Method for producing pickled sheet steel coils on a five-stand continuous mill

Abstract

This invention discloses a method for producing pickled steel coils using a five-stand continuous rolling mill, belonging to the field of steel plate production technology. The specific method includes: 1) adjusting the roll gap between the work roll groups of mills one through four to be greater than the thickness of the pickled steel plate; 2) shielding the sensor signals of mills one through four and closing the emulsion nozzles of mills one, two, three, and four; 3) replacing the work roll group of mill five with a roll group with a 0±5μm grinding crown; 4) reducing the reduction rate of the work roll group of mill five; 5) reducing the emulsion output rate of the emulsion nozzles of mill five; and 6) shielding the thickness measurement signal from the thickness gauge at the exit of mill five. This invention provides a method for producing pickled steel coils using a five-stand continuous rolling mill, enabling existing five-stand continuous rolling mills to meet the requirements for producing pickled steel coils.

Description

Technical Field

[0001] This invention belongs to the field of steel plate production technology, and relates to a method for processing pickled steel plates into pickled steel coils using a five-stand continuous rolling mill. Background Technology

[0002] The five-stand cold rolling mill consists of a PLC controller, five tandem rolling mill units, a shearing machine, and a coiler, among other main mechanical equipment. The entire line has no looper mechanisms and is specifically designed for high-precision processing of cold-rolled metal sheets (such as steel, stainless steel, and aluminum). Its core function is to further thin the hot-rolled strip to the target thickness through multiple rolling passes. The five rolling mills are designated as Mill 1, Mill 2, Mill 3, Mill 4, and Mill 5. Each mill includes a work roll set, a support roll set, sensors, and emulsion nozzles. Mill 5 is equipped with a thickness gauge at its exit. Steel plates enter from rolling mill number one. After the sensors on rolling mill number one detect the presence of steel, its work rolls depress, and the emulsion nozzles begin spraying emulsion. The steel plates that have undergone the first round of rolling through the work rolls of rolling mill number one enter rolling mill number two. After the sensors on rolling mill number two detect the presence of steel, its work rolls depress, and the emulsion nozzles begin spraying emulsion. The steel plates that have undergone the second round of rolling through the work rolls of rolling mill number two enter rolling mill number three. After the sensors on rolling mill number three detect the presence of steel, its work rolls depress, and the emulsion nozzles begin spraying emulsion. The steel plate that has undergone the third round of rolling through the work rolls of the No. 3 rolling mill enters the No. 4 rolling mill. After the sensor of the No. 4 rolling mill detects the presence of steel, its work roll group is pressed down and the emulsion nozzles begin to spray emulsion. The steel plate that has undergone the fourth round of rolling through the work rolls of the No. 4 rolling mill enters the No. 5 rolling mill. After the sensor of the No. 5 rolling mill detects the presence of steel, its work roll group is pressed down and the emulsion nozzles begin to spray emulsion. The steel plate that has undergone the fifth round of rolling through the work rolls of the No. 5 rolling mill is rolled into a steel coil by the coiler after passing through the thickness gauge, and then cut into a cold-rolled steel coil by the shearing machine.

[0003] Pickled steel sheet is an intermediate product whose surface quality and usage requirements fall between hot-rolled and cold-rolled steel sheets after the oxide layer is removed by a pickling unit, edges are trimmed, and finishing is completed. It is an ideal substitute for some hot-rolled and cold-rolled steel sheets. Compared with hot-rolled steel sheets, the main advantages of pickled steel sheets are better surface quality, easier welding, oiling, and painting, and higher dimensional accuracy. Compared with cold-rolled steel sheets, the advantage of pickled steel sheets is that, while ensuring surface quality and usage requirements, the thickness standard of pickled steel sheets is much smaller than that of cold-rolled steel sheets, and pickled steel sheets do not require multiple rolling passes. Due to the increasing market demand for pickled steel sheets and the decreasing demand for cold-rolled steel sheets, the existing five-stand continuous rolling mill can only be used for continuous rolling of cold-rolled steel coils and cannot be used for rolling pickled steel sheet coils. Producing pickled steel sheet coils requires the purchase of new rolling mills and coilers, directly increasing production costs. Summary of the Invention

[0004] The problem solved by this invention is to provide a method for producing pickled steel coils using a five-stand continuous rolling mill, so that existing five-stand continuous rolling mills can meet the requirements for producing pickled steel coils.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows: It includes rolling mills No. 1, No. 2, No. 3, No. 4, and No. 5, a shearing machine, and a coiling machine, all connected to a PLC controller. Each of the rolling mills (No. 1, No. 2, No. 3, No. 4, and No. 5) is equipped with a work roll group, a support roll group, a sensor, and an emulsion nozzle. A thickness gauge is installed at the steel outlet of the No. 5 rolling mill. The specific method is as follows:

