Dynamic control method for elevation of lower roller in heavy plate mill

Abstract

The invention discloses a dynamic control method for the elevation of a lower roll in a heavy plate mill, which comprises the heavy plate mill, the heavy plate mill adjusts a rolling elevation line through a hydraulic roll gap control system, an elevation control parameter is set in a control model of the hydraulic roll gap control system, and the elevation control parameter is used for adjusting the rolling elevation line in the rolling process; the rolling process comprises a forming rolling stage, a broadening rolling stage and a finish rolling stage; in the forming rolling stage, a control model of the hydraulic roll gap control system adjusts a rolling elevation line according to the thickness of the blank, and the set height of the rolling elevation line is inversely proportional to the thickness of the blank; in the broadening rolling stage, a control model of the hydraulic roll gap control system adjusts a rolling elevation line according to the broadening ratio of the blank, and the set height of the rolling elevation line is in direct proportion to the broadening ratio of the blank; in the finish rolling stage, the control model of the hydraulic roll gap control system adjusts the rolling elevation line according to the length of the blank, and the set height of the rolling elevation line is inversely proportional to the length of the blank.

Description

Technical Field

[0001] This invention relates to the field of rolling control in thick plate rolling mills, and more particularly to a dynamic control method for the elevation of the lower roll in a thick plate rolling mill. Background Technology

[0002] In manufacturing, a "pass" typically refers to a stage or step in the production process. In steel production, the L2 pass (i.e., thick plate rolling) includes three stages: forming rolling, widening rolling, and finishing rolling. During the aforementioned thick plate rolling process, rolling elevation lines are usually set to control the thickness of the billet and ensure the quality of rolling.

[0003] In the current thick plate rolling process, the rolling elevation line is derived from past experience by technicians and is set to a uniform value. However, the requirements for the rolling elevation line are different in the three rolling stages mentioned above.

[0004] For example, during the forming and rolling stage, different billet thicknesses require different elevation heights. This is because the steel plate head needs to remain straight during the forming stage to facilitate the steel transfer operation. Therefore, the thicker the billet, the lower the rolling elevation line should be set. Conversely, to prevent the head from warping too high, the thinner the billet, the higher the rolling elevation line should be set.

[0005] During the widening rolling process, the setting height of the rolling elevation line needs to be adjusted according to the widening ratio to prevent the steel plate from tilting upwards and causing rolling instability.

[0006] In finishing rolling, the elevation of the rolling level line needs to be adjusted according to the length of the intermediate billet. When the length of the intermediate billet is too short, the elevation of the rolling level line needs to be increased to prevent the steel plate from curling up.

[0007] In summary, the rolling elevation line changes at each stage of rolling and at each stage pass. Since the rolling elevation is currently set manually based on experience, it cannot meet the requirements of elevation changes at each stage, making it difficult to ensure rolling stability during steel plate rolling.

[0008] Therefore, it is necessary to improve the above-mentioned elevation control method to overcome the above-mentioned defects. Summary of the Invention

[0009] The purpose of this invention is to provide a dynamic control method for the lower roll elevation in a thick plate rolling mill. Based on the requirements of each stage of thick plate rolling, the rolling elevation line is set in the control model and automatically controlled, thereby quantifying the changes in the rolling elevation line, improving the stability control method for steel plate rolling, reducing difficulties in steel transfer and steel plate warping caused by unreasonable rolling elevation line settings, and solving the problems existing in the prior art.

[0010] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0011] A dynamic control method for the lower roll elevation in a thick plate rolling mill includes a thick plate rolling mill. The thick plate rolling mill adjusts the rolling elevation line through a lower hydraulic roll gap control system. The hydraulic roll gap control system has a control model, and elevation control parameters are set in the control model. The elevation control parameters are used to adjust the rolling elevation line of the hydraulic roll gap control system during the rolling process.

[0012] The rolling process includes forming rolling, widening rolling and finishing rolling stages;

[0013] During the forming and rolling stage, the control model of the hydraulic roll gap control system adjusts the rolling elevation line according to the thickness of the billet. The setting height of the rolling elevation line is inversely proportional to the thickness of the billet.

[0014] During the widening rolling stage, the control model of the hydraulic roll gap control system adjusts the rolling elevation line according to the widening ratio of the billet. The setting height of the rolling elevation line is proportional to the widening ratio of the billet.

[0015] During the finishing rolling stage, the control model of the hydraulic roll gap control system adjusts the rolling elevation line according to the length of the billet. The height of the rolling elevation line is inversely proportional to the length of the billet.

[0016] Furthermore, during the forming and rolling stage, the elevation control parameters of the control model are as follows:

[0017] When the thickness of the billet is ≥360mm, the rolling elevation line is set to 0mm;

[0018] When 360mm > billet thickness > 300mm, the rolling elevation line is set between 0mm and 5mm.

