Method and system for annealing dew point adjustment of ferritic stainless steel strip

Abstract

The application discloses an annealing dew point adjusting method and system for ferrite stainless steel strips, and relates to the technical field of stainless steel strip annealing atmosphere control. The method divides the steel strip into an edge region and a middle region along the width direction, respectively collects the protective atmosphere dew points of the two regions, compares the dew points with the target dew point range of the current annealing stage, and determines the edge dew point deviation and the middle dew point deviation. According to the deviation direction and the deviation degree of the two regions, the priority adjusting region is determined, and according to the deviation direction and the deviation degree of the priority adjusting region, the dew point compensation direction and the compensation degree are determined, and the supply ratio and / or supply flow of fresh protective gas and recycled protective gas are adjusted. After the adjustment, the dew points of the two regions are collected again and the compensation is repeated until the dew points of the two regions are in the target dew point range. The application can implement targeted adjustment based on the protective atmosphere dew point difference in the width direction of the steel strip, and improve the pertinence and stability of annealing dew point control.

Description

Technical Field

[0001] This invention relates to the field of stainless steel strip annealing atmosphere control technology, and in particular to a method and system for adjusting the dew point of ferritic stainless steel strip during annealing. Background Technology

[0002] Ferritic stainless steel strips typically require annealing after cold rolling to eliminate work hardening, improve microstructure and properties, and achieve a surface finish suitable for subsequent processing. During annealing, to reduce surface oxidation at high temperatures, hydrogen, nitrogen, or a hydrogen-nitrogen mixture is usually introduced into the annealing furnace as a protective gas. The redox state of the furnace atmosphere is controlled by adjusting the dew point of the protective atmosphere. Since ferritic stainless steel contains alloying elements such as chromium and manganese, which are prone to selective oxidation, changes in the dew point of the protective atmosphere affect the oxidation state of the strip surface. Therefore, dew point control is a crucial process affecting surface quality during the annealing of ferritic stainless steel strips.

[0003] Patent CN111979402A discloses a method for controlling the atmosphere inside an annealing furnace. By controlling atmospheric parameters such as hydrogen dew point, oxygen content, pressure, and nitrogen dew point at different control locations within the annealing furnace, a corresponding protective atmosphere is maintained in different furnace zones, thereby reducing quality problems such as surface oxidation and performance abnormalities during the annealing of stainless steel strips. While this method can control the protective atmosphere parameters at different locations within the annealing furnace, its control is primarily based on the atmosphere parameters at preset control locations within the furnace. This makes it difficult to fully reflect the differences in local atmosphere states during the actual annealing process of the steel strip. Therefore, when the atmosphere distribution within the furnace is uneven, the control accuracy for the surface oxidation state of different locations on the steel strip remains insufficient.

[0004] For example, patent CN113430339A discloses a method for controlling the protective atmosphere of a bell-type annealing furnace. This method controls conditions such as the inner bell seal detection, nitrogen purging, hydrogen purging, and the oxygen content, dew point, and purity of the protective gas to suppress the surface enrichment of manganese and silicon elements in the steel under a weakly oxidizing atmosphere, thereby improving the color difference problem at the edges of the steel coil during annealing. This solution can reduce surface quality defects in the steel coil by improving the overall protective atmosphere within the furnace. However, it mainly achieves control through overall adjustment of the protective atmosphere parameters. When the atmosphere conditions differ at different locations on the steel strip, adjusting the overall atmosphere parameters cannot simultaneously meet the actual annealing requirements of each location, and the problem of inconsistent local surface oxidation states may still occur.

[0005] Therefore, the technical problem that urgently needs to be solved in the existing process of controlling the dew point of annealing ferritic stainless steel strip is: how to implement differentiated adjustment based on the difference in dew point state between the edge and the middle of the steel strip under the protective atmosphere, so as to reduce the difference in oxidation state in the width direction of the steel strip. Summary of the Invention

[0006] This invention provides a method and system for adjusting the dew point of annealed ferritic stainless steel strip to solve the problems mentioned in the background section. To solve the above technical problems, this invention provides the following technical solution: A first aspect of the present invention relates to a method for adjusting the dew point of annealed ferritic stainless steel strip, comprising the following steps: S1. Obtain the width and operating position of the ferritic stainless steel strip, divide it into an edge region and a middle region along the width direction, and collect the protective atmosphere dew point of the two regions respectively to obtain the edge dew point value and the middle dew point value. S2. Match the target dew point range of the current annealing stage, and compare the edge dew point value and the middle dew point value with the target dew point range respectively to obtain the edge dew point deviation and the middle dew point deviation. S3. Compare the dew point deviation at the edge with the dew point deviation at the center to determine the dew point difference relationship in the width direction of the steel strip, and determine the priority adjustment area based on the dew point difference relationship when there is a dew point deviation. S4. Determine the dew point compensation direction and compensation degree of the priority adjustment area based on the deviation direction and degree of the priority adjustment area; S5. According to the dew point compensation direction and degree, adjust the supply ratio and / or supply flow rate of fresh protective gas and recovered protective gas entering the annealing furnace, and re-collect the protective atmosphere dew point of the edge region and the middle region. S6. Redetermine the edge dew point deviation and the center dew point deviation. Based on the redetermined edge dew point deviation and center dew point deviation, update the dew point difference relationship and priority adjustment area in the width direction of the steel strip. Redetermine the dew point compensation direction and compensation degree of the priority adjustment area. Repeat the dew point adjustment until the dew points of both areas are within the target dew point range.

[0007] Further, step S1 includes: Obtain the width information of the ferritic stainless steel strip entering the annealing furnace, and determine the current operating position based on the conveying process of the steel strip in the annealing furnace; According to the preset edge division range, the edge range is defined on both sides along the width direction of the steel strip. The two edge ranges together constitute the edge area, and the remaining range between the two edges is the middle area. Match the dew point collection points corresponding to the edge region and the middle region. When the steel strip runs to the annealing position corresponding to the dew point collection point, collect the protective atmosphere dew point of the two regions respectively to obtain the edge dew point value and the middle dew point value.

