Application method of wringing roller of normalizing pickling production line

Abstract

The application discloses a kind of application methods of wringing roller of normalizing pickling production line, it is related to strip steel quality technical field, normalizing pickling production line is sequentially provided with three pairs of wringing roller in pickling tank export section, and the application method of wringing roller includes, the raw material strip steel sent into normalizing pickling production line is classified, and the width is greater than or equal to first preset value and the thickness is greater than or equal to second preset value as first class, except first class as other class;When wringing first class raw material strip steel, any two pairs of three pairs of wringing roller are put into application;When wringing other class raw material strip steel, three pairs of wringing roller are all put into application.This application uses multiple wringing combination process, batch uses wringing roller, to ensure that the elasticity shape generated by its material recovers, to essentially reduce the number of defects required to be detected by pittate table detector.

Description

Technical Field

[0001] This invention relates to the field of strip steel quality technology, and in particular to a method for applying extrusion rollers in a normalizing pickling production line. Background Technology

[0002] The Bestet surface quality inspector is a testing device used for online surface quality inspection of strip steel. The main reason for the strip breakage accident during rolling at the six-stand rolling mill was that the Bestet surface quality inspector missed some defects. The reason for this was that there were too many defects to be detected, leading to operator errors in defect identification. A review of the Bestet surface quality inspector revealed that among the steel coils with the most defects, 50% were watermark defects, 40% were glue removal defects from the squeeze rolls, and 10% were other defects such as furnace bottom roll marks.

[0003] Raw strip steel enters the normalizing and pickling process of cold rolling. The pickled strip steel is then squeezed dry by squeeze rollers, which are consumable parts. Electrical steel, also known as silicon steel sheet, is subject to increasingly frequent changes in specifications. The number of times product specifications are switched on the same cold rolling production line has increased, including but not limited to thickness and width, which greatly increases the challenges faced by the squeeze rollers.

[0004] In the pickling zone, turbulent pickling of strip steel can lead to various defects. If the squeezing rolls apply too little pressure, it can cause large-area watermarks on the strip. Conversely, if the squeezing rolls apply too much pressure, it can cause adhesive peeling off the squeezing rolls. Both defects can trigger abnormal alarms on the Bestech surface inspection instrument, making inspection difficult. As surface defects increase, missed inspections can increase the risk of strip breakage during rolling mill operations, causing shutdowns and impacting overall efficiency. Furthermore, severe squeezing roll depressurization can damage the rolls themselves, increasing production costs. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a method for applying extrusion rollers in a normalizing pickling production line.

[0006] This application provides a method for applying squeeze rollers in a normalizing pickling production line. The normalizing pickling production line is equipped with three pairs of squeeze rollers in sequence at the outlet section of the pickling tank. The method for applying the squeeze rollers includes classifying the raw strip steel fed into the normalizing pickling production line into categories. The first category is defined as having a width greater than or equal to a first preset value and a thickness greater than or equal to a second preset value. The other categories are defined as other categories. When squeezing the raw strip steel of the first category, any two pairs of the three pairs of squeeze rollers are used. When squeezing the raw strip steel of other categories, all three pairs of squeeze rollers are used.

[0007] In some embodiments, when the first state of squeezing strip with a width of a first preset value is switched to the second state of squeezing strip with a width less than and adjacent to the first preset value under the same conditions, the residual acid and water on the surface of the squeezed strip is the greatest; when the third state of squeezing strip with a thickness of a second preset value is switched to the fourth state of squeezing strip with a thickness less than and adjacent to the second preset value under the same conditions, the residual acid and water on the surface of the squeezed strip is the greatest.

[0008] In some embodiments, with the thickness of the raw material strip selected as 1.8mm, 2.0mm, 2.3mm, 2.4mm, or 2.6mm, the second preset value is 2.3mm.

[0009] In some implementations, the first preset value is 1000 mm.

[0010] In some embodiments, other types of raw material strip steel include: raw material strip steel of the second type with a width greater than or equal to a first preset value and a thickness less than a second preset value; raw material strip steel of the third type with a width less than the first preset value and a thickness greater than or equal to the second preset value; and raw material strip steel of the fourth type with a width less than the first preset value and a thickness less than the second preset value.

