects:

[0068] (1) The cooling rate test device system provided by the present invention can overcome the influence of environmental conditions by improving the cooling rate test device, adding a fixing device for the temperature measuring device and controlling the relevant parameters of the U-tube, and can not only conveniently and quickly test the temperature drop curve and cooling rate of the quenching process, but also better simulate the actual working conditions on site, and ensure that the quenching liquid flows in a stable state during the test, thereby improving the accuracy and reliability of the quenching test results;

[0069] (2) The cooling rate test method provided by the present invention is easy to operate and can obtain test data simply and quickly. No steam film will be generated during the test process, so the cooling rate test will not be affected by the steam film and cause data deviation, thereby improving the accuracy and consistency of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1It is a structural schematic diagram of the cooling rate test device system provided in Example 1.

[0071] Among them, 1-cooling rate test device, 2-stirring device, 3-temperature measuring device, 4-fixing device, 5-cooling rate test collection device, 11-hollow box, 12-U-shaped tube, 121-first branch pipe, 122-second branch pipe;

[0072] Figure 2 It is a front view of the cooling rate testing device provided in Example 1.

[0073] Figure 3 It is a top view of the cooling rate testing device provided in Example 1.

[0074] Figure 4 This is a top view of the cooling rate test device provided in Example 2.

[0075] Figure 5 The cooling rate test device provided in Example 1 repeatedly performs 5 cooling rate tests on quenching liquid A, and the cooling characteristic curve is measured.

[0076] Figure 6 The cooling rate test device provided in Example 1 repeatedly performs 7 cooling rate tests on quenching liquid B, and the cooling characteristic curve is measured. DETAILED DESCRIPTION

[0077] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0078] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0079] In the following embodiments and comparative examples, the cooling rate test collection device used meets the requirements of ASTM-D6482-21 standard; the probe is a nickel-chromium alloy rod with a diameter of 12.5±0.01 mm and a thermocouple in the center; quenching liquid A is a polyether water-based quenching liquid sample with a mass concentration of 15% (its properties are relatively stable); quenching liquid B is a polyvinyl pyrrolidone water-based quenching liquid sample with a mass concentration of 15% (its properties are relatively unstable).

[0080] Example 1

[0081] This embodiment provides a cooling rate test device system for quenching liquid, the cooling rate test device system (such as Figure 1 ) comprises a cooling rate testing device 1, a stirring device 2, a temperature measuring device 3, a fixing device 4 and a cooling rate testing collecting device 5;

[0082] The cooling rate testing device 1 (such as Figure 2-3 ) is a hollow box 11 with an upper end opening; the height of the hollow box 11 is 200 mm, the length is 140 mm, and the width is 100 mm; a U-shaped tube 12 with an upper end opening is fixed in the hollow box 11; the U-shaped tube 12 is fixed to the opposite side walls of the hollow box 11 through a steel plate; the U-shaped tube 12 is not in contact with the four side walls of the hollow box 11;

[0083] The two ends of the U-shaped tube 12 have different heights, wherein the higher end is the first branch tube 121, and the lower end is the second branch tube 122;

[0084] The height ratio of the first branch pipe 121 to the hollow box body 11 is 0.75:1; the height difference between the first branch pipe 121 and the second branch pipe 122 is 40 mm; the inner diameters of the first branch pipe 121 and the second branch pipe 122 are the same; the ratio of the inner diameter of the first branch pipe 121 to the length of the hollow box body 11 is 0.38:1; the distance between the pipe walls of the first branch pipe 121 and the second branch pipe 122 is 30 mm;

[0085] The height ratio between the quenching liquid surface and the hollow box 11 is 0.9:1;

[0086] A temperature measuring device 3 is placed inside the first branch pipe 121; the temperature measuring device 3 is placed in the first branch pipe 121 at a depth of 75 mm; the top of the temperature measuring device 3 is higher than the quenching liquid surface; the temperature measuring device 3 is a probe;

[0087] A fixing device 4 is connected above the cooling rate test device 1; the fixing device 4 is used to fix the temperature measuring device 3;

[0088] The temperature measuring device 3 is connected to the cooling rate test collection device 5;

[0089] A stirring device 2 is placed inside the second branch pipe 122; the stirring device 2 includes a stirring device body and a base, and the stirring device body is located on the top of the base; the stirring device body includes a motor, a stirring rod and a stirring head; a motor is arranged at the top of the stirring device body, a stirring rod is connected to the output end of the motor, and a stirring head is fixed at the bottom end of the stirring rod; the stirring rod is placed in the second branch pipe 122 at a depth of 35 mm; and the top end of the stirring rod is higher than the quenching liquid surface.

