Manufacturing method of mirror surface oriented silicon steel with good magnetic performance and annealing parting agent

Abstract

The invention discloses a manufacturing method of mirror surface oriented silicon steel with good magnetic performance and an annealing parting agent. The manufacturing method comprises the following steps of: 1) smelting; 2) hot rolling and normalizing; 3) cold rolling; 4) decarbonization and nitriding; and 5) parting agent coating and high-temperature annealing. The annealing parting agent comprises the following components in parts by mass: 65-96 parts of Al2O3 powder, 2-15 parts of silicate powder with a particle size of 0.1-100 microns, 1-10 parts of alkaline earth metal oxide and 1-10 parts of metal chloride. According to the invention, through the annealing parting agent consisting of Al2O3 powder, silicate powder, alkaline earth metal oxide and metal chloride, a glass film bottom layer is not formed on the surface of a steel plate in a high-temperature annealing process, and the steel can be effectively purified; and meanwhile, the embedded oxide on the near surface of a substrate is removed through the corrosion reaction of chloride so as to obtain a product with a smooth and clean surface and stable magnetic performance.

Description

technical field [0001] The invention relates to a method for manufacturing oriented silicon steel, in particular to a method for manufacturing a mirror-oriented silicon steel with excellent magnetic properties and an annealing separator. Background technique [0002] After the oriented silicon steel is hot rolled, normalized and cold rolled, it must be 2 -N 2 Decarburization annealing is carried out under the protection of the atmosphere to eliminate rolling stress and form primary recrystallization. At the same time, moisture is passed into the furnace to control the carbon content in the steel strip below 30ppm to prevent magnetic aging of the finished product. During decarburization annealing, the surface of the steel strip will be oxidized to form SiO 2 and Fe 2 SiO 4 The main oxide layer has an adverse effect on further decarburization. During the subsequent high-temperature annealing process, the oxide layer chemically reacts with the annealing separator coated on...

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Problems solved by technology

However, this method is often difficult to completely wash off the magnesium silicate on the surface, nor can it completely eliminate the embedded oxide near the surface of the steel plate, which has limited effect on reducing core loss.

[0007] NSC Corporation of Japan added chloride to magnesium oxide as an annealing separator. Adding a large amount of chloride would cause certain corrosion on the surface of the steel plate during the secondary recrystallization annealing process, affect the surface inhibitor, and cause secondary recrystallization to be unstable.

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