Test method for simulating generation of oxidized scale in hot-rolled steel plate coiling
Through segmented cooling, the temperature history during the coiling process of hot-rolled steel plates is solved, and the problem of inability to accurately reflect the temperature history of different areas of the steel coils is achieved, accurate phase change results and flexible customization are achieved, and the number of tests is reduced.
Patent Information
- Application Number
- CN202411693601.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-03-21
AI Technical Summary
The existing test methods that simulate the generation of iron oxide sheets for coiling hot rolled steel plates cannot accurately reflect the temperature history and phase change process of different areas of the steel coil during the coiling process, resulting in inaccurate phase change results.
The temperature history of the coiling process is simulated by segmented cooling, and the different positions of the coil are divided for segmented cooling, and the specific cooling speed, cooling time and cooling environment are set to be close to the real temperature history.
Through the segmented cooling method, accurate phase transition results can be obtained, supporting the flexible customization of iron oxide sheets, reducing the number of production line tests, and improving the operability and accuracy of the test.
Smart Images
Figure CN119666913A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a test method for simulating the generation of oxide scale when coiling a hot-rolled steel plate, and belongs to the technical field of hot-rolling production methods. Background Art
[0002] After hot rolling, the steel plate enters the coiling and cooling stage. Although the high-pressure water descaling basically removes the oxide scale during the rolling stage, the surface temperature of the steel plate is still very high at this time, and the oxide scale will be generated again during the coiling process. Different coiling processes have an important influence on the structure type of the oxide scale. According to the Fe-O phase diagram, the FeO phase in the oxide layer undergoes eutectoid decomposition at 570°C, and the product is Fe3O4+Fe structure or pre-eutectoid Fe3O4. Therefore, different coiling processes have an important influence on the structure of the oxide layer. Since the performance of oxide layers of different structural types varies greatly, the control of the structure type of the oxide scale plays a vital role in improving the surface quality.
[0003] In the literature search, two simulation methods are generally used for the phase change of the coiling process of iron oxide scale. The first method is the isothermal phase change test method, and the second method is the continuous cooling method. In the isothermal phase change method, the simulation test starts from the entrance of the finishing rolling, and after being kept warm for a certain period of time, it is cooled to the final rolling temperature at a certain cooling rate, and then quickly cooled to the coiling temperature. After being isothermal for different times, it is quickly cooled to room temperature to observe the morphology of the iron oxide scale. In the continuous cooling method, the initial samples are all prefabricated with the same iron oxide scale, and then heated to different set coiling temperatures, kept warm for a certain period of time, and then cooled at different cooling rates to observe the phase change process of the iron oxide scale. Both methods can carry out oxygen-rich and oxygen-poor tests. Based on the existing analysis methods, both the isothermal phase change method and the continuous cooling method are quite different from the actual cooling process of the steel coil. The cooling curves of different positions of the steel coil in the actual cooling process are very different. For example, the cooling of the outer ring of the steel coil is a process of cooling at a faster cooling rate first and then at a slower cooling rate, while the cooling rate of the edge area of the outer ring is the fastest, and the cooling rate of the middle area of the outer ring is slower; the cooling of the core of the steel coil is a process of first keeping warm and then cooling slowly. Similarly, the keeping warm time and cooling rate of the outer ring, middle and other areas are not the same; and the area between the outer ring and the core also has certain differences in cooling form and cooling rate; and the contact position of the steel coil with the coiling mandrel is a process of first cooling quickly, then heating up and then cooling slowly. The temperature change of the area in contact with the coiling mandrel is complex. In order to avoid affecting the use, the tail area can be cut off during use. Neither the isothermal transformation test nor the continuous cooling method can truly reflect the temperature history of the coiling process, so the phase change process cannot be accurate.
[0004] In order to accurately study the phase change of iron oxide scale in different areas of the same steel coil during the coiling process and obtain hot-rolled steel plates with relatively uniform structure and properties of iron oxide scale in the steel coil, a new simulation test method is urgently needed. Summary of the invention
[0005] The purpose of the present invention is to provide a test method for simulating the formation of oxide scale during coiling of hot-rolled steel plates. The temperature history of the coiling process is simulated by adopting a segmented cooling method, and different positions of the same steel coil are divided for segmented cooling. The method has strong operability and is easy to implement. It is close to the actual temperature and can obtain accurate phase change results. The flexible customization of the oxide scale can provide comprehensive data support, greatly reduce the number of tests on the production line, and effectively solve the above-mentioned problems existing in the background technology.