[0011] In some implementations, the pressure of the squeeze rollers on the raw strip is dynamically adjusted according to the specifications of the raw strip and the amount of residual acid and water in the raw strip, with the standard being that the raw strip coming out of the last pair of squeeze rollers put into use has no residual acid and water and that the squeeze rollers have no glue falling off.

[0012] In some implementations, the gap pressure of the squeeze roller is 1 Bar to 5 Bar.

[0013] In some implementations, when the first two pairs of the three pairs of extrusion rolls are put into use, the first pair of any two pairs of extrusion rolls performs rough extrusion on the raw material strip, and the second pair of any two pairs of extrusion rolls performs fine extrusion on the raw material strip.

[0014] In some implementations, when all three pairs of extrusion rolls are in use, the first pair of extrusion rolls is used to perform rough extrusion of the raw strip, the second pair of extrusion rolls is used to perform fine extrusion of the raw strip, and the third pair of extrusion rolls is used to perform supplementary extrusion of the raw strip.

[0015] In some implementations, the method further includes the step of purging the squeezed raw material strip with high-pressure air.

[0016] The beneficial effects of this application are as follows: It provides a method for applying squeeze rollers in a normalizing pickling production line. Based on the premise that three pairs of squeeze rollers are sequentially installed at the outlet section of the pickling tank, the raw strip steel fed into the normalizing pickling production line is divided into a first category and other categories. The hot-rolled width of the first category of raw strip steel is greater than or equal to a first preset value and the thickness is greater than or equal to a second preset value. When squeezing the raw strip steel of the first category, any two pairs of the three pairs of squeeze rollers are used. When squeezing the raw strip steel of other categories, all three pairs of squeeze rollers are used. In actual production, the production planning for the first category is more frequent. Since only two pairs of squeeze rollers are used when squeezing the first category, different pairs of rollers can be arranged to be idle during different production of the first category. For example, the first and second pairs of squeeze rollers can be used in the previous production, and the first and third pairs of squeeze rollers can be used in the next production. Dry rolls; This application addresses the characteristics of the three pairs of dry rolls at the exit of the normalized pickling line by employing a multi-stage dry-rolling process. Batch use of the dry rolls ensures the recovery of elastic deformation caused by the material, thereby reducing residual acid and water on the strip surface during long-term production on the normalized pickling line. This fundamentally solves defects such as glue shedding and residual watermarks on the dry rolls, effectively reducing the number of defects that the Bestetin surface inspection instrument needs to detect. This lowers the missed inspection rate at the mill inlet, reducing the risk of mill speed reduction and shutdown due to missed defects. This application improves the removal of glue from the dry rolls and reduces secondary contamination of the strip by residual watermarks, optimizing the surface quality of the strip. This application also reduces dry roll wear and extends its service life. Furthermore, this application adopts a unified path and graded processing method for the application of dry rolls, facilitating on-site operation by operators. Detailed Implementation

[0017] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0018] Furthermore, reference numerals and / or reference letters may be repeated in different examples in this application. Such repetition is for simplification and clarity purposes and does not in itself indicate a relationship between the various embodiments and / or settings discussed. In addition, this application provides examples of various specific processes and materials; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0019] This application provides a method for applying squeeze rollers in a normalizing pickling production line. Based on the premise that the normalizing pickling production line has three pairs of squeeze rollers sequentially installed at the outlet section of the pickling tank, the raw material strip steel fed into the normalizing pickling production line first needs to be classified. The raw material strip steel fed into the normalizing pickling production line is referred to as raw material strip steel in the following description. The raw material strip steel is classified according to its width and thickness. The strip steel with a width greater than or equal to a first preset value and a thickness greater than or equal to a second preset value is classified as the first category. The raw material strip steel other than the first category is classified as the other category.

[0020] Through long-term production activities, the inventors summarized and found that the thickness of the raw steel strips fed into the normalizing and pickling production line was generally between 1.8mm and 2.6mm, and the width was generally between 800mm and 1300mm. With the continuous progress of production, it was found that the Bestech inspection instrument had to detect too many defects, leading to missed detections. Regarding the defects in the steel coils with the most defects, 50% were watermark defects, and 40% were defects caused by glue peeling off the squeeze rollers. Logical analysis of the occurrence of watermark defects and glue peeling off the squeeze rollers revealed that they were caused by the failure of the squeeze rollers to recover their elastic deformation in a timely manner.

