High-temperature annealing method of low-temperature and high-magnetic-induction oriented silicon steel

Abstract

The invention belongs to the technical field of manufacturing of oriented silicon steel, and in particular relates to a high-temperature annealing method of low-temperature and high-magnetic-inductionoriented silicon steel. The method comprises the following steps: providing a steel coil to be annealed at a high temperature; placing the steel coil to be annealed at the high temperature on a bottom plate; laying an anti-adhesion layer on the upper end of the steel coil placed on the bottom plate, and covering the anti-adhesion layer with a cover plate; assembling a sealing ring on the bottom plate at the periphery of the steel coil, centering the sealing ring and the steel coil, and filling the part between the sealing ring and the steel coil with a sealing layer; then, additionally arranging an inner cover on the steel coil, putting in a furnace and annealing. The method can improve the quality of the steel coil.

Description

technical field [0001] The invention belongs to the technical field of oriented silicon steel manufacturing, and in particular relates to a high-temperature annealing method for oriented silicon steel with low temperature and high magnetic induction. Background technique [0002] The production process of low temperature and high magnetic induction oriented silicon steel in the cold rolling area is as follows: hot rolled coil → normalized pickling line → rolling line → decarburization annealing line → high temperature annealing line → stretch tempering line. Oriented silicon steel is formed with SiO on the surface of the steel plate in the decarburization annealing unit 2 , FeO, Fe 2 o 3 etc. as the main component of the oxide layer, and coated with MgO as the main component of the release agent. During high temperature annealing, the surface oxide reacts with the release agent to form a glass film. [0003] The release agent needs to be prepared into a slurry before coa...

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Problems solved by technology

[0005] In the prior art, due to the heavy weight of the steel coil, there must be a temperature difference between the inner and outer rings of the steel coil and the width direction of the steel coil during the high-temperature annealing process. When the temperature exceeds 800°C, the dew point of the atmosphere in the inner cover will still be at a relatively high level. At this time, the high dew point atmosphere will in turn affect the oxide film on the surface of the upper and lower outer rings of the steel coil, making it excessively oxidized, causing local dew crystal defects and worsening The quality of the bottom layer of hundreds of meters in the outer ring affects the quality of finished products

[0006] In addition, because the lower end of the steel coil is in contact with the bottom plate of the steel coil, due to the difference in thermal expansion coefficient between the two, the lower end of the steel coil is prone to bottom deformation defects during the heating and cooling process, which will also affect the quality of the finished product

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