Method for producing oriented silicon steel without pickling after normalizing

Abstract

The invention relates to a method for producing oriented silicon steel without pickling after normalizing. The production process route of the oriented silicon steel comprises the steps of smelting, continuous casting, hot rolling, normalizing annealing, stretch straightening, shot blasting, cold rolling, decarburization annealing, nitriding, MgO coating, high-temperature annealing, hot stretch leveling and insulating film coating. According to the method, oxide scale on the surface of a strip steel is removed through a physical method after normalizing annealing, efficiency is high, the effect is good, operation is easy, and control is easy; and compared with a conventional process, pickling and subsequent waste acid treatment work are omitted, pollution of acid mist to the environment is eliminated, potential defects caused by pickling of the oriented silicon steel strip are eliminated, and the product quality is more stable and reliable.

Description

technical field [0001] The invention relates to the technical field of oriented silicon steel production, in particular to a method for producing oriented silicon steel without pickling after normalization. Background technique [0002] At present, pickling is usually carried out after the normalization process in the production process of grain-oriented silicon steel to remove the iron oxide scale generated during high-temperature heating. The traditional method firstly performs shot blasting treatment on the normalized steel plate to loosen the oxide scale, and then pickles it with hydrochloric acid. Although better cleaning effect and surface quality can be obtained after pickling, many problems will also arise: [0003] 1) In order to ensure the cleaning effect, the hydrochloric acid used must reach a certain concentration, and hydrochloric acid is a strong acid, which is volatile and produces acid mist to pollute the environment; [0004] 2) The length of the acid tan...

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Problems solved by technology

[0003] 1) In order to ensure the cleaning effect, the hydrochloric acid used must reach a certain concentration, and hydrochloric acid is a strong acid, which is volatile and produces acid mist to pollute the environment;

[0004] 2) The length of the acid tank is usually about 50 meters. After pickling, a cleaning tank with a length of about 10 meters is required, which occupies a large area;

[0005] 3) As the pickling progresses, the iron ion content in the acid tank increases continuously, and the reaction speed between hydrochloric acid and iron oxide scale slows down, while the operating speed of the unit in the process system is usually fixed, which will cause uneven pickling , resulting in under-pickling and over-pickling, which will affect the surface quality and intrinsic quality of grain-oriented silicon steel;

[0006] 4) In the pickling process, the steel strip is immersed in the hydrochloric acid, once the unit is temporarily shut down or the like, the steel strip immersed in the hydrochloric acid will be scrapped, causing losses;

[0007] 5) The problem of waste acid discharge and environmental pollution is very prominent, and it is necessary to add a large number of auxiliary equipment for subsequent treatment, occupying a large area and increasing production costs

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