Oriented silicon steel insulation coating capable of improving punched piece performance

Abstract

This invention discloses an oriented silicon steel insulation coating, which can be used to improve the performance of the laminated sheet . It has the composition weight percentage as follows: polyether-modified silicon oil, the water solution with 1% weight proportion, accounts for 0.01%-2.0%, of which the radio of hydrophilic chains to hydrophobic chains ranges from 20 / 80 to 100 / 0; aluminium dihydrogen phosphate 3%-24%, colloidal silica 4%~16%, chromic anhydride 0.15%~4.50% and the rest is water. After coated in the oriented electrical steel, the said insulation coating can remarkably enhance the laminated sheet times by the intrinsic lubricity of silicone during the machining of oriented silicon steel, and hence greatly enhance the production efficiency. Besides, due to the favorable water-solubility of the polyether-modified silicon oil and the common heat-resistance of the silicone products, the said coating is easily prepared, uniformly coated, and has good dispersibility. The coated surface is in good quality, able to endure sintering with high temperature without thermal degradation.

Description

technical field [0001] The invention relates to a coating, in particular to a coating for oriented silicon steel. Background technique [0002] The American Armco company first proposed the C-5 coating, which is an inorganic magnesium phosphate coating. Japan's Kawasaki Iron and Steel Co., Ltd. proposed a D coating that added aluminum nitrate and chromic acid on this basis. Then, Nippon Steel of Japan proposed the stress coating T-2 coating (patent number: Zhao 48-39338, Zhao 53-28043), whose components are colloidal silicon dioxide, aluminum dihydrogen phosphate and chromic anhydride. [0003] Most oriented silicon steel insulation coatings are composed of pure inorganic components. The advantages of inorganic coatings are high temperature resistance, electrical insulation, and good adhesion. In addition, the small thermal expansion coefficient and large tensile stress further reduce iron loss. However, because the components of the existing coating liquid are all inorg...

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Problems solved by technology

[0009] This type of coating is similar to the semi-organic coating used for non-oriented silicon steel. This coating can indeed increase the number of punching and shearing, but its disadvantages are: economically, raw materials such as polyvinylamine have high production costs and processes, and product prices remains high, which greatly limits the application in actual production

In terms of technology, after coating and baking the insulating coating, the coating needs to be sintered at a high temperature of 850°C. If the above-mentioned general organic resins are used, a large amount of organic matter will be thermally decomposed at this high temperature, making the organic components invalid. Can not achieve the effect of improving the performance of the original expectation

[0010] Through the investigation of oriented silicon steel products at home and abroad, and the query of patents and documents, it can be found that the insulating coating of oriented silicon steel with good punching performance is still a blank in China; many methods have been adopted in foreign countries to increase the number of punching times: US patent Rely on the removal of tough glass membranes (Mg 2 SiO 4 ) to improve sheetability, but this method sacrifices other important coating properties

The Japanese patent improves the shearability of grain-oriented electrical steel by adding organic resin, but this method has the problems of poor heat resistance of the coating and little improvement in shearability

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