Process for controlling head and tail transverse fold of strip

Abstract

The application provides a process method for controlling head and tail transverse fold of strip steel, wherein the diameter of a reversing roller of a decoiler of a unit is designed as 154 mm, and the pressure, angle and wrap angle mode of the reversing roller of the decoiler are optimized and adjusted; meanwhile, a pinch roll straightener capable of providing tension is arranged in the unit during the decoiling and tail throwing processes. The process method solves the technical problem that the pickling and skin passing products of the extremely thin hot-rolled strip steel in the headless rolling are seriously cut due to the head and tail transverse fold defects, improves the product yield and enhances the product market competitiveness.

Description

Technical Field

[0001] This invention relates to the field of strip steel head processing technology, and in particular to a process method for controlling transverse folds at the head and tail of strip steel. Background Technology

[0002] With the continuous advancement of steel rolling technology, the performance of hot-rolled thin plates is approaching that of cold-rolled plates, making "replacing cold with hot rolling" a technological reality. The development of the headless rolling production process has enabled the production of domestic hot-rolled ultra-thin hot-rolled strip steel products.

[0003] However, considering the hot rolling production process and the softer and thinner characteristics of the product, the transverse crease defect of the extremely thin hot-rolled strip seriously affects the user's acceptance of the product. According to the process settings of the continuous pickling and leveling unit, the inlet uncoiler reverse bending roll has a significant improvement on the transverse crease defect. However, in the current unit design, the strip is in a tension-free state during the uncoiling, threading, and tail-swinging processes, so the reverse bending roll cannot play a role, and the head and tail are severely cut off due to the transverse crease defect. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a process method for controlling transverse folds at the beginning and end of strip steel. This process method solves the technical problem of severe removal of transverse fold defects at the beginning and end of pickled and leveled products of endless rolled ultra-thin hot-rolled strip steel, thereby improving product yield and enhancing product market competitiveness.

[0005] To achieve the above objectives, the present invention provides a process method for controlling transverse creases at the head and tail of strip steel. In the process method, the diameter of the reverse bending roll of the uncoiler is designed to be 154mm, and the pressure, angle, and wrap angle mode of the reverse bending roll of the uncoiler are optimized and adjusted. At the same time, during the uncoiling, threading, and tail-swinging processes, a clamping straightener that can provide tension is arranged in the unit.

[0006] In this process, a pressure mode is used, with the unwinding tension set to 20KN and the pressure of the reverse bending roller set to 12KN.

[0007] Among them, the tension-providing clamping straightener rollers arranged in the unit during the unwinding, threading, and tail-swing processes are designed with a diameter of 300mm, with hydraulic cylinders arranged on both sides, and the upper and lower rollers equipped with transmission mechanisms, with a pressing pressure of 130Bar.

[0008] During the threading and tail-swinging processes, the upper pressure roller presses down, and the drive variable frequency motor provides a torque of 20KN.

[0009] The threading and tail-waving processes were continuously optimized, with an unwinding tension of 18KN and a reverse bending roller pressure of 9KN.

[0010] The straightening unit is 3 meters long when the tail is being swayed and 6 meters long when the belt is being threaded.

[0011] Compared with existing technologies, the advantages and positive effects of this invention are as follows: This invention is based on the severe transverse folds at the beginning and end of extremely thin and soft strip steel with a thickness of 0.8-1.5mm and a yield strength of 220-280MPa produced by endless rolling. By using reverse bending rolls and a tension-providing pinch straightener in combination, and by repeatedly adjusting various parameters, the transverse folds at the beginning and end are improved, thus enhancing product quality, market competitiveness, and product yield, and meeting users' requirements for product surface quality. Through continuous debugging and optimization of various process parameters of the pinch straightener and the reverse bending rolls of the uncoiler, this invention has successfully achieved pickling and leveling of hot-rolled extremely thin strip steel, improving the transverse folds at the beginning and end, and reducing the head and tail scrap rate from 0.75% to below 0.60%. Detailed Implementation

[0012] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, the structures and features of one embodiment may be advantageously incorporated into other embodiments.

