Grain-Oriented Electrical Steel Sheet Groove Pattern for Iron Loss Reduction
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Solution Overview
Problem
The existing methods for forming grooves in grain-oriented electrical steel sheets to reduce iron loss are limited by the need for high groove forming speed and low sheet threading speed, leading to unstable improvement in iron loss characteristics, and the destructive magnetic domain control method loses its effect during stress relief annealing.
Innovation Solution
A grain-oriented electrical steel sheet with grooves arranged in a specific pattern where adjacent grooves overlap, forming inclined ends, and the grooves are spaced to maintain the magnetic domain refinement effect, improving iron loss while maintaining industrial productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a groove is formed in the steel sheet surface to refine magnetic domains and reduce iron loss, then the anomalous eddy current loss is reduced, but the groove effect is lost during stress relief annealing treatment
Solution Approach 1:
The groove is formed in advance on the steel sheet surface before coiling and annealing treatment. This preliminary action ensures that the magnetic domain refinement structure is established prior to the stress relief annealing process, allowing the groove effect to be preserved throughout subsequent manufacturing steps including winding and annealing treatment
Solution Approach 2:
The steel sheet surface is segmented into multiple grooves arranged in specific patterns (parallel to rolling direction, intersecting at specific angles, or in grid patterns). This segmentation creates multiple magnetic domain refinement zones that collectively reduce iron loss while maintaining structural integrity through the annealing process
2Manufacturing precision
If high groove forming speed and low sheet threading speed are used to form grooves, then the groove formation quality is improved, but industrial productivity is reduced
Solution Approach 1:
The groove forming process uses dynamic control of groove depth, width, and spacing parameters. By optimizing these parameters within specific ranges (groove depth 1-100 μm, spacing 0.1-10 mm), the process achieves both high formation quality and improved productivity, allowing faster processing speeds without sacrificing groove effectiveness
Solution Approach 2:
The invention changes key parameters of the groove structure including depth, width, spacing, and arrangement patterns. By optimizing these parameters, the groove formation process achieves high quality magnetic domain refinement while maintaining production efficiency, eliminating the need for excessively slow processing speeds
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
The solution effectively improves iron loss characteristics and maintains the magnetic domain refinement effect, even after stress relief annealing, by arranging grooves in a specific pattern with overlapping and inclined ends, enhancing both productivity and performance.
Implementation Method 1
A magnetic domain control method of narrowing a width of a 180° magnetic domain (performing refinement of the 180° magnetic domain) by forming a strain, which extends in a direction intersecting the rolling direction, at a predetermined interval along the rolling direction
Implementation Method 2
A magnetic pole occurs at the periphery of the groove due to a variation of permeability in a void of the groove, and an interval of a 180° magnetic wall is narrowed due to the magnetic pole
Implementation Method 3
there is known a grain-oriented electrical steel sheet in which an insulating film is formed on a surface of a steel sheet (base metal) of which a crystal orientation is controlled as described above so as to reduce the classical eddy current loss
Implementation Method 4
In a case of manufacturing a wound core for a transformer by using the grain-oriented electrical steel sheet, it is necessary to perform a stress relief annealing treatment so as to remove a deformation strain that occurs when the grain-oriented electrical steel sheet is coiled in a coil shape
Data Source
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AI summary
Provided is a grain-oriented electrical steel sheet including a steel sheet having a steel sheet surface in which a groove, which extends in a direction intersecting a rolling direction and of which a groove depth direction matches a sheet thickness direction, is formed. In a case where the steel sheet surface is seen from the sheet thickness direction, the steel sheet surface is provided with a groove group that is constituted by a plurality of the grooves arranged in a sheet width direction, the grooves, which constitute the groove group, are arranged in such a manner that adjacent grooves overlap each other on a projection plane perpendicular to the rolling direction, and a plurality of the groove groups are arranged with an interval in the rolling direction.