Bidirectional chain type cooling bed

Abstract

The utility model provides a two-way chain type cooling bed. The cooling bed comprises a plurality of forward chains and a plurality of reverse chains, the running direction of the forward chains is the same as the advancing direction of the steel, and the running direction of the reverse chains is opposite to the advancing direction of the steel; a forward chain motor, wherein all the forward chains are connected with the forward chain motor; a reverse chain motor, wherein all the reverse chains are connected with the reverse chain motor; the steel splitting disc is positioned at an inlet of the cooling bed; the fans are arranged on the two sides of the cooling bed correspondingly. According to the cooling bed, steel is cooled on the cooling bed in a temperature monitoring control cooling mode, the overall-length temperature difference deviation of the steel is small, overall-length uniform cooling of the steel is achieved, material performance fluctuation is small, the structure is stable, and meanwhile the performance requirements for strength and toughness are met; and the cooling uniformity of the two ends of the steel is adjusted in real time through the temperature, and the structure uniformity and performance stability of the cooled steel are ensured.

Description

Technical Field

[0001] The utility model belongs to the field of special steel smelting and processing, and relates to a bidirectional chain cooling bed. Background Art

[0002] Engineering steel is widely used in industries such as petroleum, chemical industry, power stations, and boilers. At present, the products produced by the factory are mainly materials delivered in the normalized state, and the strength of some materials after normalizing cannot meet the national standard requirements. Therefore, the factory generally adopts convection heat exchange cooling for forced cooling, mainly through air cooling, wind cooling, and wind-mist cooling to reduce the temperature of the material from 900℃ to ≤150℃. The key equipment for carrying materials is currently the cooling bed commonly used in factories. The cooling bed includes a work surface, a mechanical transmission system, a water cooling system, a cooling bed work surface, a fixed bracket, etc. Both the cooling bed air cooling and wind-mist cooling use continuous operation cooling methods, resulting in differences in the strength of the two ends of the material, mainly manifested in the lower strength of the end away from the wind source and the large impact dispersion, which is difficult to meet the national standard requirements for engineering steel.

[0003] In addition, usually, steel is cooled rapidly after normalizing to improve material strength, and air cooling, wind cooling, and wind-mist cooling are used to cool the material from the austenitizing temperature to room temperature. Without external forced cooling, the temperature drop of the material caused by natural heat dissipation in the air is only 1% of the thermal radiation, which can be ignored. Therefore, the cooling speed of the material after normalizing is mainly increased by convection heat dissipation. Since the cooling bed uses a continuous operation method to cool the steel, the cooling process is unstable, which can easily cause uneven cooling, resulting in material bending and uneven performance.

[0004] Therefore, how to solve the problem of uniformity of heat treatment cooling is currently a technical problem in this field. Utility Model Content

[0005] The utility model aims to provide a bidirectional chain cooling bed, which uses a real-time temperature monitoring system to adjust the cooling uniformity of both ends of the steel material, thereby ensuring the uniformity of the steel material structure and the stability of the performance after cooling.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A two-way chain cooling bed is used for controlled cooling of steel after heat treatment, the cooling bed comprises: a plurality of forward chains and a plurality of reverse chains, the forward chains running in the same direction as the steel, and the reverse chains running in the opposite direction to the steel; a forward chain motor, the forward chain motor is located at the entrance of the cooling bed, and all the forward chains are connected to the forward chain motor; a reverse chain motor, the reverse chain motor is located at the exit of the cooling bed, and all the reverse chains are connected to the reverse chain motor; a steel dividing plate, the steel dividing plate is located at the entrance of the cooling bed, and the steel dividing plate pulls the steel onto the cooling bed; and fans, a plurality of the fans are respectively arranged on both sides of the cooling bed.

