Method and apparatus for on-line secondary cold rolling of tinplate

Abstract

The application relates to an online secondary cold rolling method and device for tinned plate, which comprises the following steps: inputting the tinned plate into a double-rack flattening machine; obtaining the distance between the weld of the tinned plate and the roll gap of the double-rack flattening machine; obtaining the strip thickness of the tinned plate; adjusting the inlet strip speed of the double-rack flattening machine according to the distance; adjusting the strip tension of the double-rack flattening machine according to the distance and the strip thickness; and adjusting the rolling force of the double-rack flattening machine according to the distance. The online secondary cold rolling method and device for tinned plate can solve the problem of strip breakage during the continuous rolling of the secondary cold rolling tinned plate, can provide a reasonable process parameter setting method and measure to realize online continuous rolling, and can improve the rolling stability and shorten the production cycle.

Description

Technical Field

[0001] This application relates to the field of secondary cold rolling, and more particularly to an online secondary cold rolling method and apparatus for tinplate. Background Technology

[0002] Secondary cold rolling refers to a second rolling process following the initial cold rolling in a continuous cold rolling mill, after annealing. This second rolling typically uses a two-stand leveling mill. The first stand typically has a reduction rate of 20%-40%, while the second stand uses a leveling mode with a reduction rate between 0.5%-1.5%. The thickness of secondary cold-rolled tinplate generally ranges from 0.1% to 0.3 mm. Currently, the production of secondary cold-rolled tinplate generally employs a continuous annealing followed by offline secondary cold rolling. This avoids strip breakage issues. However, if online continuous secondary cold rolling could be implemented, production efficiency could be improved and the strip production cycle shortened.

[0003] like Figure 1 As shown, due to the relatively thin strip, the reduction rate of the first stand is large during secondary cold rolling, and strip breakage frequently occurs before and after the weld. How to avoid strip breakage at the weld during online secondary cold rolling is key to achieving online rolling of tinplate, and therefore requires improvement. Summary of the Invention

[0004] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this application provides an online secondary cold rolling method and apparatus for tinplate.

[0005] In a first aspect, this application provides an online secondary cold rolling method for tinplate, the method comprising the following steps:

[0006] Input the tin-plated sheet into the double-frame leveling machine;

[0007] Obtain the distance between the weld seam of the tin-plated plate and the roll gap of the double-frame leveling machine;

[0008] Obtain the strip thickness of the tin-plated sheet;

[0009] Adjust the inlet strip speed of the double-frame leveler according to the distance;

[0010] The strip tension of the double-frame leveler is adjusted according to the distance and the strip thickness.

[0011] The rolling force of the double-stand leveler is adjusted according to the distance.

[0012] Preferably, adjusting the inlet strip speed of the dual-stand leveler according to the distance includes the following steps:

[0013] Determine whether the distance is greater than a preset distance;

[0014] If so, maintain the inlet strip speed at the first speed;

[0015] If not, reduce the inlet strip speed from the first speed to the second speed.

[0016] Preferably, the range of the first speed is 500m / min-750m / min.

[0017] Preferably, the second speed is 60 m / min.

[0018] Preferably, adjusting the strip tension of the double-frame leveler according to the distance and the strip thickness includes the following steps:

[0019] Determine whether the distance is greater than a preset distance;

[0020] If so, the strip tensions corresponding to the first frame inlet, the second frame inlet, and the second frame outlet of the dual-frame leveling machine are T1, T2, and T3, respectively;

[0021] If not, based on the strip thickness calculation coefficient a, the strip tension corresponding to the first frame inlet, the second frame inlet, and the second frame outlet is reduced to aT1, aT2, and aT3, respectively.

[0022] Preferably, the expression between the coefficient a and the strip thickness h is:

[0023] .

[0024] Preferably, adjusting the rolling force of the double-stand leveler according to the distance includes the following steps:

[0025] Determine whether the distance is greater than a preset distance;

[0026] If so, the rolling forces corresponding to the first and second stands of the dual-stand leveling machine are F1 and F2, respectively;

[0027] If not, reduce the rolling forces corresponding to the first frame and the second frame to the first rolling force and the second rolling force, respectively.

[0028] Preferably, the range of the first rolling force is 2000KN-3000KN.

