A method for controlling the thickness of oxide scale of hot-rolled wheel steel

Abstract

A method for controlling the oxide scale thickness of hot-rolled wheel steel belongs to the technical field of steel rolling control methods. The technical solution is as follows: S1, collect current rolled piece data; S2, pre-calculate the tertiary oxide scale thickness of the finished strip. If it meets the oxide scale thickness requirements, execute step S3; if it does not, execute step S4; S3, the finishing mill rolls the rolled piece into a finished product, and the process proceeds to step S6; S4, determine the number of inter-stand cooling water systems in the finishing mill. If not all are enabled, add a set of inter-stand cooling water systems, and the process proceeds to step S3; if all are enabled, execute step S5; S5, activate the oscillation mode, causing the rolled piece to oscillate on the rollers between roughing and finishing, and the process proceeds to step S3; S6, collect actual data on the finished strip, calculate the tertiary oxide scale thickness, and release the finished strip as normal if it meets the requirements; if it does not, flag it and issue an alarm. The present invention dynamically controls the oxide scale thickness of the finished strip through feedback adjustment of the online rolling process.

Description

Technical Field

[0001] The invention relates to a method for controlling the thickness of iron oxide scale of hot-rolled wheel steel, belonging to the technical field of steel rolling control methods. Background Art

[0002] A steel automobile wheel consists of a rim and spokes. The spokes and rim are made from steel sheets through a rigorous manufacturing process involving spinning (rolling), welding, and pickling. Therefore, the hot-rolled steel sheets used to make the wheels must not only possess excellent ductility and weldability, but also possess a high surface quality. This is because the tertiary scale that inevitably appears on the surface of the hot-rolled steel sheet significantly impacts the steel wheel processing. Thick tertiary scale has poor conductivity, affecting welding quality and potentially causing cracking during the forming process. Furthermore, thick tertiary scale easily adheres to the mold during the forming process, causing scratches or indentations on the workpiece surface, impacting the product's appearance. Furthermore, thick tertiary scale on the hot-rolled steel sheet increases acid consumption in the downstream pickling process, negatively impacting environmental protection and yield. To eliminate the effects of tertiary scale, wheel processing plants subject the hot-rolled steel sheet to shot blasting or pickling treatments. This not only increases process costs but also pollutes the environment. Therefore, controlling tertiary scale on the hot-rolled steel sheet is crucial for practical production.

[0003] Current research on controlling scale is focused on optimizing the rolling process, but the rolling process is not stable, which inevitably affects the stable control of scale on the surface of the finished hot-rolled plate. Other studies have predicted the scale on the finished hot-rolled strip and then corrected the hot-rolling process for curing, or provided guidance for adjusting the downstream pickling process. For example, Chinese Patent Application No. 202111003531.2, "A Method for Predicting Scale Characteristics on the Surface of Hot-Rolled Strip," calculates the thickness of the finished scale based on the final rolling temperature and coiling temperature. This lacks the key factor affecting scale thickness—oxidation time—and only allows for prediction, not dynamic online adjustment. Chinese Patent Application No. 201010209526.2, "A Soft Measurement Method for Scale Thickness on the Surface of Hot-Rolled Strip," predicts scale thickness by establishing a soft-sensing model under variable temperature conditions. The model requires process parameters after rolling as input, making it impossible to predict scale in advance or dynamically control scale thickness online. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for controlling the oxide scale thickness of hot-rolled wheel steel. By using the big data regression method to establish an accurate regression equation for the oxide scale thickness of the finished product, the oxide scale thickness of the finished strip steel is predicted in advance using set parameters as input items. By feedback adjustment of the process technology of the online rolled piece, the oxide scale thickness of the finished strip steel is dynamically controlled, effectively solving the above-mentioned problems existing in the background technology.

[0005] The technical solution of the present invention is: a method for controlling the thickness of hot-rolled wheel steel oxide scale, comprising the following steps:

[0006] S1. After the rolled piece undergoes the final rough rolling pass and is inspected by a pyrometer at the rough rolling exit, the current rolled piece data is collected;

[0007] S2. Pre-calculate the tertiary oxide scale thickness of the finished strip steel. If it meets the oxide scale thickness requirement, it is judged that it meets the tertiary oxide scale thickness requirement, and then execute S3. If it does not meet the tertiary oxide scale thickness requirement, it is judged that it does not meet the tertiary oxide scale thickness requirement, and then execute S4.