[0006] The technical solution of the present invention is: a test method for simulating the generation of oxide scale when hot-rolled steel plate is coiled, comprising the following steps: (1) Use segmented cooling to simulate the temperature change process of the coiling process; (2) Define the position of the steel coil and divide the steel coil into five positions; (3) Set the cooling rate, cooling time and cooling environment for segmented cooling at each coil position according to the coiling temperature.
[0007] In the step (1), the segmented cooling adopts three-stage cooling.
[0008] In the step (2), the position of the steel coil close to the core shaft within 10 mm of thickness is the inner ring of the steel coil, the area 10 mm inward from the outermost part of the steel coil is the outer ring of the steel coil, and the middle area between the outer ring of the steel coil and the inner ring of the steel coil is the middle of the coil. The five positions are position one, position two, position three, position four and position five, wherein position one is located at the edge of the outer ring, position two is located in the middle of the outer ring, position three is located in the non-core part of the middle of the coil, position four is located in the core part and near the core part of the middle of the coil, and position five is located at the edge of the inner ring.
[0009] In the step (3), a) For coiling temperature between 630~670℃: The first stage of position 1 has a cooling rate of 18~22℃ / min and a cooling time of 4~6min; the second stage has a cooling rate of 3~6℃ / min and a cooling time of 12~18min; the third stage has a cooling rate of 1~2℃ / min and a cooling time of 50~70min; the cooling environment is cooling in air; The first stage cooling rate of position 2 is 12~16℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 3~6℃ / min, and the cooling time is 19~22min; the third stage cooling rate is 1~2℃ / min, and the cooling time is 80~100min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~2℃ / min, and the cooling time is 130~170min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 160~200min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.8℃ / min, and the cooling time is 260~300min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 5 is 6~10℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 90~120min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 160~200min; the cooling environment is cooling in air; b) For coiling temperature between 580~629℃: The first stage cooling rate of position 1 is 16~18℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 3~6℃ / min, and the cooling time is 8~12min; the third stage cooling rate is 1~2℃ / min, and the cooling time is 30~50min; the cooling environment is cooling in air; The first stage of the second position has a cooling rate of 10~14℃ / min and a cooling time of 4~6min; the second stage has a cooling rate of 2~5℃ / min and a cooling time of 25~35min; the third stage has a cooling rate of 1~2℃ / min and a cooling time of 30~60min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~2℃ / min, and the cooling time is 90~110min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 160~200min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.8℃ / min, and the cooling time is 200~250min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 5 is 5~8℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 50~70min; the third stage cooling rate is 0.5~0.9℃ / min, and the cooling time is 160~200min; the cooling environment is cooling in air; c) For coiling temperature between 530~579℃: The first stage cooling rate of position 1 is 12~16℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 28~32min; the third stage cooling rate is 0.5~1℃ / min, and the cooling time is 55~75min; the cooling environment is cooling in air; The first stage cooling rate of position 2 is 8~12℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 40~50min; the third stage cooling rate is 0.5~1℃ / min, and the cooling time is 75~100min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~1℃ / min, and the cooling time is 50~60min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 260~300min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.7℃ / min, and the cooling time is 250~300min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 5 is 3~7℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 10~30min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 260~300min; the cooling environment is cooling in air; d) For coiling temperature between 480~529℃: The first stage cooling rate of position 1 is 9~12℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 10~20min; the third stage cooling rate is 1~2℃ / min, and the cooling time is 30~50min; the cooling environment is cooling in air; The first stage cooling rate of position 2 is 6~10℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 15~35min; the third stage cooling rate is 0.5~1℃ / min, and the cooling time is 45~65min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~1℃ / min, and the cooling time is 140~170min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 100~130min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.7℃ / min, and the cooling time is 180~210min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position five is 3~6℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 10~20min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 200~240min; the cooling environment is cooling in air.
