Low-carbon steel continuous casting and rolling production line and production technology thereof

Abstract

The invention discloses a low-carbon steel continuous casting and rolling production line and a production technology thereof. The low-carbon steel continuous casting and rolling production line and the production technology thereof are applied to the technical field of steel rolling. The production line comprises a slab continuous casting machine, a high-pressure water rough descaling device, a roughing rolling unit, a swing shear, a pushing-out and sheet stacking device, a rotating drum flying shear, a waste material removal device, an induction heating furnace, a high-pressure water fine descaling device, a middle rolling rack, a middle water cooling device, a finishing rolling unit, a laminar flow cooling device, a high-speed flying shear and a recoiling machine. The finishing rollingunit comprises four finishing rolling racks. The distance L between the middle rolling rack and the centre line of the first finishing rolling rack ranges from 10 m to 20 m. According to the low-carbon steel continuous casting and rolling production line and the production technology thereof, by means of reasonable production line arrangement and the proper production technology, the low-temperature rolling and high-temperature recoiling requirements for ferrite rolling are guaranteed; the sufficient finishing rolling total reduction rate is guaranteed; complete transforming, from austenite toferrite, of strip steel before being subjected to finishing rolling is completed; the finishing rolling is conducted in a ferrite zone, and thus real-sense ferrite rolling conducted through the continuous casting and rolling production line is achieved.

Description

technical field [0001] The invention belongs to the technical field of iron and steel rolling, and in particular relates to a low-carbon steel continuous casting and rolling production line and a production process thereof. Background technique [0002] In 1986, German SMS Siemag successfully carried out the test of thin slab continuous casting machine. In 1989, American Nucor Steel Company built the world's first CSP workshop in Crawfordsville, Indiana, marking the thin slab continuous casting and rolling. The technology was put into industrial production. Since then, various iron and steel / engineering companies in the world have continuously developed new thin slab continuous casting and rolling technologies, such as the ISP technology of German Demark Company, the CONROLL technology of Austrian Austrian Alpine Company, the QSP technology of Sumitomo Company of Japan, and the Italian Danieli Technology Co., Ltd. The company's FTSR technology, Italy's Arvedi's ESP technolo...

AI Technical Summary

Problems solved by technology

At present, there are some patents related to the application of ferrite rolling to continuous casting and rolling production lines, but there are still some problems in realizing ferrite rolling in the true sense: 1. Insufficient temperature control capability; 2. The total pressure of finishing rolling 3. Insufficient ferrite transformation and other problems, the reasons are as follows: 1. Ferrite rolling requires low-temperature rolling and high-temperature coiling, and the existing continuous casting and rolling production line finishing rolling units are usually continuously arranged side by side. There are 5 to 7 racks. This arrangement cannot meet the two requirements of temperature control (low temperature start rolling and high temperature coiling) and finish rolling total reduction rate control (55% to 75%) of ferrite rolling at the same time. To ensure low-temperature start rolling and sufficient total reduction rate, the temperature drop of strip steel after finishing rolling with 5 to 7 stands is too large, and the requirements for outlet temperature and coiling temperature cannot be guaranteed. If rolling with 5 to 7 stands is guaranteed Low-temperature rolling and high-temperature coiling require that the temperature drop during the rolling process need to be controlled. The overall speed of the continuous casting and rolling production line is stable (the whole line is consistent from continuous casting to coiling), and it is impossible to control the temperature drop by increasing the local rolling speed. , the temperature drop can only be reduced by reducing the number of racks and reducing the distance that the strip runs in the air, and reducing the number of racks will reduce the total reduction rate of finishing rolling, thereby affecting product performance; 2. The current continuous casting and rolling The structure of the production line is compact, and there is no time for the transformation of austenite to ferrite, so that the finishing rolling cannot be completely carried out in the ferrite area, which will also affect the performance of the final product

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