[0090] Example 2

[0091] This embodiment provides a cooling rate test device system for quenching liquid, which further defines the following on the basis of embodiment 1:

[0092] The cooling rate test device (such as Figure 4 The side wall of the cooling device is provided with three slots; the slots are used to fix the connecting rods; the fixing device is connected to the top of the cooling rate testing device through the three connecting rods;

[0093] The fixing device comprises a cylinder and a fixing and placing component arranged in the cylinder; the fixing and placing component is an inverted hollow truncated cone structure; a fixing sleeve is arranged at the bottom end of the fixing and placing component;

[0094] The stirring head is a petal-shaped structure.

[0095] Example 3

[0096] The present embodiment provides a cooling rate testing device system for quenching liquid, except that the height ratio of the first branch pipe to the hollow box is 0.72:1, the height difference between the first branch pipe and the second branch pipe is 35 mm, the ratio of the inner diameter of the first branch pipe to the length of the hollow box is 0.35:1, and the distance between the tube walls of the first branch pipe and the second branch pipe is 35 mm, other conditions are the same as those in Example 2.

[0097] Example 4

[0098] The present embodiment provides a cooling rate testing device system for quenching liquid, except that the height ratio of the first branch pipe to the hollow box is 0.82:1, the height difference between the first branch pipe and the second branch pipe is 45 mm, the ratio of the inner diameter of the first branch pipe to the length of the hollow box is 0.4:1, and the distance between the tube walls of the first branch pipe and the second branch pipe is 25 mm, other conditions are the same as those in Example 2.

[0099] Example 5

[0100] This embodiment provides a cooling rate test device system for quenching liquid. Except that the height ratio of the first branch pipe to the hollow box is 0.6:1, other conditions are the same as those of Embodiment 2.

[0101] Example 6

[0102] This embodiment provides a cooling rate test device system for quenching liquid. Except that the height ratio of the first branch pipe to the hollow box is 0.9:1, other conditions are the same as those of Embodiment 2.

[0103] Example 7

[0104] This embodiment provides a cooling rate test device system for quenching liquid, in which the height of the first branch pipe is kept unchanged and only the height of the second branch pipe is adjusted, so that the height difference between the first branch pipe and the second branch pipe is 20 mm, and other conditions are the same as those in Example 2.

[0105] Example 8

[0106] This embodiment provides a cooling rate test device system for quenching liquid, in which the height of the first branch pipe is kept unchanged and only the height of the second branch pipe is adjusted, so that the height difference between the first branch pipe and the second branch pipe is 55 mm, and other conditions are the same as those in Example 2.

[0107] Example 9

[0108] This embodiment provides a cooling rate test device system for quenching liquid. Except for keeping the inner diameters of the first branch pipe and the second branch pipe unchanged and adjusting the distance between the pipe walls of the first branch pipe and the second branch pipe to 15 mm, other conditions are the same as those in Embodiment 2.

[0109] Example 10

[0110] This embodiment provides a cooling rate test device system for quenching liquid. Except that the ratio of the inner diameter of the first branch pipe to the length of the hollow box is 0.35:1 and the distance between the tube walls of the first branch pipe and the second branch pipe is 40 mm, other conditions are the same as those in Example 2.

[0111] Embodiment 11

[0112] This embodiment provides a cooling rate test device system for quenching liquid. Except that the depth of the stirring rod placed in the second branch pipe is 20 mm, other conditions are the same as those in Embodiment 2.

[0113] Example 12

[0114] This embodiment provides a cooling rate test device system for quenching liquid. Except that the depth of the stirring rod placed in the second branch pipe is 45 mm, other conditions are the same as those in Example 2.