[0010] The beneficial effects of the present invention are as follows: by adopting the segmented cooling method to simulate the temperature history of the coiling process, different positions of the same steel coil are divided for segmented cooling, which has strong operability and is easy to implement. It is close to the actual temperature and can obtain accurate phase change results. The flexible customization of iron oxide scale can provide comprehensive data support and greatly reduce the number of tests on the production line. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 is a schematic cross-sectional view of a steel coil of the present invention; Figure 2 It is a schematic diagram of different positions of the same steel coil of the present invention; In the figure: outer ring of steel coil Ⅰ, middle part of coil Ⅱ, inner ring of steel coil Ⅲ, core shaft Ⅳ, position one 1, position two 2, position three 3, position four 4, position five 5. DETAILED DESCRIPTION
[0012] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions in the implementation cases of the present invention will be clearly and completely described below in conjunction with the drawings in the implementation cases. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0013] A test method for simulating the formation of oxide scale during coiling of hot-rolled steel plates, comprising the following steps: (1) Use segmented cooling to simulate the temperature change process of the coiling process; (2) Define the position of the steel coil and divide the steel coil into five positions; (3) Set the cooling rate, cooling time and cooling environment for segmented cooling at each coil position according to the coiling temperature.
[0014] In the step (1), the segmented cooling adopts three-stage cooling.
[0015] In the step (2), the position of the steel coil close to the core shaft within 10 mm of thickness is the inner ring of the steel coil, the area 10 mm inward from the outermost part of the steel coil is the outer ring of the steel coil, and the middle area between the outer ring of the steel coil and the inner ring of the steel coil is the middle of the coil. The five positions are position one, position two, position three, position four and position five, wherein position one is located at the edge of the outer ring, position two is located in the middle of the outer ring, position three is located in the non-core part of the middle of the coil, position four is located in the core part and near the core part of the middle of the coil, and position five is located at the edge of the inner ring.
[0016] In the step (3), a) For coiling temperature between 630~670℃: The first stage of position 1 has a cooling rate of 18~22℃ / min and a cooling time of 4~6min; the second stage has a cooling rate of 3~6℃ / min and a cooling time of 12~18min; the third stage has a cooling rate of 1~2℃ / min and a cooling time of 50~70min; the cooling environment is cooling in air; The first stage cooling rate of position 2 is 12~16℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 3~6℃ / min, and the cooling time is 19~22min; the third stage cooling rate is 1~2℃ / min, and the cooling time is 80~100min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~2℃ / min, and the cooling time is 130~170min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 160~200min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.8℃ / min, and the cooling time is 260~300min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 5 is 6~10℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 90~120min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 160~200min; the cooling environment is cooling in air; b) For coiling temperature between 580~629℃: The first stage cooling rate of position 1 is 16~18℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 3~6℃ / min, and the cooling time is 8~12min; the third stage cooling rate is 1~2℃ / min, and the cooling time is 30~50min; the cooling environment is cooling in air; The first stage of the second position has a cooling rate of 10~14℃ / min and a cooling time of 4~6min; the second stage has a cooling rate of 2~5℃ / min and a cooling time of 25~35min; the third stage has a cooling rate of 1~2℃ / min and a cooling time of 30~60min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~2℃ / min, and the cooling time is 90~110min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 160~200min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.8℃ / min, and the cooling time is 200~250min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 5 is 5~8℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 50~70min; the third stage cooling rate is 0.5~0.9℃ / min, and the cooling time is 160~200min; the cooling environment is cooling in air; c) For coiling temperature between 530~579℃: The first stage cooling rate of position 1 is 12~16℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 28~32min; the third stage cooling rate is 0.5~1℃ / min, and the cooling time is 55~75min; the cooling environment is cooling in air; The first stage cooling rate of position 2 is 8~12℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 40~50min; the third stage cooling rate is 0.5~1℃ / min, and the cooling time is 75~100min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~1℃ / min, and the cooling time is 50~60min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 260~300min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.7℃ / min, and the cooling time is 250~300min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 5 is 3~7℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 10~30min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 260~300min; the cooling environment is cooling in air; d) For coiling temperature between 480~529℃: The first stage cooling rate of position 1 is 9~12℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 10~20min; the third stage cooling rate is 1~2℃ / min, and the cooling time is 30~50min; the cooling environment is cooling in air; The first stage cooling rate of position 2 is 6~10℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 15~35min; the third stage cooling rate is 0.5~1℃ / min, and the cooling time is 45~65min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~1℃ / min, and the cooling time is 140~170min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 100~130min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.7℃ / min, and the cooling time is 180~210min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position five is 3~6℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 10~20min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 200~240min; the cooling environment is cooling in air. Example 1
[0017] 1. A three-stage cooling method is used to simulate the temperature change process of the coiling process, and a certain cooling rate and cooling time are set for each cooling stage.
