Laser-Treated Grain-Oriented Steel for Transformer Cores
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing grain-oriented flat steel products struggle to minimize magnetic loss values and optimize magnetostrictive properties, particularly in transformer applications, where high demands exist for low remagnetization loss and reduced noise emissions, while avoiding damage to insulating layers and increased noise from laser treatments.
Innovation Solution
A method involving laser treatment of flat steel products to form line-shaped deformations, with optimized parameters such as distance, exposure time, and energy density, to minimize magnetization losses and apparent power, thereby reducing noise emissions and maintaining insulating layer integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If mechanical processing (scratching or piercing) is applied to the surface of the flat steel product, then magnetization losses are reduced, but the insulating layer is damaged
Solution Approach 1:
The patent replaces mechanical processing methods (scratching or piercing) with laser treatment to create line-shaped deformations on the surface. This substitution allows achieving the same magnetic property improvement (reduced magnetization losses) without mechanically damaging the insulating layer, as the laser induces thermal tension and dislocation formation rather than direct mechanical contact.
Solution Approach 2:
The patent applies controlled laser parameters (power, exposure time, scanning speed) to create specific thermal effects that produce line-shaped deformations. By optimizing these parameters, the treatment reduces magnetization losses while maintaining insulating layer integrity, as the thermal process is more selective and controllable compared to mechanical methods.
2Loss of energy
If laser treatment is applied to reduce magnetization losses, then magnetic properties are improved, but noise emissions increase due to increased secondary magnetic structures
Solution Approach 1:
The patent applies partial laser treatment by creating line-shaped deformations only in specific regions where magnetic flux emerges from the surface, rather than treating the entire surface. This selective approach reduces magnetization losses at critical locations while limiting the overall increase in secondary magnetic structures, thereby controlling noise emissions.
Solution Approach 2:
The patent creates localized line-shaped deformations at specific positions on the steel product surface where magnetic flux emerges. This local treatment approach targets the formation of terminating domains precisely where needed to reduce magnetization losses, while avoiding excessive secondary structure formation in other regions that would increase noise emissions.
3Loss of energy
If high tensile stresses are applied to reduce domain spacing, then magnetization losses are reduced, but the required stress values cannot be achieved to a limited extent
Solution Approach 1:
The patent replaces the need for applying high mechanical tensile stresses with laser-induced thermal tension. The laser beam creates localized heating that generates thermal expansion and subsequent tension stresses during cooling, achieving the required stress levels for domain spacing reduction without the limitations of mechanical stress application methods.
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 method effectively reduces magnetization losses by up to 13% and minimizes noise emissions, ensuring the flat steel products meet stringent transformer performance requirements without compromising the insulating layer, by refining main domains and limiting the increase in secondary magnetic structures.
Implementation Method 1
a laser beam is focused on the surface of the flat steel product to be treated and thermal tension is generated in the base material
Implementation Method 2
a laser beam is focused on the surface of the flat steel product to be treated
Implementation Method 3
In the course of the laser treatment, line-shaped deformations are formed into the surface of the flat steel product by means of a laser beam emitted with a power P
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a method for producing a grain-oriented flat steel product that is intended for the manufacture of parts for electrotechnical applications and has minimized magnetic loss values and optimized magneto-restrictive properties, said method comprising the work steps of a) providing a flat steel product, and b) laser-treating the flat steel product, wherein, in the course of the laser treatment, linear deformations, which are arranged with a spacing a, are molded into the surface of the flat steel product by means of a laser beam emitted by a laser radiation source with a power P. The method according to the invention for producing flat steel products is optimally suitable for the manufacture of parts for transformers. This is achieved in that the apparent power S1.7/50 of the flat steel product before and after the laser treatment (operation b)), determined at a frequency of 50 Hertz and a polarization of 1.7 Tesla, is measured, and in that the parameters of the laser treatment are varied in such a way that the difference between the apparent power S1.7/50 measured before and after the laser treatment is less than 40%.