[0008] Furthermore, in the above-mentioned bidirectional chain cooling bed, the forward chains and the reverse chains are alternately arranged at intervals; there are 6 to 9 forward chains, and all the forward chains are connected to the same forward chain drive motor through a long shaft; the number of the reverse chains is consistent with the number of the forward chains, and all the reverse chains are connected to the same reverse chain drive motor through a long shaft; the distance between the forward chain and the axis of the cooling bed is smaller than the distance between the reverse chain and the axis of the cooling bed.

[0009] Furthermore, in the above-mentioned bidirectional chain cooling bed, a loading platform is provided at the entrance of the cooling bed, and a unloading platform is provided at the exit of the cooling bed; the steel material is a pipe or a bar, the outer diameter of the pipe is 100mm-600mm, the wall thickness is 10mm-130mm, and the diameter of the bar is 60mm-350mm; the cooling rate of the fan is 5℃ / min-10℃ / min; the total cooling time t2 of the steel on the cooling bed is 3700s-4400s.

[0010] Furthermore, in the above-mentioned bidirectional chain cooling bed, a thermometer is arranged above the exit of the cooling bed, and the thermometer is connected to a control system. The thermometer performs full-length temperature detection on the steel every 5s to 300s, and the control system records the temperature of the steel measured by the thermometer; the forward chain motor and the reverse chain motor are both connected to the control system, and the control system can adjust the cooling speed of the steel according to the temperature difference at both ends of the steel.

[0011] Furthermore, in the above-mentioned bidirectional chain cooling bed, the fan includes a first fan, and a plurality of the first fans are arranged on one side of the cooling bed, and the first fan blows air toward one end of the steel; a total of 8 first fans are arranged, and the first fans are arranged from the entrance of the cooling bed to the middle of the cooling bed; a first water pipe is arranged on the first fan, and the first water pipe can spray cooling water toward one end of the steel.

[0012] Furthermore, in the above-mentioned bidirectional chain cooling bed, the fan includes a second fan, and a plurality of the second fans are arranged on the other side of the cooling bed, and the second fans blow air toward the other end of the steel; a total of 8 second fans are arranged, and the second fans are arranged from the middle of the cooling bed to the outlet of the cooling bed; a second water pipe is arranged on the second fan, and the second water pipe can spray cooling water toward the other end of the steel.

[0013] Furthermore, in the above-mentioned two-way chain cooling bed, the spacing between two adjacent forward chains and reverse chains is 18cm to 25cm; a plurality of columns are arranged on the forward chain, and the plurality of columns are evenly arranged along the circumference of the forward chain, and the steel is located between two adjacent columns.

[0014] Furthermore, in the above-mentioned bidirectional chain cooling bed, the running speed of the forward chain is controlled at a minimum frequency of 1 Hz; the reverse chain controls the rotation speed of the steel, the steel is placed on the reverse chain, and the operation of the reverse chain drives the steel to rotate, and the rotation of the steel makes the steel evenly contact the air convection and evenly cool down; when the outer diameter of the steel is ≤350mm, the running speed v of the reverse chain is 1mm / s~3mm / s; when the outer diameter of the steel is >350mm, the running speed v of the reverse chain is 3mm / s~5mm / s; after cooling by the cooling bed, the surface temperature of the steel is ≤150℃ and the temperature difference over the entire length is ≤50℃.

[0015] Furthermore, in the above-mentioned bidirectional chain cooling bed, when the temperature difference between the two ends of the steel is ≥15°C, the fan at the low-temperature end of the steel is turned off, and when the temperature difference between the two ends of the steel is <10°C, the fan at the low-temperature end of the steel is turned on.

[0016] Furthermore, in the above-mentioned bidirectional chain cooling bed, the reverse chain runs continuously, and when the temperature difference between the two ends of the steel is ≥15°C, the forward chain is stopped; when the temperature difference between the two ends of the steel is <15°C, the forward chain is started.