[0018] 2. Define the area within 10mm of the steel coil close to the mandrel IV as the inner circle III of the steel coil, the area 10mm inward from the outermost part of the steel coil as the outer circle I of the steel coil, and the area between the outer circle I of the steel coil and the inner circle III of the steel coil as the middle part II of the steel coil. Figure 1 Five processes are used to simulate the temperature changes at different positions of the same steel coil. Position 1 is located at the edge of the outer ring I, position 2 is located in the middle of the outer ring I, position 3 is located in the non-core part of the middle part II, position 4 is located in the core and near the core of the middle part II, and position 5 is located at the edge of the inner ring III.
[0019] 3. The coiling temperature is 650℃ and the following specific processes are performed: The first stage cooling rate of position one is 18°C / min, and the cooling time is 4min; the second stage cooling rate is 3°C / min, and the cooling time is 12min; the third stage cooling rate is 2°C / min, and the cooling time is 70min; the cooling environment is cooling in air.
[0020] The first stage cooling rate of position 2 is 16°C / min, and the cooling time is 4min; the second stage cooling rate is 6°C / min, and the cooling time is 22min; the third stage cooling rate is 1°C / min, and the cooling time is 80min; the cooling environment is cooling in air.
[0021] The first stage cooling rate of position three is 0℃ / min, and the cooling time is 5min; the second stage cooling rate is 1℃ / min, and the cooling time is 130min; the third stage cooling rate is 0.3℃ / min, and the cooling time is 160min; the cooling environment is an oxygen-deficient environment.
[0022] The first stage cooling rate of position four is 0℃ / min, and the cooling time is 40min; the second stage cooling rate is 0.8℃ / min, and the cooling time is 260min; the third stage cooling rate is 0.3℃ / min, and the cooling time is 120min; the cooling environment is an oxygen-deficient environment.
[0023] The first stage cooling rate of position five is 6°C / min, and the cooling time is 5min; the second stage cooling rate is 2°C / min, and the cooling time is 100min; the third stage cooling rate is 0.7°C / min, and the cooling time is 180min; the cooling environment is cooling in air. Example 2
[0024] 1. A three-stage cooling method is used to simulate the temperature change process of the coiling process, and a certain cooling rate and cooling time are set for each cooling stage.
[0025] 2. Define the area within 10mm of the steel coil close to the mandrel IV as the inner circle III of the steel coil, the area 10mm inward from the outermost part of the steel coil as the outer circle I of the steel coil, and the area between the outer circle I of the steel coil and the inner circle III of the steel coil as the middle part II of the steel coil. Figure 1 Five processes are used to simulate the temperature changes at different positions of the same steel coil. Position 1 is located at the edge of the outer ring I, position 2 is located in the middle of the outer ring I, position 3 is located in the non-core part of the middle part II, position 4 is located in the core and near the core of the middle part II, and position 5 is located at the edge of the inner ring III.
[0026] 3. The coiling temperature is 600℃ and the following specific processes are performed: The first stage cooling rate of position one is 18°C / min, and the cooling time is 6min; the second stage cooling rate is 6°C / min, and the cooling time is 12min; the third stage cooling rate is 2°C / min, and the cooling time is 40min; the cooling environment is cooling in air.
[0027] The first stage cooling rate of position 2 is 10°C / min, and the cooling time is 4min; the second stage cooling rate is 3°C / min, and the cooling time is 35min; the third stage cooling rate is 1°C / min, and the cooling time is 45min; the cooling environment is cooling in air.
[0028] The first stage cooling rate of position three is 0℃ / min, and the cooling time is 6min; the second stage cooling rate is 0.5℃ / min, and the cooling time is 90min; the third stage cooling rate is 0.3℃ / min, and the cooling time is 180min; the cooling environment is an oxygen-deficient environment.
[0029] The first stage cooling rate of position four is 0℃ / min, and the cooling time is 50min; the second stage cooling rate is 0.4℃ / min, and the cooling time is 200min; the third stage cooling rate is 0.7℃ / min, and the cooling time is 120min; the cooling environment is an oxygen-deficient environment.
[0030] The first stage cooling rate of position five is 5°C / min, and the cooling time is 6min; the second stage cooling rate is 2°C / min, and the cooling time is 70min; the third stage cooling rate is 0.5°C / min, and the cooling time is 200min; the cooling environment is cooling in air. Example 3
[0031] 1. A three-stage cooling method is used to simulate the temperature change process of the coiling process, and a certain cooling rate and cooling time are set for each cooling stage.
