Producing method of electrical steel extremely-thick insulating coating with good film-forming property

Abstract

A producing method of an electrical steel extremely-thick insulating coating with a good film-forming property comprises the following steps that (1) adopted insulating paint is composed of, by weight, 10%-60% of organic resin, 28%-60% of inorganic color filler, 1%-15% of auxiliaries and solvents and the balance pure water; (2) surface treatment is conducted on a substrate, wherein surface modification treatment is conducted on the Fe-Si alloy substrate with the silicon content ranging from 1.5wt% to 3.0wt%, the surface of the substrate is covered with an oxidation film layer, and the surface roughness of the substrate is greater than or equal to 0.4 micron; (3) annealing is conducted, wherein the annealing temperature ranges from 780 DEG C to 1000 DEG C and is kept for 10 seconds-20 seconds, and the annealing atmosphere is a hydrogen and nitrogen gas mixture; (4) baking and curing are conducted, the baking process or the multi-band high infrared heating process or a combination of the baking process and the multi-band high infrared heating process is adopted. The film-forming property of the coating obtained with the method is excellent, and meanwhile the method has the advantages that the solid content required by the electrical steel environment-friendly extremely-thick insulating coating is high, surface insulativity and adhesiveness are excellent, and hot-pressing stability and corrosion resistance are good.

Description

technical field [0001] The invention relates to the production technology of electrical steel products, in particular to a production method of an extremely thick insulating coating for electrical steel with good film-forming properties. The ultra-thick insulating coating is applied to electrical steel sheets for large and medium-sized generators. In addition to ensuring the basic properties such as insulation, punching and shearing processability, and heat resistance required by the coating, it also has excellent film-forming properties, which are specifically reflected in the good adhesion of the coating and better protection for the substrate. Background technique [0002] Electrical steel products are widely used in the iron core materials of motors and transformers. In order to reduce the short circuit between the laminations of electrical steel sheets and increase the eddy current loss, it is necessary to coat the surface with an insulating coating. Large and medium-si...

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Problems solved by technology

C6 coatings require extremely high surface insulation, H-level heat resistance, and hot-press stability. The coating formula generally contains a large amount of inorganic fillers with submicron particle sizes, and the dry film thickness of the coating is controlled to be 2 to 7 μm; The thick coating is applied on the surface of the steel plate, and there are great difficulties in the production and preparation process of the product, which can easily lead to coating defects, and make the film quality poor, manifested as poor coating adhesion and coating powder formation A series of problems such as bright spots, poor scratch resistance of the coating, coating peeling or paint bursting during stamping and shearing, seriously deteriorate the use characteristics of C6 coating products, and even cannot be used

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