Automatic slow cooling device for H13 die steel module after quenching

Abstract

The utility model discloses an automatic slow cooling device for an H13 die steel module after quenching, which is a rectangular box body enclosed by four wall panels, a movable cover plate 3 matched with the box body is arranged at the top of the box body, refractory fiber layers 4 are laid on the inner side walls of the four wall panels and the cover plate 3, a refractory concrete layer 5 is laid on the ground in the box body, and the refractory concrete layer 5 is coated on the outer side wall of the box body. A fire-resistant concrete layer 5 is arranged on the cover plate 3, a support 6 is arranged on the fire-resistant concrete layer 5 and used for placing a module 7, a variable-frequency axial flow fan 8 is installed at the bottom of a side wall panel of the box body, a plurality of exhaust holes 9 are evenly formed in the cover plate 3, a plurality of thermometers 10 are further arranged on the inner side wall of the cover plate, and the variable-frequency axial flow fan 8 and the thermometers 10 are both electrically connected with a control system 11. The variable-frequency axial flow fan 8, the thermodetector 10 and the control system 11 form a closed-loop automatic temperature control system, the temperature in the box body can be observed, regulated and controlled in real time, and automatic slow cooling of the H13 die steel large-scale module after quenching can be achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of steel processing, and in particular relates to an automatic slow cooling device for H13 die steel modules after quenching. Background Art

[0002] In recent years, my country's automobile industry has developed rapidly, and the specifications of H13 mold steel modules have also expanded rapidly towards large-scale demand. Customers not only require H13 modules to have larger specifications, but also have higher and higher requirements for internal quality.

[0003] It is an effective way to improve the quality of H13 large die steel modules by adjusting and improving the internal structure of the primary products by quenching. However, due to the special quenching process of H13 large modules, the module specifications are huge, the weight of a single module exceeds 5 tons, the module thickness can reach 700mm, and the width reaches 1000mm. The quenching strength requirements are very high, and the quenching time is very short. Usually, the internal temperature is required to reach less than 300 degrees Celsius within 40 minutes. During the quenching process, the internal temperature of the module is extremely uneven, which will form huge internal stress. The temperature after quenching needs to be cooled to 150 degrees Celsius before entering the next heat treatment process. During this cooling process, the surface temperature, edge temperature and corner temperature of the H13 large module are very different from the temperature of the center of the module. The temperature difference between the center and the internal points is also extremely uneven, which is very easy to accumulate huge internal stress, causing the module to crack and cause huge economic losses. At present, domestic enterprises have no better technical measures to ensure the core quality of H13 die steel large modules after quenching, except reducing the quenching intensity and delaying the heat preservation after quenching for a long time, while reducing the core quality. Utility Model Content

[0004] The purpose of the utility model is to provide an automatic slow cooling device, which can realize the automatic slow cooling and temperature equalization function of the H13 die steel module after quenching. Under the premise of ensuring the quality of the core of the module, the H13 large module is prevented from cracking in the slow cooling stage after quenching. At the same time, the slow cooling process can be completed in a shorter time, thereby improving production quality and efficiency.

[0005] In order to achieve the above-mentioned purpose, the utility model provides an automatic slow cooling device for H13 mold steel modules after quenching, and the device comprises: a box body, which is a rectangular box structure surrounded by two front wall panels and two side wall panels; a cover plate, which is a movable rectangular cover plate and is adapted to the top of the box body; a refractory fiber layer, which is laid on the inner wall of the box body and the lower side of the cover plate; a refractory concrete layer, which is laid on the ground inside the box body; and a support, which is fixedly arranged on the refractory concrete layer and is used to place the mold steel module after quenching.

[0006] Furthermore, a variable frequency axial flow fan is installed at the bottom of the side panel of the box, and a plurality of exhaust holes are evenly arranged on the cover plate. The variable frequency axial flow fan can inject cold air into the slow cooling device from the bottom of the box.

