A method for preventing the quality defect of a flat steel coil from being scratched

Abstract

The present application relates to a kind of flat production method for preventing strip coil bruise quality defects, 1) uncoiling control, flat machine selects heavy roll mode rolling, uncoiling tension is 2500-3000kgf, winding tension is zero, uncoiling and winding tension total is 2500-3000kgf, reach 5-10 times lower tension of flat mode, make steel coil loose roll when not produce deformation misregistration loose;2) heavy roll mode control rolling 5-8 meters after stop;3) flat machine is switched into flat mode and continues to roll, uncoiler tension is 5000-10000kgf, winding tension is 10000-21000kgf, work roll opening is 2-6mm, uncoiling and winding is tension 15000-31000kgf.The flat machine of the present application adopts heavy roll control production+flat stable production two modes combination production method, solve the problem of control head and tail bruise when producing in flat process production.At the same time, it also avoids the problem that the tail plate surface quality of raw material coil is poor, which is easy to cause the deviation of the head adjustment roll gap, and the damage of flat roll by plate surface foreign matter.

Description

Technical Field

[0001] This invention belongs to the field of hot rolling leveling technology, and specifically relates to a leveling production method for preventing strip coils from suffering quality defects. Background Technology

[0002] Currently, the main quality defects of leveling units fall into three categories: scratches, transverse creases, and dents. Among these three types, scratches account for a large proportion, making them an urgent research topic. Scratches are related to low coiling tension, hot-rolling and cold-rolling shrinkage of raw materials, poor coil shape and form, inappropriate leveling uncoiling tension and speed, improper steel coil hoisting, and repeated hoisting.

[0003] Steel companies employ different methods to control strip steel damage depending on the specific circumstances of their individual units. However, for thin and soft strip steel, damage within the first and last 80 meters can still occur during the leveling process. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a hot rolling leveling production method to prevent strip steel from being damaged and of poor quality, thereby solving the problem of damage at the beginning and end of the leveling process.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A leveling production method for preventing strip coil bruising defects includes the following steps:

[0007] 1) Uncoiling control: The leveling mill selects the recoiling mode for rolling, with an uncoiling tension of 2500-3000 kgf and a coiling tension of zero. The total uncoiling and coiling tension is 2500-3000 kgf, which is 5-10 times lower than the leveling mode, so that the steel coil does not deform, misalign or loosen when it is uncoiled.

[0008] 2) In rewinding mode, stop rolling after 5-8 meters;

[0009] 3) The leveler is switched to leveling mode to continue rolling. The tension of the uncoiler is 5000-10000 kgf, the tension of the coil is 10000-21000 kgf, the opening of the work roll is 2-6 mm, and the tension of uncoiler plus coil is 15000-31000 kgf.

[0010] In step 1), the production strip speed is controlled to be 50-60 m / min.

[0011] After the production process in step 3) is completed, the stable production strip speed is 200-300 m / min.

[0012] The steel plate thickness of the steel coil is 2-6mm.

[0013] Compared with existing technologies, the beneficial effects of this invention are:

[0014] This invention's leveling machine employs a production method combining rewinding control production and stable leveling production, solving the problem of head and tail damage during the leveling process. It also avoids the problem of the leveling rollers being easily damaged by foreign objects on the surface of the leveling rolls when adjusting the roll gap at the head of the steel coil due to the poor quality of the raw material coil's tail surface. Detailed Implementation

[0015] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. The reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0016] A leveling production method for preventing strip coil bruising defects includes the following steps:

[0017] 1) Uncoiling control: The leveling mill selects the recoiling mode for rolling, with an uncoiling tension of 2500-3000 kgf and a coiling tension of zero. The total uncoiling and coiling tension is 2500-3000 kgf, which is 5-10 times lower than the leveling mode, so that the steel coil does not deform, misalign or loosen when it is uncoiled.

[0018] 2) In rewinding mode, stop rolling after 5-8 meters;

[0019] 3) The leveler is switched to leveling mode to continue rolling. The tension of the uncoiler is 5000-10000 kgf, the tension of the coil is 10000-21000 kgf, the opening of the work roll is 2-6 mm, and the tension of uncoiler plus coil is 15000-31000 kgf.

[0020] In step 1), the production strip speed is controlled to be 50-60 m / min.

[0021] After the production process in step 3) is completed, the stable production strip speed is 200-300 m / min.

[0022] The steel plate thickness of the steel coil is 2-6mm.

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] Example 1:

[0025] A leveling production method to prevent quality defects such as bruising on steel coils, where the steel plate thickness of the coil is 2.55 mm. This includes:

[0026] 1) Uncoiling control: The leveler is selected for recoiling mode rolling, the uncoiling tension is 3000 kgf, the coiling tension is zero, the total uncoiling and coiling tension is 3000 kgf, and the strip speed is 55 m / min; so that the steel coil does not deform, misalign or loosen when it is uncoiled.

[0027] 2) Rewinding mode controls production to stop after 5.5 meters;

[0028] 3) The leveler is switched to leveling mode to continue rolling. The uncoiler tension is 5000 kgf, the coiling tension is 10000 kgf, the work roll opening is 2.5 mm, the exit leveling tension is 15000 kgf, and the strip speed is 300 m / min.

[0029] Example 2:

[0030] A leveling production method to prevent quality defects such as bruising on steel coils, wherein the steel plate thickness of the coil is 5.05mm, includes:

[0031] 1) Uncoiling control: The leveler is selected for recoiling mode rolling, with an uncoiling tension of 3000 kgf and a coiling tension of zero. The total uncoiling and coiling tension is 3000 kgf. The strip speed is 58 m / min; this prevents deformation, misalignment, and loosening of the steel coil during uncoiling.

[0032] 2) Rewinding mode controls production to stop after 6.5 meters;

[0033] 3) The leveler is switched to leveling mode to continue rolling. The uncoiler tension is 10000 kgf, the coiling tension is 21000 kgf, the work roll opening is 5 mm, the exit leveling tension is 31000 kgf, and the strip speed is 200 m / min.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A leveling production method for preventing quality defects such as bruising on steel coils, characterized in that, Includes the following steps: 1) Uncoiling control: The leveling mill selects the recoiling mode for rolling, with an uncoiling tension of 2500-3000 kgf and a coiling tension of zero. The total uncoiling and coiling tension is 2500-3000 kgf, which is 5-10 times lower than the leveling mode, so that the steel coil does not deform, misalign or loosen when it is uncoiled. 2) In rewinding mode, stop rolling after 5-8 meters; 3) The leveler is switched to leveling mode to continue rolling. The tension of the uncoiler is 5000-10000 kgf, the tension of the coil is 10000-21000 kgf, the opening of the work roll is 2-6 mm, and the tension of uncoiler plus coil is 15000-31000 kgf.

2. The leveling production method for preventing strip coil bruising quality defects according to claim 1, characterized in that, In step 1), the production strip speed is controlled to be 50-60 m / min.

3. The leveling production method for preventing strip coil bruising quality defects according to claim 1, characterized in that, After the production process in step 3) is completed, the stable production strip speed is 200-300 m / min.

4. The leveling production method for preventing strip coil bruising quality defects according to claim 1, characterized in that, The steel plate thickness of the steel coil is 2-6mm.