[0006] 1) Adjust the roll gap between the working roll groups of the No. 1 rolling mill to be greater than the thickness of the pickled plate, adjust the roll gap between the working roll groups of the No. 2 rolling mill to be greater than the thickness of the pickled plate, adjust the roll gap between the working roll groups of the No. 3 rolling mill to be greater than the thickness of the pickled plate, and adjust the roll gap between the working roll groups of the No. 4 rolling mill to be greater than the thickness of the pickled plate, so that the pickled plate will not be rolled by the No. 1 rolling mill, the No. 2 rolling mill, the No. 3 rolling mill, and the No. 4 rolling mill;

[0007] 2) Shield the sensor signals of the No. 1, No. 2, No. 3 and No. 4 rolling mills, and shut down the emulsion nozzles of the No. 1, No. 2, No. 3 and No. 4 rolling mills to prevent the work roll groups of the No. 1, No. 2, No. 3 and No. 4 rolling mills from pressing down and the emulsion nozzles from spraying emulsion when the pickled plate passes through the No. 1, No. 2, No. 3 and No. 4 rolling mills.

[0008] 3) Replace the No. 5 rolling mill work roll group with a roll group with a grinding crown of 0±5μm;

[0009] 4) Reduce the reduction rate of the No. 5 rolling mill work roll group. The grinding crown of the No. 5 rolling mill work roll group is 0±5μm, so its reduction rate needs to be reduced accordingly.

[0010] 5) Reduce the output rate of the emulsion nozzles of the No. 5 rolling mill, the reduction rate of the work roll group of the No. 5 rolling mill, and the amount of emulsion used for lubrication and cooling also needs to be reduced accordingly;

[0011] 6) Shield the thickness measurement signal of the thickness gauge at the No. 5 mill outlet. The thickness of the pickled plate does not need to reach the thickness of the cold-rolled plate. If the thickness gauge detects that the thickness of the plate rolled out from the No. 5 mill outlet does not meet the thickness standard of the cold-rolled plate, it will issue an alarm.

[0012] A more specific technical solution than the above-mentioned technical solution is as follows: the shearing machine is equipped with a thickness tester, the thickness tester is connected to the PLC control, the thickness tester is used to monitor the thickness curve of the pickled plate, and the shearing machine cuts off the weld seam of the pickled plate.

[0013] Furthermore, the coiling speed of the coiler is adjusted to 80m / min. Reducing the steel feeding speed allows the thickness tester to accurately monitor the thickness curve of the pickled plate.

[0014] Further adjustments were made: the roll gap between the No. 1 rolling mill work roll group was adjusted to 20 mm, the roll gap between the No. 2 rolling mill work roll group was adjusted to 16 mm, the roll gap between the No. 3 rolling mill work roll group was adjusted to 12 mm, and the roll gap between the No. 4 rolling mill work roll group was adjusted to 8 mm.

[0015] Furthermore, the reduction parameters of the No. 5 rolling mill work roll group are set to 2.7mm for 1.9mm.

[0016] Furthermore, the output flow rate of the emulsion nozzle of the No. 5 rolling mill is set to 800L / min.

[0017] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art: by modifying the existing five-stand continuous rolling mill used for producing cold-rolled sheets, a production method suitable for pickled steel coils is developed. Using this method, the high-efficiency production requirements of pickled sheets can be met without purchasing new rolling mills and coilers. When the market demand for cold-rolled sheets increases, it is only necessary to restore the original settings of the five-stand continuous rolling mill to produce cold-rolled sheets, which can change with the changes in market demand. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the macroscopic layout of the present invention.

[0019] In the diagram: 1. Rolling mill No. 1; 2. Rolling mill No. 2; 3. Rolling mill No. 3; 4. Rolling mill No. 4; 5. Rolling mill No. 5; 51. Thickness gauge; 6. Shearing machine; 7. Coiling machine; 8. Work roll group; 9. Support roll group. Detailed Implementation

[0020] The invention will be further described in detail below with reference to the accompanying drawings and examples:

[0021] like Figure 1The method for producing pickled steel coils using a five-stand continuous rolling mill, as shown, includes rolling mill 1, rolling mill 2, rolling mill 3, rolling mill 4, rolling mill 5, shearing machine 6, and coiler 7, all connected to a PLC controller. Rolling mills 1, 2, 3, 4, and 5 are each equipped with work roll groups 8, support roll groups 9, sensors, and emulsion nozzles. A thickness gauge 51 is installed at the exit of rolling mill 5. The specific method is as follows:

[0022] 1) Adjust the roll gap between the 8 working rolls of No. 1 rolling mill to 20mm, adjust the roll gap between the 8 working rolls of No. 2 rolling mill to 16mm, adjust the roll gap between the 8 working rolls of No. 3 rolling mill to 12mm, and adjust the roll gap between the 8 working rolls of No. 4 rolling mill to 8mm, so that the pickled plate will not be crushed by the rolls of No. 1 rolling mill, No. 2 rolling mill, No. 3 rolling mill, and No. 4 rolling mill;

[0023] 2) Shield the sensor signals of No. 1, No. 2, No. 3 and No. 4 rolling mills, and close the emulsion nozzles of No. 1, No. 2, No. 3 and No. 4 rolling mills to prevent the work roll groups 8 of No. 1, No. 2, No. 3 and No. 4 rolling mills from pressing down and the emulsion nozzles from spraying emulsion when the pickled plate passes through No. 1, No. 2, No. 3 and No. 4 rolling mills.

