Smooth production method for preventing quality defect of contusion of strip steel coil

Abstract

The invention relates to a flattening production method for preventing bruise quality defects of a strip steel coil, which comprises the following steps: 1) uncoiling control: a flattening machine selects a recoiling mode for rolling, the uncoiling tension is 2500-3000kgf, the coiling tension is zero, the total of the uncoiling tension and the coiling tension is 2500-3000kgf, and the tension is 5-10 times lower than that of a flattening mode, so that the steel coil is not deformed, staggered and loosened when the steel coil is loosened; (2) rolling is controlled to be 5-8 m in a recoiling mode, and then rolling is stopped; and (3) a temper mill is switched into a leveling mode to continue rolling, the tension of an uncoiler ranges from 5000 kgf to 10000 kgf, the coiling tension ranges from 10000 kgf to 21000 kgf, the opening degree of a working roller ranges from 2 mm to 6 mm, and the uncoiling and coiling tension ranges from 15000 kgf to 31000 kgf. The temper mill adopts a production method of combining two modes of recoiling control production and leveling stable production, and solves the problem of control head and tail contusion during leveling process production. And meanwhile, the problems that the head of the steel coil deviates when the roll gap is adjusted and the leveling roll is damaged by foreign matters on the plate surface due to poor quality of the tail plate surface of the raw material steel coil are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of hot rolling skin pass, and particularly relates to a skin pass production method for preventing quality defects of strip coil bruising. Background Art

[0002] At present, there are three major types of quality defects in the skin pass mill: bruising, transverse crease marks, and indentation marks; among the three types of defects, the bruising defect accounts for a relatively large proportion. Therefore, the bruising defect is an urgent research topic. Bruising is related to small coiling tension, thermal shrinkage of raw material hot coils, poor shape and coiling shape of raw material coils, inappropriate uncoiling tension and speed in skin pass, improper handling and repeated handling of steel coils, etc.

[0003] Steel enterprises adopt different methods for controlling strip bruising according to the actual conditions of their respective mills. However, for thin and soft strip during skin pass production, bruising problems still occur within 80 meters at the head and tail. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a hot rolling skin pass production method for preventing quality defects of strip bruising, and solve the bruising problems at the head and tail during skin pass production.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] A skin pass production method for preventing quality defects of strip coil bruising, comprising the following steps:

[0007] 1) Uncoiling control: The skin pass mill selects the recoiling mode for rolling, the uncoiling tension is 2500 - 3000 kgf, the coiling tension is zero, and the sum of the uncoiling and coiling tensions is 2500 - 3000 kgf, achieving a tension 5 - 10 times lower than the skin pass mode, so that no deformation, misalignment, or loosening occurs when the steel coil is loose-wound.

[0008] 2) Stop after controlling and rolling for 5 - 8 meters in the recoiling mode.

[0009] 3) The skin pass mill switches to the skin pass mode and continues rolling. The uncoiling machine tension is 5000 - 10000 kgf, the coiling tension is 10000 - 21000 kgf, the working roll opening is 2 - 6 mm, and the sum of the uncoiling and coiling tensions is 15000 - 31000 kgf.

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

[0011] In step 3), after controlling the production to end, the stable production strip speed is 200 - 300 m / min.

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

[0013] Compared with the existing technology, the beneficial effects of the present invention are as follows:

[0014] The leveler of the present invention adopts a production method combining the recoiling control production and the leveling stable production, which solves the problem of controlling the bruises at the head and tail during the leveling process. At the same time, it also avoids the problem that due to the poor quality of the tail plate surface of the raw material steel coil, it is very easy to cause the deviation of the steel coil head when adjusting the roll gap, and the foreign matter on the plate surface damages the leveling roll. Specific embodiments

[0015] It should be noted that unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The mention of "embodiment" in this article means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of this application. The appearance of this phrase in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0016] A leveling production method for preventing quality defects of strip coil bruises, comprising the following steps:

[0017] 1) Uncoiling control, the leveler selects the recoiling mode for rolling, the uncoiling tension is 2500 - 3000 kgf, the coiling tension is zero, and the sum of the uncoiling and coiling tensions is 2500 - 3000 kgf, reaching a tension 5 - 10 times lower than the leveling mode, so that no deformation, misalignment or loosening occurs when the steel coil is unrolled.

