Grain-Oriented Electrical Steel Magnetic Domain Refinement for Low Iron Loss
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Solution Overview
Problem
Existing methods for producing grain-oriented electrical steel sheets face challenges in achieving low iron loss while maintaining productivity and cost-effectiveness, particularly when introducing strain from both sides of the steel sheet, which requires complex control and increased costs or reduced productivity.
Innovation Solution
Adjusting the position where the electron beam diameter is minimized in the thickness direction of the steel sheet by using a dynamic focus function, and evaluating strain distribution based on leakage magnetic flux to optimize magnetic domain refinement, thereby increasing the ratio of magnetic poles generated in the same area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If strain is introduced from both sides of the steel sheet to increase pole generation area, then iron loss reduction is improved, but device complexity and cost increase
Solution Approach 1:
The patent divides the strain introduction process into two separate single-side irradiation steps instead of attempting simultaneous double-side irradiation. The steel sheet is irradiated from one side, then flipped and irradiated from the other side, effectively segmenting the complex process into manageable stages that achieve the same pole generation effect without requiring complex dual-sided coordination
Solution Approach 2:
The patent applies preliminary focus adjustment before irradiation to optimize the beam convergence point within the steel sheet thickness. By pre-positioning the minimum beam diameter location at a specific depth from the surface, the process maximizes strain penetration and pole generation efficiency in a single-side irradiation, reducing the need for complex multi-sided coordination
2Loss of energy
If strain is introduced from both sides of the steel sheet, then iron loss reduction is improved, but productivity decreases
Solution Approach 1:
The patent segments the irradiation process into two sequential single-side operations rather than requiring simultaneous dual-sided processing. This allows each side to be treated independently with optimized parameters, and the steel sheet can be processed through the same irradiation apparatus twice, maintaining high equipment utilization while achieving deep strain penetration equivalent to double-sided introduction
Solution Approach 2:
By pre-optimizing the beam focus position and irradiation parameters for single-side processing, the patent ensures that each irradiation pass achieves maximum strain penetration depth. This preliminary optimization allows the single-side approach to match or exceed the effectiveness of simultaneous double-sided irradiation, eliminating productivity losses
3Loss of energy
If beam focus is adjusted to increase strain depth, then magnetic domain refining effect is improved, but manufacturing precision control becomes more difficult
Solution Approach 1:
The patent applies preliminary focus adjustment to position the minimum beam diameter at a predetermined depth within the steel sheet before irradiation begins. This pre-positioning of the focal point ensures consistent strain distribution depth and maximizes pole generation within the material bulk, while the focus setting can be predetermined and replicated across production batches, reducing real-time control complexity
Solution Approach 2:
The patent optimizes specific irradiation parameters including beam current, accelerating voltage, and focus position to achieve the desired strain penetration depth. By establishing optimized parameter ranges and settings for single-side irradiation, the process achieves deep strain introduction with controlled and repeatable manufacturing precision
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a grain-oriented electrical steel sheet with significantly reduced iron loss, enhancing energy efficiency in transformers by improving the magnetic domain refining effect and meeting future efficiency regulations.
Implementation Method 1
applying magnetic domain refining treatment by irradiation with an electron beam or a laser beam
Implementation Method 2
uses the anti-magnetic field effect caused by the magnetic poles generated in the vicinity of the strain introduction portion
Implementation Method 3
adjusting the position where the beam diameter is minimized in the thickness direction of the steel sheet by means of focus adjustment
Implementation Method 4
evaluating strain distribution based on leakage magnetic flux
Data Source
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AI summary
Disclosed is a grain-oriented electrical steel sheet with extremely low iron loss by means of a magnetic domain refining technique. In a grain-oriented electrical steel sheet having a plurality of magnetic domains refined via a local strain introduction portion, when a direct-current external magnetic field is applied to the steel sheet in a rolling direction, for a magnetic flux leaked from the local strain introduction portion at a position 1.0 mm away from a surface of the steel sheet at a side of the local strain introduction portion, a value obtained by dividing an intensity level of a total leakage magnetic flux by an intensity level of a magnetic flux leaked due to causes other than strain is more than 1.2.