A hot continuous rolling method and a hot continuous rolling device for a strip steel head portion

Abstract

The application discloses a hot continuous rolling method and device for a strip head, relates to the technical field of hot continuous rolling, and can improve the rolling stability of the strip head. The hot continuous rolling method for the strip head comprises the following steps: based on a set building-up angle, a loop is arranged between two adjacent groups of rolling rolls, in the operation direction of the strip, the connecting line between the nth loop and the nth group of rolling rolls is a first connecting line, the connecting line between the nth group of rolling rolls and the nth+1 group of rolling rolls in the operation direction of the strip is a second connecting line, and the building-up angle is the included angle between the first connecting line and the second connecting line, wherein n is a natural number greater than zero; based on the thickness variation of the head of the strip, the roll gap spacing of the rolling roll is adjusted; the loop tension after the roll gap spacing is adjusted is obtained, the position of the loop is adjusted based on the loop tension; and based on the position of the loop, the roll gap opening and closing state of the nth+1 group of rolling rolls is controlled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of strip steel processing, and particularly relates to a hot continuous rolling method and a hot continuous rolling device for a head of strip steel. BACKGROUND

[0002] At present, the threading of the strip steel is the most difficult link to control in a conventional hot continuous rolling production line. The thickness fluctuates due to temperature changes and setting deviations, and the loop building angle is too high or too low. The loop tension size affects the thickness, rolling force and roll gap.

[0003] Therefore, how to improve the rolling stability of the head of the strip steel is an urgent problem to be solved. SUMMARY

[0004] The hot continuous rolling method and the hot continuous rolling device for the head of the strip steel provided by the embodiments of the present application can improve the rolling stability of the head of the strip steel.

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

[0006] Based on the set loop building angle, a loop is arranged between two adjacent groups of rolling mills. In the operation direction of the strip steel, the line connecting the nth loop and the nth group of rolling mills is the first line, the line connecting the nth group of rolling mills and the nth+1 group of rolling mills is the second line, and the loop building angle is the included angle between the first line and the second line, wherein n is a natural number greater than zero;

[0007] Based on the thickness variation of the head of the strip steel, the roll gap spacing of the rolling mill is adjusted;

[0008] The loop tension after the adjustment of the roll gap spacing is obtained, and based on the loop tension, the position of the loop is adjusted;

[0009] Based on the position of the loop, the roll gap opening and closing state of the nth+1 group of rolling mills is controlled.

[0010] In some embodiments, the step of obtaining the loop tension after the adjustment of the roll gap further comprises:

[0011] The loop tension is compared with a tension threshold value, and in the case that the loop tension is less than the tension threshold value, the roll gap of the nth+1 group of rolling mills is kept open.

[0012] In some embodiments, the tension threshold value is 70% of the set tension, and the set tension is calculated based on the set loop building angle.

[0013] In some embodiments, based on the position of the loop, the step of controlling the roll gap opening and closing of the nth+1 group of rolling mills comprises:

[0014] The angle of the nth loop is determined.

[0015] In a case where the angle of the loop is higher than the first threshold value, the roll gap of the n+1 th group of rolling rollers is kept in an open state;

[0016] In a case where the angle of the loop is lower than the second threshold value, the roll gap of the n+1 th group of rolling rollers is kept in a closed state;

[0017] The second threshold value is less than the first threshold value.

[0018] In some embodiments, the step of setting the loop between the adjacent rolling rollers based on the set build angle comprises:

[0019] The set build angle is determined based on an actual build angle and an optimal build angle;

[0020] The actual build angle is an actual angle of the loop after the loop is built, and the optimal build angle is calculated based on a strip variety and / or a strip specification.

[0021] In some embodiments, the step of setting the loop between the adjacent rolling rollers based on the set build angle further comprises:

[0022] The strip running speed is adjusted based on a comparison result of the actual build angle and the optimal build angle.

[0023] In some embodiments, in a case where a thickness of the strip for rolling is less than 2 mm, the adjustment speed of the rolling rollers in the running direction of the strip is set to be gradually reduced one by one.