[0019] When the thickness of the billet is ≥280mm and ≥300mm, the rolling elevation line is set to 5mm.

[0020] When 280mm > billet thickness > 250mm, the rolling elevation line is set between 5mm and 10mm.

[0021] When the thickness of the billet is 250mm, the rolling elevation line is set to 10mm;

[0022] When 250mm > billet thickness > 200mm, the rolling elevation line is set between 10-15mm.

[0023] When the thickness of the billet is ≥150mm and ≥200mm, the rolling elevation line is set at 15mm.

[0024] When 150mm > billet thickness > 120mm, the rolling elevation line is set between 15-18mm;

[0025] When the thickness of the billet is ≤120mm, the rolling elevation line is set to 18mm.

[0026] Furthermore, during the widening rolling stage, the elevation control parameters of the control model are:

[0027] When the width ratio of the billet is ≤1.7, the rolling elevation line is set to 5mm;

[0028] When 1.7 < the width ratio of the billet < 1.9, the rolling elevation line is set between 5mm and 10mm.

[0029] When 1.9 ≤ the width ratio of the billet ≤ 2.1, the rolling elevation line is set to 10mm;

[0030] When 2.1 < the width ratio of the billet < 2.3, the rolling elevation line is set between 10mm and 15mm.

[0031] When 2.3 ≤ the width ratio of the billet ≤ 2.5, the rolling elevation line is set to 15mm;

[0032] When 2.5 < the width ratio of the billet < 2.7, the rolling elevation line is set between 15mm and 20mm;

[0033] When 2.7 ≤ the width ratio of the billet ≤ 2.9, the rolling elevation line is set to 20mm;

[0034] When 2.9 < the width ratio of the billet < 3.1, the rolling elevation line is set between 20mm and 25mm.

[0035] When 3.1 ≤ the width ratio of the billet ≤ 3.3, the rolling elevation line is set to 25mm;

[0036] When 3.3 < the width ratio of the billet < 3.5, the rolling elevation line is set between 20mm and 25mm.

[0037] When the width ratio of the billet is ≥3.5, the rolling elevation line is set to 30mm.

[0038] Furthermore, during the finishing rolling stage, the elevation control parameters of the control model are:

[0039] When the length of the billet is ≥6.6m, the rolling elevation line is set to 15mm;

[0040] When 6.6m > billet length > 5.6m, the rolling elevation line should be set between 15mm and 20mm.

[0041] When the length of the billet is 5.6m, the rolling elevation line is set to 20mm;

[0042] When 5.6m > billet length > 4.6m, the rolling elevation line should be set between 20mm and 25mm.

[0043] When the length of the billet is 4.6m, the rolling elevation line is set to 25mm;

[0044] When 4.6m > billet length > 3.6m, the rolling elevation line should be set between 25mm and 30mm.

[0045] When the length of the billet is ≤3.6m, the rolling elevation line is set to 30mm.

[0046] In summary, the present invention has the following beneficial effects:

[0047] This invention expands upon a new technology for automatically controlling the setting of rolling elevation lines on the L2 model according to the requirements of each stage in a thick plate rolling mill. It quantifies the changes in rolling elevation lines, improves the stable control method for steel plate rolling, and reduces unstable rolling conditions such as difficulties in steel transfer and steel plate warping caused by the short width ratio of the intermediate billet due to unreasonable setting of rolling elevation lines. This is conducive to increasing output, reducing labor intensity, and improving the automation control technology. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the dynamic control method for the lower roll elevation in a thick plate rolling mill as described in this invention.

[0049] Figure 2 This is a schematic diagram of Embodiment 1 of the present invention. Detailed Implementation

[0050] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to the figures and specific embodiments.

[0051] like Figure 1 As shown, the present invention proposes a dynamic control method for the lower roll elevation in a thick plate rolling mill. According to the requirements of each stage of thick plate rolling, the rolling elevation line is set in the control model and automatically controlled, thereby quantifying the change of the rolling elevation line, improving the stability control method of steel plate rolling, and reducing the difficulties in steel transfer and steel plate warping caused by unreasonable setting of rolling elevation line.

[0052] Specifically, this includes a thick plate rolling mill, which adjusts the rolling elevation line through a lower-mounted hydraulic roll gap control system. The hydraulic roll gap control system has a control model, within which elevation control parameters are set. These elevation control parameters are used to adjust the rolling elevation line of the hydraulic roll gap control system during the rolling process.

[0053] The rolling process includes forming rolling, widening rolling and finishing rolling stages;

[0054] During the forming and rolling stage, the control model of the hydraulic roll gap control system adjusts the rolling elevation line according to the thickness of the billet. The setting height of the rolling elevation line is inversely proportional to the thickness of the billet.