[0017] It can be seen from the analysis that the utility model discloses a bidirectional chain cooling bed. The cooling bed controls the cooling mode by temperature monitoring, and cools the steel (pipe or bar) on the cooling bed. The temperature difference deviation of the whole length of the steel is small, and the uniform cooling of the whole length of the steel is achieved. The material performance fluctuation is small, the organization is stable, and the performance requirements of strength and toughness are met at the same time. The utility model uses real-time temperature monitoring to adjust the cooling uniformity of both ends of the steel, ensuring the uniformity of the steel organization and the stability of the performance after cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an embodiment of the utility model.

[0019] Figure 2 The figure is a schematic top view of the structure of an embodiment of the utility model.

[0020] Figure 3 This is a cooling rate curve diagram of the two ends of the seamless steel pipe in Example 1 of the utility model.

[0021] Figure 4 It is a cooling rate curve diagram of the two ends of the seamless steel pipe in comparative example 1 of the present invention.

[0022] Figure 5 This is a comparison chart of the mechanical properties of the seamless steel pipe of the utility model that was cooled by Example 1 and Comparative Example 1 respectively.

[0023] Figure 6 This is a comparison chart of the mechanical properties of the seamless steel pipe of the utility model that was cooled by Example 2 and Comparative Example 2 respectively.

[0024] Figure 7 This is a comparison chart of the impact performance of the seamless steel pipe of the utility model that was cooled by Example 1 and Comparative Example 1 respectively.

[0025] Figure 8 This is a comparison chart of the impact performance of the seamless steel pipe of the utility model that was cooled by Example 2 and Comparative Example 2 respectively.

[0026] Fig. 9 This is a tissue diagram of one end of the seamless steel pipe close to the fan when the cooling bed of Example 1 of the utility model is in operation.

[0027] Fig.10 This is a tissue diagram of the end of the seamless steel pipe away from the fan when the cooling bed of Example 1 of the utility model is in operation.

[0028] Fig.11 This is a tissue diagram of one end of the seamless steel pipe close to the fan when the cooling bed of Comparative Example 1 of the present invention is in operation.

[0029] Fig.12 This is a tissue diagram of the end of the seamless steel pipe away from the fan when the cooling bed of Comparative Example 1 of the utility model is in operation.

[0030] Explanation of the reference numerals: 1 forward chain; 2 reverse chain; 3 temperature measuring instrument; 4 steel material; 5 first fan; 6 second fan; 7 column; 8 divided steel plate; 9 long axis; 10 forward chain motor; 11 reverse chain motor; 12 loading platform; 13 unloading platform. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. Each example is provided by way of explanation of the present invention and does not limit the present invention. In fact, it will be clear to those skilled in the art that modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature shown or described as a part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desired that the present invention includes such modifications and variations within the scope of the appended claims and their equivalents.

[0032] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. The terms "connected", "connected" and "set" used in the present invention should be understood in a broad sense. For example, they can be fixed connections or detachable connections; they can be directly connected or indirectly connected through intermediate components; they can be wired electrical connections, radio connections, or wireless communication signal connections. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0033] One or more examples of the utility model are shown in the attached drawings. The detailed description uses numbers and letters to refer to the features in the drawings. Similar or similar marks in the drawings and descriptions have been used to refer to similar or similar parts of the utility model. As used herein, the terms "first", "second", and "third" etc. are used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of individual components.

