Method for preventing scale pits of steel plate

Abstract

The invention relates to a method for preventing scale pits of a steel plate, which includes the following steps:(1) installing a wiper plate: adding a wiper plate on the working roll of a roller; (2) removing scales through high-pressure water and blowing air: adding an air blower on the tag board of the roller, wherein an air source is nitrogen; and removing the scales on the surface of the steel plate through the high-pressure water and blowing the nitrogen to the descaled steel plate. When rolling the steel plate, water is sprayed to cool the working roll of the roller and the wiper plateprevents the cooling water of the rolling system of the roller from directly spraying the surface of the steel plate, thus retarding oxidation rate of the steel plate. Meanwhile, the scales on the surface of the steel plate are removed through the high-pressure water and the nitrogen is blown to the descaled steel plate. In the process of throwing the rolled piece out of the roller and relieving the stress, under the diluting action of the nitrogen blown out, oxydic air surrounding the steel plate can be reduced and thereby a protective gas layer can be formed around the steel plate, thus preventing oxidation once again and reducing amount of secondary scales.

Description

technical field [0001] The invention relates to steel rolling, in particular to a method capable of preventing oxidized scale pits on steel plates. Background technique [0002] During the production process of medium and heavy plates, the pitting of iron scale on the surface of the steel plate has always been the main quality problem that plagues major steel mills. The scale pit at the rolling mill mainly includes the primary scale pit and the secondary scale pit (scale produced at the rolling mill). [0003] The primary iron sheet is the oxidized iron sheet produced during the heating process in the heating furnace. When the descaling is not clean due to insufficient pressure in the descaling box or clogged nozzles, it can also be sprayed with salt, using the blasting effect of the salt and the high pressure of the four rollers at the rolling mill. Water for secondary descaling. And the thickness of the primary iron sheet is usually up to 1mm. After descaling, the temper...

AI Technical Summary

Problems solved by technology

But it was too late, the resulting quality loss has become a fait accompli irreparable

[0005] Therefore, the secondary iron sheet pressing of the steel plate is a headache for all major steel mills. It is difficult to control the oxide iron sheet pressing on the surface of the steel plate. In fact, it mainly means that the secondary iron sheet is invisible and intangible during the hot rolling process, and the secondary pressing pit is difficult to control