A method for controlling the rolling bias of a wide thin gauge 304 stainless steel

Abstract

The present application relates to a kind of control wide thin gauge 304 stainless steel rolling bias method, belong to reversible cold rolling technical field, solve the problem of roll system bias in the reversible cold rolling process of wide thin gauge 304 stainless steel, the present application proposes the control method of wide thin gauge 304 stainless steel rolling bias problem, this method involves pass and deformation rate control, rolling tension parameter control, and three aspects of shape control, strong system and practicality.After using the control method provided by the present application, the bias incidence rate is reduced from previous 10% to 0.5% or less, significantly improve the stability of stainless steel wide thin gauge cold plate rolling.

Description

Technical Field

[0001] This invention belongs to the field of reversible cold rolling technology, specifically relating to a method for controlling the rolling bias of wide-width, thin-gauge 304 series stainless steel. Background Technology

[0002] Wide-width, thin-gauge 304 series stainless steel sheets mainly refer to 304 series stainless steel cold-rolled sheets with a thickness ≤0.5mm and a width ≥1350mm. Wide-width, thin-gauge 304 series stainless steel cold-rolled sheets are usually rolled in multiple passes using a Sendzimir 20-roll mill. During rolling, the roll system is prone to severe roll system misalignment problems, that is, the deviation between the 406 support rolls ASU racks 6, 7, and 8 and racks 1, 2, and 3 reaches about 50%-90%. This results in the operator still needing to manually adjust the sheet shape after rolling, leading to a large number of strip breaks and a significant reduction in production efficiency. Therefore, there is an urgent need to propose a method that is easy to operate on-site and can quickly and effectively solve the roll system misalignment problem during the reversible cold rolling of wide-width, thin-gauge 304 series stainless steel. Summary of the Invention

[0003] The main objective of this invention is to overcome the shortcomings of the prior art, solve the problem of roll bias in the reversible cold rolling process of wide-width, thin-gauge 304 series stainless steel, and provide a method for controlling the rolling bias of wide-width, thin-gauge 304 series stainless steel, thereby rapidly and effectively improving the stability control level of cold-rolled thin-gauge 304 series stainless steel.

[0004] The design concept of this invention is as follows: Through field testing, it has been verified that the mechanism of rolling bias is mismatched rolling process parameters and improper strip shape control operation, which causes the strip to deviate towards the operating side or transmission side during the rolling process. After deviation, bias finally occurs when the automatic strip shape control function is engaged. Based on the cause of this problem, this invention proposes a control method for the rolling bias problem of wide-width, thin-gauge 304 series stainless steel. This method involves three aspects: rolling pass and deformation rate control, rolling tension parameter control, and strip shape control, and is highly systematic and practical.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is: a method for controlling the rolling bias of wide-width, thin-gauge 304 series stainless steel, wherein: (1) Rolling passes and deformation rate control: The total number of rolling passes is 8-11, the deformation rate of the first pass is controlled at 23%-26%, the deformation rate of the finished product passes is controlled at 9%-12%, and the total deformation rate is controlled at 75%-85%; (2) Rolling tension parameter control: First pass: Unit tension is 260 N / mm 2 -280N / mm 2 The unit tension difference before and after is 180 N / mm. 2 -220N / mm2 ; Passes 2-4: Initial unit tension 320 N / mm 2 -340N / mm 2 The unit tension difference before and after is 5 N / mm 2 -10N / mm 2 ; Passes 5 to pre-finishing stage: Unit tension is 340 N / mm 2 -350N / mm 2 The unit tension difference before and after is 10 N / mm. 2 -15N / mm 2 ; Finished product pass: Previous unit tension is 350 N / mm 2 -370N / mm 2 The unit tension difference before and after is 25 N / mm. 2 -35N / mm 2 ; (3) Plate shape control: The automatic control function for the first pass's plate shape is turned off, while the automatic control function for the remaining passes' plate shape is turned on. If the steel coil is found to tend to deviate towards the drive side during the rolling process, the sheet shape tilt compensation during the rolling process is -7 to -15 N / mm. 2 If the steel coil is found to tend to deviate towards the operating side during the rolling process, the sheet shape tilt compensation during the rolling process shall be 7~15 N / mm. 2 .