[0021] In production scenarios where the thickness of the raw strip in the previous batch is smaller than that in the subsequent batch, the elastic deformation of the squeeze roller that cannot recover instantaneously has little impact on the squeezing effect. However, when the thickness of the raw strip in the previous batch is larger than that in the subsequent batch, the elastic deformation of the squeeze roller that cannot recover instantaneously has a significant impact on the squeezing effect. The inventors have discovered that a similar factor exists with the width of the raw strip. When the width of the raw strip in the previous batch is smaller than that in the subsequent batch, the elastic deformation of the squeeze roller that cannot recover instantaneously has little impact on the squeezing effect. However, when the width of the raw strip in the previous batch is larger than that in the subsequent batch, the elastic deformation of the squeeze roller that cannot recover instantaneously has a significant impact on the squeezing effect.

[0022] Therefore, based on the thickness and width specifications of raw material strip steel in long-term production activities, the aforementioned second preset value and first preset value were selected respectively. Raw material strip steel with a width greater than or equal to the first preset value and a thickness greater than or equal to the second preset value was designated as Category I raw material strip steel, and raw material strip steel other than Category I was designated as other categories of raw material strip steel. In the extrusion roller application method of this application, when extruding Category I raw material strip steel, any two pairs of the three pairs of extrusion rollers are used; when extruding other categories of raw material strip steel, all three pairs of extrusion rollers are used.

[0023] In long-term on-site production activities, there are more production plans for Category I raw material strip steel, and fewer plans for other types of raw material strip steel. When applying the scheme of this application, it is more common for any two pairs of the three pairs of extrusion rollers to be used when extruding Category I raw material strip steel, while it is less common for all three pairs of extrusion rollers to be used when extruding other types of raw material strip steel.

[0024] In situations where the previous batch of raw strip steel was extruded using the first type of raw material, and the subsequent batch was extruded using other types of raw material strip steel, the elastic deformation of the extrusion rollers, which could not be recovered instantaneously, had a significant impact on the extrusion effect of the subsequent batch. By applying the method of this application, when the raw strip steel of the subsequent batch is extruded, a pair of extrusion rollers that were idle during the production of the previous batch are put into use to ensure that the extrusion effect of the raw strip steel of the subsequent batch meets the technical requirements.

[0025] In the case of switching between extruding other types of raw material strips in the previous batch and extruding the first type of raw material strips in the next batch, the elastic deformation of the extrusion rollers that cannot recover instantaneously has little impact on the extrusion effect of the next batch. When extruding the raw material strips in the next batch, the scheme of using any two pairs of the three pairs of extrusion rollers can ensure that the extrusion effect of the raw material strips in the next batch meets the technical requirements.

[0026] Since the first type of raw material strip only involves two pairs of extrusion rollers during extrusion, different pairs of rollers can be idled during different first-type production processes. Furthermore, the specific locations of the idle rollers can be set. The three pairs of extrusion rollers sequentially located at the pickling tank outlet are named the first pair, second pair, and third pair according to the production line direction. In scenarios involving the extrusion of the first type of raw material strip, the first, second, and third pairs of extrusion rollers are sequentially switched to an idle state, ensuring the uniformity of the number of times each pair of rollers is switched to an idle state, and protecting each pair of rollers.

[0027] The inventors considered that the elastic deformation of the squeeze rollers used for fine extrusion is greater than that of the squeeze rollers used for rough extrusion. Therefore, they further designed the idle sequence of the rollers, prioritizing the switch to idle for rollers with greater elastic deformation and sequentially switching all three pairs of rollers to idle. For example, the first and second pairs of squeeze rollers are used in the first cycle, followed by the first and third pairs, then the second and third pairs, and finally the first and second pairs, and so on.