[0008] Further, step S2 includes: Read the current operating position of the ferritic stainless steel strip, determine the current annealing stage of the strip, and match the preset target dew point range for the corresponding annealing stage. The edge dew point value and the middle dew point value are compared with the upper and lower boundaries of the target dew point range, respectively. If the value is higher than the upper boundary of the target dew point range, it is determined to be a high deviation; if the value is lower than the lower boundary of the target dew point range, it is determined to be a low deviation; if the value is within the target dew point range, it is determined to be no deviation. Obtain the degree of deviation of the dew point value of the area where high or low deviation occurs relative to the corresponding boundary of the target dew point range. Record the area where no dew point deviation occurs as a no-deviation state. Correlate the deviation direction and deviation degree of each area to obtain the edge dew point deviation and the middle dew point deviation.

[0009] Further, step S3 includes: Read the edge dew point deviation and the center dew point deviation, and obtain the corresponding deviation direction and degree respectively; Compare the deviation directions of the two regions to determine whether the edge region and the middle region are in the same deviation state, the opposite deviation state, or one of the regions is in a unilateral deviation state with no deviation. Compare the degree of deviation between the two regions under the same-direction deviation state, opposite-direction deviation state, or unilateral deviation state, record the magnitude relationship and difference of the deviation degree, and obtain the dew point difference relationship in the width direction of the steel strip. The dew point deviation status of the edge region and the middle region is read from the dew point difference relationship; when only one region has a dew point deviation, the region with the dew point deviation is determined as the priority adjustment region for the current annealing stage; when both the edge region and the middle region have dew point deviations and the degree of deviation is not equal, the region with the larger degree of deviation is determined as the priority adjustment region for the current annealing stage; when both the edge region and the middle region have dew point deviations and the degree of deviation is equal, the edge region is determined as the priority adjustment region for the current annealing stage.

[0010] Further, step S4 includes: Read the direction and degree of deviation of the preferred adjustment region from the dew point difference relationship; The direction in which the dew point value of the priority adjustment area reverts from its current deviation state to the boundary corresponding to the target dew point range is determined as the dew point compensation direction. The degree of deviation between the current dew point value of the priority adjustment area and the boundary corresponding to the target dew point range is determined as the degree of dew point compensation in this round.

[0011] Further, step S5 includes: Read the dew point compensation direction and compensation degree of the priority adjustment area, and determine the gas supply adjustment amount of fresh protective gas and recovered protective gas according to the compensation degree; When the dew point compensation direction is to lower the dew point, increase the supply ratio and / or supply flow rate of fresh protective gas; when the dew point compensation direction is to raise the dew point, increase the supply ratio and / or supply flow rate of recovered protective gas, and determine the corresponding adjustment range according to the compensation degree. After adjusting the supply of fresh and recycled protective gas, the protective atmosphere dew points of the edge and central regions are collected in the same sampling cycle to obtain the adjusted edge and central dew point values.

[0012] Further, step S6 includes: The adjusted edge dew point value and center dew point value are compared with the target dew point range of the current annealing stage, and the edge dew point deviation and center dew point deviation are re-determined. The dew point difference relationship is re-established based on the re-determined edge dew point deviation and the middle dew point deviation, and the priority adjustment area for this round is re-determined based on the re-established dew point difference relationship. Based on the deviation direction and degree of the priority adjustment area in this round, the dew point compensation direction and degree are redefined and the next round of adjustment is entered. The process of dew point collection, deviation comparison, priority adjustment area determination and dew point compensation is repeated until the edge dew point value and the middle dew point value are both within the target dew point range.

[0013] A second aspect of the present invention relates to an annealing dew point adjustment system for ferritic stainless steel strips, comprising: The regional dew point acquisition module is used to obtain the width and operating position of the ferritic stainless steel strip. It is divided into an edge region and a middle region along the width direction, and the protective atmosphere dew point of the two regions is collected respectively to obtain the edge dew point value and the middle dew point value. The dew point deviation determination module is used to match the target dew point range of the current annealing stage. It compares the edge dew point value and the middle dew point value with the target dew point range to obtain the edge dew point deviation and the middle dew point deviation. The priority area determination module is used to compare the deviation direction and degree of the edge dew point deviation and the center dew point deviation, determine the dew point difference relationship in the width direction of the steel strip, and determine the priority adjustment area according to the dew point difference relationship when there is a dew point deviation. The dew point compensation determination module is used to determine the dew point compensation direction and compensation degree of the priority adjustment area based on the deviation direction and deviation degree of the priority adjustment area. The zoned dew point adjustment module is used to adjust the supply ratio and / or supply flow rate of fresh protective gas and recovered protective gas entering the annealing furnace according to the dew point compensation direction and degree, and to re-collect the protective atmosphere dew point of the edge region and the middle region. The closed-loop compensation correction module is used to redetermine the edge dew point deviation and the center dew point deviation. Based on the redetermined edge dew point deviation and center dew point deviation, it updates the dew point difference relationship and priority adjustment area in the width direction of the steel strip, and redetermines the dew point compensation direction and compensation degree of the priority adjustment area. The dew point adjustment is repeated until the dew points of both areas are within the target dew point range.

[0014] A third aspect of the present invention relates to an electronic device comprising: processor; Memory used to store processor-executable instructions; The processor is configured to invoke instructions stored in the memory to execute the aforementioned method.

[0015] A fourth aspect of the present invention relates to a computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, implement the aforementioned method.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention achieves differentiated identification and targeted adjustment of the dew point status in the width direction of the steel strip by separately obtaining the protective atmosphere dew point of the edge region and the middle region, and determining the priority adjustment region based on the deviation direction and degree of deviation of the two regions.

