Grain-Oriented Electrical Steel Oxide Layer for Magnetic Domain Control
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Solution Overview
Problem
Existing grain oriented electrical steel sheets face challenges in simultaneously improving core loss and excitation power, particularly due to limitations in permeability and magnetic domain refinement methods.
Innovation Solution
The solution involves adjusting the maximum Al content in the metal oxide layer and optimizing the magnetic domain width ratio on both sides of the steel sheet, along with specific manufacturing processes such as primary and secondary recrystallization annealing and magnetic domain refinement treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If magnetic domain refinement is performed using laser, plasma, electron beam or other methods to reduce magnetic domain size, then abnormal eddy current loss is reduced, but local residual stress limits magnetic domain wall mobility, decreasing permeability and deteriorating excitation power
Solution Approach 1:
The invention changes the chemical composition parameters of the metal oxide layer, specifically controlling the Al content to 0.03-0.15 wt% and Fe content to 0.85-1.50 wt%, to achieve optimal magnetic domain refinement that reduces eddy current loss while maintaining permeability and excitation power
Solution Approach 2:
The invention uses a composite metal oxide layer containing multiple elements (Al, Fe, and other metal elements) to create a refined magnetic domain structure that simultaneously reduces abnormal eddy current loss and maintains magnetic properties
2Ease of manufacture
If the grain size is made coarse to achieve Goss texture with integration degree less than 3 degrees, then manufacturing is simplified, but the width of magnetic domain becomes wider and speed of domain walls increases, increasing abnormal eddy current loss
Solution Approach 1:
The invention changes the oxidation amount parameter during primary recrystallization annealing to control the metal oxide layer thickness and composition, achieving magnetic domain refinement without requiring complex manufacturing processes
Solution Approach 2:
The invention introduces a metal oxide layer as an intermediary substance that mediates between the base iron and insulating coating, controlling magnetic domain width to reduce abnormal eddy current loss while maintaining ease of manufacture
3Manufacturing precision
If oxidation amount during primary recrystallization annealing is increased to form thicker metal oxide layer, then magnetic domain refinement is enhanced, but manufacturing complexity and process control difficulty increase
Solution Approach 1:
The invention optimizes the oxidation amount parameter within a specific range (controlling Al content at 0.03-0.15 wt% and Fe content at 0.85-1.50 wt%) to achieve effective magnetic domain refinement while maintaining simple and controllable manufacturing processes
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 effectively minimizes the heat-affected zone, maximizes iron loss reduction, and simultaneously improves excitation power and permeability, leading to enhanced performance in transformer applications.
Implementation Method 1
When the grain size is coarse, the width of the magnetic domain becomes wider, and the speed of the domain walls increases, increasing an abnormal eddy current loss
Implementation Method 2
In order to reduce the abnormal eddy current loss, various methods of refining a magnetic domain using laser, plasma, electron beam and the like are used
Implementation Method 3
a primary recrystallization annealing, and a secondary recrystallization annealing
Data Source
AI summary
A grain oriented electrical steel sheet according to an exemplary embodiment of the present invention includes a grain oriented electrical steel sheet base material and a metal oxide layer present on both sides of the grain oriented electrical steel sheet base material. A maximum Al fraction in the metal oxide layer is 0.15 to 1.0 wt %, and a ratio (DWL/DWS) of an average magnetic domain width (DWL) of a side with a large average magnetic domain width to an average magnetic domain width (DWS) of a side with a small average magnetic domain width of one side and the other side of the electrical steel sheet base material is 1.2 to 1.8.