[0115] Comparative Example 1

[0116] This comparative example provides a cooling rate test device system for quenching liquid. Except that a concave-shaped trough with an open upper end is fixed in the hollow box, that is, the angles between adjacent sides are all 90°, other conditions are the same as those in Example 2.

[0117] Comparative Example 2

[0118] This comparative example provides a cooling rate test device system for quenching liquid. Except that a stirring device is placed inside the first branch pipe and a temperature measuring device is placed inside the second branch pipe, other conditions are the same as those of Example 2.

[0119] Comparative Example 3

[0120] This comparative example provides a cooling rate test device system for quenching liquid, in which the height of the first branch pipe is kept unchanged and only the height of the second branch pipe is adjusted so that the height difference between the first branch pipe and the second branch pipe is 0 mm. Other conditions are the same as those in Example 2.

[0121] The cooling rate test device system provided in the above embodiment and comparative example is applied to the cooling rate test method of quenching liquid A, comprising the following steps:

[0122] (1) The temperature measuring device 3 is first heated to a temperature of 855° C., and the quenching liquid A is second heated to a temperature of 40° C.;

[0123] (2) transferring the second heated quenching liquid A into the hollow box 11, placing the first heated temperature measuring device 3 into the first branch pipe 121 through the fixing device 4, and starting stirring at the same time to perform a quenching liquid cooling rate test;

[0124] The stirring speed is 1300 rpm; the temperature measuring device 3 is placed in the quenching liquid A for 60 seconds;

[0125] (3) Based on the data collected by the cooling rate test collection device 5, a cooling characteristic curve of the quenching liquid A is obtained, and then the cooling characteristic curve is analyzed and calculated to obtain the cooling rate;

[0126] The cooling rate is the time required for the quenching liquid A to cool from 855°C to 200°C.

[0127] When the cooling rate test device system provided in the above embodiment and comparative example is used for testing, the cooling rate results obtained are shown in Table 1.

[0128] Table 1

[0129]

[0130]

[0131] From Table 1, we can see that:

[0132] (1) The cooling rate test device system provided in Examples 1-4 of the present invention has a cooling rate that is consistent with the theoretical cooling rate range, indicating that the quenching test results of the present invention are accurate and reliable.

[0133] (2) By comparing Example 1 with Examples 5-6, it can be seen that when the height of the first branch pipe and the second branch pipe is too low, the flow speed of the quenching liquid around the probe is too fast, which shortens the heat exchange time between the quenching liquid and the probe, resulting in a low cooling rate obtained by the test; when the height of the first branch pipe and the second branch pipe is too high, the contact area between the probe and the quenching liquid increases, the flow resistance of the quenching liquid increases, and the temperature gradient decreases, resulting in a low cooling rate obtained by the test.

[0134] (3) By comparing Example 1 with Examples 7-8 and Comparative Example 3, it can be seen that when the height difference between the first branch and the second branch is too small, the flow rate of the quenching liquid in the U-tube will slow down, resulting in a decrease in the renewal rate of the quenching liquid around the probe, thereby slowing down the cooling rate of the probe, and ultimately resulting in a low cooling rate value. When there is no height difference between the first branch and the second branch of the U-tube, the quenching liquid in the U-tube hardly flows, and the quenching liquid around the probe cannot be effectively renewed, which will cause the cooling rate of the probe to be significantly low. When the height difference between the first branch and the second branch is too large, the convective heat transfer and local cooling effect will be enhanced, thereby improving the heat exchange efficiency, resulting in a high cooling rate obtained in the test.

[0135] (4) Comprehensively comparing Example 1 with Examples 9-10, it can be seen that when the distance between the walls of the first branch and the second branch is too small, the flow space of the quenching liquid will be limited, so that the flow speed of the quenching liquid around the probe is reduced, and the heat exchange efficiency between the probe and the quenching liquid is increased. At the same time, too small a distance may also cause turbulence in the flow of the quenching liquid in the U-tube, further enhancing the heat transfer and increasing the cooling rate value; when the distance between the walls of the first branch and the second branch is too large, the flow space of the quenching liquid will be increased, so that the flow speed of the quenching liquid around the probe is accelerated, and the heat exchange time between the probe and the quenching liquid is reduced. At the same time, too large a distance may also cause excessive advection in the flow of the quenching liquid in the U-tube, weakening the heat transfer and causing the cooling rate value to be low.

