Hot continuous rolling method and hot continuous rolling device for strip steel head

Abstract

The invention discloses a hot continuous rolling method and a hot continuous rolling device for a strip steel head, relates to the technical field of hot continuous rolling, and can improve the rolling stability of the strip steel head. The hot continuous rolling method for the strip steel head comprises the steps that on the basis of a set opening angle, loops are arranged between every two adjacent sets of rolling rollers, in the running direction of strip steel, the connecting line of the nth loop and the nth set of rolling rollers serves as a first connecting line, and the connecting line of the nth set of rolling rollers and the (n + 1) th set of rolling rollers in the running direction of the strip steel serves as a second connecting line, the field angle is an included angle between the first connecting line and the second connecting line, and n is a natural number larger than zero; based on the head thickness variable quantity of the strip steel, the roller gap distance of the rolling rollers is adjusted; the tension of the loop after the roller gap distance is adjusted is obtained, and the position of the loop is adjusted based on the tension of the loop; and controlling the roll gap opening and closing state of the (n + 1) th group of rolling rolls based on the position of the loop.

Description

Technical Field

[0001] The present application relates to the technical field of strip steel processing, and in particular to a hot rolling method and a hot rolling device for a strip steel head. Background Art

[0002] At present, the most difficult part to control in conventional hot rolling production lines is the strip threading. Affected by temperature changes, setting deviations, etc., the thickness will fluctuate, and the looper tension angle may be too high or too low. The size of the looper tension will affect the thickness, rolling force, and roll gap.

[0003] In summary, how to improve the rolling stability of the strip head is an urgent problem to be solved. Summary of the invention

[0004] A hot rolling method and a hot rolling device for a strip head provided in an embodiment of the present application can improve the rolling stability of the strip head.

[0005] A first aspect of an embodiment of the present application provides a method for hot continuous rolling of a strip head, comprising:

[0006] Based on the set tension angle, a looper is set between two adjacent groups of rolling rollers. In the running direction of the strip, the line connecting the nth looper and the nth group of rolling rollers is the first line, and the line connecting the nth group of rolling rollers and the n+1th group of rolling rollers in the running direction of the strip is the second line. The tension angle is the angle between the first line and the second line, where n is a natural number greater than zero.

[0007] Based on the thickness variation of the head of the strip, the gap between the rolling rolls is adjusted;

[0008] Obtain the looper tension after adjusting the roller gap spacing, and adjust the looper position based on the looper tension;

[0009] Based on the position of the looper, the opening and closing state of the roll gap of the n+1th group of rolling rolls is controlled.

[0010] In some embodiments, after the step of obtaining the looper tension after adjusting the roll gap, the step further includes:

[0011] The loop tension is compared with the tension threshold, and when the loop tension is less than the tension threshold, the roll gap of the n+1th group of rolling rolls is kept open.

[0012] In some embodiments, the tension threshold is 70% of the set tension, and the set tension is calculated by setting the tension build-up angle.

[0013] In some embodiments, the step of controlling the opening and closing of the roll gap of the n+1th group of rolling rolls based on the position of the looper includes:

[0014] Determine the angle of the nth looper;

[0015] When the angle of the looper is higher than the first threshold value, the roll gap of the n+1th group of rolling rolls is kept open;

[0016] When the angle of the looper is lower than the second threshold value, the roll gap of the n+1th group of rolling rolls is kept closed;

[0017] The second threshold is smaller than the first threshold.

[0018] In some embodiments, based on setting the tension angle, the step of setting a looper between adjacent rolling rolls includes:

[0019] Determine a set opening angle based on the actual opening angle and the optimal opening angle;

[0020] The actual opening angle is the actual angle after the loop is opened, and the optimal opening angle is calculated according to the type and / or specification of the strip steel.

[0021] In some embodiments, based on the setting of the tension angle, the step of providing a looper between adjacent rolling rolls further includes:

[0022] Based on the comparison results between the actual opening angle and the optimal opening angle, the strip threading speed is adjusted.