[0032] 2. Define the area within 10mm of the steel coil close to the mandrel IV as the inner circle III of the steel coil, the area 10mm inward from the outermost part of the steel coil as the outer circle I of the steel coil, and the area between the outer circle I of the steel coil and the inner circle III of the steel coil as the middle part II of the steel coil. Figure 1 Five processes are used to simulate the temperature changes at different positions of the same steel coil. Position 1 is located at the edge of the outer ring I, position 2 is located in the middle of the outer ring I, position 3 is located in the non-core part of the middle part II, position 4 is located in the core and near the core of the middle part II, and position 5 is located at the edge of the inner ring III.
[0033] 3. The coiling temperature is 550℃ and the following specific processes are performed: The first stage cooling rate of position one is 15°C / min, and the cooling time is 5min; the second stage cooling rate is 2°C / min, and the cooling time is 28min; the third stage cooling rate is 0.5°C / min, and the cooling time is 75min; the cooling environment is cooling in air.
[0034] The first stage cooling rate of position 2 is 8°C / min, and the cooling time is 4min; the second stage cooling rate is 4°C / min, and the cooling time is 40min; the third stage cooling rate is 0.8°C / min, and the cooling time is 75min; the cooling environment is cooling in air.
[0035] The first stage cooling rate of position three is 0℃ / min, and the cooling time is 5min; the second stage cooling rate is 1℃ / min, and the cooling time is 55min; the third stage cooling rate is 0.3℃ / min, and the cooling time is 300min; the cooling environment is an oxygen-deficient environment.
[0036] The first stage cooling rate of position four is 0℃ / min, and the cooling time is 50min; the second stage cooling rate is 0.5℃ / min, and the cooling time is 250min; the third stage cooling rate is 0.4℃ / min, and the cooling time is 100min; the cooling environment is an oxygen-deficient environment.
[0037] The first stage cooling rate of position five is 5°C / min, and the cooling time is 6min; the second stage cooling rate is 2°C / min, and the cooling time is 29min; the third stage cooling rate is 0.3°C / min, and the cooling time is 300min; the cooling environment is cooling in air. Example 4
[0038] 1. A three-stage cooling method is used to simulate the temperature change process of the coiling process, and a certain cooling rate and cooling time are set for each cooling stage.
[0039] 2. Define the area within 10mm of the steel coil close to the mandrel IV as the inner circle III of the steel coil, the area 10mm inward from the outermost part of the steel coil as the outer circle I of the steel coil, and the area between the outer circle I of the steel coil and the inner circle III of the steel coil as the middle part II of the steel coil. Figure 1 Five processes are used to simulate the temperature changes at different positions of the same steel coil. Position 1 is located at the edge of the outer ring I, position 2 is located in the middle of the outer ring I, position 3 is located in the non-core part of the middle part II, position 4 is located in the core and near the core of the middle part II, and position 5 is located at the edge of the inner ring III.
[0040] 3. The coiling temperature is 500℃ and the following specific processes are performed: The first stage cooling rate of position one is 10°C / min, and the cooling time is 5min; the second stage cooling rate is 2°C / min, and the cooling time is 20min; the third stage cooling rate is 1°C / min, and the cooling time is 30min; the cooling environment is cooling in air.
[0041] The first stage cooling rate of position 2 is 6°C / min, and the cooling time is 6 minutes; the second stage cooling rate is 4°C / min, and the cooling time is 15 minutes; the third stage cooling rate is 1°C / min, and the cooling time is 45 minutes; the cooling environment is cooling in air.
[0042] The first stage cooling rate of position three is 0℃ / min, and the cooling time is 6min; the second stage cooling rate is 1℃ / min, and the cooling time is 140min; the third stage cooling rate is 0.3℃ / min, and the cooling time is 100min; the cooling environment is an oxygen-deficient environment.
[0043] The first stage cooling rate of position four is 0℃ / min, and the cooling time is 60min; the second stage cooling rate is 0.4℃ / min, and the cooling time is 180min; the third stage cooling rate is 0.3℃ / min, and the cooling time is 90min; the cooling environment is an oxygen-deficient environment.
[0044] The first stage of position 5 has a cooling rate of 3°C / min and a cooling time of 4 minutes; the second stage has a cooling rate of 1°C / min and a cooling time of 10 minutes; the third stage has a cooling rate of 0.7°C / min and a cooling time of 200 minutes; the cooling environment is cooling in air The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. Any modification or partial replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.