[0007] Furthermore, a plurality of thermometers are arranged on the inner wall of the cover plate.

[0008] Furthermore, the above-mentioned slow cooling device also includes a control system, and the variable frequency axial flow fan and the thermometer are electrically connected to the control system. The variable frequency axial flow fan, the thermometer and the control system form a closed-loop automatic temperature control system, which can observe and regulate the temperature in the box in real time.

[0009] Furthermore, the four side panels and the cover plate of the box are all made of A3 steel.

[0010] Furthermore, the laying thickness of the above-mentioned refractory fiber layer is 50 mm.

[0011] Furthermore, the laying thickness of the above-mentioned refractory concrete layer is 200mm.

[0012] Furthermore, the above-mentioned support is a cast iron support.

[0013] The slow cooling device of the utility model has the following advantages:

[0014] The variable frequency axial flow fan 8, thermometer 10 and control system 11 of the slow cooling device form a closed-loop automatic temperature control system. The instrument operation panel of the automatic temperature control system is equipped with a human-machine dialogue interface. A suitable cooling speed can be set according to the temperature of the slow cooling device at a specific stage, the thickness of the module in the device, and the total weight of the module in the device, so as to observe and regulate the temperature in the box in real time, and realize automatic slow cooling of large H13 die steel modules after quenching.

[0015] This slow cooling device is a low-temperature automatic slow cooling device specially used for H3 die steel large modules above 5 tons after quenching. It is suitable for the automatic slow cooling process of 300 degrees Celsius to 150 degrees Celsius after quenching of H13 large modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a front view of the internal structure of the slow cooling device of the utility model.

[0017] Figure 2 This is a side view of the internal structure of the slow cooling device of the utility model.

[0018] Figure 3 This is a top view of the internal structure of the slow cooling device of the utility model. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1

[0021] This embodiment provides an automatic slow cooling device for H13 die steel module after quenching. Figures 1 to 3 The device is a rectangular box structure surrounded by two front wall panels 1 and two side wall panels 2. The side wall panels are fixedly connected by welding. A movable cover plate 3 adapted to the box is provided on the top of the box. The front wall panels 1, the side wall panels 2 and the inner side walls of the cover plate 3 are all coated with a refractory fiber layer 4, and the optimal coating thickness of the refractory fiber layer 4 is 50 mm. A refractory concrete layer 5 is coated on the ground inside the box, and the optimal coating thickness of the refractory concrete layer 5 is 200 mm. A support 6 is provided on the refractory concrete layer 5, and the support 6 is used to place the module 7.

[0022] Among them, the four side panels and the cover plate of the box are all A3 steel, and the support 6 is a cast iron support; a variable frequency axial flow fan 8 is installed at the bottom of the side wall panel of the box, a number of exhaust holes 9 are evenly opened on the cover plate 3, and a number of thermometers 10 are also arranged on the inner wall of the cover plate 3. The variable frequency axial flow fan 8 and the thermometer 10 are electrically connected to the control system 11. The variable frequency axial flow fan 8, the thermometer 10 and the control system 11 form a closed-loop automatic temperature control system, which can observe and regulate the temperature in the box in real time, and can realize automatic slow cooling of large modules of H13 mold steel after quenching.

[0023] The working principle of this slow cooling device is as follows:

[0024] After quenching, when the center surface temperature of the steel module reaches the range of 250°C to 200°C, the cover plate 3 of the slow cooling device is lifted to the specified location by an overhead crane, and the quenched H13 module 7 is lifted onto the support 6 in the slow cooling device. Then, the cover plate 3 is lifted to the top of the slow cooling device, aligned with the box formed by the front wall panel 1 and the side wall panel 2, and the box is closed.