[0034] like Figures 1 to 12 As shown, according to an embodiment of the utility model, a two-way chain cooling bed is provided for controlling cooling of a steel material 4 after heat treatment, such as Figure 1 and Figure 2As shown, the cooling bed includes: a plurality of forward chains 1 and a plurality of reverse chains 2. The running direction of the forward chain 1 is the same as the traveling direction of the steel 4. The forward chain 1 drives the steel 4 to move on the cooling bed. The running direction of the reverse chain 2 is opposite to the traveling direction of the steel 4. The reverse chain 2 drives the steel 4 to rotate continuously on the cooling bed. A forward chain motor 10. The forward chain motor 10 is located at the entrance of the cooling bed. All forward chains 1 are connected to the forward chain motor 10. A reverse chain motor 11. The reverse chain motor 11 is located at the exit of the cooling bed. All reverse chains 2 are connected to the reverse chain motor 11. A steel dividing plate 8. The steel dividing plate 8 is located at the entrance of the cooling bed. The steel dividing plate 8 pulls the steel 4 onto the cooling bed. A fan. Several fans are respectively arranged on both sides of the cooling bed. The cooling bed can perform air cooling, wind cooling and water cooling on the steel 4. By using the cooling bed to cool the steel 4, the cooling speed at both ends of the steel 4 can be controlled, and uniform cooling of the entire length of the steel 4 can be achieved, thereby obtaining the steel 4 with uniform structure and performance. The steel 4 has small performance fluctuation and stable structure, and at the same time meets the performance requirements of strength and toughness, which effectively solves the technical problem of uniformity of heat treatment cooling.

[0035] Furthermore, the forward chains 1 and the reverse chains 2 are arranged alternately at intervals, and there are 6 to 9 forward chains 1, all of which are connected to the same forward chain 1 drive motor through the long shaft 9, the number of reverse chains 2 is the same as the number of forward chains 1, and all of which are connected to the same reverse chain 2 drive motor through the long shaft 9, and the distance between the forward chain 1 and the axis of the cooling bed is less than the distance between the reverse chain 2 and the axis of the cooling bed. One forward chain 1 and one reverse chain 2 form a group of chains, and 6 to 9 groups of chains are evenly arranged on the cooling bed. During the operation of the cooling bed, the forward chain 1 can be stopped and started, and the reverse chain 2 drives the steel 4 to rotate continuously. The continuous rotation of the steel 4 can prevent the steel 4 from being suspended for a long time and bending at both ends, and can also make the surface of the steel 4 evenly contact the air for convection cooling, so that the steel 4 is cooled evenly, and then the steel 4 can be evenly cooled.

[0036] Further, a loading stand 12 is provided at the entrance of the cooling bed, and a unloading stand 13 is provided at the exit of the cooling bed. The steel material 4 is a pipe or a bar, the outer diameter of the pipe is 100mm-600mm, the wall thickness is 10mm-130mm, the diameter of the bar is 60mm-350mm, the cooling rate of the fan is 5℃ / min-10℃ / min, and the total cooling time t2 of the steel material 4 on the cooling bed is 3700s-4400s. The total cooling time of the steel material 4 on the cooling bed is mainly determined by the outer diameter and wall thickness of the steel material 4. The larger the outer diameter, the larger the heat exchange area, the faster the cooling speed, and the thicker the wall thickness, the more heat is accumulated inside, the greater the cooling intensity is required, and the longer the total cooling time is.

[0037] Furthermore, a thermometer 3 is provided above the exit of the cooling bed, and the thermometer 3 is connected to the control system. The thermometer 3 detects the temperature of the steel 4 over the entire length every 5s to 300s. The more frequently the thermometer 3 is refreshed, the more accurate the detection is. In one embodiment of the utility model, the thermometer 3 detects the temperature of the steel 4 over the entire length every 60s. The thermometer 3 detects 5 points in the length direction of each steel pipe, and finally controls the difference between the two ends as the control factor. The monitoring system adjusts the operation and stop of the forward chain 1 according to the difference between the two ends of the temperature steel 4. The control system records the temperature of the steel 4 measured by the thermometer 3 and calculates the cooling rate curves at the two ends of the steel 4. The forward chain motor 10 and the reverse chain motor 11 are both connected to the control system. The control system can adjust the cooling rate of the steel 4 according to the temperature difference at the two ends of the steel 4. The calculation formula of the cooling rate is:

[0038]

[0039] In Formula 1, Nu f is the cooling rate; Re f is the Reynolds number (Re f The Reynolds number in the empirical formula for heat exchange is a transitional flow around the pipe, a flow state between laminar flow and turbulent flow), 10 4 ≤Re f ≤1.2×10 5 ; Pr f is the air exchange capacity, 0.6≤Pr f ≤120.