Claims
1. A test method for simulating the formation of oxide scale during hot-rolled steel coiling, characterized in that The following steps are involved: (1) Use segmented cooling to simulate the temperature change process of the coiling process; (2) Define the position of the steel coil and divide the steel coil into five positions; (3) Set the cooling rate, cooling time and cooling environment for segmented cooling at each coil position according to the coiling temperature.
2. A test method for simulating the formation of oxide scale during coiling of hot rolled steel sheets according to claim 1, characterized in that: In the step (1), the segmented cooling adopts three-stage cooling.
3. The test method for simulating the formation of oxide scale during coiling of hot rolled steel sheets according to claim 1, characterized in that: In the step (2), the position of the steel coil close to the core shaft within 10 mm of thickness is the inner ring of the steel coil, the area 10 mm inward from the outermost part of the steel coil is the outer ring of the steel coil, and the middle area between the outer ring of the steel coil and the inner ring of the steel coil is the middle of the coil. The five positions are position one, position two, position three, position four and position five, wherein position one is located at the edge of the outer ring, position two is located in the middle of the outer ring, position three is located in the non-core part of the middle of the coil, position four is located in the core part and near the core part of the middle of the coil, and position five is located at the edge of the inner ring.
4. The test method for simulating the formation of oxide scale during coiling of hot rolled steel sheets according to claim 1, characterized in that: In the step (3), a) For coiling temperature between 630~670℃: The first stage of position 1 has a cooling rate of 18~22℃ / min and a cooling time of 4~6min; the second stage has a cooling rate of 3~6℃ / min and a cooling time of 12~18min; the third stage has a cooling rate of 1~2℃ / min and a cooling time of 50~70min; the cooling environment is cooling in air; The first stage cooling rate of position 2 is 12~16℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 3~6℃ / min, and the cooling time is 19~22min; the third stage cooling rate is 1~2℃ / min, and the cooling time is 80~100min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~2℃ / min, and the cooling time is 130~170min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 160~200min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.8℃ / min, and the cooling time is 260~300min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 5 is 6~10℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 90~120min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 160~200min; the cooling environment is cooling in air; b) For coiling temperature between 580~629℃: The first stage cooling rate of position 1 is 16~18℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 3~6℃ / min, and the cooling time is 8~12min; the third stage cooling rate is 1~2℃ / min, and the cooling time is 30~50min; the cooling environment is cooling in air; The first stage of the second position has a cooling rate of 10~14℃ / min and a cooling time of 4~6min; the second stage has a cooling rate of 2~5℃ / min and a cooling time of 25~35min; the third stage has a cooling rate of 1~2℃ / min and a cooling time of 30~60min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~2℃ / min, and the cooling time is 90~110min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 160~200min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.8℃ / min, and the cooling time is 200~250min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 5 is 5~8℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 50~70min; the third stage cooling rate is 0.5~0.9℃ / min, and the cooling time is 160~200min; the cooling environment is cooling in air; c) For coiling temperature between 530~579℃: The first stage cooling rate of position 1 is 12~16℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 28~32min; the third stage cooling rate is 0.5~1℃ / min, and the cooling time is 55~75min; the cooling environment is cooling in air; The first stage cooling rate of position 2 is 8~12℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 40~50min; the third stage cooling rate is 0.5~1℃ / min, and the cooling time is 75~100min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~1℃ / min, and the cooling time is 50~60min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 260~300min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.7℃ / min, and the cooling time is 250~300min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 5 is 3~7℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 10~30min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 260~300min; the cooling environment is cooling in air; d) For coiling temperature between 480~529℃: The first stage cooling rate of position 1 is 9~12℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 10~20min; the third stage cooling rate is 1~2℃ / min, and the cooling time is 30~50min; the cooling environment is cooling in air; The first stage cooling rate of position 2 is 6~10℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 2~4℃ / min, and the cooling time is 15~35min; the third stage cooling rate is 0.5~1℃ / min, and the cooling time is 45~65min; the cooling environment is cooling in air; The first stage cooling rate of position three is 0℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 0.5~1℃ / min, and the cooling time is 140~170min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 100~130min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position 4 is 0℃ / min, and the cooling time is 40~60min; the second stage cooling rate is 0.4~0.7℃ / min, and the cooling time is 180~210min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 90~120min; the cooling environment is an oxygen-deficient environment; The first stage cooling rate of position five is 3~6℃ / min, and the cooling time is 4~6min; the second stage cooling rate is 1~2℃ / min, and the cooling time is 10~20min; the third stage cooling rate is 0.3~0.7℃ / min, and the cooling time is 200~240min; the cooling environment is cooling in air.