[0008] S3, the finishing mill rolls the rolled piece into a finished product, and then goes to step S6;

[0009] S4. Determine the number of cooling water openings between the stands of the finishing mill. If not all are opened, add one group of cooling water openings between the stands in the order from front to back based on the default number of openings, and go to step S3; if all are opened, go to step S5;

[0010] S5, activate the oscillation mode, the rolled piece oscillates on the roller table between rough rolling and finishing rolling for 10 seconds, and then go to step S3;

[0011] S6. Collect the actual data of the finished steel strips and calculate the tertiary oxide scale thickness of the finished steel strips. If the thickness meets the requirements, the steel strips will be released normally. If the thickness does not meet the requirements, the steel strips will be marked and an alarm will be issued to proceed with the review process.

[0012] In step S2, the formula for precalculating the thickness δ of the tertiary oxide scale of the finished strip steel is:

[0013] δ=0.316*H+0.0888*FDT-0.879*Vt-C

[0014] Where, 64≤C≤65; H is the target thickness of the finished product, in mm; FDT is the final rolling temperature, in °C; Vt is the final stand finishing rolling speed, in m / s.

[0015] In the formula, C=64.8.

[0016] In step S2, the thickness of the iron oxide scale is determined by the thickness of the finished product H. When H is less than 6.0 mm, the upper limit of the thickness of the iron oxide scale δ t =7.5μm; when 6≤H<10.0mm, δt =9μm; when H≥10.0mm, δ t =12μm.

[0017] In step S1, the current rolled piece data includes the set final stand finishing rolling speed, the target thickness of the finished product and the set final rolling temperature of the current rolled piece.

[0018] In step S6, the actual data of the finished steel strip includes the actual final stand finishing rolling speed of the finished steel strip, the target thickness of the finished product and the actual finishing temperature.

[0019] The beneficial effects of the present invention are: by using the big data regression method to establish an accurate regression equation for the thickness of the finished iron oxide scale, the set parameters are used as input items to predict the thickness of the iron oxide scale of the finished steel strip in advance, and the thickness of the iron oxide scale of the finished steel strip is dynamically controlled by feedback adjustment of the process technology of the online rolled piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions in the invention implementation cases will be clearly and completely described below in conjunction with the drawings in the implementation cases. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] A method for controlling the thickness of iron oxide scale of hot-rolled wheel steel comprises the following steps:

[0023] S1. After the rolled piece undergoes the final rough rolling pass and is inspected by a pyrometer at the rough rolling exit, the current rolled piece data is collected;

[0024] S2. Pre-calculate the tertiary oxide scale thickness of the finished strip steel. If it meets the oxide scale thickness requirement, it is judged that it meets the tertiary oxide scale thickness requirement, and then execute S3. If it does not meet the tertiary oxide scale thickness requirement, it is judged that it does not meet the tertiary oxide scale thickness requirement, and then execute S4.

[0025] S3, the finishing mill rolls the rolled piece into a finished product, and then goes to step S6;

[0026] S4. Determine the number of cooling water openings between the stands of the finishing mill. If not all are opened, add one group of cooling water openings between the stands in the order from front to back based on the default number of openings, and go to step S3; if all are opened, go to step S5;

[0027] S5, activate the oscillation mode, the rolled piece oscillates on the roller table between rough rolling and finishing rolling for 10 seconds, and then go to step S3;

[0028] S6. Collect the actual data of the finished steel strips and calculate the tertiary oxide scale thickness of the finished steel strips. If the thickness meets the requirements, the steel strips will be released normally. If the thickness does not meet the requirements, the steel strips will be marked and an alarm will be issued to proceed with the review process.

[0029] In step S2, the formula for precalculating the thickness δ of the tertiary oxide scale of the finished strip steel is:

[0030] δ=0.316*H+0.0888*FDT-0.879*Vt-C

[0031] Where, 64≤C≤65; H is the target thickness of the finished product, in mm; FDT is the final rolling temperature, in °C; Vt is the final stand finishing rolling speed, in m / s.

[0032] In the formula, C=64.8.

[0033] In step S2, the thickness of the iron oxide scale is determined by the thickness of the finished product H. When H is less than 6.0 mm, the upper limit of the thickness of the iron oxide scale δ t =7.5μm; when 6≤H<10.0mm, δ t =9μm; when H≥10.0mm, δ t =12μm.

[0034] In step S1, the current rolled piece data includes the set final stand finishing rolling speed, the target thickness of the finished product and the set final rolling temperature of the current rolled piece.