[0023] In some embodiments, when the thickness of the steel strip to be rolled is less than 2 mm, the adjustment speeds of the rolling rollers in the running direction of the steel strip are uniformly reduced one by one.

[0024] In some embodiments, when the thickness of the strip steel for rolling is less than 2 mm, in the running direction of the strip steel, the adjustment speed of the nth group of rolling rollers is less than 0.3 mm / s, the adjustment speed of the n+1th group of rolling rollers is less than 0.2 mm / s, and the adjustment speed of the n+2th group of rolling rollers is less than 0.1 mm / s.

[0025] In some embodiments, when the angle of the looper is higher than the first set angle, the speed increase operation of the nth group of rolling rollers is prohibited;

[0026] When the angle of the looper is lower than the second set angle, the speed reduction operation of the nth group of rolling rolls is prohibited;

[0027] The first setting angle is higher than the second setting angle.

[0028] A second aspect of the embodiment of the present application provides a hot rolling device, comprising:

[0029] Multiple sets of rolling rollers;

[0030] A plurality of loopers are arranged between adjacent rolling rolls;

[0031] A control cabinet is connected with the looper and the rolling roller, and the control cabinet controls the looper and the rolling roller by adopting any of the above-mentioned hot rolling methods for the strip head.

[0032] The beneficial effects of this application are:

[0033] The present application associates the looper and the roll gap so that the parameters of the looper and the roll gap can be adjusted accordingly, thereby avoiding AGC (Automatic Gage Control) adjustment that causes a large change in the thickness of the strip after tension recovery, ensuring stable adjustment of the strip thickness, and improving the rolling stability of the strip; at the same time, the parameters of the roll gap or the looper can be limited based on the parameters of the looper or the roll gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic flow chart of a hot rolling method for a strip head provided in an embodiment of the present application;

[0035] Figure 2 A schematic partial structural diagram of a hot rolling device provided in an embodiment of the present application.

[0036] The reference numerals in the figure represent respectively:

[0037] 100, looper; 200, rolling roller; θ, tension angle. DETAILED DESCRIPTION

[0038] In order to better understand the technical solutions provided by the embodiments of this specification, the technical solutions of the embodiments of this specification are described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of this specification and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this specification, rather than limitations on the technical solutions of this specification. In the absence of conflict, the embodiments of this specification and the technical features in the embodiments can be combined with each other.

[0039] In this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the statement "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. The term "more than two" includes two or more than two situations.

[0040] At present, the control methods for strip steel, such as automatic thickness control (AGC), are adjusted by changing the roll gap to eliminate the fluctuation of rolling thickness, by maintaining the tension of the strip to reduce the influence of tension on thickness, and by adjusting the speed to change the flow rate per second to achieve the stability of the inter-frame amount. Therefore, when adjusting the AGC, the loop and the roll gap are regarded as separate systems, and the loop and the roll gap are adjusted separately to change the corresponding parameters. However, the two are completely unrelated, resulting in the mutual influence between the adjustment system based on the loop and the adjustment system based on the roll gap, and adversely affecting the thickness control and rolling stability control of the strip steel.

[0041] At the same time, the thickness fluctuation of the strip may be caused by the change of tension. At this time, the roll gap adjustment direction may be reversed. When the AGC system is adjusted and the tension returns to normal, since the adjustment direction of this part of the roll gap is opposite, the roll gap adjustment of the subsequent rolling rolls will be increased, which will not only cause the thickness of the strip to increase, but also affect the rolling stability due to the large roll gap adjustment.

[0042] In addition, the existing control method does not limit the roll gap adjustment speed. When the deviation is large and the adjustment is too fast, it is easy to cause an imbalance in the second flow rate between the frames, resulting in strip tension loss and unstable rolling, which is not conducive to the strip rolling operation.

[0043] A hot rolling method and a hot rolling device for a strip head provided in an embodiment of the present application can improve the rolling stability of the strip head.