[0017] 2. This invention determines the direction and degree of dew point compensation, adjusts the supply ratio and / or flow rate of fresh protective gas and recovered protective gas, and re-determines the priority adjustment area and the direction and degree of dew point compensation based on the latest dew point deviation in each collection cycle, so that the dew point of the edge area and the middle area gradually returns to the target dew point range, thereby improving the utilization rate of recovered protective gas while meeting the annealing atmosphere requirements. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating a method for adjusting the dew point of annealing ferritic stainless steel strip according to an embodiment of the present invention. Figure 2 This is a functional block diagram of an annealing dew point adjustment system for ferritic stainless steel strip provided in an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be described more clearly and completely below. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0020] In this embodiment, the dew point collection cycle is used as the control cycle for dew point adjustment, and the tracked steel strip segment that has run to the corresponding dew point collection point is used as the data association object. The steel strip segment identifier, current running position, current annealing stage, edge dew point value, middle dew point value, and adjustment results of each round are associated and recorded according to the same collection cycle, so that each round of dew point judgment and compensation corresponds to the same steel strip segment and the same annealing position.

[0021] The fresh protective gas is a protective gas that is directly supplied to the annealing furnace after being refined. The recovered protective gas is a protective gas that is discharged from the annealing furnace and then recycled and refined before being supplied for use again. The purity of the fresh protective gas is higher than that of the recovered protective gas and its dew point is lower than that of the recovered protective gas. The system changes the dew point of the protective atmosphere entering the annealing furnace by adjusting the supply ratio and / or supply flow rate of the fresh and recovered protective gas. In this embodiment, the dew point compensation direction and degree of the priority adjustment area are used as the basis for gas supply control, and the gas supply control quantity is updated round by round based on the subsequent dew point collection results.

[0022] For example, in one embodiment, the purity of the fresh protective gas after purification is 99.99%, and the dew point is approximately -70°C; the purity of the recovered protective gas after purification is 92%–95%, and the dew point is approximately -60°C. Thus, increasing the supply ratio and / or supply flow rate of the fresh protective gas can lower the dew point of the mixed protective gas, and increasing the supply ratio and / or supply flow rate of the recovered protective gas can adjust the dew point of the mixed protective gas to a higher level. Moreover, the increase in dew point is achieved by increasing the utilization ratio of the recovered protective gas without employing additional humidification.

[0023] Within each control cycle, the system identifies deviation states in the same direction, opposite direction, or unilateral deviation states based on the dew point deviation at the edge and at the center, and determines the priority adjustment area for the current round according to the dew point difference relationship. When only one area has dew point deviation, the area with dew point deviation is determined as the priority adjustment area. When both areas have dew point deviation and the degree of deviation is not equal, the area with the greater degree of deviation is determined as the priority adjustment area. When both areas have dew point deviation and the degree of deviation is equal, the edge area is determined as the priority adjustment area. After each round of adjustment is completed, the dew point is re-collected and the dew point difference relationship and priority adjustment area are re-determined, without using the priority adjustment results of the previous round.

[0024] Reference Figure 1 The diagram shown is a flowchart illustrating a method for adjusting the annealing dew point of ferritic stainless steel strip according to an embodiment of the present invention. In this embodiment, the method for adjusting the annealing dew point of ferritic stainless steel strip includes: S1. Obtain the width and operating position of the ferritic stainless steel strip, divide it into an edge region and a middle region along the width direction, and collect the protective atmosphere dew point of the two regions respectively to obtain the edge dew point value and the middle dew point value. In this embodiment of the invention, step S1 includes: Obtain the width information of the ferritic stainless steel strip entering the annealing furnace, and determine the current operating position based on the conveying process of the steel strip in the annealing furnace; According to the preset edge division range, the edge range is defined on both sides along the width direction of the steel strip. The two edge ranges together constitute the edge area, and the remaining range between the two edges is the middle area. Match the dew point collection points corresponding to the edge region and the middle region. When the steel strip runs to the annealing position corresponding to the dew point collection point, collect the protective atmosphere dew point of the two regions respectively to obtain the edge dew point value and the middle dew point value.

[0025] The production information corresponding to the ferritic stainless steel strip entering the annealing furnace is obtained. The strip width information is read from the production information, and the strip segment continuously tracked along the strip running direction is used as the position recording object. When the strip enters the annealing furnace, a strip segment position reference is established. The subsequent conveying process is continuously associated with the strip segment position reference to update the corresponding position of the tracked strip segment in the annealing furnace. When the tracked strip segment runs to the annealing position corresponding to the dew point collection point, the position record of the strip segment in the current collection cycle is determined as the current running position of the strip, so that the subsequent target dew point range, dew point collection results and dew point deviation are all consistent with the same tracked strip segment.

[0026] The width information is read to determine the boundary positions on both sides of the steel strip width direction. According to the preset edge division range, continuous edge ranges are defined from both sides towards the inside of the steel strip. The edge ranges on both sides of the steel strip are jointly determined as the edge region. Then, the boundary of the two edge ranges towards the inside of the steel strip is used as the dividing position. The steel strip range continuously covered between the two dividing positions is determined as the middle region. The edge region and the middle region jointly cover the entire width direction of the current steel strip. The positional relationship between the edge region and the middle region relative to the width direction of the steel strip remains unchanged during the movement of the steel strip along the annealing furnace.

[0027] According to the positions of the edge region and the middle region in the width direction of the steel strip, the corresponding dew point collection points in the annealing furnace are matched respectively, so that the two side ranges correspond to the edge dew point collection points and the middle region corresponds to the middle dew point collection points. When the current running position of the steel strip reaches the annealing position corresponding to the dew point collection point, the dew point of the protective atmosphere at each point is collected in the same collection cycle. The dew point collection results corresponding to the two side ranges are averaged as the edge dew point value, and the dew point collection results corresponding to the middle region are used as the middle dew point value, thereby obtaining the edge dew point value and the middle dew point value corresponding to the current annealing position.