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

[0025] In some embodiments, in a case where the angle of the loop is higher than a first set angle, the speed-increasing operation of the n th group of rolling rollers is prohibited;

[0026] In a case where the angle of the loop is lower than a second set angle, the speed-decreasing operation of the n th group of rolling rollers is prohibited;

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

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

[0029] A plurality of groups of rolling rollers;

[0030] A plurality of loops, which are arranged between adjacent rolling rollers;

[0031] A control cabinet is connected with the loop and the rolling roller, and the control cabinet controls the loop and the rolling roller by using the hot strip head rolling method of any one of the above.

[0032] The beneficial effects of the present application are:

[0033] The present application associates the loop and the roll gap, and the parameters of the loop and the roll gap can be adjusted accordingly, avoiding the large thickness change of the strip after the tension is restored due to the AGC (AGC, Automatic Gage Control) adjustment, 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 loop can be limited based on the parameters of the loop or the roll gap. BRIEF DESCRIPTION OF DRAWINGS

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

[0035] Figure 2 A schematic partial structure diagram of a hot rolling device provided by an embodiment of the present application is shown in the figure.

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

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

[0038] In order to better understand the technical solutions provided by the embodiments of the present application, the technical solutions of the embodiments of the present application will be described in detail below by means of the accompanying drawings and specific embodiments. It should be understood that the specific features in the embodiments of the present application and the embodiments are detailed descriptions of the technical solutions of the embodiments of the present application, and not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0039] In this document, the terms such as first and second are used only 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", "contain" 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 not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or equipment including the element. The term "more than two" includes two or more than two.

[0040] Currently, the control method for the strip steel, such as the automatic gauge control (AGC) adjustment, is to eliminate the fluctuation of the rolling thickness by changing the roll gap, to reduce the influence of the tension on the thickness by maintaining the tension of the strip steel, and to achieve the interstand volume stability by changing the second flow through speed regulation, so that the loop and the roll gap are regarded as separate systems during the AGC adjustment, and the loop and the roll gap are adjusted to change the corresponding parameters, however, the two are irrelevant, causing the adjustment system based on the loop and the adjustment system based on the roll gap to influence each other, and adversely affecting the thickness control and the rolling stability control of the strip steel.

[0041] Meanwhile, the thickness fluctuation of the strip steel can be caused by the tension change, at this time, the adjustment direction of the roll gap can be opposite, when the AGC system is adjusted and the tension is restored to normal, due to the opposite adjustment direction of the part of the roll gap, the roll gap adjustment of the subsequent rolling mill is increased, not only leading to the increase of the thickness of the strip steel, but also affecting the rolling stability due to the large adjustment amount of the roll gap.

[0042] In addition, the existing control method does not limit the adjustment speed of the roll gap, and when the deviation is large and the adjustment is too fast, the interstand second flow imbalance is easily caused, leading to the tension loss and the rolling instability of the strip steel, which is not conducive to the rolling operation of the strip steel.

[0043] The hot continuous rolling method and the hot continuous rolling device for the head of the strip steel provided by the embodiments of the present application can improve the rolling stability of the head of the strip steel.

[0044] The first aspect of the present application, Figure 1 The schematic flow chart of the hot continuous rolling method for the head of the strip steel provided by the embodiments of the present application is shown in Figure 1 The hot continuous rolling method for the head of the strip steel provided by the embodiments of the present application is provided, which comprises:

[0045] S100: based on the set loop angle, a loop is arranged between the adjacent two groups of rolling mills, and based on the thickness of the head of the strip steel and the preformed thickness, the corresponding set loop angle can be adjusted.

[0046] For example, the head of the strip steel passes through one group of rolling mills, a loop and another group of rolling mills in sequence to form a loop angle. By changing the position of the loop or adjusting the rolling mill, the loop angle can be changed, so that the angle of the loop angle formed by the strip steel is the set loop angle, or the angle range of the loop angle is within the set range of the set loop angle.

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

[0048] In some examples, the strip steel can be transported through multiple sets of rolling rollers and multiple loops, according to the passing sequence of the strip steel head, the multiple sets of rolling rollers can be divided into the first set of rolling rollers, the second set of rolling rollers, the nth set of rolling rollers and the mth set of rolling rollers according to the passing order of the strip steel, 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 loops can also be divided into the first loop, the nth loop and the mth loop according to the order, where n and m are defined as above.