[0044] In the first aspect of this application, Figure 1 A schematic flow chart of a hot rolling method for a strip head provided in an embodiment of the present application, see Figure 1 , provides a hot continuous rolling method for a strip head, comprising:

[0045] S100: Based on the set tensioning angle, a looper is set between two adjacent groups of rolling rolls, and the corresponding set tensioning angle can be adjusted based on the thickness of the strip head and the prefabricated thickness.

[0046] Exemplarily, the head of the strip passes through one set of rolling rollers, the looper and another set of rolling rollers in sequence to form a build-up angle. The build-up angle can be changed by changing the position of the looper or adjusting the rolling rollers, so that the angle of the build-up angle formed by the strip is the set build-up angle, or the angle range of the build-up angle is within the set range of the set build-up angle.

[0047] In some examples, the number of groups of rolling rolls is greater than or equal to two, and the number of loops is greater than one, so that the above-mentioned tensioning angle can be formed.

[0048] In some examples, the strip can be transmitted through multiple groups of rolling rollers and multiple loopers. According to the order in which the head of the strip passes, the multiple groups of rolling rollers can be divided into the first group of rolling rollers, the second group of rolling rollers, the nth group of rolling rollers and the mth group of rolling rollers according to the passing position of the strip, where n and m are natural numbers greater than zero, m is greater than n, and n and m can be infinite. Correspondingly, the multiple loopers can also be divided into the first looper, the nth looper and the mth looper according to the position, where n and m are defined as above.

[0049] Exemplarily, any group of rolling rollers may include two or more rollers, and a roll gap may be formed between the rollers. The opening and closing of the roll gap and the opening size of the roll gap may be controlled by controlling the positions of the rollers, thereby dynamically adjusting the tension angle during the rolling process of the strip.

[0050] In some examples, in the running direction of the strip, the line connecting the nth loop and the nth group of rolling rollers is the first line, the line connecting the nth group of rolling rollers and the n+1th group of rolling rollers in the running direction of the strip is the second line, the tension angle is the angle between the first line and the second line, and n is a natural number greater than zero.

[0051] Exemplarily, the second connecting line may be a connecting line between the center points of the roll gaps between adjacent rolling rolls, and the angle of the tensioning angle may be recorded as an acute angle.

[0052] In some examples, the setting of the tension angle may be set based on the thickness of the strip head and the required thickness. Different setting of the tension angle may result in different changes in the thickness of the strip head after rolling by the corresponding rolling rollers.

[0053] S200: Based on the thickness variation of the strip head, the roll gap spacing of the rolling rolls is adjusted, thereby dynamically adjusting the rolling rolls to ensure the thickness of the strip head after rolling.

[0054] Exemplarily, the thickness of the head of the steel strip before rolling and the required thickness are obtained, and the thickness of the head of the steel strip after passing through the corresponding rolling rollers is regulated by adjusting the roll gap spacings of multiple groups of rolling rollers respectively.

[0055] S300: Acquire the loop tension after adjusting the roller gap distance, and adjust the position of the loop based on the loop tension.

[0056] Exemplarily, by adjusting the position of the loop, the tension angle corresponding to the loop can be changed to regulate the tension of the loop.

[0057] S400: Based on the position of the looper, the roll gap of the n+1 group of rolling rolls is controlled to be open and closed. The roll gap is opened, for example, the roll gap between the n+1 group of rolling rolls is larger than the thickness when the strip head passes through, thereby releasing the tension of the strip. The roll gap is closed, for example, the roll gap between the n+1 group of rolling rolls is smaller than or equal to the thickness when the strip head passes through, thereby maintaining the tension of the strip.