[0028] Therefore, by dividing the edge region and the middle region according to the actual width of the steel strip and obtaining the corresponding protective atmosphere dew point respectively, the edge dew point value and the middle dew point value can reflect the atmosphere state of different regions in the width direction of the steel strip, providing a data basis for subsequent dew point deviation comparison and differential adjustment.

[0029] S2. Match the target dew point range of the current annealing stage, and compare the edge dew point value and the middle dew point value with the target dew point range respectively to obtain the edge dew point deviation and the middle dew point deviation. In this embodiment of the invention, step S2 includes: Read the current operating position of the ferritic stainless steel strip, determine the current annealing stage of the strip, and match the preset target dew point range for the corresponding annealing stage. The edge dew point value and the middle dew point value are compared with the upper and lower boundaries of the target dew point range, respectively. If the value is higher than the upper boundary of the target dew point range, it is determined to be a high deviation; if the value is lower than the lower boundary of the target dew point range, it is determined to be a low deviation; if the value is within the target dew point range, it is determined to be no deviation. Obtain the degree of deviation of the dew point value of the area where high or low deviation occurs relative to the corresponding boundary of the target dew point range. Record the area where no dew point deviation occurs as a no-deviation state. Correlate the deviation direction and deviation degree of each area to obtain the edge dew point deviation and the middle dew point deviation.

[0030] The current operating position of the ferritic stainless steel strip is read, and the current operating position is compared one by one with the position range corresponding to each annealing stage pre-divided along the running direction of the strip in the annealing furnace. When the current operating position enters the position range of the corresponding annealing stage, the annealing stage is determined as the current annealing stage of the strip. Then, the target dew point range corresponding to the current annealing stage is read from the annealing process record, and the upper and lower boundaries of the target dew point range are determined, so that the current operating position, the current annealing stage and the target dew point range maintain a corresponding relationship.

[0031] Read the edge dew point value and the middle dew point value. Compare the edge dew point value with the upper and lower boundaries of the target dew point range, respectively. Then compare the middle dew point value in the same way. When the corresponding dew point value is higher than the upper boundary, the area is determined to be a high deviation. When the corresponding dew point value is lower than the lower boundary, the area is determined to be a low deviation. When the corresponding dew point value is within the range defined by the upper and lower boundaries, the area is determined to be no deviation. This allows the edge area and the middle area to obtain the deviation direction corresponding to their own dew point state.

[0032] For areas identified as having a high deviation, the degree of deviation is determined by the interval by which the dew point value of that area exceeds the upper boundary of the target dew point range. For areas identified as having a low deviation, the degree of deviation is determined by the interval by which the lower boundary of the target dew point range exceeds the dew point value of that area. For areas identified as having no deviation, the state of no deviation is maintained. The deviation direction and degree of deviation of the edge areas are recorded together as the edge dew point deviation, and the deviation direction and degree of deviation of the middle areas are recorded together as the middle dew point deviation. The edge dew point deviation and the middle dew point deviation are compared using the same target dew point range.

[0033] Therefore, by matching the target dew point range according to the current annealing stage and determining the deviation direction and degree of the edge region and the middle region respectively, the edge dew point deviation and the middle dew point deviation have a unified comparison benchmark, providing a clear basis for determining the subsequent dew point difference relationship.

[0034] S3. Compare the dew point deviation at the edge with the dew point deviation at the center to determine the dew point difference relationship in the width direction of the steel strip, and determine the priority adjustment area based on the dew point difference relationship when there is a dew point deviation. In this embodiment of the invention, step S3 includes: Read the edge dew point deviation and the center dew point deviation, and obtain the corresponding deviation direction and degree respectively; Compare the deviation directions of the two regions to determine whether the edge region and the middle region are in the same deviation state, the opposite deviation state, or one of the regions is in a unilateral deviation state with no deviation. Compare the degree of deviation between the two regions under the same-direction deviation state, opposite-direction deviation state, or unilateral deviation state, record the magnitude relationship and difference of the deviation degree, and obtain the dew point difference relationship in the width direction of the steel strip. The dew point deviation status of the edge region and the middle region is read from the dew point difference relationship; when only one region has a dew point deviation, the region with the dew point deviation is determined as the priority adjustment region for the current annealing stage; when both the edge region and the middle region have dew point deviations and the degree of deviation is not equal, the region with the larger degree of deviation is determined as the priority adjustment region for the current annealing stage; when both the edge region and the middle region have dew point deviations and the degree of deviation is equal, the edge region is determined as the priority adjustment region for the current annealing stage.

[0035] The deviation direction and degree of deviation for the edge region and the middle region are read from the edge dew point deviation and the middle dew point deviation respectively. The deviation direction is determined by high deviation, low deviation and no deviation. The correspondence between the degree of deviation of each region and the corresponding deviation direction is retained so that the edge region and the middle region form a complete dew point deviation state.

[0036] When both the edge and middle regions are in a state of no deviation, it indicates that the edge and middle dew point values ​​are within the target dew point range of the current annealing stage in the current acquisition cycle. At this time, no priority adjustment region is generated, dew point compensation is not performed in this acquisition cycle, and the protective atmosphere dew point of the edge and middle regions is re-acquired in the next acquisition cycle.

[0037] By comparing the deviation directions of the edge region and the middle region one by one, when both regions deviate in the high direction or both deviate in the low direction, it is determined to be a deviation in the same direction. When one region deviates in the high direction and the other region deviates in the low direction, it is determined to be a deviation in opposite directions. When one region deviates in the high direction or the low direction and the other region has no deviation, it is determined to be a deviation on one side. This clarifies the deviation combination state of the edge region and the middle region under the current annealing stage.