[0049] For example, any set of rolling rollers can include two or more rollers, and a roll gap can be formed between the rollers. The opening and size of the roll gap can be controlled by controlling the position of the rollers, so that the building angle can be dynamically adjusted during the rolling process of the strip steel.

[0050] In some examples, in the operation direction of the strip steel, the line connecting the nth loop and the nth set of rolling rollers is the first line, the line connecting the nth set of rolling rollers and the nth+1 set of rolling rollers in the operation direction of the strip steel is the second line, the building angle is the included angle between the first line and the second line, and n is a natural number greater than zero.

[0051] For example, the second line can be the line connecting the center points of the roll gaps of adjacent rolling rollers, and the angle of the building angle can be recorded as an acute angle.

[0052] In some examples, the building angle can be set based on the thickness of the strip steel head and the required thickness, and the thickness of the strip steel head after rolling by the corresponding rolling rollers changes differently when the building angle is set differently.

[0053] S200: Adjust the roll gap spacing of the rolling rollers based on the thickness variation of the strip steel head, so as to dynamically adjust the rolling rollers to ensure the thickness of the rolled strip steel head.

[0054] For example, the thickness of the strip steel head before rolling and the required thickness are obtained, and the thickness of the strip steel head after rolling by the corresponding rolling rollers is adjusted by respectively adjusting the roll gap spacing of the multiple sets of rolling rollers.

[0055] S300: Obtain the loop tension after adjusting the roll gap spacing, and adjust the position of the loop based on the loop tension.

[0056] For example, by adjusting the position of the loop, the building angle corresponding to the loop can be changed to adjust the loop tension.

[0057] S400: based on the position of the loop, control the opening and closing state of the roll gap of the n+1 group of rolling rollers. The opening state of the roll gap, for example, the roll gap between the n+1 group of rolling rollers is greater than the thickness when the strip head passes, so as to release the tension of the strip. The closed state of the roll gap, for example, the roll gap between the n+1 group of rolling rollers is less than or equal to the thickness when the strip head passes, so as to maintain the tension of the strip.

[0058] For example, the AGC adjustment system only adjusts the roll gap of the rolling roller alone, when the thickness of the strip changes, even if the thickness fluctuation of the strip may be caused by tension changes, the AGC system will make corresponding adjustments to the rolling roller to change the thickness of the strip. For example, when the tension at one of the loops is too large, it will cause the strip to be too thin, and when the strip is too thin, the AGC system will open the roll gap of the next group of rolling rollers, but the tension of the strip will quickly recover, and the thickness gauge is at the outlet of the last rack, and the detection is delayed, so that when the tension of the strip quickly recovers, the recovery time is less than the time for the strip at the loop to be transmitted to the thickness gauge, and the thickness of the strip corresponding to the loop has returned to normal, but the roll gap adjustment amount of the rolling roller after the loop is still increasing according to the detection of the thickness gauge, causing the strip thickness to increase. At the same time, due to the large adjustment amount of the subsequent roll gap, the stability of the strip rolling is affected. The control method of the present application can correspondingly adjust the roll gap of the next group or subsequent group of rolling rollers by analyzing the tension, to avoid the thickness variation of the strip after the tension recovers.

[0059] For example, by associating the loop and the roll gap, the parameters of the loop and the roll gap can be adjusted accordingly, to avoid the thickness variation of the strip after the tension recovers caused by AGC adjustment, to ensure stable adjustment of the thickness of the strip, and to improve the stability of the strip rolling; at the same time, the parameters of the roll gap or the loop can be limited based on the parameters of the loop or the roll gap. In addition, due to the existence of the lost tension section in the strip rolling process, the centering of the strip is difficult to guarantee, and there are phenomena such as deviation and rolling. By controlling the loop and the roll gap, the present application can improve the thickness hit rate of the strip head while ensuring the stability of the strip.

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

[0061] S110: based on the actual tension angle and the optimal tension angle, determine the set tension angle.

[0062] For example, the actual tension angle can be the actual angle after the loop is tensioned, and the optimal tension angle can be calculated by at least one of the parameters of the strip variety and specification.

[0063] In some examples, the actual angle of each loop when tensioning can be collected when the strip is being fed, and the data can be stored according to the steel grade and specification, to facilitate subsequent tensioning.