[0058] Exemplarily, the AGC adjustment system will only adjust the roll gap of the rolling rollers individually. When the thickness of the strip changes, even if the thickness fluctuation of the strip may be caused by the change in tension, the AGC system will make corresponding adjustments to the rolling rollers to change the thickness of the strip. For example, when the tension at one of the loops is too large, the strip will be thin. When the strip is thin, the AGC system will open the roll gap of the next group of rolling rollers, but the tension of the strip will recover quickly, and the thickness gauge is at the exit of the last rack, and its detection is delayed, so when the tension of the strip is quickly recovered, the recovery time will be less than the time for the strip at the loop to be transmitted to the thickness gauge). The strip thickness corresponding to the loop is normal, but the roll gap adjustment amount of the rolling roller after the loop is still correspondingly increased according to the detection of the thickness gauge, resulting in a larger thickness of the strip. At the same time, due to the large adjustment amount of the subsequent roll gap, it will affect the stability of the strip rolling. The control method of the present application can adjust the roll gap of the next group or subsequent groups of rolling rollers accordingly through the analysis of the tension to avoid the problem of thickness excess caused by the recovery of the strip tension.

[0059] Exemplarily, the present application associates the looper and the roll gap so that the parameters of the looper and the roll gap can be adjusted accordingly, thereby avoiding the AGC adjustment causing a large change in the thickness of the strip after the tension is restored, ensuring the stable adjustment of the strip thickness, and improving the rolling stability of the strip; at the same time, the parameters of the roll gap or the looper can be limited based on the parameters of the looper or the roll gap. In addition, due to the existence of a tension loss section during the strip rolling process, the centering of the strip is difficult to ensure, and there are phenomena such as deviation and crushing. The present application controls the looper and the roll gap, while ensuring the threading stability, it can also improve the thickness hit rate of the strip head.

[0060] In some examples, S100: the step of setting a looper between adjacent rolling rolls based on the set tension angle includes:

[0061] S110: Determine a set opening angle based on the actual opening angle and the optimal opening angle.

[0062] Exemplarily, the actual opening angle may be the actual angle after the loop is opened, and the optimal opening angle may be calculated based on at least one parameter of the strip type and specification.

[0063] In some examples, the actual angles of each loop when the strip is threaded can be collected, and the data can be stored according to steel type and specification to facilitate subsequent construction.

[0064] In some examples, each looper can set an optimal opening angle according to different steel grades and specifications. For example, when rolling thin pickled plates, the optimal opening angle from the first looper to the third looper can be 20 degrees, and the optimal opening angle from the fourth looper to the sixth looper can be 15 degrees.

[0065] In some examples, S100: the step of setting a looper between adjacent rolling rolls based on the set tension angle further includes:

[0066] S120: Based on the comparison result between the actual opening angle and the optimal opening angle, the strip threading speed is adjusted.

[0067] For example, different tensioning angles correspond to different strip tensions. Based on the different strip tensions, the strip threading speed is adjusted to avoid the phenomenon of steel pulling.

[0068] In some examples, after the step of S300: obtaining the looper tension after adjusting the roll gap, the method further includes:

[0069] S310, comparing the loop tension with the tension threshold, and when the loop tension is less than the tension threshold, keeping the roll gap of the n+1th group of rolling rolls open.

[0070] For example, the size of the looper tension will affect the thickness of the strip, the rolling force, and the roll gap. Associating the open and close state of the roll gap of the rolling roll with the strip tension can ensure the stability of rolling. For example, when the looper tension is less than the tension threshold, it is determined that the looper tension is small, and the roll gap of the next group of rolling rolls is opened to facilitate subsequent roll gap adjustment to adjust the looper tension.

[0071] In some examples, the tension threshold may be 70% of a set tension, and the set tension may be calculated by setting a tension build-up angle.

[0072] Exemplarily, when the strip tension is less than 70% of the set tension and lasts for a certain period of time, such as 0.3s, the roll gap of the n+1th group of rolling rolls remains open, that is, the roll gap of the rolling rolls is prohibited from closing.

[0073] In some examples, S400: based on the position of the looper, the step of controlling the opening and closing of the roll gap of the n+1th group of rolling rolls includes:

[0074] S410: Determine the angle of the nth loop.

