Method for Reducing Thermal Stress Peeling of Roller Oxide Film

Abstract

The invention discloses a method for reducing thermal stress peeling of an oxidation film on a roller and belongs to the technical field of steel rolling techniques. The method for reducing thermal stress peeling of the oxidation film on the roller is used for reducing heat transfer during contact of strip steel and the roller so as to achieve the purposes of decreasing the roller temperature, reducing thermal stress cracks of the roller and improving the surface quality of products. The method for reducing thermal stress peeling of the oxidation film on the roller comprises the steps that when the strip steel is rolled, the nip rolling speed of a finish rolling unit F1 is controlled to be not smaller than 1 m / s; the spraying angle and spraying pressure of peeling-prevention water on the inlet side of the roller are controlled; the spraying angle adopts the lower limit of 45 degrees and the upper limit that a sprayed water flow is not blocked by the roller; and the spraying pressure is8-12 bar. According to the method for reducing thermal stress peeling of the oxidation film on the roller, the spraying angle and spraying pressure of the peeling-prevention water on the inlet side of the roller on the lower side of a rack of the finish rolling unit are controlled reasonably, so that heat transfer during contact of the strip steel and the roller is reduced, accordingly, the roller temperature is decreased, the thermal stress cracking defect of the roller is reduced, and the surface quality of the products is improved.

Description

technical field [0001] The invention belongs to the technical field of steel rolling technology, and in particular relates to a method for reducing thermal stress spalling of an oxide film of a roll. Background technique [0002] Hot-rolled rolls are exposed to high-temperature and high-pressure working environments for a long time, and are subjected to heavy loads, which are prone to various roll defects, which become factors that restrict the improvement of product quality and dimensional accuracy. Among them, the control of roll temperature is the most influential among all factors, and it is also the most operable. For a long time, various scholars and engineers have focused on improving the efficiency and uniformity of cooling of rolls. [0003] CN 105598172 A discloses a method for preventing the peeling of the oxide film on the rolls of a hot strip continuous rolling mill. On the entrance side of the rolling mill, cooling liquid (mist) is sprayed into the rolls to ke...

AI Technical Summary

Problems solved by technology

However, these research results have ignored the thermal stress problem caused by the cooling process of the roll.

The cooling process of the roll will inevitably generate thermal stress. The higher the temperature, the faster the cooling rate, the greater the stress. During the cyclic heating and cooling process, the inside of the roll receives alternating loads, which will eventually cause thermal cracks and affect the surface quality of the product.

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