[0055] During the widening rolling stage, the control model of the hydraulic roll gap control system adjusts the rolling elevation line according to the widening ratio of the billet. The setting height of the rolling elevation line is proportional to the widening ratio of the billet.

[0056] During the finishing rolling stage, the control model of the hydraulic roll gap control system adjusts the rolling elevation line according to the length of the billet. The height of the rolling elevation line is inversely proportional to the length of the billet.

[0057] Example 1

[0058] In this embodiment, a blank with an initial thickness of about 250 mm is used for illustration.

[0059] Referring to Table 1, the elevation control parameters of the control model during the forming and rolling stage are as follows:

[0060] When the thickness of the billet is ≥360mm, the rolling elevation line is set to 0mm;

[0061] When 360mm > billet thickness > 300mm, the rolling elevation line is set between 0mm and 5mm.

[0062] When the thickness of the billet is ≥280mm and ≥300mm, the rolling elevation line is set to 5mm.

[0063] When 280mm > billet thickness > 250mm, the rolling elevation line is set between 5mm and 10mm.

[0064] When the thickness of the billet is 250mm, the rolling elevation line is set to 10mm;

[0065] When 250mm > billet thickness > 200mm, the rolling elevation line is set between 10-15mm.

[0066] When the thickness of the billet is ≥150mm and ≥200mm, the rolling elevation line is set at 15mm.

[0067] When 150mm > billet thickness > 120mm, the rolling elevation line is set between 15-18mm;

[0068] When the thickness of the billet is ≤120mm, the rolling elevation line is set to 18mm.

[0069] billet thickness (mm) 360 300 280 250 200 150 120 Rolling elevation line (mm) 0 5 5 10 15 15 18

[0070] Table 1

[0071] Referring to Table 2, the elevation control parameters of the control model during the widening rolling stage are:

[0072] When the width ratio of the billet is ≤1.7, the rolling elevation line is set to 5mm;

[0073] When 1.7 < the width ratio of the billet < 1.9, the rolling elevation line is set between 5mm and 10mm.

[0074] When 1.9 ≤ the width ratio of the billet ≤ 2.1, the rolling elevation line is set to 10mm;

[0075] When 2.1 < the width ratio of the billet < 2.3, the rolling elevation line is set between 10mm and 15mm.

[0076] When 2.3 ≤ the width ratio of the billet ≤ 2.5, the rolling elevation line is set to 15mm;

[0077] When 2.5 < the width ratio of the billet < 2.7, the rolling elevation line is set between 15mm and 20mm;

[0078] When 2.7 ≤ the width ratio of the billet ≤ 2.9, the rolling elevation line is set to 20mm;

[0079] When 2.9 < the width ratio of the billet < 3.1, the rolling elevation line is set between 20mm and 25mm.

[0080] When 3.1 ≤ the width ratio of the billet ≤ 3.3, the rolling elevation line is set to 25mm;

[0081] When 3.3 < the width ratio of the billet < 3.5, the rolling elevation line is set between 20mm and 25mm.

[0082] When the width ratio of the billet is ≥3.5, the rolling elevation line is set to 30mm.

[0083] Width ratio 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5 Rolling elevation line (mm) 5 5 10 10 15 15 20 20 25 25 30

[0084] Table 2

[0085] Referring to Table 3, the elevation control parameters of the control model during the finishing rolling stage are as follows:

[0086] When the length of the billet is ≥6.6m, the rolling elevation line is set to 15mm;

[0087] When 6.6m > billet length > 5.6m, the rolling elevation line should be set between 15mm and 20mm.

[0088] When the length of the billet is 5.6m, the rolling elevation line is set to 20mm;

[0089] When 5.6m > billet length > 4.6m, the rolling elevation line should be set between 20mm and 25mm.

[0090] When the length of the billet is 4.6m, the rolling elevation line is set to 25mm;

[0091] When 4.6m > billet length > 3.6m, the rolling elevation line should be set between 25mm and 30mm.

[0092] When the length of the billet is ≤3.6m, the rolling elevation line is set to 30mm.

[0093] intermediate billet length m 2.6 3.6 4.6 5.6 6.6 Rolling elevation (mm) 30 30 25 20 15

[0094] Table 3

[0095] By employing L2 data-driven rolling control technology at each stage of the rolling process, stability is further improved, reducing difficulties in steel transfer and warping, thus lowering the labor intensity for manual corrections and increasing rolling efficiency, thereby enhancing automation control technology. In the forming stage, lowering the rolling elevation line mitigates the difficulties caused by steel warping during transfer. Furthermore, considering different elevations based on the billet size better suits actual production needs. In the widening stage, adjusting the rolling elevation line according to the widening ratio mitigates rolling difficulties caused by steel warping. Additionally, increasing the rolling elevation based on the billet's widening ratio better meets actual production needs and reduces the likelihood of steel warping during the widening stage.

