Container steel plate shape convexity control method

Abstract

The invention relates to the technical field of steel plate shape control for containers, in particular to a plate shape convexity control method for steel for containers. The method specifically comprises the following steps that 1, a CVC working roller is adopted by a hot rolling F1-F3 finishing mill; 2, transmitting quality design convexity target value data of the manufacturing management system to a finish rolling secondary model; 3, optimizing the plate shape parameter roll shifting initial position parameter of the finish rolling secondary model, and setting the plate shape parameter roll shifting initial position parameter of the finish rolling secondary model to be 20-40mm; 4, optimizing the cooling water pressure of the working rollers of the finishing mill groups, wherein the cooling water pressure of the working rollers of the finishing mill groups F1-F7 is controlled to be 0.55-0.85 MPa; 5, according to different target thicknesses of products, different thicknesses of intermediate billets are input; if the target thickness is less than or equal to 2.0 mm, the thickness of the intermediate billet is greater than 30mm and greater than 40mm; if the target thickness is larger than 2.0 mm, the thickness of the intermediate billet is larger than or equal to 40 mm. Precise control over the plate shape convexity of the container steel is achieved, the requirement of customers for the strip steel thickness is met, and the product quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of plate shape control of steel for containers, and in particular to a plate shape convexity control method of steel for containers. Background Art

[0002] The materials of containers mainly include steel, aluminum and stainless steel. Steel container is the most common type of container material. It is widely used for its durability, strong carrying capacity and low cost. Steel containers are generally welded from high-strength steel plates and coated with anti-corrosion paint to adapt to various harsh transportation environments.

[0003] During the production of hot-rolled strip steel, the strip shape is an important aspect of the strip quality. The quality of the product shape is not only related to whether the subsequent production process can be carried out smoothly and effectively, but also to whether it can meet the needs of users. As containers develop towards lightweight and thinning, users have higher and higher requirements for the control accuracy of the shape convexity of strip products.

[0004] However, the current plate convexity of container steel is large. When the negative tolerance of the target thickness is large, the edge thickness of the strip is prone to being too thin and not meeting the standard; when the negative tolerance of the target thickness is small, the yield rate will be reduced. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides a method for controlling the plate convexity of container steel, which can achieve precise control of the plate convexity of container steel, ensure that the edge thickness of the strip meets the standard, and improve product quality.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for controlling the plate shape convexity of container steel comprises the following steps:

[0008] 1) Hot rolling F1-F3 finishing mills use CVC working rolls;

[0009] 2) Transmitting the convexity target value data of the manufacturing management system quality design to the finishing rolling secondary model;

[0010] 3) Optimize the initial position parameters of the roller shifting of the secondary model plate shape parameters of the finishing rolling, and set the initial position of the roller shifting of the secondary model plate shape parameters of the finishing rolling to 20-40 mm;

[0011] 4) Optimize the cooling water pressure of the working rolls of the finishing mill, and control the cooling water pressure of the working rolls of the F1-F7 finishing mill at 0.55-0.85 MPa;

[0012] 5) According to the different target thickness of the product, different intermediate billet thicknesses are used;

[0013] If the target thickness is ≤2.0mm, then 40mm>intermediate billet thickness>30mm;

[0014] If the target thickness is greater than 2.0 mm, the intermediate billet thickness shall be greater than or equal to 40 mm.

[0015] Furthermore, in step 1), the diameter of the CVC working rolls of the hot rolling F1-F3 finishing mills is 710-800 mm, and the bending roll force is 600-800 kN.

[0016] Further, in step 3, if the target thickness = 2.0mm, the initial position of the roller shifting of the finishing second-level model plate shape parameter is set to 20mm; if 2.0mm<target thickness<4.0mm, the initial position of the roller shifting of the finishing second-level model plate shape parameter is set to 30mm; if the target thickness is greater than 4.0mm, the initial position of the roller shifting of the finishing second-level model plate shape parameter is set to 40mm.

