A kind of chromium-free insulating coating liquid and its preparation method and grain-oriented silicon steel plate

Abstract

The invention provides a chrome-free insulating coating solution, a preparation method thereof and an oriented silicon steel plate. The chromium-free insulating coating solution comprises the following components: 150-200 parts by weight of phosphate solution, 8-15 parts by weight of citric acid, 2-8 parts by weight of magnesium hydroxide, 7-10 parts by weight of boric acid, 160-250 parts by weight of silica sol, 1-10 parts by weight of tartaric acid, 1-10 parts by weight of antimony trifluoride, 1-10 parts by weight of phosphotungstic acid, and 100-300 parts by weight of water. The preparation method of the chromium-free insulating coating liquid is as follows: add phosphate solution, boric acid and water, stir; add antimony trifluoride, citric acid and tartaric acid in turn, stir; add magnesium hydroxide and phosphotungstic acid to make the pH 1- 5. Add silica sol and stir to obtain the chromium-free insulating coating solution. The chromium-free insulating coating of the invention has extremely high interlayer resistance and surface hardness, excellent corrosion resistance and extremely strong surface tension, and exhibits an excellent effect of improving magnetic properties.

Description

technical field [0001] The invention belongs to the technical field of silicon steel, and in particular relates to a chromium-free insulating coating liquid, a preparation method thereof, and an oriented silicon steel plate. Background technique [0002] As an important magnetic material, grain-oriented silicon steel has excellent properties of high magnetic induction and low iron loss, and is often widely used as the core material of power transformers. The insulating coating coated on the surface of oriented silicon steel not only has the functions of anti-rust, corrosion resistance and insulation, but also the tension generated on the surface can also reduce iron loss, reduce the magnetostriction coefficient, and reduce the energy consumption and noise of the transformer. Therefore, the insulating coating is an important part of grain-oriented silicon steel. [0003] However, the vast majority of insulating coating solutions currently in use contain chromate. After the ...

AI Technical Summary

Problems solved by technology

However, no matter which of the above technologies is used, the overall performance of the coating cannot be achieved to achieve the performance equivalent to that of chromium-containing coatings.

Images