[0018] 2) Stop after controlling and rolling for 5 - 8 meters in the recoiling mode.

[0019] 3) The leveler switches to the leveling mode and continues rolling. The uncoiling tension of the uncoiler is 5000 - 10000 kgf, the coiling tension is 10000 - 21000 kgf, the opening of the work roll is 2 - 6 mm, and the sum of the uncoiling and coiling tensions is 15000 - 31000 kgf.

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

[0021] After the control production in step 3), the stable production speed of the strip steel is controlled at 200 - 300 m / min.

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

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0024] Embodiment 1:

[0025] A temper rolling production method for preventing quality defects of strip steel coils, where the thickness of the steel plate of the coil is 2.55 MM. It includes:

[0026] 1) Uncoiling control: The temper mill selects the recoiling mode for rolling, the uncoiling tension is 3000 kgf, the coiling tension is zero, the total of the uncoiling and coiling tensions is 3000 kgf, and the strip speed is 55 m / min; when the steel coil is uncoiled, no deformation, misalignment, or loosening occurs.

[0027] 2) Control the recoiling mode and stop after producing 5.5 meters.

[0028] 3) The temper mill switches to the tempering mode and continues rolling. The uncoiling machine tension is 5000 kgf, the coiling tension is 10000 kgf, the working roll opening is 2.5 mm, the outlet tempering tension is 15000 kg, and the strip speed is 300 m / min.

[0029] Embodiment 2:

[0030] A temper rolling production method for preventing quality defects of strip steel coils, where the thickness of the steel plate of the coil is 5.05 mm, including:

[0031] 1) Uncoiling control: The temper mill selects the recoiling mode for rolling, the uncoiling tension is 3000 kgf, the coiling tension is zero, the total of the uncoiling and coiling tensions is 3000 kgf. The strip speed is 58 m / min; when the steel coil is uncoiled, it is not easy to produce deformation, misalignment, or loosening.

[0032] 2) Control the recoiling mode and stop after producing 6.5 meters.

[0033] 3) The temper mill switches to the tempering mode and continues rolling. The uncoiling machine tension is 10000 kgf, the coiling tension is 21000 kgf, the working roll opening is 5 mm, the outlet tempering tension is 31000 kg, and the strip speed is 200 m / min.

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

Claims

1. A temper rolling production method for preventing quality defects of strip steel coils, characterized in that, It includes the following steps: 1) Uncoiling control: The temper mill selects the recoiling mode for rolling. The uncoiling tension is 2500 - 3000 kgf, the coiling tension is zero, and the total uncoiling plus coiling tension is 2500 - 3000 kgf, achieving a tension 5 - 10 times lower than that in the tempering mode, so that no deformation, misalignment, or loosening occurs when the steel coil is uncoiled; 2) Control the recoiling mode to roll for 5 - 8 meters and then stop; 3) The temper mill switches to the tempering mode and continues rolling. The uncoiler tension is 5000 - 10000 kgf, the coiler tension is 10000 - 21000 kgf, the work roll opening is 2 - 6 mm, and the uncoiling plus coiling tension is 15000 - 31000 kgf.

2. The temper rolling production method for preventing the quality defect of strip coil bruise according to claim 1, characterized in that, In step 1), control the production strip speed to be 50 - 60 m / min.

3. A temper rolling production method for preventing strip coil bruise quality defects according to claim 1, characterized in that, In step 3), after the production is controlled to end, stabilize the production strip speed to be 200 - 300 m / min.

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