[0040] Further, the fan includes a first fan 5, such as Figure 2As shown, a plurality of first fans 5 are provided on one side of the cooling bed, and the first fans 5 blow air to one end of the steel 4. There are 8 first fans 5 in total, and the first fans 5 are arranged from the entrance of the cooling bed to the middle of the cooling bed. The first fans 5 are provided with a first water pipe, and the first water pipe can spray cooling water to one end of the steel 4. The fan includes a second fan 6. A plurality of second fans 6 are provided on the other side of the cooling bed, and the second fans 6 blow air to the other end of the steel 4. There are 8 second fans 6 in total, and the second fans 6 are arranged from the middle of the cooling bed to the outlet of the cooling bed. The second fans 6 are provided with a second water pipe, and the second water pipe can spray cooling water to the other end of the steel 4. The first fan 5 and the second fan 6 can perform air cooling on the steel 4, and the first water pipe and the second water pipe spray cooling water on the steel 4, and can perform water cooling on the steel 4. Different cooling methods are formulated according to different steel grades and requirements. One process is used for steel 4 of one composition and is set in advance. The steel 4 enters the cooling bed and is immediately cooled according to the requirements. When the steel 4 needs wind and mist cooling, the first water pipe and the second water pipe are opened when the steel 4 enters the cooling bed. The first fan 5 and the second fan 6 are staggered on both sides of the cooling bed, which can improve the heat exchange efficiency between the steel 4 and the air.

[0041] Furthermore, the distance between two adjacent forward chains 1 and reverse chains 2 is 18 cm to 25 cm, such as Figure 1 As shown, a plurality of columns 7 are arranged on the forward chain 1, and the plurality of columns 7 are evenly arranged along the circumference of the forward chain 1, and the steel material 4 is located between two adjacent columns 7. A plurality of columns 7 are arranged on the forward chain 1, and the plurality of columns 7 are evenly arranged along the circumference of the forward chain 1, and the steel material 4 is located between two adjacent columns 7.

[0042] Further, the running speed of the forward chain 1 is controlled at a minimum frequency of 1 Hz (about 100 mm / s), and the reverse chain 2 controls the speed of rotation of the steel 4. The steel 4 is placed on the reverse chain 2, and the reverse chain 2 drives the steel 4 to rotate. The rotation of the steel 4 makes the steel 4 evenly contact the air convection and cools down evenly. When the outer diameter of the steel 4 is ≤350 mm, the running speed v of the reverse chain 2 is 1 mm / s to 3 mm / s. When the outer diameter of the steel 4 is greater than 350 mm, the running speed v of the reverse chain 2 is 3 mm / s to 5 mm / s. After cooling on the cooling bed, the surface temperature of the steel 4 is ≤150°C and the temperature difference of the entire length is ≤50°C. When the temperature difference between the two ends of the steel 4 is ≥15°C, the fan at the low temperature end of the steel 4 is turned off. When the temperature difference between the two ends of the steel 4 is less than 10°C, the fan at the low temperature end of the steel 4 is turned on. The reverse chain 2 runs continuously, and the forward chain 1 adopts the intercept waiting mode operation. When the temperature difference between the two ends of the steel 4 is ≥15℃, the forward chain 1 is stopped. When the temperature difference between the two ends of the steel 4 is <15℃, the forward chain 1 is started. The time from stopping to starting of the forward chain 1 is the intercept waiting time t1, and the intercept waiting time t1 is 30s to 110s.

