Insulating coating composition for electromagnetic steel sheets, electromagnetic steel sheets, and method for manufacturing the same.

JP2026508881APending Publication Date: 2026-03-13POHANG IRON & STEEL CO LTD
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Patent Information

Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
Filing Date
2023-12-20
Publication Date
2026-03-13

AI Technical Summary

Technical Problem

Existing electromagnetic steel sheet coatings lack durability in high-temperature and high-humidity environments, exhibit poor corrosion resistance, and have inadequate heat resistance during stress relief annealing, while also failing to maintain excellent insulating properties in high-frequency magnetic fields.

Method used

An insulating coating composition comprising 100 parts by weight of metal phosphate, 25 to 150 parts by weight of silica, 15 to 60 parts by weight of metal oxyhydroxide, and 0.5 to 10 parts by weight of a reducing agent, applied to an electrical steel sheet substrate and heat-treated at 750-1000°C for 10-300 seconds.

Benefits of technology

The coating provides excellent durability, extreme corrosion resistance, and heat resistance at high temperatures, maintaining excellent insulating properties in high-frequency magnetic fields.

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Abstract

The objective is to provide an electrical steel sheet insulating coating composition, an electrical steel sheet, and a method for manufacturing the same, which exhibit excellent durability in high-temperature and high-humidity environments, extreme corrosion resistance, and excellent heat resistance at very high temperatures such as stress relief annealing (SRA), by appropriately combining the components of the insulating coating composition. [Solution] The insulating coating composition for electrical steel sheets of the present invention comprises 100 parts by weight of a metal phosphate, 25 to 150 parts by weight of silica, 15 to 60 parts by weight of a metal oxyhydroxide, and 0.5 to 10 parts by weight of a reducing agent, wherein the metal phosphate comprises one or more of Mg, Ca, Ba, Sr, Zn, and Al, the silica has a pH of 8 to 12, the metal oxyhydroxide comprises one or more of TiOOH, ZrOOH, and MnOOH, and the reducing agent comprises one or more of ammonia, glycol, polyol, and sulfate.
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Citation Information

Patent Citations

  • Chromium-free insulating film agent for electromagnetic steel sheet

    JP2007023329A

  • Non-oriented electromagnetic steel sheet

    JP2018090836A

  • Insulating coating treatment solution, and grain oriented electrical steel sheet having insulating coating film attached thereto and method for manufacturing same

    WO2020026627A1