[0038] In the same-direction deviation state, opposite-direction deviation state, or unilateral deviation state, the deviation degree of the edge region and the middle region are read respectively. The deviation degree of the two regions is directly compared, and the deviation degree of which region is deeper and the deviation difference between the two are recorded. The deviation combination state, the magnitude relationship of the deviation degree, and the deviation difference are used together as the dew point difference relationship in the width direction of the steel strip, so that the dew point difference relationship reflects the difference in the deviation direction and the deviation degree between the edge region and the middle region.

[0039] The deviation status and degree of the edge region and the middle region are read from the dew point difference relationship in the width direction of the steel strip. When only one region has a high-direction deviation or a low-direction deviation, the region with dew point deviation is directly determined as the priority adjustment region for the current annealing stage. When both the edge region and the middle region have dew point deviations and the degree of deviation is not equal, the region with a greater degree of deviation is determined as the priority adjustment region for the current annealing stage. When both the edge region and the middle region have dew point deviations and the degree of deviation is equal, the edge region is directly determined as the priority adjustment region for the current annealing stage, so that each round of dew point compensation has a unique priority adjustment region.

[0040] Therefore, by comparing the deviation direction and degree between the edge region and the middle region, the dew point difference relationship in the width direction of the steel strip is formed, and the priority adjustment area is determined accordingly, providing a clear adjustment target for subsequent zonal dew point compensation.

[0041] S4. Determine the dew point compensation direction and compensation degree of the priority adjustment area based on the deviation direction and degree of the priority adjustment area; In this embodiment of the invention, step S4 includes: Read the direction and degree of deviation of the preferred adjustment region from the dew point difference relationship; The direction in which the dew point value of the priority adjustment area reverts from its current deviation state to the boundary corresponding to the target dew point range is determined as the dew point compensation direction. The degree of deviation between the current dew point value of the priority adjustment area and the boundary corresponding to the target dew point range is determined as the degree of dew point compensation in this round.

[0042] The priority adjustment area determined by the current acquisition cycle is read from the dew point difference relationship in the width direction of the steel strip, and the deviation direction and deviation degree corresponding to the priority adjustment area are extracted. The combination of deviation directions, the magnitude of deviation, and the difference in deviation degree between the edge area and the middle area are used to characterize the dew point difference relationship in the width direction of the steel strip and determine the priority adjustment area, but are not directly used as the degree of dew point compensation in this round.

[0043] The deviation direction of the priority adjustment area is read. When the priority adjustment area is in a high deviation state, the direction in which its dew point value decreases towards the upper boundary of the target dew point range is determined as the dew point compensation direction. When the priority adjustment area is in a low deviation state, the direction in which its dew point value increases towards the lower boundary of the target dew point range is determined as the dew point compensation direction, so that the dew point compensation direction always points to the corresponding boundary of the target dew point range.

[0044] The deviation of the current dew point value of the priority adjustment area from the corresponding boundary of the target dew point range is read, and this deviation is determined as the dew point compensation level for this round. When the priority adjustment area is in a high-direction deviation state, the dew point compensation level is determined by the degree of deviation of its current dew point value from the upper boundary of the target dew point range. When the priority adjustment area is in a low-direction deviation state, the dew point compensation level is determined by the degree of deviation of the lower boundary of the target dew point range from its current dew point value, ensuring that the dew point compensation level for this round always corresponds to the degree to which the priority adjustment area itself needs to return to the target dew point range. After completing this round of dew point adjustment, the edge dew point deviation and the middle dew point deviation are re-determined in the next collection cycle, and the priority adjustment area and the corresponding dew point compensation direction and compensation level are re-determined based on the latest dew point difference relationship.

[0045] Therefore, by determining the dew point compensation direction based on the deviation direction of the priority adjustment area, and determining the degree of dew point compensation based on the degree of deviation of the priority adjustment area relative to the boundary of the target dew point range, the current round of dew point compensation corresponds to the actual deviation state of the priority adjustment area itself.

[0046] S5. According to the dew point compensation direction and degree, adjust the supply ratio and / or supply flow rate of fresh protective gas and recovered protective gas entering the annealing furnace, and re-collect the protective atmosphere dew point of the edge region and the middle region. In this embodiment of the invention, step S5 includes: Read the dew point compensation direction and compensation degree of the priority adjustment area, and determine the gas supply adjustment amount of fresh protective gas and recovered protective gas according to the compensation degree; When the dew point compensation direction is to lower the dew point, increase the supply ratio and / or supply flow rate of fresh protective gas; when the dew point compensation direction is to raise the dew point, increase the supply ratio and / or supply flow rate of recovered protective gas, and determine the corresponding adjustment range according to the compensation degree. After adjusting the supply of fresh and recycled protective gas, the protective atmosphere dew points of the edge and central regions are collected in the same sampling cycle to obtain the adjusted edge and central dew point values.

[0047] The dew point compensation direction and degree of the priority adjustment area are read, and the gas supply control amount of fresh protective gas and recovered protective gas is determined in the preset gas supply control correspondence. The dew point compensation degree is associated with the corresponding gas supply control amount according to the dew point compensation direction, so that the actual dew point deviation state of the current priority adjustment area is used as the control basis for this round of gas supply adjustment.

[0048] The system pre-establishes a mapping relationship between dew point compensation level and gas supply adjustment amount for each annealing stage. This mapping relationship is established by the stable control records formed for the corresponding annealing stage. The system associates the degree of dew point change before and after each dew point adjustment with the corresponding gas supply adjustment amount and arranges them in ascending order of dew point change level to form a searchable control record sequence. When performing the current adjustment, the system reads the current dew point compensation level and selects the dew point change record that is not lower than the current dew point compensation level and is closest to it from the control record sequence. The gas supply adjustment amount corresponding to this record is used as the adjustment range for this round. When the current dew point compensation level exceeds the maximum dew point change record in the control record sequence, the gas supply adjustment amount corresponding to the maximum dew point change record is used as the upper limit of the adjustment for this round. The dew point compensation direction is to increase the supply ratio and / or supply flow rate of fresh protective gas when lowering the dew point, and to increase the supply ratio and / or supply flow rate of recovered protective gas when raising the dew point.

