Oriented Electrical Steel Insulation Coating for Noise Reduction

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Solution Overview

Problem

Existing oriented electrical steel sheets face challenges in achieving optimal magnetic characteristics and reducing noise caused by magnetic deformation, with current insulation coatings either failing to provide sufficient noise reduction or compromising transformer efficiency and insulation quality.

Innovation Solution

An insulation coating composition for oriented electrical steel sheets is developed, comprising 0.1 to 7 wt% hollow nanoparticles, 0.1 to 5 wt% ceramic nanofibers, 0.1 to 5 wt% mesoporous nanoparticles, 30 to 60 wt% colloidal silica nanoparticles, and 30 to 60 wt% metal phosphate, applied to a sheet with specific elemental compositions of boron (B) or vanadium (V), silicon (Si), aluminum (Al), and manganese (Mn), followed by a heat treatment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an insulation coating is formed on the surface of the oriented electrical steel sheet to minimize power loss, then electrical insulating properties are improved, but noise quality deteriorates due to magnetic deformation

Engineering Contradiction:
Improveelectrical insulating propertiesVSAvoidnoise quality
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies a composite insulation coating containing multiple types of nanoparticles (silica nanoparticles, alumina nanoparticles, titania nanoparticles) combined with phosphate compounds. This composite structure provides both electrical insulation and noise reduction by creating a multi-phase material system where different components contribute to different functional requirements, resolving the contradiction between insulation performance and noise quality.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The insulation coating incorporates porous structures formed by the nanoparticle network, which creates air pockets and discontinuous phases that dampen magnetic deformation vibrations. The porous morphology allows the coating to maintain electrical insulation while providing mechanical damping to reduce noise generated by magnetostriction.

Inventive Principle:
Principle #31Porous materials

2Reliability

If high temperature heating is applied to produce precipitates for grain growth suppression, then magnetic characteristics are improved, but energy consumption and process complexity increase

Engineering Contradiction:
Improvemagnetic characteristicsVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent modifies the chemical composition parameters of the steel slab by adding specific elements (Sb, B, Ti, Nb, V) that change the precipitation behavior and grain growth characteristics. These compositional changes enable effective grain growth suppression at lower temperatures, reducing the thermal energy required while achieving the same magnetic performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of relying on traditional high-temperature precipitate formation, the patent uses alternative alloying elements that create analogous grain boundary strengthening effects through different mechanisms (e.g., Sb forming intermetallic compounds, B forming borides). These substitute mechanisms achieve similar grain growth suppression without requiring the same high thermal energy input.

Inventive Principle:
Principle #26Copying

3Loss of energy

If the crystal grain sizes are made irregular and coarse after final annealing to improve magnetic characteristics, then power loss is reduced, but noise quality deteriorates

Engineering Contradiction:
Improvepower lossVSAvoidnoise quality
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The patent creates local variations in crystal grain structure through controlled precipitate distribution, where different regions have optimized grain sizes and orientations. The insulation coating is also applied with varying thickness and composition to create local damping zones that specifically target noise-generating areas while preserving the overall magnetic performance benefits of the grain structure.

Inventive Principle:
Principle #3Local quality

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 reduces noise while maintaining excellent magnetic characteristics, improving transformer efficiency and insulation quality by converting vibration energy into heat and enhancing heat resistance and manufacturing feasibility.

Implementation Method 1

effectively reduces noise while maintaining excellent magnetic characteristics, improving transformer efficiency and insulation quality by converting vibration energy into heat

Methodology Applied
Scientific EffectVibration energy conversion: Viscous Heating

Implementation Method 2

a series of processes of subjecting components including the components of a steel slab to heating, hot rolling, hot band annealing, primary recrystallization annealing, and final annealing

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 3

an oriented electrical steel sheet having extremely excellent magnetic characteristics in a rolling direction because the orientation of crystal grains has a texture arranged in a {100} direction

Methodology Applied
Scientific EffectRecrystallization: Crystallisation

Implementation Method 4

an insulation coating is generally formed on the surface of the oriented electrical steel sheet... basically needs to have high electrical insulating properties

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Data Source

PatentEP3219825B1Oriented electrical steel sheet having insulating coating formed on surface thereof, and preparation method therefor
Publication Date: 2019.08.28 POHANG IRON & STEEL CO LTD
  • EP3219825B1 patent drawingFigure 1

AI summary

Provided are an insulation coating composition for an oriented electrical steel sheet, an oriented electrical steel sheet having an insulation coating formed on the surface thereof by using the same, and a manufacturing method thereof, and specifically, it is possible to provide an insulation coating composition for an oriented electrical steel sheet, including 0.1 to 7 wt% of hollow nanoparticles, 0.1 to 5 wt% of ceramic nanofibers, 0.1 to 5 wt% of mesoporous nanoparticles, 30 to 60 wt% of colloidal silica nanoparticles, and 30 to 60 wt% of phosphate, and to provide an oriented electrical steel sheet including an insulation coating produced by the composition on the surface of the oriented electrical steel sheet, including 0.005 to 0.05 wt% of any one element selected from boron (B), vanadium (V), or a combination thereof, 2.6 to 4.3 wt% of silicon (Si), 0.020 to 0.040 wt% of aluminum (Al), 0.01 to 0.20 wt% of manganese (Mn), in which the balance is composed of Fe and other inevitable impurities, and a manufacturing method thereof.