[0029] Preferably, the range of the second rolling force is 2000KN-3000KN.

[0030] Secondly, this application provides an online secondary cold rolling apparatus for tinplate, comprising:

[0031] The input module is used to input tin-plated sheets into the double-frame leveling machine;

[0032] The distance acquisition module is used to acquire the distance between the weld seam of the tin-plated plate and the roller gap of the double-frame leveling machine;

[0033] A thickness acquisition module is used to acquire the thickness of the strip steel of the tin-plated sheet;

[0034] A speed adjustment module is used to adjust the inlet strip speed of the dual-frame leveler according to the distance.

[0035] A tension adjustment module is used to adjust the strip tension of the double-frame leveler according to the distance and the strip thickness;

[0036] A rolling force adjustment module is used to adjust the rolling force of the double-stand leveler according to the distance.

[0037] The technical solutions provided in this application have the following advantages compared with the prior art:

[0038] The online secondary cold rolling method and apparatus for tinplate provided in this application can solve the problem of strip breakage during continuous rolling of tinplate in secondary cold rolling. It can provide reasonable process parameter setting methods and measures to achieve online continuous rolling, improve rolling stability and shorten the production cycle. Attached Figure Description

[0039] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the rolling strip that appears before and after the weld in the secondary cold rolling process of the prior art;

[0042] Figure 2 A schematic flowchart of an online secondary cold rolling method for tinplate provided in this application embodiment;

[0043] Figure 3 This is a schematic diagram of an online secondary cold rolling device for tinplate provided in an embodiment of this application;

[0044] Figure 4 This is a schematic diagram of a double-stand leveling machine in an online secondary cold rolling method for tinplate provided in an embodiment of this application;

[0045] Figure 5This is a schematic diagram of the online rolling process parameters for 0.159mm DR material in an online secondary cold rolling method for tinplate provided in an embodiment of this application. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] Figure 2 This is a schematic flowchart of an online secondary cold rolling method for tinplate provided in an embodiment of this application.

[0048] This application provides a method for online secondary cold rolling of tinplate, the method comprising the following steps:

[0049] S1: Input the tin-plated sheet into the double-frame leveling machine;

[0050] Specifically, the tinplate that needs to be cold rolled a second time is fed into the double-stand leveling machine. The tinplate can be fed into the double-stand leveling machine by automatic input equipment (such as robotic arms, conveyor belts, etc.).

[0051] S2: Obtain the distance between the weld seam of the tin-plated plate and the roll gap of the double-frame leveling machine;

[0052] Specifically, the distance between the weld seam of the tinplate and the roll gap of the double-stand leveler is defined as L. This distance L can be measured by a rangefinder (such as an infrared rangefinder) and then fed to the double-stand leveler.

[0053] S3: Obtain the thickness of the strip steel of the tin-plated sheet;

[0054] Specifically, the thickness of the tinplate strip can be measured by a rangefinder (such as an infrared rangefinder) and then fed to the double-rack leveler. Alternatively, the thickness can be measured in advance before the tinplate is fed into the double-rack leveler, and the thickness parameter can be input into the double-rack leveler.

[0055] S4: Adjust the inlet strip speed of the double-frame leveler according to the distance;

[0056] In this embodiment of the application, adjusting the inlet strip speed of the dual-stand leveler according to the distance includes the following steps:

[0057] Determine whether the distance is greater than a preset distance;

[0058] If so, maintain the inlet strip speed at the first speed;

[0059] If not, reduce the inlet strip speed from the first speed to the second speed.

[0060] Figure 4 This is a schematic diagram of a dual-frame leveling machine. The following is an example. Figure 4 This example illustrates the specific steps for adjusting the inlet strip speed of the double-stand leveler based on the distance between the weld seam of the tinplate and the roll gap of the leveler. Specifically, both stand #1 and stand #2 have four rolls. In the secondary cold rolling mode, stand #1 is responsible for thinning, with a reduction rate of 20%-40%, while stand #2 is responsible for leveling. The challenge in achieving continuous rolling lies in ensuring a stable transition of the weld seam when it passes through stand #1, preventing strip breakage.