[0006] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By standardizing the total number of rolling passes, the deformation rate per pass, and the total deformation rate, it is possible to ensure a reasonable distribution of rolling pressure in each pass, complete rolling in fewer passes, and improve rolling efficiency. 2. By standardizing the rolling tension parameters, the rolling pressure can be significantly reduced in the horizontal stress state, ensuring the straightness of the plate after each rolling pass and improving the curling stability. 3. By standardizing the operation of strip shape control, the deviation of strip caused by material difference and improper operation can be reduced.

[0007] In summary, the control method provided by this invention has successfully solved the problem of bias during the rolling of wide-width, thin-gauge 304 series stainless steel, reducing the bias occurrence rate from 10% to below 0.5%. Implementation

[0008] The present invention will now be described in further detail with reference to the embodiments.

[0009] In this specific embodiment, a cold-rolled 304 stainless steel sheet with a thickness of 0.4 mm and a width of 1540 mm is rolled using a Sendzimir 20-roll mill. A method for controlling the rolling bias in wide-width, thin-gauge 304 stainless steel is provided, wherein: (1) Rolling passes and deformation rate control: The total number of rolling passes is 10, the deformation rate of the first pass is controlled at 25%, the deformation rate of the finished product passes is controlled at 9.5%, and the total deformation rate is controlled at 83%; (2) Rolling tension parameter control: First pass: Unit tension is 280 N / mm 2 The unit tension is 70 N / mm. 2 ; Passes 2-4: Initial unit tension 330 N / mm 2 The unit tension is 320 N / mm. 2 ; Passes 5-9: Initial unit tension 340 N / mm 2 The unit tension is 330 N / mm. 2 ; 10th pass: Unit tension 350 N / mm 2 The unit tension is 320 N / mm. 2 ; (3) Shape control: The automatic shape control function for the first pass is turned off, while the automatic shape control function for the remaining passes is turned on; during the rolling process, it was found that the steel coil tended to deviate towards the drive side, so the shape tilt compensation during the rolling process was -9 N / mm. 2 ; .

[0010] No bias was observed during the rolling process, and the stability of the rolling process met expectations.

[0011] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for controlling the bias during rolling of wide-width, thin-gauge 304 series stainless steel, characterized in that: (1) Rolling passes and deformation rate control: The total number of rolling passes is 8-11, the deformation rate of the first pass is controlled at 23%-26%, the deformation rate of the finished product passes is controlled at 9%-12%, and the total deformation rate is controlled at 75%-85%; (2) Rolling tension parameter control: First pass: Unit tension is 260 N / mm 2 -280N / mm 2 The unit tension difference before and after is 180 N / mm. 2 -220N / mm 2 ; Passes 2-4: Initial unit tension 320 N / mm 2 -340N / mm 2 The unit tension difference before and after is 5 N / mm 2 -10N / mm 2 ; Passes 5 to pre-finishing stage: Unit tension is 340 N / mm 2 -350N / mm 2 The unit tension difference before and after is 10 N / mm. 2 -15N / mm 2 ; Finished product pass: Previous unit tension is 350 N / mm 2 -370N / mm 2 The unit tension difference before and after is 25 N / mm. 2 -35N / mm 2 ; (3) Plate shape control: The automatic control function for the first pass's plate shape is turned off, while the automatic control function for the remaining passes' plate shape is turned on. If the steel coil is found to tend to deviate towards the drive side during the rolling process, the sheet shape tilt compensation during the rolling process is -7 to -15 N / mm. 2 If the steel coil is found to tend to deviate towards the operating side during the rolling process, the sheet shape tilt compensation during the rolling process shall be 7~15 N / mm. 2 .