[0025] Since the inner sides of the front wall panel 1, the side wall panel 2 and the cover panel 3 in the slow cooling device are all coated with a refractory fiber layer 4, these refractory fibers have certain thermal insulation properties in the enclosed space formed by the front wall panel 1, the side wall panel 2 and the cover panel 3, and also have a heat dissipation function different from that of a general slow cooling furnace, so that the quenched H13 module 7 can be slowly cooled in the quenching slow cooling device.

[0026] The quenching process of H13 module is carried out block by block, and the quenching operation of the next block can be carried out only after the quenching of the previous block is completed. When the quenching surface temperature of a module reaches the specified value of 200 degrees Celsius for the quenching of the H13 module, the cover plate 3 of the slow cooling device can be opened by the overhead crane, and then the quenched module is lifted into the predetermined position of the slow cooling device, and the cover plate 3 is covered. The quenched module enters the slow cooling and temperature uniformity state, automatically eliminating the internal stress generated during the quenching process, and does not require any additional energy. The quenching is carried out block by block, and the slow cooling device is loaded block by block. The temperature of the modules in the device will gradually rise as the number of modules increases, until it reaches 230 degrees Celsius to 300 degrees Celsius, making the slow cooling effect more obvious. Under this condition, the temperature inside each module will be fully homogenized, the temperature of each point inside the module will tend to be consistent, and the stress intensity will be greatly reduced. After a period of time, when the last module enters the slow cooling device, the automatic cooling program can be started to implement automatic cooling control on the module. The temperature control system 11 is equipped with an automatic temperature control program. The variable frequency axial flow fan 8 is started according to the program instructions to start working. The fan injects cold air into the device from the lower part of the slow cooling device, exchanges heat with the modules in the slow cooling device, and the hot air after heat exchange is discharged from the exhaust hole 9 of the cover plate 3; when the temperature in the slow cooling device is lower than the given temperature value issued by the temperature control system 11, the temperature control system will issue an instruction to shut down the variable frequency axial flow fan 8. Only when the temperature instruction of the temperature control system is lower than the temperature measured in the slow cooling device, the axial flow fan will be restarted until the module temperature reaches 150 degrees Celsius, the slow cooling is completed, and the next heat treatment process is entered.

[0027] Among them, the temperature in the device will undergo the following changes during the slow cooling process:

[0028] Since the surface temperature of the large module after quenching is about 200°C, which is much lower than the core temperature of the module of 300°C, when the module is initially placed in the slow cooling device, the surface temperature of the module will rise rapidly due to the diffusion of the higher core temperature to the surface, and the temperature in the slow cooling device will also rise synchronously due to the heat dissipation of the module. This is the temperature return stage after quenching of H13 module 7. The surface temperature of H13 module 7 does not enter the temperature balance and decline stage until the surface temperature of H13 module 7 rises to the maximum value.

[0029] In the slow cooling device, after the H13 module 7 has gone through the temperature return stage, the internal temperature and surface temperature of the module will show a downward trend. Since the heat storage of the H13 module 7 in the temperature return stage has raised the air temperature in the closed slow cooling device to a temperature close to the surface temperature of the steel module 7, the temperature difference between the surface temperature of the steel module 7 and the air temperature in the slow cooling device is relatively small. At the same time, since the quenching slow cooling device has a certain heat preservation performance, the surface temperature of the H13 module 7 drops slowly.

[0030] After the H13 module has been in the slow cooling device for a period of time, the stress intensity inside the module will be reduced to a predetermined level, and the temperature measured by the thermometer 10 installed on the cover plate 3 will also reach the designed predetermined value. In this case, the automatic temperature control system can be started to implement the automatic slow cooling process. The automatic slow cooling process is set according to the time when the module enters the slow cooling device, the thickness, width, weight and other parameters of the module. The temperature reduction control is usually implemented by reducing the temperature by a value per hour to ensure that the module temperature in the slow cooling device reaches the specified value within the specified time without causing the module to crack.