[0049] Fresh protective gas and recycled protective gas each have independent flow regulation functions. The two protective gases are mixed through a common pipeline and then supplied to the annealing furnace. When the flow rate of the two gas supplies is adjusted, causing a change in the total gas supply, the furnace pressure regulation mechanism adjusts the flow rate of the released gas according to the change in the furnace pressure, so that the pressure inside the annealing furnace is maintained within the preset process range.

[0050] The priority adjustment region is used to determine the direction and degree of adjustment of the supply of fresh protective gas and recycled protective gas in the current collection cycle, and does not mean that the fresh protective gas and recycled protective gas are supplied independently only to the priority adjustment region.

[0051] After updating the supply control of fresh protective gas and recovered protective gas, the next dew point collection cycle begins. The detection results of the corresponding dew point collection points in the edge and middle regions are read respectively. The dew point collection results corresponding to the two edge regions are averaged to form the adjusted edge dew point value. The detection results of the corresponding dew point collection points in the middle region are used as the adjusted middle dew point value. The adjusted edge dew point value and the middle dew point value maintain the same correspondence between the tracked steel strip segment, annealing position and collection cycle, and are used as inputs for subsequently re-determining the edge dew point deviation and the middle dew point deviation.

[0052] Thus, by adjusting the supply ratio and / or flow rate of fresh protective gas and recycled protective gas based on the dew point compensation demand of the priority adjustment area, and re-acquiring the dew point of the two areas, closed-loop regulation of the protective atmosphere based on the dew point difference in the steel strip width direction is achieved.

[0053] S6. Redetermine the edge dew point deviation and the center dew point deviation. Based on the redetermined edge dew point deviation and center dew point deviation, update the dew point difference relationship and priority adjustment area in the width direction of the steel strip. Redetermine the dew point compensation direction and compensation degree of the priority adjustment area. Repeat the dew point adjustment until the dew points of both areas are within the target dew point range.

[0054] In this embodiment of the invention, step S6 includes: The adjusted edge dew point value and center dew point value are compared with the target dew point range of the current annealing stage, and the edge dew point deviation and center dew point deviation are re-determined. The dew point difference relationship is re-established based on the re-determined edge dew point deviation and the middle dew point deviation, and the priority adjustment area for this round is re-determined based on the re-established dew point difference relationship. Based on the deviation direction and degree of the priority adjustment area in this round, the dew point compensation direction and degree are redefined and the next round of adjustment is entered. The process of dew point collection, deviation comparison, priority adjustment area determination and dew point compensation is repeated until the edge dew point value and the middle dew point value are both within the target dew point range.

[0055] The adjusted edge dew point value and center dew point value are compared with the upper and lower boundaries of the target dew point range for the current annealing stage, respectively. When the corresponding dew point value is higher than the upper boundary of the target dew point range, it is determined as a high-direction deviation and the degree of deviation beyond the upper boundary is recorded. When the corresponding dew point value is lower than the lower boundary of the target dew point range, it is determined as a low-direction deviation and the degree of deviation below the lower boundary is recorded. When the corresponding dew point value is within the target dew point range, it is determined as a no-deviation state. The deviation direction and degree of deviation of the edge region are re-recorded as the edge dew point deviation, and the deviation direction and degree of deviation of the center region are re-recorded as the center dew point deviation.

[0056] Based on the redefined edge dew point deviation and center dew point deviation, the dew point difference relationship in the steel strip width direction is re-formed according to step S3 based on the latest deviation direction and degree, and the priority adjustment area for this round is redefined; when both the edge area and the center area are in a state of no deviation, the priority adjustment area for this round is not generated, dew point compensation is not performed in this collection cycle, and the next collection cycle is entered to re-collect dew points and determine deviations.

[0057] When at least one area has a dew point deviation, step S4 is followed to redetermine the dew point compensation direction and compensation degree for this round based on the deviation direction and degree of the priority adjustment area in this round, and step S5 is followed to update the gas supply control quantity of fresh protective gas and recovered protective gas. The dew point compensation direction and compensation degree for this round are determined by the deviation direction and degree of the priority adjustment area itself, which is redetermined in the current collection cycle. The priority adjustment area, dew point compensation direction, and dew point compensation degree determined in the previous collection cycle are not used as the control quantity for this round.

[0058] Therefore, by re-determining the priority adjustment area and the direction and degree of dew point compensation based on the latest dew point deviation in each collection cycle, the protective atmosphere dew point in the peripheral and central regions can be gradually brought back to the target dew point range.

[0059] Taking a round of same-direction high-direction deviation as an example, when the edge dew point deviation is greater than the middle dew point deviation, the system determines the edge area as the priority adjustment area for this round based on the dew point difference relationship, and determines the dew point compensation level for this round based on the degree of deviation of the current dew point value of the edge area from the upper boundary of the target dew point range. The corresponding control quantity is obtained through the preset mapping relationship between the dew point compensation level and the gas supply adjustment amount. After completing this round of adjustment and re-collecting the dew point, the system re-establishes the dew point difference relationship based on the latest edge dew point deviation and middle dew point deviation, and redetermines the priority adjustment area for the next round and the corresponding dew point compensation direction and compensation level, until both areas enter the target dew point range.

[0060] The target dew point range, edge division range, priority adjustment area determination rules, and mapping relationship between dew point compensation degree and gas supply adjustment amount for each annealing stage are all pre-stored as process control data for the corresponding steel grade and annealing stage. When the system is running, it reads the corresponding control data according to the current annealing stage of the tracked steel strip segment, and re-determines the dew point difference relationship, priority adjustment area, dew point compensation direction and compensation degree, and corresponding gas supply control amount round by round based on the latest acquisition results.