[0043] Since the first fan 5 and the second fan 6 are arranged on both sides of the cooling bed, and the first fan 5 and the second fan 6 are arranged staggered, the air heat exchange area of ​​steel 4 of different specifications is different, resulting in inconsistent cooling speeds at both ends of the steel 4, and then resulting in a temperature difference at both ends of the steel 4 during the cooling process. After the steel 4 is on the cooling bed, the temperature data is received by the thermometer 3, and the control system controls the stop and start time of the forward chain 1 according to the temperature difference at both ends of the steel 4 measured by the thermometer 3, and then controls the intercept waiting time t1 of the cooling bed and the operation of the fan, and controls the running speed v of the reverse chain 2 according to the specifications of the steel 4, and then controls the rotation speed of the steel 4. The intercept waiting time t1 of the cooling bed and the running speed v of the reverse chain 2 jointly determine the cooling uniformity of the entire length of the steel 4. The thicker the steel 4, the longer the waiting time, that is, the cooling speed of the steel 4 is in direct proportion to the material thickness, and the rotation speed v of the steel 4 is adjusted by adjusting the running speed of the reverse chain 2, and then the cooling speed of the steel 4 is fine-tuned to ensure uniform cooling. The steel 4 is cooled uniformly by adjusting the cooling rate of the steel 4, so as to prevent the performance of the steel 4 from being affected by the uneven cooling of the two ends of the steel 4. The cooling bed can uniformly control the cooling rate of the entire length of the steel 4 during the operation on the cooling bed, and achieve efficient, accurate and uniform control of the cooling rate of the entire length of the steel 4, ensuring that the cooling rates of the two ends are close to uniform, and obtaining a steel 4 with uniform structure and performance.

[0044] Example 1

[0045] A seamless steel pipe with a low carbon steel 16Mn component and a specification of 298.5×36mm (outer diameter×wall thickness) was used as the test material. The main components of the seamless steel pipe are shown in Table 1. After being completely austenitized at 900-940℃, the cooling bed was used to perform forced cooling using intercept waiting air cooling to complete the entire normalizing cooling process. The cooling parameters are shown in Table 2. The cooling rate curve at both ends of the seamless steel pipe is shown in Figure 3 shown.

[0046] Example 2

[0047] The difference between this embodiment and embodiment 1 is that a seamless steel pipe with a low carbon steel composition of 16Mn and a specification of 298.5×60mm (outer diameter×wall thickness) is used as the test material, and the cooling bed is used to perform forced cooling by intercept waiting wind mist cooling. The main components of the seamless steel pipe are shown in Table 1, and the cooling parameters in the test are shown in Table 2.

[0048] Comparative Example 1

[0049] The difference between this comparative example and Example 1 is that the cooling bed uses continuous air cooling (forward chain 1 runs continuously) to force cool the seamless steel pipe. The cooling parameters are shown in Table 2. The cooling rate curve at both ends of the seamless steel pipe is shown in Figure 4 shown.

[0050] Comparative Example 2

[0051] The difference between this comparative example and Example 2 is that the seamless steel pipe is forced to cool by continuous air cooling (forward chain 1 runs continuously) using a cooling bed, and its cooling parameters are shown in Table 2.

[0052] Table 1. Main chemical composition of experimental steel grades (%)

[0053]

[0054] Table 2. Main cooling parameters of experimental steel grades

[0055]

[0056] Notes: 1. Intercept waiting time t1 is the waiting time that the seamless steel pipe stays on the cooling bed; v is the running speed of the reverse chain 2; t2 is the total cooling time of the steel 4 on the cooling bed; T is the temperature difference at both ends of the seamless steel pipe after leaving the cooling bed.