[0031] Example 2

[0032] The present embodiment provides an automatic slow cooling device, specifically a rectangular box structure surrounded by two 4-meter-long and 1.8-meter-high front wall panels 1 and two 3-meter-wide and 1.8-meter-high side wall panels 2. The box is covered with a rectangular cover plate 3 with a length of 4 meters and a width of 3 meters. A 50mm thick refractory fiber layer 4 is laid on the inner side walls around the box and the inner side of the cover plate 3 to prevent the steel module from cooling down too quickly. The box is fixed on the ground, and a 200mm thick refractory concrete layer 5 is laid on the ground inside the box to place the support 6 and the module 7 for load bearing.

[0033] This device can be used for slow cooling after quenching of H13 modules weighing 5 to 7 tons. The length of the steel module is 1.3 to 1.7 meters, the width is 1 meter, and the thickness is 0.5 to 0.7 meters. Each batch quenches 4 to 6 pieces with a total weight of about 25 tons.

[0034] The surface temperature of the H13 module 7 after quenching is related to the surface area of ​​the slow cooling device and the thickness of the refractory fiber layer 4. The design dimensions of the device are 4 meters (length) * 3 meters (width) * 1.8 meters (height). The refractory fiber layer 4 uses a 50mm ultra-thin insulation layer, so that the device has both a certain insulation effect and a certain heat dissipation effect. The extremely uneven temperature condition formed by quenching in various parts of the H13 module 7 after quenching creates a good condition for slow diffusion and continuous decline. Under this condition, the heat accumulated in the high-temperature area of ​​the core of the H13 module 7 after quenching will be slowly transferred to the surface and corners according to the corresponding temperature gradient until the temperature of each point of the H13 module 7 is basically the same. This process is a temperature equalization process. During the entire diffusion process of the internal temperature of the H13 module 7, the temperature difference inside the steel module 7 is gradually reduced, and the stress intensity inside the steel module 7 is gradually reduced as the temperature difference decreases, and the cracking risk of the steel module 7 is effectively controlled.

[0035] Although the content of the utility model has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the utility model. After reading the above content, various modifications and substitutions of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be limited by the attached claims.

Claims

1. An automatic slow cooling device for H13 die steel module after quenching, characterized in that: The device contains: The box body is a rectangular box body structure surrounded by two front wall panels (1) and two side wall panels (2); A cover plate (3), which is a movable rectangular cover plate and is adapted to fit the top of the box body; A refractory fiber layer (4) is laid on the inner wall of the box body and the lower side of the cover plate (3); A refractory concrete layer (5) is laid on the ground inside the box; and The support (6) is fixedly arranged on the refractory concrete layer (5) and is used for placing the quenched die steel module (7).

2. The slow cooling device according to claim 1, characterized in that: A variable frequency axial flow fan (8) is installed at the bottom of the side panel of the box body, and a plurality of exhaust holes (9) are evenly arranged on the cover plate (3). The variable frequency axial flow fan (8) can inject cold air into the slow cooling device from the bottom of the box body.

3. The slow cooling device according to claim 2, characterized in that: A plurality of thermometers (10) are also arranged on the inner side wall of the cover plate (3).

4. The slow cooling device according to claim 3, characterized in that: The slow cooling device also includes a control system (11), and the variable frequency axial flow fan (8) and the thermometer (10) are electrically connected to the control system (11). The variable frequency axial flow fan (8), the thermometer (10) and the control system (11) form a closed-loop automatic temperature control system, which can observe and regulate the temperature inside the box in real time.

5. The slow cooling device according to any one of claims 1 to 4, characterized in that: The four side panels and the cover plate (3) of the box body are all made of A3 steel.

6. The slow cooling device according to any one of claims 1 to 4, characterized in that: The laying thickness of the refractory fiber layer (4) is 50 mm.

7. The slow cooling device according to any one of claims 1 to 4, characterized in that: The laying thickness of the refractory concrete layer (5) is 200 mm.

8. The slow cooling device according to any one of claims 1 to 4, characterized in that: The support (6) is a cast iron support.

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