ELECTRICAL STEEL SHEET WITH ORIENTED GRAIN STRUCTURE AND METHOD FOR FORMING AN INSULATING COATING
Patent Information
- Authority / Receiving Office
- RU · RU
- Patent Type
- Applications
- Current Assignee / Owner
- NIPPON STEEL CORPORATION
- Filing Date
- 2024-04-05
- Publication Date
- 2026-07-01
Claims
1. A sheet of grain-oriented electrical steel containing: base steel sheet; a glass coating formed on the surface of the base steel sheet; and an insulating coating formed on the surface of a glass coating, wherein: the base steel sheet has a sheet thickness of 0.15-0.35 mm, the insulating coating comprises a metal phosphate, amorphous silicon dioxide and an alkaline earth metallic element other than magnesium, wherein the amorphous silicon dioxide is contained in an amount of 50-150 parts by weight, and wherein the alkaline earth metallic element is contained in an amount of 1.0-20 parts by weight in total, relative to 100 parts by weight of the metal phosphate, and The insulating coating has a water content of 0-0.04 wt%.
2. A sheet of electrical steel with an oriented grain structure according to paragraph 1, in which: the alkaline earth metallic element is one element or two or more elements selected from Ca, Sr and Ba.
3. A method for forming an insulating coating, comprising: a solution preparation step in which a solution for an insulating coating is prepared containing 50-150 parts by weight of colloidal silicon dioxide in relation to the silicon dioxide content and 1.25-83.3 parts by weight of a hydroxide or hydrogen carbonate of an alkaline earth metallic element other than magnesium in relation to 100 parts by weight of a metal phosphate, wherein the solution for an insulating coating has a solid content amount of 8-50% by weight; and a coating and drying step of applying an insulating coating solution to a steel sheet, heating the steel sheet to a temperature range of 800-900°C so that the heating rate between 100 and 600°C is 40-200°C / sec, and maintaining the insulating coating solution in the temperature range for 5-90 seconds.
4. A method for forming an insulating coating according to paragraph 3, in which: At the solution preparation stage, 1-5 parts by weight of phosphonic acid relative to 100 parts by weight of metal phosphate are added to the insulating coating solution.