[0061] like Figure 2 The diagram shown is a functional block diagram of an annealing dew point adjustment system for ferritic stainless steel strip provided in an embodiment of the present invention.

[0062] The ferritic stainless steel strip annealing dew point adjustment system 100 can be installed in electronic equipment. Depending on the functions implemented, the ferritic stainless steel strip annealing dew point adjustment system 100 may include a regional dew point acquisition module 101, a dew point deviation determination module 102, a priority region determination module 103, a dew point compensation determination module 104, a zoned dew point adjustment module 105, and a closed-loop compensation correction module 106.

[0063] In this embodiment, the functions of each module are as follows: The regional dew point acquisition module 101 is used to obtain the width and running position of the ferritic stainless steel strip, divide it into an edge region and a middle region along the width direction, and collect the protective atmosphere dew point of the two regions respectively to obtain the edge dew point value and the middle dew point value. The dew point deviation determination module 102 is connected to the area dew point acquisition module 101 and is used to match the target dew point range of the current annealing stage. The edge dew point value and the middle dew point value are compared with the target dew point range to obtain the edge dew point deviation and the middle dew point deviation. The priority area determination module 103 is connected to the dew point deviation determination module 102. It is used to compare the deviation direction and degree of the edge dew point deviation and the middle dew point deviation, determine the dew point difference relationship in the width direction of the steel strip, and determine the priority adjustment area according to the dew point difference relationship when there is a dew point deviation. The dew point compensation determination module 104 is connected to the priority area determination module 103 and is used to determine the dew point compensation direction and compensation degree of the priority adjustment area according to the deviation direction and deviation degree of the priority adjustment area. The partition dew point adjustment module 105 is connected to the dew point compensation determination module 104, and is used to adjust the supply ratio and / or supply flow rate of fresh protective gas and recovered protective gas entering the annealing furnace according to the dew point compensation direction and compensation degree, and to re-collect the protective atmosphere dew point of the edge area and the middle area. The closed-loop compensation correction module 106 is connected to the partition dew point adjustment module 105. It redetermines the edge dew point deviation and the middle dew point deviation, updates the dew point difference relationship and priority adjustment area in the width direction of the steel strip according to the redetermined edge dew point deviation and the middle dew point deviation, and redetermines the dew point compensation direction and compensation degree of the priority adjustment area. The dew point adjustment is repeated until the dew points of both areas are within the target dew point range.

[0064] During system execution, each module uses the tracked steel belt segment, area identifier, and acquisition cycle as the basis for data association. The area dew point acquisition module outputs the edge dew point value and the center dew point value. The dew point deviation determination module determines the deviation direction and degree of the two areas. The priority area determination module determines the priority adjustment area for this round according to the dew point difference relationship. When both areas have dew point deviations and the degree of deviation is equal, the edge area is determined as the priority adjustment area. The dew point compensation determination module determines the dew point compensation direction and compensation degree according to the deviation direction and degree of the priority adjustment area. The zone dew point adjustment module converts the dew point compensation degree into the gas supply adjustment amount through a preset mapping relationship. The closed-loop compensation correction module re-triggers the determination of the dew point difference relationship and the priority adjustment area after each acquisition cycle, thus forming a complete system closed-loop control process.

[0065] A third aspect of the present invention relates to an electronic device, comprising: processor; Memory used to store processor-executable instructions; The processor is configured to invoke instructions stored in the memory to execute the aforementioned method.

[0066] A fourth aspect of the present invention relates to a computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, implement the aforementioned method.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for adjusting the dew point of annealed ferritic stainless steel strip, characterized in that, Includes the following steps: S1. Obtain the width and operating position of the ferritic stainless steel strip, divide it into an edge region and a middle region along the width direction, and collect the protective atmosphere dew point of the two regions respectively to obtain the edge dew point value and the middle dew point value. S2. Match the target dew point range of the current annealing stage, and compare the edge dew point value and the middle dew point value with the target dew point range respectively to obtain the edge dew point deviation and the middle dew point deviation. S3. Compare the dew point deviation at the edge with the dew point deviation at the center to determine the dew point difference relationship in the width direction of the steel strip, and determine the priority adjustment area based on the dew point difference relationship when there is a dew point deviation. S4. Determine the dew point compensation direction and compensation degree of the priority adjustment area based on the deviation direction and degree of the priority adjustment area; S5. According to the dew point compensation direction and degree, adjust the supply ratio and / or supply flow rate of fresh protective gas and recovered protective gas entering the annealing furnace, and re-collect the protective atmosphere dew point of the edge region and the middle region. S6. Redetermine the edge dew point deviation and the center dew point deviation. Based on the redetermined edge dew point deviation and center dew point deviation, update the dew point difference relationship and priority adjustment area in the width direction of the steel strip. Redetermine the dew point compensation direction and compensation degree of the priority adjustment area. Repeat the dew point adjustment until the dew points of both areas are within the target dew point range.

2. The method for adjusting the dew point of annealed ferritic stainless steel strip according to claim 1, characterized in that, Step S1 includes: Obtain the width information of the ferritic stainless steel strip entering the annealing furnace, and determine the current operating position based on the conveying process of the steel strip in the annealing furnace; According to the preset edge division range, the edge range is defined on both sides along the width direction of the steel strip. The two edge ranges together constitute the edge area, and the remaining range between the two edges is the middle area. Match the dew point collection points corresponding to the edge region and the middle region. When the steel strip runs to the annealing position corresponding to the dew point collection point, collect the protective atmosphere dew point of the two regions respectively to obtain the edge dew point value and the middle dew point value.

