Manufacturing method of non-directional electromagnetic steel sheet

TWI941536BActive Publication Date: 2026-10-01JFE STEEL CORP
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Patent Information

Application Number
TW115104107
Authority / Receiving Office
TW · TW
Patent Type
Patents
Current Assignee / Owner
Priority Date
2025-02-04
Filing Date
2026-02-03
Publication Date
2026-10-01
Estimated Expiration
2046-02-02

AI Technical Summary

Technical Problem

Existing methods for manufacturing non-directional electromagnetic steel sheets using induction heating fail to reliably increase magnetic flux density due to variations in heating rates before and after the recrystallization temperature range, leading to detrimental {111}-oriented grain growth.

Method used

A manufacturing method involving hot-rolling steel with 2.5% Si, followed by cold-rolling and final annealing with controlled heating rates: 150°C/s to 250°C/s initially, then holding for 0.5-6s, and subsequent heating at 20°C/s or higher to 800°C-1100°C, combining induction and radiation heating.

Benefits of technology

Achieves non-directional electromagnetic steel sheets with high magnetic flux density by controlling heating modes during final annealing, even with induction heating, thereby minimizing {111}-oriented grain growth.

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Abstract

A method for manufacturing non-directional electromagnetic steel plates with high magnetic flux density is proposed. A method for manufacturing a non-directional electromagnetic steel sheet containing 2.5% by mass or more Si is as follows: after hot rolling of steel raw materials, annealing as needed, and cold rolling once or twice or more with intermediate annealing to produce a cold-rolled steel sheet, during the final annealing of the cold-rolled steel sheet, (1) heating from room temperature to a rapid heating stop temperature in the range of 500°C or higher and below the recrystallization start temperature, at an average heating rate of 150°C / s to 250°C / s, and holding for a specified holding time, and then heating the cold-rolled steel sheet at an average heating rate of 20°C / s or higher until the maximum temperature is reached after the holding time; or (2) heating from room temperature to a rapid heating stop temperature above the recrystallization start temperature, at an average heating rate of 150°C / s to 250°C / s, and holding for a specified holding time, and then heating the cold-rolled steel sheet at an average heating rate of 50°C / s or higher until the maximum temperature is reached after the holding time.
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Citation Information

Patent Citations

  • Ultrahigh-magnetic-induction cold-rolled non-oriented electrical steel plate and preparation method thereof

    CN117947329A

  • Method for producing hot-rolled steel sheet for non-oriented electrical steel sheet, and method for producing non-oriented electrical steel sheet

    CN118318053A

  • High-strength tellurium-copper alloy material and preparation method thereof

    CN118389879A

  • Non-directional electromagnetic steel sheet manufacturing method

    WO2017098800A1

  • Non-oriented electromagnetic steel sheet and method for manufacturing same

    WO2023112891A1