[0096] In this document, the terms "upper," "lower," "front," "back," "left," "right," "top," "bottom," "inner," "outer," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used for the clarity of expressing the technical solution and for the convenience of description, and therefore should not be construed as limiting the present invention.

[0097] In this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0098] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for dynamic control of the lower roll elevation in a thick plate rolling mill, comprising a thick plate rolling mill, wherein the thick plate rolling mill adjusts the rolling elevation line through a lower-mounted hydraulic roll gap control system, characterized in that... The hydraulic roll gap control system has a control model, within which elevation control parameters are set. These elevation control parameters are used to adjust the rolling elevation line of the hydraulic roll gap control system during the rolling process. The rolling process includes forming rolling, widening rolling and finishing rolling stages; During the forming and rolling stage, the control model of the hydraulic roll gap control system adjusts the rolling elevation line according to the thickness of the billet. The setting height of the rolling elevation line is inversely proportional to the thickness of the billet. During the widening rolling stage, the control model of the hydraulic roll gap control system adjusts the rolling elevation line according to the widening ratio of the billet. The setting height of the rolling elevation line is proportional to the widening ratio of the billet. During the finishing rolling stage, the control model of the hydraulic roll gap control system adjusts the rolling elevation line according to the length of the billet. The height of the rolling elevation line is inversely proportional to the length of the billet.

2. The dynamic control method for the lower roll elevation in a thick plate rolling mill according to claim 1, characterized in that, During the forming and rolling stage, the elevation control parameters of the control model are: When the thickness of the billet is ≥360mm, the rolling elevation line is set to 0mm; When 360mm > billet thickness > 300mm, the rolling elevation line is set between 0mm and 5mm. When the thickness of the billet is ≥280mm and ≥300mm, the rolling elevation line is set to 5mm. When 280mm > billet thickness > 250mm, the rolling elevation line is set between 5mm and 10mm. When the thickness of the billet is 250mm, the rolling elevation line is set to 10mm; When 250mm > billet thickness > 200mm, the rolling elevation line is set between 10-15mm. When the thickness of the billet is ≥150mm and ≥200mm, the rolling elevation line is set at 15mm. When 150mm > billet thickness > 120mm, the rolling elevation line is set between 15-18mm; When the thickness of the billet is ≤120mm, the rolling elevation line is set to 18mm.

3. The dynamic control method for the lower roll elevation in a thick plate rolling mill according to claim 1, characterized in that, During the widening rolling stage, the elevation control parameters of the control model are: When the width ratio of the billet is ≤1.7, the rolling elevation line is set to 5mm; When 1.7 < the width ratio of the billet < 1.9, the rolling elevation line is set between 5mm and 10mm. When 1.9 ≤ the width ratio of the billet ≤ 2.1, the rolling elevation line is set to 10mm; When 2.1 < the width ratio of the billet < 2.3, the rolling elevation line is set between 10mm and 15mm. When 2.3 ≤ the width ratio of the billet ≤ 2.5, the rolling elevation line is set to 15mm; When 2.5 < the width ratio of the billet < 2.7, the rolling elevation line is set between 15mm and 20mm; When 2.7 ≤ the width ratio of the billet ≤ 2.9, the rolling elevation line is set to 20mm; When 2.9 < the width ratio of the billet < 3.1, the rolling elevation line is set between 20mm and 25mm. When 3.1 ≤ the width ratio of the billet ≤ 3.3, the rolling elevation line is set to 25mm; When 3.3 < the width ratio of the billet < 3.5, the rolling elevation line is set between 20mm and 25mm. When the width ratio of the billet is ≥3.5, the rolling elevation line is set to 30mm.

4. The dynamic control method for the lower roll elevation in a thick plate rolling mill according to claim 1, characterized in that, During the finishing rolling stage, the elevation control parameters of the control model are: When the length of the billet is ≥6.6m, the rolling elevation line is set to 15mm; When 6.6m > billet length > 5.6m, the rolling elevation line should be set between 15mm and 20mm. When the length of the billet is 5.6m, the rolling elevation line is set to 20mm; When 5.6m > billet length > 4.6m, the rolling elevation line should be set between 20mm and 25mm. When the length of the billet is 4.6m, the rolling elevation line is set to 25mm; When 4.6m > billet length > 3.6m, the rolling elevation line should be set between 25mm and 30mm. When the length of the billet is ≤3.6m, the rolling elevation line is set to 30mm.

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