[0075] For example, after the tensioning angle of the loop is determined, the strip tension can be determined, and based on the strip tension, the roll gap spacing of the rolling rolls adjacent to the loop can be regulated.

[0076] S420: When the angle of the loop is higher than the first threshold value, the roll gap of the n+1th group of rolling rolls remains open.

[0077] Exemplarily, the angle of the loop is too high, so that the strip tension at the loop may be relatively large, and the roll gap of the next group of rolling rolls is opened, thereby providing a margin for adjusting the roll gap of the next or subsequent group of rolling rolls.

[0078] In some examples, the first threshold may be 28 degrees.

[0079] S430: When the angle of the loop is lower than a second threshold, the roll gap of the n+1th group of rolling rolls is kept closed, and the second threshold is smaller than the first threshold.

[0080] Exemplarily, the roll gap of the next group of rolling rolls of the loop is closed, thereby determining the strip tension corresponding to the loop, so as to avoid excessive tension of subsequent loops and affect the strip tension of the loop.

[0081] In some examples, the second threshold may be 15 degrees.

[0082] In some examples, when the thickness of the steel strip to be rolled is less than 2 mm, the adjustment speeds of the rolling rollers in the running direction of the steel strip are uniformly reduced one by one.

[0083] For example, when the thickness of the rolled steel strip is below 2 mm, the adjustment speed of the roll gap is limited to avoid the phenomenon of the steel strip losing tension due to the excessively fast adjustment speed.

[0084] In some examples, when the thickness of the strip for rolling is less than 2 mm, in the running direction of the strip, the adjustment speed of the nth group of rolling rollers can be less than 0.3 mm / s, the adjustment speed of the n+1th group is less than 0.2 mm / s, and the adjustment speed of the n+2th group of rolling rollers is less than 0.1 mm / s.

[0085] Illustratively, in the transmission direction of the strip, the adjustment speed of the fifth group of rolling rollers can be lower than 0.3 mm / s, the adjustment speed of the sixth group of rolling rollers can be lower than 0.2 mm / s, and the adjustment speed of the seventh group of rolling rollers can be lower than 0.1 mm / s.

[0086] In some examples, when the angle of the nth loop is higher than the first set angle, the speed increase operation of the nth group of rolling rolls is prohibited, thereby associating the loop angle with manual speed intervention to eliminate invalid intervention.

[0087] Exemplarily, the speed increase operation is a manual speed increase when the opening angle of the nth loop is higher than the set angle.

[0088] In some examples, the first set angle can be set according to actual conditions.

[0089] In some examples, when the angle of the nth loop is lower than the second set angle, the speed reduction operation of the nth group of rolling rollers is prohibited, and the first set angle is higher than the second set angle.

[0090] In some examples, the second set angle can be set according to actual conditions.

[0091] Figure 2 A schematic partial structural diagram of a hot rolling device provided in an embodiment of the present application. In some examples, reference Figure 2 The present application proposes a hot rolling device, comprising: a plurality of rolling rollers 200, a plurality of loopers 100 and a control cabinet. The loopers 100 are arranged between two adjacent rolling rollers 200, and the control cabinet can be connected to the loopers 100 and the rolling rollers 200 respectively. Figure 2 (shown in the figure) the hot rolling method of the strip head in any of the above technical solutions can be used to control the looper 100 and the rolling roller 200. In addition, the control cabinet model can be reasonably selected according to the on-site processing conditions.

[0092] Exemplary, reference Figure 2 In the running direction of the strip, the line connecting the nth looper 100 and the nth group of rolling rollers 200 is the first line, and the line connecting the nth group of rolling rollers 200 and the n+1th group of rolling rollers 200 in the running direction of the strip is the second line, and the tension angle θ is the angle between the first line and the second line. Figure 2 F n As shown, the n+1th group of rolling rollers 200 is, for example Figure 2 F n+1 As shown, the opening angle θ is Figure 2 As shown in the mark θ.