[0017] Furthermore, in step 4), the cooling water pressure of the working rolls of the finishing mill group of the F1 rolling mill is controlled at 0.80-0.85 MPa.

[0018] Furthermore, in step 4), the cooling water pressure of the working rolls of the finishing mill group of the F2 rolling mill is controlled at 0.80-0.85 MPa.

[0019] Furthermore, in step 4), the cooling water pressure of the working rolls of the finishing mill group of the F3 rolling mill is controlled at 0.75-0.85 MPa.

[0020] Furthermore, in step 4), the cooling water pressure of the working rolls of the finishing mill group of the F4 rolling mill is controlled at 0.70-0.80 MPa.

[0021] Furthermore, in step 4), the cooling water pressure of the working rolls of the finishing mill group of the F5 rolling mill is controlled at 0.65-0.75 MPa.

[0022] Furthermore, in step 4), the cooling water pressure of the working rolls of the finishing mill group of the F6 rolling mill is controlled at 0.55-0.65 MPa.

[0023] Furthermore, in step 4), the cooling water pressure of the working rolls of the finishing mill group of the F7 rolling mill is controlled at 0.65-0.75 MPa.

[0024] Compared with the existing method, the beneficial effects of the present invention are:

[0025] The secondary model for controlling the plate shape on site is to control the rolling line to produce the final hot-rolled products according to different specifications and steel grades, and cannot distinguish the customized convexity requirements of different users for plate and strip products. Therefore, the target value of the plate shape convexity of the secondary model in the prior art can only be set based on the empirical value, which has the problem that the target value does not match the actual needs of the user.

[0026] Quality design is to set the process parameters of hot-rolled plates and strips according to the requirements of the product agreement. The present invention adds a target value of plate shape convexity in the quality design. The actual convexity parameters required by the user are recorded in the quality design. The quality design stores the actual convexity information required by the user, and the secondary model is the specific execution mechanism of the on-site rolling line. The present invention opens up the convexity data channel between the quality design and the secondary model, and transmits the convexity data actually required by the user to the secondary model, so as to realize precise control of the plate shape convexity value, thereby improving the problem of large strip shape convexity.

[0027] The method of the present invention can realize accurate control of the plate shape convexity of container steel, meet the user's requirements for strip thickness, and improve product quality. The present invention has been applied to actual production, and the plate shape convexity of container strip steel with a target thickness of ≤2.0mm is reduced from 40μm to 30μm; the plate shape convexity of container strip steel with a target thickness of >2.0mm is reduced from 60μm to 50μm. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the convex cross-sectional curve of the front plate shape after implementing Example 1 of the present invention.

[0029] Figure 2 This is the convex cross-sectional curve of the plate shape after implementation of Example 1 of the present invention.

[0030] Figure 3 This is the convexity cross-sectional curve of the front plate shape according to Example 2 of the present invention.

[0031] Figure 4 This is the convex cross-sectional curve of the plate shape after implementation of Example 2 of the present invention.

[0032] Figure 5 This is the convexity cross-sectional curve of the front plate shape according to Example 3 of the present invention.

[0033] Figure 6 This is the convex cross-sectional curve of the plate shape after implementation of Example 3 of the present invention. DETAILED DESCRIPTION

[0034] The present invention discloses a method for controlling the plate convexity of container steel. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0035] A method for controlling the plate shape convexity of container steel comprises the following steps:

[0036] 1. The hot rolling F1-F3 finishing mill adopts CVC working rolls; the diameter of CVC working rolls is 710-800mm, and the bending roll force is 350-500kN.