[0028] In summary, this application, targeting the characteristics of the three pairs of extrusion rolls at the outlet of the normalized pickling line, adopts a multi-extrusion combined process and uses the extrusion rolls in batches to ensure that the elastic deformation of the material can be restored. This reduces the amount of residual acid and water on the surface of the strip steel during long-term production on the normalized pickling production line, and fundamentally solves defects such as glue peeling and residual watermarks on the extrusion rolls. This is equivalent to reducing the number of defects that the Bestar surface inspection instrument needs to detect, which can reduce the missed detection rate at the mill inlet operation, thereby reducing the risk of the mill slowing down and stopping due to missed defects. This application can improve the removal of adhesive from the squeeze roller, reduce secondary contamination of the strip steel caused by residual watermarks, and optimize the surface quality of the strip steel; this application can reduce the wear of the squeeze roller and extend its service life; this application adopts a unified path and graded treatment method for the application of squeeze rollers, which is convenient for operators to operate on site.

[0029] In some embodiments, the first and second preset values ​​are limited, and the test is conducted under the same conditions based on the approximate range of thickness and width of the raw strip steel fed into the normalizing and pickling production line.

[0030] Specifically, under the same conditions, the squeeze roller squeezes the raw strip steel with two adjacent width parameters. The first simulation is set to squeeze the strip steel with the larger width parameter, and the second simulation is set to squeeze the strip steel with the smaller width parameter that is adjacent to it. When switching from the first state to the second state, residual acid and water appear on the surface of the strip steel. It can be measured that the degree of residual acid and water on the surface of the strip steel is the greatest under a certain condition. At this time, the width parameter of the strip steel corresponding to the first state under this condition is selected as the first preset value. That is to say, when the first state of the squeeze roller squeezing the strip steel with the width of the first preset value is switched to the second state of squeezing the strip steel with the width of the first preset value, the degree of residual acid and water on the surface of the squeezed strip steel is the greatest.

[0031] Similarly, under the same conditions, when the third state of squeezing strip steel with a thickness of the second preset value is switched to the fourth state of squeezing strip steel with a thickness less than and adjacent to the second preset value, the residual acid and water on the surface of the squeezed strip steel is the greatest.

[0032] The aforementioned simulation experiment refers to a simulation experiment with a single variable, such as squeezing two adjacent strip steel pieces with different width parameters under the same conditions. Except for the change in width between the two batches of strip steel, all other parameters remain constant. For different strip steel pieces with different parameters, there are commonly used production parameters on-site, specifically the extrusion pressure values ​​between each pair of squeezing rollers and the strip steel for different parameters. These parameters can be applied in the simulation experiment. The simulation experiment in this application needs to measure the degree of residual acid and water on the strip steel surface when the width or thickness changes.

[0033] In some implementations, given that the thickness of the raw strip steel fed into the normalizing and pickling production line is selected as 1.8 mm, 2.0 mm, 2.3 mm, 2.4 mm, or 2.6 mm, the second preset value is 2.3 mm.

[0034] In some implementations, the first preset value is 1000mm, provided that the width of the raw strip steel fed into the normalizing and pickling production line is generally between 800mm and 1300mm.

[0035] In some embodiments, other types of raw material strips are further classified, specifically including: a second type of raw material strip with a width greater than or equal to a first preset value and a thickness less than a second preset value; a third type of raw material strip with a width less than the first preset value and a thickness greater than or equal to the second preset value; and a fourth type of raw material strip with a width less than the first preset value and a thickness less than the second preset value. When extruding the second, third, and fourth types of raw material strips, a scheme in which all three pairs of extrusion rollers are used is employed. By reclassifying other types of raw material strips, the production parameters of the extrusion rollers can be adjusted specifically for different situations where the previous batch is of type one and the subsequent batch is of type two, three, or four.

[0036] In some embodiments, the raw strip steel is squeezed dry using squeeze rollers. The roller pressure value of the squeeze rollers on the raw strip steel involves the specific pressure value between the squeeze rollers and the raw strip steel, which is dynamically adjusted according to the specifications of the raw strip steel and the amount of residual acid and water. The standard is that the raw strip steel exiting the last pair of squeeze rollers has no residual acid or water and the squeeze rollers have no adhesive residue. In the actual production activities involved by the inventors, after applying the solution of this application, the roller gap pressure of the squeeze rollers is set between 1 Bar and 5 Bar.