[0093] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0094] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

[0095] Although the preferred embodiments of this specification have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of this specification.

[0096] Obviously, those skilled in the art can make various changes and modifications to this specification without departing from the spirit and scope of this specification. Thus, if these modifications and variations of this specification fall within the scope of the claims of this specification and their equivalents, this specification is also intended to include these modifications and variations.

Claims

1. A hot rolling method for a strip head, characterized in that: include: Based on the setting of the tension angle, a looper is set between two adjacent groups of rolling rollers, in the running direction of the strip, the connection line between the nth looper and the nth group of rolling rollers is the first connection line, and the connection line between the nth group of rolling rollers and the n+1th group of rolling rollers in the running direction of the strip is the second connection line, and the tension angle is the angle between the first connection line and the second connection line, wherein n is a natural number greater than zero; Adjusting the roll gap of the rolling rolls based on the thickness variation of the head of the strip; Acquire the loop tension after adjusting the roller gap spacing, and adjust the position of the loop based on the loop tension; Based on the position of the loop, the opening and closing state of the roll gap of the n+1th group of rolling rolls is controlled.

2. The hot rolling method for a strip head according to claim 1, characterized in that: The step of obtaining the looper tension after adjusting the roll gap also includes: The loop tension is compared with a tension threshold, and when the loop tension is less than the tension threshold, the roll gap of the n+1th group of rolling rolls is kept open.

3. The hot rolling method for a strip head according to claim 2, characterized in that: The tension threshold is 70% of the set tension, and the set tension is calculated by the set tension angle.

4. The hot rolling method for a strip head according to claim 1, characterized in that: The step of controlling the opening and closing of the roll gap of the n+1th group of rolling rolls based on the position of the loop comprises: Determining the angle of the nth said loop; When the angle of the looper is higher than a first threshold, the roll gap of the n+1th group of rolling rolls is kept open; When the angle of the looper is lower than a second threshold, the roll gap of the n+1th group of rolling rolls is kept closed; The second threshold is smaller than the first threshold.

5. The hot rolling method for a strip head according to claim 1, characterized in that: The step of setting a looper between adjacent rolling rolls based on setting the tension angle comprises: Determining the set opening angle based on the actual opening angle and the optimal opening angle; Among them, the actual opening angle is the actual angle after the loop is opened, and the optimal opening angle is calculated based on the strip steel type and / or specification.

6. The method for hot continuous rolling of a strip head according to claim 5, characterized in that: The step of setting a looper between adjacent rolling rolls based on setting the tension angle also includes: Based on the comparison result between the actual opening angle and the optimal opening angle, the strip threading speed of the strip is adjusted.

7. The method for hot continuous rolling of a strip head according to claim 1, characterized in that: When the thickness of the steel strip to be rolled is less than 2 mm, the adjustment speeds of the rolling rolls in the running direction of the steel strip are uniformly reduced one by one.

8. The method for hot continuous rolling of a strip head according to claim 7, characterized in that: When the thickness of the strip steel used for rolling is less than 2 mm, in the running direction of the strip steel, the adjustment speed of the nth group of rolling rollers is less than 0.3 mm / s, the adjustment speed of the n+1th group of rolling rollers is less than 0.2 mm / s, and the adjustment speed of the n+2th group of rolling rollers is less than 0.1 mm / s.

9. The method for hot continuous rolling of a strip head according to claim 1, characterized in that: When the angle of the nth loop is higher than the first set angle, the speed increase operation of the nth group of rolling rolls is prohibited; When the angle of the nth loop is lower than the second set angle, the speed reduction operation of the nth group of rolling rollers is prohibited; Wherein, the first setting angle is higher than the second setting angle.

10. A hot rolling device, characterized in that: include: Multiple sets of rolling rollers; A plurality of loopers are arranged between adjacent rolling rolls; A control cabinet is connected to the looper and the rolling roller, and the control cabinet uses the hot rolling method for the strip head as described in any one of claims 1-9 to control the looper and the rolling roller.

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