[0037] 2. Transfer the convexity target value data in the hot rolling convexity table of the management and information system quality design to the finishing rolling secondary model;

[0038] 3. Optimize the initial position parameters of the roller shifting of the secondary model plate shape parameters of the finishing rolling, and change them from the original full specification of 0mm to 20mm and 30mm; if the target thickness is ≤2.0mm, the initial position of the roller shifting of the secondary model plate shape parameters of the finishing rolling is set to 20mm; if the target thickness is greater than 2.0mm, the initial position of the roller shifting of the secondary model plate shape parameters of the finishing rolling is set to 30mm.

[0039] 4. Optimize the cooling water pressure of the working rolls of the finishing mill. The cooling water pressure of the working rolls of the finishing mill of F1 rolling mill is controlled at 0.80-0.85MPa, the cooling water pressure of the working rolls of the finishing mill of F2 rolling mill is controlled at 0.80-0.85MPa, the cooling water pressure of the working rolls of the finishing mill of F3 rolling mill is controlled at 0.75-0.85MPa, the cooling water pressure of the working rolls of the finishing mill of F4 rolling mill is controlled at 0.70-0.80MPa, the cooling water pressure of the working rolls of the finishing mill of F5 rolling mill is controlled at 0.65-0.75MPa, the cooling water pressure of the working rolls of the finishing mill of F6 rolling mill is controlled at 0.55-0.65MPa, and the cooling water pressure of the working rolls of the finishing mill of F7 rolling mill is controlled at 0.65-0.75MPa.

[0040] 5. According to the different target thickness of the product, different intermediate billet thicknesses are used;

[0041] If the target thickness is ≤2.0mm, then 40mm>intermediate billet thickness>30mm;

[0042] If the target thickness is greater than 2.0 mm, the intermediate billet thickness shall be greater than or equal to 40 mm.

[0043] Embodiment 1:

[0044] SPA-H container steel with a thickness of 4.1mm and a width of 1180mm complies with the standard Q / ASB 202-2023. It is mainly used to make shipping containers. The thick hot-rolled strip is mainly used for container structural parts.

[0045] A method for controlling the plate shape convexity of SPA-H steel, wherein the product thickness is greater than 2.0 mm, specifically comprises the following steps:

[0046] 1. The hot rolling F3 finishing mill adopts CVC working rolls with a bending roll force of 65kN;

[0047] 2. Through the manufacturing management system, the quality design convexity target value of 45μm telegram data is sent to the secondary model through the planning information of the PES system.

[0048] 3. The initial position of the roller shifting in the secondary model plate shape parameters of finishing rolling is 30mm.

[0049] 4. Optimize the cooling water pressure of the working rolls of the finishing mill. The cooling water pressure of the working rolls of the finishing mill of F1 rolling mill is controlled at 0.85MPa, the cooling water pressure of the working rolls of the finishing mill of F2 rolling mill is controlled at 0.85MPa, the cooling water pressure of the working rolls of the finishing mill of F3 rolling mill is controlled at 0.85MPa, the cooling water pressure of the working rolls of the finishing mill of F4 rolling mill is controlled at 0.80MPa, the cooling water pressure of the working rolls of the finishing mill of F5 rolling mill is controlled at 0.75MPa, the cooling water pressure of the working rolls of the finishing mill of F6 rolling mill is controlled at 0.65MPa, and the cooling water pressure of the working rolls of the finishing mill of F7 rolling mill is controlled at 0.75MPa.

[0050] Figure 1 In order to obtain the cross-sectional curve diagram using the existing plate convexity control method for container steel, Figure 1 The strip shape convexity is 60μm, and the thickness difference between the middle and edge of the strip is large, resulting in a strip shape problem with large convexity in the middle. Figure 2 This is a cross-sectional curve diagram obtained by the plate shape convexity control method of the embodiment of the present invention. After being controlled and adjusted by the method of the embodiment of the present invention, Figure 2 The strip shape convexity is 45μm, the thickness difference between the middle and edge of the strip is significantly reduced, and the problem of large convexity of the strip shape is effectively solved.