[0035] In step S6, the actual data of the finished steel strip includes the actual final stand finishing rolling speed of the finished steel strip, the target thickness of the finished product and the actual finishing temperature.

[0036] In practical application, the present invention comprises the following steps:

[0037] S1. After the rolled piece undergoes the final rough rolling pass and is tested by a pyrometer at the rough rolling exit, data on the set final stand finishing rolling speed, target thickness of the finished product, and set final rolling temperature of the rolled piece are collected;

[0038] S2. Use the following formula (1) to calculate the thickness of the iron oxide scale, such as δ-δ t <0, execute step S3; if δ-δ t ≥0, execute step S4;

[0039] δ =0.316*H+0.0888*FDT-0.879*V t -C (1)

[0040] In formula (1), 64≤C≤65; H is the target thickness of the finished product, in mm; FDT is the final rolling temperature, in °C; V t It is the strip threading speed of the final stand finishing rolling, in m / s.

[0041] S3, the finishing mill rolls the rolled piece into a finished product, and then goes to step S6;

[0042] S4. Determine the number of cooling water units between the stands of the finishing mill that are turned on. If not all are turned on, add one more cooling water unit between the stands in the default number of units turned on, and go to step S3. If all are turned on, go to step S5.

[0043] S5, activate the oscillation mode, the rolled piece oscillates on the roller table between rough rolling and finishing rolling for 10 seconds, and then go to step S3;

[0044] S6. Collect the actual final stand finishing rolling speed, target thickness and actual final rolling temperature data of the finished strip, and use formula (1) to calculate the tertiary oxide scale thickness of the finished strip, such as δ-δ t <0, normal release; such as δ-δ t ≥0, the alarm will go through the review process;

[0045] where δ t The upper limit of the thickness of the iron oxide scale is determined by the thickness of the finished product H. When H is less than 6.0 mm, the upper limit of the thickness of the iron oxide scale δ t =7.5μm; when 6≤H<10.0mm, δ t =9μm; when H≥10.0mm, δ t =12μm.

[0046] Examples 1-9 were produced according to the above-mentioned embodiment, see Table 1.

[0047] Table 1

[0048]

[0049]

[0050] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. Any modification or partial replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for controlling the thickness of hot-rolled wheel steel oxide scale, characterized in that The following steps are involved: S1. After the rolled piece undergoes the final rough rolling pass and is tested by a pyrometer at the rough rolling exit, current rolled piece data is collected; the current rolled piece data includes the set final stand finishing rolling speed, the target thickness of the finished product, and the set final rolling temperature; S2. Pre-calculate the tertiary oxide scale thickness of the finished strip. If it meets the oxide scale thickness requirement, it is judged that it does and then proceed to step S3. If it does not meet the oxide scale thickness requirement, it is judged that it does not meet the oxide scale thickness requirement and then proceed to step S4. S3, the finishing mill rolls the rolled piece into a finished product, and then goes to step S6; S4. Determine the number of cooling water openings between the stands of the finishing mill. If not all are opened, add one group of cooling water openings between the stands in the order from front to back based on the default number of openings, and go to step S3. If all are enabled, proceed to step S5; S5, activate the oscillation mode, the rolled piece oscillates on the roller table between the rough rolling and the finishing rolling for 10 seconds, and then go to step S3; S6. Collect the actual data of the finished strip and calculate the tertiary oxide scale thickness of the finished strip. If the strip meets the oxide scale thickness requirement, it will be released normally. If the strip does not meet the oxide scale thickness requirement, it will be marked as an alarm and go through the review process. The actual data of the finished strip includes the actual final stand finishing rolling speed of the finished strip, the target thickness of the finished product, and the actual final rolling temperature. In step S2, the formula for precalculating the thickness δ of the tertiary oxide scale of the finished strip steel is: δ =0.316*H+0.0888*FDT-0.879*Vt-C Where, 64≤C≤65; H is the target thickness of the finished product, in mm; FDT is the final rolling temperature, in °C; Vt is the final stand finishing rolling speed, in m / s.

2. The method for controlling the thickness of hot-rolled wheel steel oxide scale according to claim 1, characterized in that: In the formula, C=64.

8.

3. The method for controlling the thickness of hot-rolled wheel steel oxide scale according to claim 1, characterized in that: In step S2, the thickness of the iron oxide scale is determined by the thickness of the finished product H. When H is less than 6.0 mm, the upper limit of the thickness of the iron oxide scale δ t =7.5μm; when 6≤H<10.0mm, δ t =9μm; when H≥10.0mm, δ t =12μm.

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