[0064] In some examples, each loop can be set with an optimal build angle according to different steel grades and specifications. For example, when rolling thin-gauge pickling plate, the optimal build angle of the first loop to the third loop can be 20 degrees, and the optimal build angle of the fourth loop to the sixth loop can be 15 degrees.

[0065] In some examples, S100: based on the set build angle, the step of setting the loop between the adjacent rolling rolls further comprises:

[0066] S120: based on the comparison result of the actual build angle and the optimal build angle, adjusting the strip threading speed.

[0067] For example, the angle of the build angle is different, and the corresponding strip tension is different. Based on the different strip tension, the strip threading speed is adjusted to avoid the phenomenon of drawing steel.

[0068] In some examples, S300: after the step of obtaining the loop tension after adjusting the roll gap, further comprises:

[0069] S310, compare the loop tension with the tension threshold value, and in the case that the loop tension is less than the tension threshold value, keep the roll gap of the nth+1 group of rolling rolls open.

[0070] For example, the size of the loop tension will affect the thickness of the strip, the rolling force and the roll gap. Associating the on-off state of the roll gap of the rolling roll with the strip tension can ensure the stability of rolling. For example, when the loop tension is less than the tension threshold value, it is determined that the loop tension is small, and the roll gap of the next group of rolling rolls is opened, so that the subsequent roll gap is adjusted to adjust the tension of the loop.

[0071] In some examples, the tension threshold value can be 70% of the set tension, and the set tension can be calculated by setting the build angle.

[0072] For example, in the case that the strip tension is less than 70% of the set tension and lasts for a certain time, for example, 0.3s, the roll gap of the nth+1 group of rolling rolls is kept open, that is, the roll gap of the rolling roll is prohibited to be closed.

[0073] In some examples, S400: based on the position of the loop, the step of controlling the opening and closing of the roll gap of the nth+1 group of rolling rolls comprises:

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

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

[0076] S420: In the case that the angle of the loop is higher than the first threshold value, the roll gap of the n+1th group of rolling rollers is kept in an open state.

[0077] For example, the angle of the loop is too high, so that the strip tension at the loop can be large, the roll gap of the next group of rolling rollers is open, thereby providing a margin for the roll gap adjustment of the next group or subsequent group of rolling rollers.

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

[0079] S430: In the case that the angle of the loop is lower than the second threshold value, the roll gap of the n+1th group of rolling rollers is kept in a closed state, and the second threshold value is less than the first threshold value.

[0080] For example, the roll gap of the next group of rolling rollers is closed, thereby determining the strip tension corresponding to the loop to avoid excessive tension of the subsequent loop affecting the strip tension of the loop.

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

[0082] In some examples, in the case that the thickness of the strip for rolling is less than 2 mm, the adjustment speed of the rolling rollers in the operation direction of the strip is set to decrease uniformly.

[0083] For example, when the thickness of the strip for rolling is less than 2 mm, the adjustment speed of the roll gap is limited to avoid the phenomenon of strip tension loss caused by too fast adjustment speed.

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

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

[0086] In some examples, in the case that the angle of the n th loop is higher than the first set angle, the speed-up operation of the n th group of rolling rollers is prohibited, thereby associating the loop angle and manual speed intervention to eliminate invalid intervention.

[0087] For example, the speed-up operation is a manual speed-up, and the angle of the n th 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 looper is lower than the second set angle, the deceleration operation of the nth set of rolling rolls 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 the actual situation.

[0091] Figure 2 This is a schematic partial structural diagram of a hot continuous rolling mill provided for embodiments of this application. In some examples, reference is made to... Figure 2 This application proposes a hot continuous rolling mill apparatus, comprising: multiple sets of rolling rolls 200, multiple loopers 100, and a control cabinet. The loopers 100 are disposed between two adjacent sets of rolling rolls 200. The control cabinet can be connected to both the loopers 100 and the rolling rolls 200. (The control cabinet is not included in the main text.) Figure 2 (As shown in the diagram) The hot continuous rolling method for the strip head in any of the above technical solutions can be used to control the looper 100 and the rolling roll 200. Furthermore, the control cabinet model can be reasonably selected based on the on-site processing conditions.

