Method and device for spraying silicic acid produced from oriented silicon steel having good bottom layer

Abstract

The invention relates to a method for spraying magnesium silicate produced from oriented silicon steel having a good bottom layer, which comprises the following steps: putting oriented silicon steel strip steel after rolling and decarburizing annealing into a plasma spraying magnesium silicate chamber to perform plasma spraying magnesium silicate treatment; setting at least four plasma emission sources (1, 2, 3 and 4) in an up-down staggering mode on the strip steel in the plasma spraying magnesium silicate chamber; and setting gas injection cooling devices on the other side of the strip steelopposite to each plasma emission source, wherein the distance from the plasma emission sources to the strip steel is between 100 and 200 meters, the spraying time is between 200 and 300 seconds, andthe plasma Ar gas flow is between 14 and 20 liters per minute. The magnesium silicate bottom layer in the method has evener forming effect and excellent adhesive property; and the production process steps are simplified and the process stability is greatly improved.

Description

technical field [0001] The invention relates to the production technology of oriented silicon steel, in particular to a silicic acid spraying method and device for the production of oriented silicon steel with a good bottom layer. Background technique [0002] Oriented silicon steel is an iron-silicon alloy with a silicon content of about 3% and other components mainly iron. It is an indispensable and important soft magnetic alloy for electric power, electronics and military industries. It is mainly used as the iron core of transformers. Because of its complex production process and strict manufacturing technology, it is called the "handicraft" of today's global steel industry. [0003] The difference between grain-oriented silicon steel and other steel types is mainly three aspects: [0004] 1) It has a Gaussian texture, that is, (110)[001] texture, which has the best magnetic properties in the rolling direction of the silicon steel plate. The Goss texture of grain-orient...

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Problems solved by technology

[0014] If the arc power is too low, part of the ionized gas and a lower temperature plasma flame will be obtained, which will cause insufficient heating of the particles, and the coating will have lower bonding strength, hardness and deposition efficiency.

[0015]③ Powder supply: The powder supply speed must be compatible with the input power. If it is too large, raw powder (unmelted) will appear, resulting in a decrease in spraying efficiency; if it is too low, the powder Severe oxidation and overheating of the substrate

Otherwise, it may lead to the failure of this process. Under the strict requirements of temperature, dew point and atmosphere, if the equipment fluctuates slightly, it will lead to the inability to form uniform and dense SiO on the surface of the steel plate. 2 film, thereby affecting the formation of the magnesium silicate bottom layer;

[0023] Second, in order to ensure the formation of a good magnesium silicate bottom layer, there are strict requirements on the particle size, hydration rate, and impurity elements of MgO, and the baking temperature and time of MgO are also strictly controlled. If these conditions cannot Meeting the standard requirements will affect the formation of the bottom layer of magnesium silicate;

[0024] Third, a long time (about 10 hours or more) low heat preservation annealing is required in the high temperature annealing stage to eliminate the crystal water in MgO, so the production efficiency is reduced;

[0025] Fourth, in the high-temperature annealing stage, it is necessary to strictly control the heating rate in order to provide sufficient conditions for the formation of the magnesium silicate bottom layer, which will also lead to a reduction in production efficiency;

[0026] Fifth, in the high-temperature annealing stage, due to the thick magnesium oxide coating and low thermal conductivity, the temperature difference between the cold and hot spots of the steel coil is large, so the temperature rise of the steel coil must be reduced speed, which will also lead to a reduction in production efficiency

[0027] It can be seen from the above that the formation process of the bottom layer is relatively long at present, and there are many control factors related to the quality of the bottom layer with significant influence. class defects, and even the phenomenon of dew crystals at the bottom

Serious bottom dew crystals will cause damage to grain-oriented silicon steel during use, resulting in huge economic losses

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