Method for producing thin format hot rolled steel plate

Abstract

The invention discloses a production method for a light-gauge hot rolled steel plate, which comprises the steps that: a. the distance between an upper roller and a lower roller of each frame of a hot strip mill is adjusted and the percent of reduction epsilon 1 of a first frame is adjusted to be 53 percent to 63 percent, wherein, the epsilon 1 is equal to (H1-h1) / H1, therein, H1 is the thickness of a slab at an inlet of the frame, h1 is the thickness of a slab at an outlet of the fame; b. high temperature slabs are sent to a rolling inlet of the frames that are arranged in sequence for rolling; c. the light-gauge hot rolled steel plate is output from a rolling outlet of a last frame after the slabs are rolled by the varied frames. The invention promotes the percent of reduction of the first frame as high as possible when ensuring security to reduce the load of rollers of rear frames, thereby improving rolling efficiency and product quality.

Description

technical field [0001] The invention relates to the field of steel rolling, in particular to a production method of thin-gauge hot-rolled steel plates. Background technique [0002] Thin-gauge hot-rolled steel plates refer to hot-rolled steel plates with a thickness of less than 2.0mm. When traditional process steel mills produce thin-gauge hot-rolled steel plates, they use 30-35mm slabs to be rolled to specifications below 2.0mm, from slabs to finished products. The total amount of deformation is only 93%, so the amount of deformation allocated to each rack (the racks are F1, F2, F3, F4... from front to back) is relatively small, even F1, F2, and F3 with the largest amount of deformation It will not exceed 50%. Due to the small amount of deformation, the required rolling load is also low. The thickness of the slab at the entrance of the finishing mill in the thin slab continuous casting and rolling process reaches 50-70mm, and the total deformation from the slab to the fini...

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Problems solved by technology

[0003] 1. According to the commonly used rolling load distribution principle, the first few stands of the rolling mill should distribute as much load as possible so that the slab can be deformed as much as possible at high temperature, but the F1 stand considers the problem of slab bite, If the amount of deformation is too large, it may cause the slab to be unable to bite in, so the setting of the reduction rate of the F1 frame is generally conservative, generally set at about 50%; when rolling a thin gauge hot-rolled steel plate, the total deformation The amount of deformation increases, while the deformation of F1 is too small, resulting in excessive deformation of the rear frame, resulting in excessive rolling load of the rear frame;

[0004] 2. The rolling load of F3 and F4 frames is too large, the frame vibration is serious, and the oxide film on the surface of the roll is easy to peel off, resulting in quality defects of the oxide scale on the surface of the strip;

[0005] 3. The rolling load of F5 and F6 stands is too large, so that the flatness control system cannot adjust the wave shape online, and flatness defects are prone to occur

[0006] In order to solve the above problems and realize the mass production of thin-gauge hot-rolled steel plates, various steel mills have adopted various measures, some of which add a roughing mill before the finishing mill to reduce the thickness of the slab at the entrance of the finishing mill, thereby reducing the thickness of the slab. Small rolling load, using this method requires a large economic investment. At the same time, the whole plant is in a state of shutdown during the construction period, which has a great impact on production. In addition, due to the limited space on site, some steel plants have no space to install this equipment; At the cost of sacrificing production, some steel mills reduce the rolling load of the finishing mill by reducing the thickness of the slab from 60mm to 50mm or even thinner. This method has a greater impact on production capacity

With the same production rhythm, the production capacity is reduced by about 20% compared with the production of 50mm billet and 60mm billet, which will have a great impact on the output and cost of the enterprise.

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