[0136] (5) By comparing Example 1 with Examples 11-12, it can be seen that when the depth of the stirring rod placed in the U-tube is too shallow, the quenching liquid is not stirred sufficiently, resulting in uneven temperature distribution of the quenching liquid. In this case, after the probe is inserted into the quenching liquid, the temperature of the quenching liquid in the local area may be high, resulting in a slow cooling rate of the probe, which makes the measured cooling rate value low. At the same time, due to insufficient stirring, the fluidity of the quenching liquid is poor, and the heat transfer efficiency on the surface of the probe is reduced, which will also lead to a low cooling rate value; when the stirring rod is placed in the U-tube too deep, the quenching liquid will be stirred too violently, which may cause bubbles to form in the quenching liquid. The bubbles will adhere to the surface of the probe to form an insulating layer, which affects the heat transfer efficiency of the probe, causing the cooling rate value to fluctuate, resulting in unstable cooling rate values ​​obtained in the test.

[0137] (6) Comprehensive comparison of Example 1 and Comparative Example 1 shows that if the U-shaped tube is changed to a rectangular concave trough, the concave trough structure is relatively more open, resulting in a more dispersed flow path of the quenching liquid in the trough, resulting in a reduction in the contact area between the quenching liquid and the probe, and a reduction in the contact tightness, thereby affecting the heat conduction efficiency. In addition, the structure of the concave trough may cause the quenching liquid to form eddies or other irregular flows in the trough, resulting in a lower cooling rate obtained by the test; Comprehensive comparison of Example 1 and Comparative Example 2 shows that if the positions of the temperature measuring device and the stirring device are swapped, a vortex is easily formed, resulting in a lower cooling rate obtained by the test.

[0138] The cooling rate test device system provided in Example 1 is used to perform repeated tests on quenching liquid A and quenching liquid B for several times. The cooling rate test method for quenching liquid A is performed according to the above method; when the cooling rate test for quenching liquid B is performed, the following steps are included:

[0139] (1) The temperature measuring device 3 is first heated to a temperature of 555° C., and the quenching liquid B is second heated to a temperature of 55° C.;

[0140] (2) transferring the second heated quenching liquid B into the hollow box 11, and placing the first heated temperature measuring device 3 in the first branch pipe 121 through the fixing device 4, while starting stirring, to perform a quenching liquid cooling rate test;

[0141] The stirring speed is 800 rpm; the temperature measuring device 3 is placed in the quenching liquid B for 60 seconds;

[0142] (3) Based on the data collected by the cooling rate test collection device 5, a cooling characteristic curve of the quenching liquid B is obtained, and then the cooling characteristic curve is analyzed and calculated to obtain the cooling rate;

[0143] The cooling rate is the time required for the quenching liquid B to cool from 555°C to 150°C.

[0144] The several cooling characteristic curves of quenching liquid A and quenching liquid B measured by the above test method are as follows: Figure 5-6 As shown; the cooling rate results of the obtained quenching liquid A and quenching liquid B are shown in Table 2-3 respectively.

[0145] Table 2

[0146]

[0147]

[0148] Table 3

[0149]

[0150] It can be seen from Tables 2 and 3 that the cooling rate tests were repeated on quenching liquid A and quenching liquid B. Regardless of whether the quenching liquid was stable or unstable, no steam film was generated during the test, and the cooling rate obtained from the test was also within the allowable deviation range, indicating that the cooling rate testing device system and testing method provided by the present invention have stable and repeatable data obtained from the test and have a wide range of applications.