[0037] When the first two pairs of the three squeeze rolls are in use, the first pair of any two pairs performs rough extrusion on the raw strip, and the second pair of any two pairs performs fine extrusion. Here, "first pair" and "second pair" refer to any two pairs of squeeze rolls that are rearranged along the strip's movement direction. When all three pairs of squeeze rolls are in use, the first pair performs rough extrusion on the raw strip, the second pair performs fine extrusion, and the third pair performs supplementary extrusion. After the squeeze rolls have dried the raw strip, high-pressure air can be used for purging using fan-shaped nozzles.

[0038] The above solution enables graded treatment of raw strip steel, significantly reduces residual acid and water on the strip steel surface, reduces the burden of subsequent water washing, and lowers the risk of strip steel corrosion.

[0039] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0040] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0041] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for applying squeeze rollers in a normalizing pickling production line, characterized in that, The normalizing pickling production line has three pairs of squeezing rollers sequentially installed at the outlet section of the pickling tank. The application method of the squeezing rollers includes: The raw material strips fed into the normalizing pickling production line are classified into categories. The raw material strips with a width greater than or equal to a first preset value and a thickness greater than or equal to a second preset value are classified into the first category. All other raw material strips are classified into other categories. When extruding the raw strip steel of the first type, any two pairs of the three pairs of extrusion rollers are put into use. When extruding other types of raw material strips, all three pairs of extrusion rollers are put into use.

2. The method of applying the squeeze roller as described in claim 1, characterized in that, When the first state of squeezing strip with a width of the first preset value is switched to the second state of squeezing strip with a width less than and adjacent to the first preset value under the same conditions, the residual acid and water on the surface of the squeezed strip is the greatest. Under the same conditions, when the squeezing roller switches from the third state of squeezing strip steel with a thickness of the second preset value to the fourth state of squeezing strip steel with a thickness less than and adjacent to the second preset value, the residual acid and water on the surface of the squeezed strip steel is at its maximum.

3. The method of applying the squeeze roller as described in claim 2, characterized in that, Given that the thickness of the raw material strip is selected as 1.8mm, 2.0mm, 2.3mm, 2.4mm, or 2.6mm, the second preset value is 2.3mm.

4. The method of applying the squeeze roller as described in claim 2, characterized in that, The first preset value is 1000mm.

5. The method of applying the squeeze roller as described in any one of claims 1-4, characterized in that, The other types of raw material strip steel include: The second type of raw material strip steel with a width greater than or equal to the first preset value and a thickness less than the second preset value; The third type of raw material strip steel with a width less than the first preset value and a thickness greater than or equal to the second preset value; The fourth type of raw material strip steel has a width smaller than the first preset value and a thickness smaller than the second preset value.

6. The method of applying the squeeze roller as described in claim 5, characterized in that, The pressure value of the extrusion roller on the raw material strip is dynamically adjusted according to the specifications of the raw material strip and the amount of residual acid and water in the raw material strip, with the standard being that the raw material strip coming out of the last pair of extrusion rollers put into use has no residual acid and water and the extrusion roller has no glue falling off.

7. The method of applying the squeeze roller as described in claim 6, characterized in that, The gap pressure of the squeeze roller is 1 Bar-5 Bar.

8. The method of applying the squeeze roller as described in claim 6, characterized in that, When any two pairs of the three pairs of extrusion rolls are put into use, the first pair of extrusion rolls of any two pairs of extrusion rolls is used to perform rough extrusion on the raw material strip, and the second pair of extrusion rolls of any two pairs of extrusion rolls is used to perform fine extrusion on the raw material strip.

9. The method of applying the squeeze roller as described in claim 8, characterized in that, When all three pairs of extrusion rolls are in use, the first pair of extrusion rolls is used to perform rough extrusion on the raw material strip, the second pair of extrusion rolls is used to perform fine extrusion on the raw material strip, and the third pair of extrusion rolls is used to perform supplementary extrusion on the raw material strip.

10. The method of applying the squeeze roller as described in claim 1, characterized in that, It also includes the following steps: The squeezed raw material strip is then purged with high-pressure air.