[0051] Embodiment 2:

[0052] SPA-H container steel with a thickness of 1.87mm and a width of 1179mm complies with the standard Q / ASB 202-2023. It is mainly used to make shipping containers. Thin hot-rolled strip steel is mainly used for container bottom plates, etc.

[0053] A method for controlling the plate shape convexity of SPA-H steel, wherein the product thickness is ≤2.0 mm, specifically comprises the following steps:

[0054] 1. The hot rolling F3 finishing mill adopts CVC working rolls with a bending roll force of 60kN;

[0055] 2. Through the manufacturing management system, the quality design convexity target value of 35μm telegram data is sent to the secondary model through the planning information of the PES system.

[0056] 3. The initial position of the roller shifting in the secondary model plate shape parameters of finishing rolling is 20mm.

[0057] 4. Optimize the cooling water pressure of the working rolls of the finishing mill. The cooling water pressure of the working rolls of the finishing mill of F1 rolling mill is controlled at 0.80MPa, the cooling water pressure of the working rolls of the finishing mill of F2 rolling mill is controlled at 0.80MPa, the cooling water pressure of the working rolls of the finishing mill of F3 rolling mill is controlled at 0.75MPa, the cooling water pressure of the working rolls of the finishing mill of F4 rolling mill is controlled at 0.70MPa, the cooling water pressure of the working rolls of the finishing mill of F5 rolling mill is controlled at 0.65MPa, the cooling water pressure of the working rolls of the finishing mill of F6 rolling mill is controlled at 0.55MPa, and the cooling water pressure of the working rolls of the finishing mill of F7 rolling mill is controlled at 0.65MPa.

[0058] Figure 3 In order to obtain the cross-sectional curve diagram using the existing plate convexity control method for container steel, Figure 3 The strip shape convexity is 44μm, and the thickness difference between the middle and edge of the strip is large, resulting in a strip shape problem with large convexity in the middle. Figure 4 This is a cross-sectional curve diagram obtained by the plate shape convexity control method of the embodiment of the present invention. After being controlled and adjusted by the method of the embodiment of the present invention, Figure 4 The strip shape convexity is 35μm, the thickness difference between the middle and edge of the strip is significantly reduced, and the problem of large convexity of the strip shape is effectively solved.

[0059] Embodiment 3:

[0060] SPA-H container steel with a thickness of 1.48mm and a width of 1179mm complies with the standard Q / ASB 202-2023. It is mainly used to make shipping containers. The ultra-thin hot-rolled strip is mainly used for container panels, etc.

[0061] A method for controlling the plate shape convexity of SPA-H steel, wherein the product thickness is ≤2.0 mm, specifically comprises the following steps:

[0062] 1. The hot rolling F3 finishing mill adopts CVC working rolls with a bending roll force of 65kN;

[0063] 2. Through the manufacturing management system, the quality design convexity target value of 35μm telegram data is sent to the secondary model through the planning information of the PES system.

[0064] 3. The initial position of the roller shifting in the secondary model plate shape parameters of finishing rolling is 20mm.

[0065] 4. Optimize the cooling water pressure of the working rolls of the finishing mill. The cooling water pressure of the working rolls of the finishing mill of F1 rolling mill is controlled at 0.80MPa, the cooling water pressure of the working rolls of the finishing mill of F2 rolling mill is controlled at 0.80MPa, the cooling water pressure of the working rolls of the finishing mill of F3 rolling mill is controlled at 0.75MPa, the cooling water pressure of the working rolls of the finishing mill of F4 rolling mill is controlled at 0.70MPa, the cooling water pressure of the working rolls of the finishing mill of F5 rolling mill is controlled at 0.65MPa, the cooling water pressure of the working rolls of the finishing mill of F6 rolling mill is controlled at 0.55MPa, and the cooling water pressure of the working rolls of the finishing mill of F7 rolling mill is controlled at 0.65MPa.