[0061] like Figure 4 During the online secondary cold rolling process, when the strip is threaded onto the leveling mill and continuously rolled, the strip speed at the inlet is V0 and the strip speed at the outlet is V1 during normal rolling. Based on the reduction rate, the rolling force F1 for stand #1 and the rolling force F2 for stand #2 are calculated. Simultaneously, a certain tension is applied at the inlet and outlet of the stands to achieve normal strip rolling. T1 is the inlet tension of stand #1, T2 is the tension between stand #1 and stand #2, and T3 is the outlet tension of stand #2.

[0062] When the weld seam is about to reach the No. 1 stand weld seam, the leveling speed parameters are set to ensure that the weld seam passes stably through the No. 1 and No. 2 stands without strip breakage. During stable rolling, the entry strip speed V0 in a stable state can generally reach 500m / min-750m / min (first speed). When the weld seam is about to reach the No. 1 stand weld seam, the entry strip speed V0 is reduced to 60m / min. At this time, the strip passes through the No. 1 stand roll gap at a speed of 60m / min. After the weld seam passes through the No. 2 stand roll gap, the speed is increased to the normal speed. That is to say, the relationship between V0 and L is: when L≤30m, V0=60m / min (second speed); when L>30m, V0 is the normal speed greater than 60m / min.

[0063] S5: Adjust the strip tension of the double-frame leveler according to the distance and the strip thickness;

[0064] In this embodiment of the application, adjusting the strip tension of the double-frame leveling machine according to the distance and the strip thickness includes the following steps:

[0065] Determine whether the distance is greater than a preset distance;

[0066] If so, the strip tensions corresponding to the first frame inlet, the second frame inlet, and the second frame outlet of the dual-frame leveling machine are T1, T2, and T3, respectively;

[0067] If not, based on the strip thickness calculation coefficient a, the strip tension corresponding to the first frame inlet, the second frame inlet, and the second frame outlet is reduced to aT1, aT2, and aT3, respectively.

[0068] The following is still in the style of Figure 4 The following example illustrates the specific steps for adjusting the strip tension of the double-stand leveler based on the distance between the weld seam of the tinplate and the roll gap of the double-stand leveler, as well as the strip thickness. Specifically, when the measured distance L > 30m, the tensions at the inlet of stand #1, the inlet of stand #2, and the outlet of stand #2 are maintained at T1, T2, and T3, respectively; when the measured distance L ≤ 30m, the tensions at the inlet of stand #1, the inlet of stand #2, and the outlet of stand #2 are reduced to a*T1, a*T2, and a*T3, respectively (a ≤ 1).

[0069] In this embodiment of the application, the expression between the coefficient a and the strip thickness h is:

[0070] .

[0071] S6: Adjust the rolling force of the double-stand leveler according to the distance.

[0072] In this embodiment of the application, adjusting the rolling force of the double-stand leveling mill according to the distance includes the following steps:

[0073] Determine whether the distance is greater than a preset distance;

[0074] If so, the rolling forces corresponding to the first and second stands of the dual-stand leveling machine are F1 and F2, respectively;

[0075] If not, reduce the rolling forces corresponding to the first frame and the second frame to the first rolling force and the second rolling force, respectively.

[0076] The following is still in the style of Figure 4 Taking the distance between the weld seam of the tinplate and the roll gap of the double-stand leveler as an example, the specific steps for adjusting the rolling force of the double-stand leveler are as follows: Specifically, when the measured distance L > 30m, the rolling force of stand #1 is kept at F1, and the rolling force of stand #2 is kept at F2; when the measured distance L ≤ 30m, the rolling forces of stands #1 and #2 are reduced to 2000KN-3000KN. More specifically, the rolling forces of stands #1 and #2 can be the same or different.

[0077] The following specific embodiments further illustrate the online secondary cold rolling method for tinplate provided in this application.

[0078] In a certain factory, a continuous annealing leveling mill is producing 0.159mm secondary cold-rolled steel with a strip thickness of 0.2mm. The reduction rate of the first stand is 20%, and the leveling elongation rate of the second stand is 0.6%. During normal rolling, the rolling force of the first stand is 4000KN, and the rolling force of the second stand is 2200KN. The inlet tension of the leveling mill is 23KN for both the first and second stands, and the outlet tension is 17KN for the second stand. When the distance L from the weld seam to the roll gap is ≤30m, the tension coefficient α is taken as 0.45; the rolling forces of the first and second stands are taken as 2000KN, and the leveling mill speed is reduced to 60m / min. The actual production curve is as follows. Figure 5 As shown, this method can ensure a stable transition of the weld seam when it passes through frame #1, without any breakage.