[0057] Analysis of the test results of Example 1, Example 2, Comparative Example 1 and Comparative Example 2:

[0058] 1. Mechanical properties analysis

[0059] After testing different cooling methods (intercept waiting air cooling and continuous air cooling) of two specifications of 16Mn steel pipes, the distribution of yield strength and impact toughness results is shown in Figures 5 to 8 .from Figure 5 , Figure 6 It can be seen that both ends of the steel controlled by the intercept waiting air cooling process can meet the performance requirements of yield strength>335MPa and -20℃ V-type impact energy>130J, and the strength difference between the two ends of steel 4 is only 15MPa, and the impact value difference between the two ends of steel 4 is only 50J. Figure 7 , Figure 8 It can be seen that when continuous air cooling is used, there is a significant difference in the strength of the two ends of steel 4. The wind strength at the end far away from the wind source is obviously insufficient, the dispersion of impact energy is large, and the control of performance uniformity is very difficult. In contrast, the performance of steel 4 cooled by the intercept waiting air cooling process is significantly better than that of steel 4 cooled by the continuous air cooling process. This is because the intercept waiting cooling speed is more uniform than the continuous cooling speed. The cooling speed of the entire length of the material can be controlled by controlling the operation, pause, and re-operation of the cooling bed, thereby improving the uniformity of strength and toughness indicators.

[0060] 2. Brinell hardness analysis and discussion

[0061] In order to further verify the uniformity of performance, full-length and full-wall hardness analysis was performed on two specifications (steel pipes controlled by different cooling methods were subjected to four-quadrant Brinell hardness tests on the head, middle and tail of the pipe, as shown in Table 3). From the cross-sectional hardness values, it can be seen that the hardness value and range value of the intercept-wait cooling control method are comparable, while the hardness value range of the continuous cooling control method is very large. This is because the intercept-wait cooling can achieve uniform control of the cooling rate of the entire length of the steel pipe, thereby obtaining uniform microstructure and mechanical properties.

[0062] Table 3 Hardness comparison of 16MnC in different cooling methods

[0063]

[0064] 3. Microstructure analysis and discussion

[0065] Fig. 9 This is the organizational diagram of the end of the seamless steel pipe in Example 1 close to the fan. Fig.10 This is the structural diagram of the end of the seamless steel pipe of Example 1 away from the fan. Fig.11 This is the organizational diagram of the seamless steel pipe of Comparative Example 1 at one end close to the fan. Fig.12 This is the organization diagram of the end of the seamless steel pipe of Comparative Example 1 away from the fan. Figures 9 to 12 It can be seen that when continuous cooling is used, the end close to the wind source cools faster, there is a mixed crystal phenomenon, and the grain size grade is 7-3. The end far away from the wind source has better structure without coarse structure, and the grain size grade is 6. When intercept waiting cooling is used, the structure at both ends is uniform, with no obvious difference, and the grain size at both ends is 6.

[0066] From the above description, it can be seen that the above embodiments of the utility model achieve the following technical effects:

[0067] (1) The cooling method is controlled by temperature monitoring, and the steel 4 (tube or bar) is cooled on a cooling bed. The temperature difference deviation of the entire length of the steel 4 is small, and uniform cooling of the entire length of the steel 4 is achieved. The material performance fluctuation is small, the organization is stable, and the performance requirements of strength and toughness are met at the same time;

[0068] (2) The utility model utilizes temperature to monitor in real time and adjust the cooling uniformity of both ends of the steel material 4, thereby ensuring the uniformity of the structure and the stability of the performance of the steel material 4 obtained after cooling.

[0069] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. For those skilled in the art, the utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A two-way chain cooling bed, used for controlled cooling of steel after heat treatment, characterized in that: The cooling bed comprises: A plurality of forward chains and a plurality of reverse chains, wherein the forward chains run in the same direction as the traveling direction of the steel, and the reverse chains run in the opposite direction to the traveling direction of the steel; A forward chain motor, the forward chain motor is located at the entrance of the cooling bed, and all the forward chains are connected to the forward chain motor; A reverse chain motor, the reverse chain motor is located at the outlet of the cooling bed, and all the reverse chains are connected to the reverse chain motor; A steel dividing plate, the steel dividing plate is located at the entrance of the cooling bed, and the steel dividing plate pulls the steel material onto the cooling bed; A plurality of fans are respectively arranged on both sides of the cooling bed.