[0092] For example, refer to Figure 2 In the strip's running direction, the line connecting the nth looper 100 and the nth group of rolling rolls 200 is the first connecting line, and the line connecting the nth group of rolling rolls 200 and the (n+1)th group of rolling rolls 200 in the strip's running direction is the second connecting line. The tension angle θ is the angle between the first connecting line and the second connecting line. The nth group of rolling rolls 200 is, for example... Figure 2 F in n As shown, the (n+1)th group of rolling rolls 200, for example Figure 2 F in n+1 As shown, the angle θ is established as follows: Figure 2 The label θ is shown in the figure.

[0093] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0094] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

[0095] While the preferred embodiments of the application have been described, additional variations and modifications can be made to the preferred embodiments by those skilled in the art once they have the benefit of the present disclosure. Therefore, the appended claims are intended to encompass all such variations and modifications as falling within the scope of the present application. What is claimed is:

[0096] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the application can be practiced otherwise than as specifically described herein.

Claims

1. A hot continuous rolling method for the head of a strip, characterized in that, include: Based on the set tension angle, a looper is set between two adjacent sets of rolling rolls. In the strip's operating direction, the line connecting the nth looper and the nth set of rolling rolls is the first line, and the line connecting the nth set of rolling rolls and the (n+1)th set of rolling rolls in the strip's operating direction 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. The roll gap spacing of the rolling rolls is adjusted based on the change in the head thickness of the strip. Obtain the looper tension after adjusting the roll gap, and adjust the position of the looper based on the looper tension; Based on the position of the looper, the opening and closing state of the roll gap of the (n+1)th group of rolling rolls is controlled; When the thickness of the strip used for rolling is less than 2 mm, the adjustment speed of the rolling rolls in the operating direction of the strip is set to be reduced uniformly one by one. When the thickness of the strip used for rolling is less than 2 mm, the adjustment speed of the nth group of rolling rolls is less than 0.3 mm / s, the adjustment speed of the (n+1)th group of rolling rolls is less than 0.2 mm / s, and the adjustment speed of the (n+2)th group of rolling rolls is less than 0.1 mm / s in the operating direction of the strip.

2. The hot continuous rolling method for the head of strip steel according to claim 1, characterized in that, The step of obtaining the looper tension after adjusting the roll gap further includes: The looper tension is compared with the tension threshold. If the looper tension is less than the tension threshold, the roll gap of the (n+1)th set of rolling rolls is kept open.

3. The hot continuous rolling method for the head of strip steel according to claim 2, characterized in that, The tension threshold is 70% of the set tension, which is calculated using the set tension angle.

4. The hot continuous rolling method for the head of strip steel according to claim 1, characterized in that, The step of controlling the opening and closing of the roll gap of the (n+1)th group of rolling rolls based on the position of the looper includes: Determine the angle of the nth loop; When the angle of the looper is higher than the first threshold, the roll gap of the (n+1)th group of rolling rolls remains open; When the angle of the looper is lower than the second threshold, the roll gap of the (n+1)th set of rolling rolls remains closed. Wherein, the second threshold is less than the first threshold.

5. The hot continuous rolling method for the head of strip steel according to claim 1, characterized in that, The step of setting a looper between adjacent rolling rolls based on a set tension angle includes: The set setting angle is determined based on the actual setting angle and the optimal setting angle; Wherein, the actual tension angle is the actual angle after the looper tensions are established, and the optimal tension angle is calculated based on the strip steel type and / or specifications.

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

7. The hot continuous rolling method for the head of strip steel according to claim 1, characterized in that, If the angle of the nth looper is higher than the first set angle, the speed increase operation of the nth set of rolling rolls is prohibited; If the angle of the nth looper is lower than the second set angle, the deceleration operation of the nth set of rolling rolls is prohibited; The first set angle is higher than the second set angle.

8. A hot continuous rolling mill apparatus, characterized in that, include: Multiple sets of rolling rolls; Multiple loopers are positioned between adjacent rolling rolls; A control cabinet is connected to the looper and the rolling rolls, and the control cabinet controls the looper and the rolling rolls using the hot continuous rolling method for the strip head as described in any one of claims 1-7.

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