[0079] like Figure 3 This application provides an online secondary cold rolling apparatus for tinplate, comprising:

[0080] Input module 10 is used to input tin-plated sheets into the dual-frame leveling machine;

[0081] The distance acquisition module 20 is used to acquire the distance between the weld seam of the tin-plated plate and the roller gap of the double-frame leveling machine;

[0082] Thickness acquisition module 30 is used to acquire the thickness of the strip steel of the tin-plated sheet;

[0083] Speed ​​adjustment module 40 is used to adjust the inlet strip speed of the dual-frame leveler according to the distance.

[0084] Tension adjustment module 50 is used to adjust the strip tension of the double-frame leveler according to the distance and the strip thickness;

[0085] The rolling force adjustment module 60 is used to adjust the rolling force of the double-stand leveler according to the distance.

[0086] The online secondary cold rolling apparatus for tinplate provided in this application can perform the online secondary cold rolling method for tinplate provided in this application.

[0087] The online secondary cold rolling method and apparatus for tinplate provided in this application can solve the problem of strip breakage during continuous rolling of tinplate in secondary cold rolling. It can provide reasonable process parameter setting methods and measures to achieve online continuous rolling, improve rolling stability and shorten the production cycle.

[0088] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0089] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for online secondary cold rolling of tinplate, characterized in that, The method includes the following steps: Input the tin-plated sheet into the double-frame leveling machine; Obtain the distance between the weld seam of the tin-plated plate and the roll gap of the double-frame leveling machine; Obtain the strip thickness of the tin-plated sheet; Adjust the inlet strip speed of the double-frame leveler according to the distance; The strip tension of the double-frame leveler is adjusted according to the distance and the strip thickness. The rolling force of the double-stand leveler is adjusted according to the distance. The step of adjusting the inlet strip speed of the dual-frame leveler according to the distance includes the following steps: Determine whether the distance is greater than a preset distance; If so, maintain the inlet strip speed at the first speed; If not, reduce the inlet strip speed from the first speed to the second speed; The range of the first speed is: 500m / min-750m / min; The second speed is 60 m / min; The step of adjusting the strip tension of the double-frame leveling machine according to the distance and the strip thickness includes the following steps: Determine whether the distance is greater than a preset distance; If so, the strip tensions corresponding to the first frame inlet, the second frame inlet, and the second frame outlet of the dual-frame leveling machine are T1, T2, and T3, respectively; If not, based on the strip thickness calculation coefficient a, the strip tension corresponding to the first frame inlet, the second frame inlet, and the second frame outlet is reduced to aT1, aT2, and aT3, respectively. The expression relating the coefficient a to the strip thickness h is as follows: In the formula, h is in mm.

2. The online secondary cold rolling method for tinplate according to claim 1, characterized in that, The step of adjusting the rolling force of the double-stand leveler according to the distance includes the following steps: Determine whether the distance is greater than a preset distance; If so, the rolling forces corresponding to the first and second stands of the dual-stand leveling machine are F1 and F2, respectively; If not, reduce the rolling forces corresponding to the first frame and the second frame to the first rolling force and the second rolling force, respectively.

3. The online secondary cold rolling method for tinplate according to claim 2, characterized in that, The range of the first rolling force is 2000KN-3000KN.

4. The online secondary cold rolling method for tinplate according to claim 2, characterized in that, The range of the second rolling force is 2000KN-3000KN.

5. An online secondary cold rolling apparatus for tinplate, applied to the method described in any one of claims 1 to 4, characterized in that, include: The input module is used to input tin-plated sheets into the double-frame leveling machine; The distance acquisition module is used to acquire the distance between the weld seam of the tin-plated plate and the roller gap of the double-frame leveling machine; A thickness acquisition module is used to acquire the thickness of the strip steel of the tin-plated sheet; A speed adjustment module is used to adjust the inlet strip speed of the dual-frame leveler according to the distance. A tension adjustment module is used to adjust the strip tension of the double-frame leveler according to the distance and the strip thickness; A rolling force adjustment module is used to adjust the rolling force of the double-stand leveler according to the distance.

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