[0066] Figure 5 In order to obtain the cross-sectional curve diagram using the existing plate convexity control method for container steel, Figure 5 The strip shape convexity is 45μm, and the thickness difference between the middle and edge of the strip is large, resulting in a large convexity plate shape problem. Figure 6 This is a cross-sectional curve diagram obtained by the plate shape convexity control method of the embodiment of the present invention. After being controlled and adjusted by the method of the embodiment of the present invention, Figure 6 The strip shape convexity is 33μm, the thickness difference between the middle and edge of the strip is significantly reduced, and the strip shape problem of large convexity in the middle is effectively solved.

[0067] The present invention can realize accurate control of the plate shape convexity of container steel, meet the user's requirements on strip steel thickness, and improve product quality.

[0068] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for controlling the plate shape convexity of container steel, characterized in that: The specific steps include: 1) Hot rolling F1-F3 finishing mills use CVC working rolls; 2) Transmitting the convexity target value data of the manufacturing management system quality design to the finishing rolling secondary model; 3) Optimize the initial position parameters of the roller shifting of the secondary model plate shape parameters of the finishing rolling, and set the initial position of the roller shifting of the secondary model plate shape parameters of the finishing rolling to 20-40 mm; 4) Optimize the cooling water pressure of the working rolls of the finishing mill, and control the cooling water pressure of the working rolls of the F1-F7 finishing mill at 0.55-0.85 MPa; 5) According to the different target thickness of the product, different intermediate billet thicknesses are used; If the target thickness is ≤2.0mm, then 30mm<intermediate billet thickness<40mm; If the target thickness is greater than 2.0 mm, the intermediate billet thickness shall be greater than or equal to 40 mm.

2. A method for controlling the plate shape convexity of container steel according to claim 1, characterized in that: In step 1), the diameter of the CVC working roll of the hot rolling F1-F3 finishing mill is 710-800 mm, and the bending roll force is 600-800 kN.

3. A method for controlling the plate shape convexity of container steel according to claim 1, characterized in that: In step 3, if the target thickness = 2.0 mm, the initial position of the roller shifting of the finishing rolling secondary model plate shape parameter is set to 20 mm; If 2.0mm<target thickness<4.0mm, set the initial position of the roller shifting of the finishing rolling secondary model plate shape parameter to 30mm; If the target thickness is greater than 4.0 mm, the initial position of the roller shifting of the finishing rolling secondary model plate shape parameter is set to 40 mm.

4. The method for controlling the plate shape convexity of container steel according to claim 1, characterized in that: In step 4), the cooling water pressure of the working rolls of the finishing mill group of the F1 rolling mill is controlled at 0.80-0.85 MPa.

5. The method for controlling the plate shape convexity of container steel according to claim 1, characterized in that: In step 4), the cooling water pressure of the working rolls of the finishing mill of the F2 rolling mill is controlled at 0.80-0.85 MPa.

6. The method for controlling the plate shape convexity of container steel according to claim 1, characterized in that: In step 4), the cooling water pressure of the working rolls of the finishing mill of the F3 rolling mill is controlled at 0.75-0.85 MPa.

7. The method for controlling the plate shape convexity of container steel according to claim 1, characterized in that: In step 4), the cooling water pressure of the working rolls of the finishing mill of the F4 rolling mill is controlled at 0.70-0.80 MPa.

8. The method for controlling the plate shape convexity of container steel according to claim 1, characterized in that: In step 4), the cooling water pressure of the working rolls of the finishing mill of the F5 rolling mill is controlled at 0.65-0.75 MPa.

9. The method for controlling the plate shape convexity of container steel according to claim 1, characterized in that: In step 4), the cooling water pressure of the working rolls of the finishing mill of the F6 rolling mill is controlled at 0.55-0.65 MPa.

10. The method for controlling the plate shape convexity of container steel according to claim 1, characterized in that: In step 4), the cooling water pressure of the working rolls of the finishing mill of the F7 rolling mill is controlled at 0.65-0.75 MPa.

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