[0151] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A cooling rate test device system for quenching liquid, characterized in that: The cooling rate test device system comprises a cooling rate test device, a stirring device, a temperature measuring device, a fixing device and a cooling rate test collection device; The cooling rate test device is a hollow box with an open top; a U-shaped tube with an open top is fixed in the hollow box; The two ends of the U-shaped tube have different heights, wherein the end with a higher height is the first branch tube, and the end with a lower height is the second branch tube; A temperature measuring device is placed inside the first branch pipe; A stirring device is placed inside the second branch pipe; A fixing device is connected above the cooling rate testing device; the fixing device is used to fix the temperature measuring device; The temperature measuring device is connected to the cooling rate test collection device.

2. The cooling rate test device system according to claim 1, characterized in that: The U-shaped tube is fixed to the opposite side walls of the hollow box through steel plates; Preferably, the U-shaped tube is not in contact with any of the four side walls of the hollow box.

3. The cooling rate test device system according to claim 1 or 2, characterized in that: The height of the hollow box is 180-220 mm; Preferably, the length of the hollow box is 120-160 mm.

4. The cooling rate test device system according to any one of claims 1 to 3, characterized in that: The height ratio of the first branch pipe to the hollow box is (0.72-0.82):1; Preferably, the height difference between the first branch pipe and the second branch pipe is 35-45 mm.

5. The cooling rate test device system according to any one of claims 1 to 4, characterized in that: The inner diameters of the first branch pipe and the second branch pipe are the same; Preferably, the ratio of the inner diameter of the first branch pipe to the length of the hollow box is (0.35-0.4):1; Preferably, the distance between the tube walls of the first branch tube and the second branch tube is 25-35 mm.

6. The cooling rate test device system according to any one of claims 1 to 5, characterized in that: The height ratio of the quenching liquid surface to the hollow box is (0.85-0.92):1; Preferably, the temperature measuring device is placed in the first branch pipe at a depth of 70-80 mm; Preferably, the top of the temperature measuring device is higher than the quenching liquid surface; Preferably, the temperature measuring device comprises a probe.

7. The cooling rate test device system according to any one of claims 1 to 6, characterized in that: The side wall of the cooling rate testing device is provided with a plurality of slots; Preferably, the slot is used to fix the connecting rod; Preferably, the fixing device is connected to the upper part of the cooling rate testing device through a plurality of connecting rods; Preferably, the fixing device comprises a cylinder and a fixing and placing component arranged in the cylinder; Preferably, the fixed placement component is an inverted hollow truncated cone structure; Preferably, a fixing sleeve is provided at the bottom end of the fixing and placing component.

8. The cooling rate test device system according to any one of claims 1 to 7, characterized in that: The stirring device comprises a stirring device body and a base, wherein the stirring device body is located on the top of the base; Preferably, the stirring device body comprises a motor, a stirring rod and a stirring head; Preferably, a motor is provided at the top of the stirring device body, a stirring rod is connected to the output end of the motor, and a stirring head is fixed at the bottom end of the stirring rod; Preferably, the stirring head is a petal-shaped structure; Preferably, the stirring rod is placed in the second branch pipe at a depth of 30-40 mm; Preferably, the top end of the stirring rod is higher than the quenching liquid level.

9. A cooling rate test method for a quenching liquid, characterized in that: The cooling rate test method is performed using the cooling rate test device system according to any one of claims 1 to 8, comprising the following steps: (1) performing a first heating on the temperature measuring device and a second heating on the quenching liquid; (2) transferring the second heated quenching liquid into the hollow box, placing the first heated temperature measuring device in the first branch pipe through a fixing device, and starting stirring at the same time to perform a quenching liquid cooling rate test; (3) Based on the data collected by the cooling rate test acquisition device, the cooling characteristic curve and cooling rate of the quenching liquid are obtained.

10. The cooling rate test method according to claim 9, characterized in that: The stirring speed in step (2) includes the following situations: (a) If the theoretical cooling rate of the quenching liquid is 0-65°C / s, excluding 0°C / s, the stirring speed is 550-650 rpm; or (b) if the theoretical cooling rate of the quenching liquid is 65-120°C / s, excluding 65°C / s, the stirring speed is 750-950 rpm; or (c) If the theoretical cooling rate of the quenching liquid is greater than 120°C / s, the stirring speed is greater than 1000 rpm.

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