2. The two-way chain cooling bed according to claim 1, characterized in that: The forward chains and the reverse chains are arranged alternately at intervals; There are 6 to 9 forward chains, and all the forward chains are connected to the same forward chain driving motor through a long shaft; The number of the reverse chains is consistent with the number of the forward chains, and all the reverse chains are connected to the same reverse chain driving motor through a long shaft; The distance between the forward chain and the axis of the cooling bed is smaller than the distance between the reverse chain and the axis of the cooling bed.

3. The two-way chain cooling bed according to claim 1, characterized in that: A loading platform is provided at the entrance of the cooling bed, and a unloading platform is provided at the exit of the cooling bed; The steel material is a tube or a bar, the outer diameter of the tube is 100mm-600mm, the wall thickness is 10mm-130mm, and the diameter of the bar is 60mm-350mm; The cooling rate of the fan is 5°C / min-10°C / min; The total cooling time t2 of the steel on the cooling bed is 3700s-4400s.

4. The two-way chain cooling bed according to claim 1, characterized in that: A temperature measuring instrument is provided above the outlet of the cooling bed, and the temperature measuring instrument is connected to a control system. The temperature measuring instrument detects the temperature of the steel material over the entire length every 5 seconds to 300 seconds, and the control system records the temperature of the steel material measured by the temperature measuring instrument. The forward chain motor and the reverse chain motor are both connected to a control system, and the control system can adjust the cooling speed of the steel according to the temperature difference between the two ends of the steel.

5. The two-way chain cooling bed according to claim 1, characterized in that: The fan includes a first fan, and a plurality of the first fans are arranged on one side of the cooling bed, and the first fans blow air toward one end of the steel; There are 8 first fans in total, and the first fans are arranged from the entrance of the cooling bed to the middle of the cooling bed; The first fan is provided with a first water pipe, and the first water pipe can spray cooling water toward one end of the steel material.

6. The two-way chain cooling bed according to claim 1, characterized in that: The fan includes a second fan, and a plurality of the second fans are arranged on the other side of the cooling bed, and the second fans blow air toward the other end of the steel; A total of eight second fans are provided, and the second fans are arranged from the middle of the cooling bed to the outlet of the cooling bed; The second fan is provided with a second water pipe, and the second water pipe can spray cooling water toward the other end of the steel material.

7. The two-way chain cooling bed according to claim 1, characterized in that: The distance between two adjacent forward chains and reverse chains is 18cm to 25cm; A plurality of columns are arranged on the forward chain, and the plurality of columns are evenly arranged along the circumference of the forward chain, and the steel material is located between two adjacent columns.

8. The two-way chain cooling bed according to claim 1, characterized in that: The running speed of the forward chain is controlled at a minimum frequency of 1 Hz; The reverse chain controls the rotation speed of the steel material. The steel material is placed on the reverse chain. The reverse chain drives the steel material to rotate. The rotation of the steel material makes the steel material evenly contact with the air for uniform convection cooling. When the outer diameter of the steel is ≤350 mm, the running speed v of the reverse chain is 1 mm / s to 3 mm / s; When the outer diameter of the steel material is greater than 350 mm, the running speed v of the reverse chain is 3 mm / s to 5 mm / s; After being cooled on the cooling bed, the surface temperature of the steel is ≤150°C and the temperature difference over the entire length is ≤50°C.

9. The two-way chain cooling bed according to claim 1, characterized in that: When the temperature difference between the two ends of the steel material is ≥15°C, the fan at the low-temperature end of the steel material is turned off. When the temperature difference between the two ends of the steel material is less than 10° C., the fan at the low-temperature end of the steel material is turned on.

10. The two-way chain cooling bed according to claim 1, characterized in that: The reverse chain continues to run, When the temperature difference between the two ends of the steel material is ≥15°C, the forward chain is stopped. When the temperature difference between the two ends of the steel material is less than 15° C., the forward chain starts to operate.

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