3. The method for adjusting the dew point of annealed ferritic stainless steel strip according to claim 1, characterized in that, Step S2 includes: Read the current operating position of the ferritic stainless steel strip, determine the current annealing stage of the strip, and match the preset target dew point range for the corresponding annealing stage. The edge dew point value and the middle dew point value are compared with the upper and lower boundaries of the target dew point range, respectively. If the value is higher than the upper boundary of the target dew point range, it is determined to be a high deviation; if the value is lower than the lower boundary of the target dew point range, it is determined to be a low deviation; if the value is within the target dew point range, it is determined to be no deviation. Obtain the degree of deviation of the dew point value of the area where high or low deviation occurs relative to the corresponding boundary of the target dew point range. Record the area where no dew point deviation occurs as a no-deviation state. Correlate the deviation direction and deviation degree of each area to obtain the edge dew point deviation and the middle dew point deviation.

4. The method for adjusting the dew point of annealed ferritic stainless steel strip according to claim 1, characterized in that, Step S3 includes: Read the edge dew point deviation and the center dew point deviation, and obtain the corresponding deviation direction and degree respectively; Compare the deviation directions of the two regions to determine whether the edge region and the middle region are in the same direction of deviation, in opposite directions of deviation, or one of the regions is in a unilateral deviation state with no deviation. Compare the degree of deviation between the two regions under the same-direction deviation state, opposite-direction deviation state, or unilateral deviation state, record the magnitude relationship and difference of the deviation degree, and obtain the dew point difference relationship in the width direction of the steel strip. The dew point deviation status of the edge region and the middle region is read from the dew point difference relationship; when only one region has a dew point deviation, the region with the dew point deviation is determined as the priority adjustment region for the current annealing stage; when both the edge region and the middle region have dew point deviations and the degree of deviation is not equal, the region with the larger degree of deviation is determined as the priority adjustment region for the current annealing stage; when both the edge region and the middle region have dew point deviations and the degree of deviation is equal, the edge region is determined as the priority adjustment region for the current annealing stage.

5. The method for adjusting the dew point of annealed ferritic stainless steel strip according to claim 1, characterized in that, Step S4 includes: Read the direction and degree of deviation of the preferred adjustment region from the dew point difference relationship; The direction in which the dew point value of the priority adjustment area reverts from its current deviation state to the boundary corresponding to the target dew point range is determined as the dew point compensation direction. The degree of deviation between the current dew point value of the priority adjustment area and the boundary corresponding to the target dew point range is determined as the degree of dew point compensation in this round.

6. The method for adjusting the dew point of annealed ferritic stainless steel strip according to claim 1, characterized in that, Step S5 includes: Read the dew point compensation direction and compensation degree of the priority adjustment area, and determine the gas supply adjustment amount of fresh protective gas and recovered protective gas according to the compensation degree; When the dew point compensation direction is to lower the dew point, increase the supply ratio and / or supply flow rate of fresh protective gas; when the dew point compensation direction is to raise the dew point, increase the supply ratio and / or supply flow rate of recovered protective gas, and determine the corresponding adjustment range according to the compensation degree. After adjusting the supply of fresh and recycled protective gas, the protective atmosphere dew points of the edge and central regions are collected in the same sampling cycle to obtain the adjusted edge and central dew point values.

7. The method for adjusting the dew point of annealed ferritic stainless steel strip according to claim 1, characterized in that, Step S6 includes: The adjusted edge dew point value and center dew point value are compared with the target dew point range of the current annealing stage to redetermine the edge dew point deviation and center dew point deviation. The dew point difference relationship is re-established based on the re-determined edge dew point deviation and the middle dew point deviation, and the priority adjustment area for this round is re-determined based on the re-established dew point difference relationship. Based on the deviation direction and degree of the priority adjustment area in this round, the dew point compensation direction and degree are redefined and the next round of adjustment is entered. The process of dew point collection, deviation comparison, priority adjustment area determination and dew point compensation is repeated until the edge dew point value and the middle dew point value are both within the target dew point range.

8. A dew point adjustment system for annealed ferritic stainless steel strips, characterized in that, The method for adjusting the annealing dew point of ferritic stainless steel strip according to any one of claims 1 to 7 includes: The regional dew point acquisition module is used to obtain the width and operating position of the ferritic stainless steel strip. It is divided into an edge region and a middle region along the width direction, and the protective atmosphere dew point of the two regions is collected respectively to obtain the edge dew point value and the middle dew point value. The dew point deviation determination module is used to match the target dew point range of the current annealing stage. It compares the edge dew point value and the middle dew point value with the target dew point range to obtain the edge dew point deviation and the middle dew point deviation. The priority area determination module is used to compare the deviation direction and degree of the edge dew point deviation and the center dew point deviation, determine the dew point difference relationship in the width direction of the steel strip, and determine the priority adjustment area according to the dew point difference relationship when there is a dew point deviation. The dew point compensation determination module is used to determine the dew point compensation direction and compensation degree of the priority adjustment area based on the deviation direction and deviation degree of the priority adjustment area. The zoned dew point adjustment module is used to adjust the supply ratio and / or supply flow rate of fresh protective gas and recovered protective gas entering the annealing furnace according to the dew point compensation direction and degree, and to re-collect the protective atmosphere dew point of the edge region and the middle region. The closed-loop compensation correction module is used to redetermine the edge dew point deviation and the center dew point deviation. Based on the redetermined edge dew point deviation and center dew point deviation, it updates the dew point difference relationship and priority adjustment area in the width direction of the steel strip, and redetermines the dew point compensation direction and compensation degree of the priority adjustment area. The dew point adjustment is repeated until the dew points of both areas are within the target dew point range.

9. An electronic device, characterized in that, include: processor; Memory used to store processor-executable instructions; The processor is configured to invoke instructions stored in the memory to execute the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, When the computer program instructions are executed by the processor, they implement the method described in any one of claims 1 to 7.

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