A Method of Controlling the Flatness of Hot-rolled Strip Steel by Changing the Width of Cooling Water Spray

Abstract

The invention discloses a method for controlling straightness of hot-rolling strip steel by changing the spraying width of cooling water, and relates to control equipment or a control method special for a metal rolling machine or a machined product of the metal rolling machine. The method is used for a laminar flow cooling system of a hot rolling line. The method comprises the following steps: according to the width B (unit mm), the edge wave width c (unit mm) and the equipment total cooling width L (unit mm) of a strip steel product, on the basis of a formula that S is equal to L-b+c, a single-side shelter width S is determined, and the spraying width of the cooling water is changed by blocking header nozzles of a corresponding cooling header. According to the method, nozzles on the two sides of the cooling header within a certain range are blocked, and the spraying width of the cooling water is changed; the straightness of the hot-rolling strip steel can be effectively controlled, and the method can adapt to changes of a product width; and the strip shape quality and the product yield are improved. The method is used for transformation of an existing hot rolling line, strip steel transverse temperature uniformity in the cooling process can be effectively improved, meanwhile, a heater or a baffle device can be omitted, and transformation cost of the hot rolling line is saved.

Description

technical field [0001] The invention relates to a control device or method specially suitable for a metal rolling mill or its processed products, especially a method for controlling the flatness of a hot-rolled steel strip by changing the spray width of cooling water. Background technique [0002] The hot-rolled strip production process usually mainly includes heating, rough rolling, finish rolling, cooling and coiling. With the development of different hot-rolled strip products, the cooling process after rolling has become one of the key links in the production of hot-rolled strip. one. In the production of hot-rolled strip steel, in order to obtain good material properties, it is usually necessary to control the temperature within a certain range by means of water cooling. The output roller table cooling system of modern hot rolling mill generally adopts laminar flow cooling method, such as figure 1 The schematic diagram of the hot rolling line shown shows that the lamin...

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Problems solved by technology

[0005] In the above-mentioned patent, aiming at the plate shape problem caused by the uneven distribution of temperature in the transverse direction (slab width direction) during the cooling process, the above-mentioned patent proposes a technical solution to improve the temperature uniformity and the quality of the plate shape, whether it is local supplementary heat or the edge of the steel plate. For the cooling water to be shielded, it is necessary to install complex equipment and devices. For the existing hot rolling line transformation, the project is complicated and the investment is huge

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