[0013] One embodiment of the present invention provides a process method for controlling transverse creases at the head and tail of strip steel. In the process method, the diameter of the uncoiler's reverse bending roll is designed to be 154mm, and the pressure, angle, and wrap angle mode of the uncoiler's reverse bending roll are optimized and adjusted. At the same time, during the uncoiling, threading, and tail-swinging processes, a clamping straightener that can provide tension is arranged in the unit.

[0014] Traditional continuous pickling and leveling units have an uncoiler with a reverse bending roll diameter of 120-140mm. In this embodiment, the uncoiler's reverse bending roll diameter is designed to be 154mm. Due to the increased roll diameter, the ability to improve transverse folds is reduced. By optimizing and adjusting the pressure, angle, and wrap angle modes of the uncoiler's reverse bending roll, and using the pressure mode with an uncoiling tension of 20KN and a reverse bending roll pressure of 12KN, the transverse folds are effectively improved.

[0015] During the uncoiling, threading, and tail-swing processes, traditional units only provide a small amount of tension between the clamping straightener and the uncoiling machine to assist in threading. In this embodiment, the unit is equipped with a clamping straightener that can provide tension. The roller diameter is designed to be 300mm, and hydraulic cylinders are arranged on both sides. The upper and lower rollers are equipped with a transmission mechanism, and the pressing pressure is 130Bar. When threading and tail-swinging, the upper pressure roller presses down, and the transmission variable frequency motor provides a torque of 20KN.

[0016] During the threading and tail-swing process, the reverse bending roller continuously presses down, and the front pinch roller of the straightener continuously presses down, establishing tension between the uncoiler and the straightener. If the tension is too high, the front pinch roller of the straightener will slip with the strip. If the tension is too low, the reverse bending roller will not function. In this embodiment, through continuous optimization, the uncoiling tension is 18KN and the reverse bending roller pressure is 9KN, which can effectively improve the head and tail transverse creases.

[0017] To ensure welding quality, the straightening unit of the straightening machine continuously presses down during the conventional threading and tail-swing processes, which can cause transverse creases. In this embodiment, through continuous optimization, the straightening unit is pressed down for 3 meters during tail-swing and 6 meters during threading to meet welding requirements, effectively improving the transverse creases at the beginning and end.

[0018] In summary, this embodiment addresses the severe transverse folds at the beginning and end of extremely thin and soft strip steel with a thickness of 0.8-1.5mm and a yield strength of 220-280MPa produced by endless rolling. By using a reverse bending roll and a tension-providing pinch straightener in conjunction, and through repeated adjustments to various parameters, the transverse folds at the beginning and end are improved, resulting in enhanced product quality, increased market competitiveness, higher yield, and compliance with user requirements for product surface quality. The process method disclosed in this embodiment, through continuous debugging and optimization of various process parameters of the pinch straightener and the uncoiler reverse bending roll, successfully achieves pickling and leveling of hot-rolled extremely thin strip steel, improving the transverse folds at the beginning and end, and reducing the head and tail scrap rate from 0.75% to below 0.60%.

[0019] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A process for controlling the transverse fold of the head and tail of a strip, applied to the production of a very thin and soft strip with a thickness of 0.8-1.5 mm and a yield strength of 220-280 MPa; characterized in that: The diameter of the reverse bending roll of the uncoiler in the process is designed as 154 mm, and the pressure, angle and wrap angle mode of the reverse bending roll of the uncoiler are optimized and debugged; meanwhile, the pinch straightener capable of providing tension is arranged in the uncoiling and threading and tailing-off process of the unit; In the process, the pressure mode is used, the uncoiling tension is set as 20 KN, and the reverse bending roll pressure is set as 12 KN; In the uncoiling and threading and tailing-off process of the unit, the pinch straightener capable of providing tension is arranged, the roll diameter is designed as 300 mm, the hydraulic cylinders are arranged on both sides, the transmission mechanism is arranged on the upper and lower rolls, and the pressing pressure is 130 Bar; In the uncoiling and threading and tailing-off process, the uncoiling tension is continuously optimized as 18 KN, and the reverse bending roll pressure is 9 KN; The pressing length of the straightening unit is 3 meters in the tailing-off process, and the pressing length of the straightening unit is 6 meters in the threading process.

2. The process of claim 1, wherein: In the threading and tailing-off process, the upper pressing roll is pressed down, and the transmission frequency conversion motor provides the torque of 20 KN.