[0024] 3) Replace the No. 5 working roll group 8 of the No. 5 rolling mill with a roll group with a grinding crown of 0±5μm;

[0025] 4) Reduce the reduction rate of the No. 5 working roll group 8. The reduction parameters of the No. 5 working roll group 8 are set to 2.7mm to 1.9mm. The grinding crown of the No. 5 working roll group 8 is 0±5μm, so its reduction rate needs to be reduced accordingly.

[0026] 5) Reduce the output rate of the emulsion nozzle of No. 5 mill and set the output rate of the emulsion nozzle of No. 5 mill to 800L / min. The reduction rate of the work roll group 8 of No. 5 mill should also be reduced accordingly.

[0027] 6) Shield the thickness measurement signal of the thickness gauge 51 at the outlet of No. 5 rolling mill. The thickness of the pickled plate does not need to reach the thickness of the cold rolled plate. If the thickness gauge 51 detects that the thickness of the plate rolled from the outlet of No. 5 rolling mill does not meet the thickness standard of cold rolled plate, it will issue an alarm.

[0028] The shearing machine 6 is equipped with a thickness gauge connected to a PLC control system. The thickness gauge is used to monitor the thickness curve of the pickled plate. The shearing machine 6 cuts the weld seam of the pickled plate. The coiling speed of the coiling machine 7 is adjusted to 80m / min. Reducing the feed speed allows the thickness gauge to accurately monitor the thickness curve of the pickled plate.

[0029] It should be noted that the PLC controller provided by this invention is a common device in the prior art. It only requires connection through the connection relationships given in the embodiments of this invention, and conventional configuration of the PLC controller is sufficient to obtain the technical solution of this invention. No improvements are involved in software programming. As for the parameter settings and usage methods of the PLC controller, those skilled in the art can purchase the PLC controller and refer to the accompanying instruction manual to set up the corresponding control; therefore, they will not be described in detail here.

Claims

1. A method for producing pickled steel coils using a five-stand continuous rolling mill, comprising a No. 1 rolling mill, a No. 2 rolling mill, a No. 3 rolling mill, a No. 4 rolling mill, a No. 5 rolling mill, a shearing machine, and a coiling machine, all connected to a PLC controller. Each of the No. 1, No. 2, No. 3, No. 4, and No. 5 rolling mills is equipped with a work roll group, a support roll group, a sensor, and an emulsion nozzle. A thickness gauge is installed at the exit of the No. 5 rolling mill. The method is characterized in that... The specific method is as follows: 1) Adjust the roll gap between the working roll groups of the No. 1 rolling mill to be greater than the thickness of the pickled plate, adjust the roll gap between the working roll groups of the No. 2 rolling mill to be greater than the thickness of the pickled plate, adjust the roll gap between the working roll groups of the No. 3 rolling mill to be greater than the thickness of the pickled plate, and adjust the roll gap between the working roll groups of the No. 4 rolling mill to be greater than the thickness of the pickled plate. 2) Shield the sensor signals of the No. 1, No. 2, No. 3 and No. 4 rolling mills, and shut down the emulsion nozzles of the No. 1, No. 2, No. 3 and No. 4 rolling mills; 3) Replace the No. 5 rolling mill work roll group with a roll group with a grinding crown of 0±5μm; 4) Reduce the reduction rate of the No. 5 rolling mill work roll group; 5) Reduce the output rate of the emulsion nozzle of the No. 5 rolling mill; 6) Shield the thickness measurement signal of the thickness gauge at the outlet of the No. 5 rolling mill.

2. The method for producing pickled steel coils using a five-stand continuous rolling mill according to claim 1, characterized in that: The shearing machine is equipped with a thickness tester, which is connected to the PLC control.

3. The method for producing pickled steel coils using a five-stand continuous rolling mill according to claim 2, characterized in that: The coiling speed of the coiler is adjusted to 80 m / min.

4. The method for producing pickled steel coils using a five-stand continuous rolling mill according to claim 1 or 3, characterized in that: Adjust the roll gap between the No. 1 rolling mill work roll group to 20mm, adjust the roll gap between the No. 2 rolling mill work roll group to 16mm, adjust the roll gap between the No. 3 rolling mill work roll group to 12mm, and adjust the roll gap between the No. 4 rolling mill work roll group to 8mm.

5. The method for producing pickled steel coils using a five-stand continuous rolling mill according to claim 4, characterized in that: The reduction parameters of the No. 5 rolling mill work roll group are set to 2.7mm for 1.9mm.

6. The method for producing pickled steel coils using a five-stand continuous rolling mill according to claim 5, characterized in that: The output flow rate of the emulsion nozzle of the No. 5 rolling mill is set to 800L / min.

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