Insulation Coating Film Composition for Oriented Electrical Steel Sheets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reduction in tension of insulation coating films on oriented electrical steel sheets during stress relief annealing leads to increased core loss and decreased insulation properties, affecting the magnetic and marketability of the steel sheets.
Innovation Solution
A composition comprising a composite metal phosphate and colloidal silicas with different average particle diameters is applied to the steel sheets, maintaining tension and adhesion even after high-temperature annealing, minimizing core loss and insulation property degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional insulation coating film is formed on oriented electrical steel sheet and subjected to stress relief annealing, then stress relief is achieved, but tension of the insulation coating film is reduced causing core loss increase and insulation property decrease
Solution Approach 1:
The patent uses a composite coating material consisting of colloidal silica and water glass in a specific weight ratio (3:7 to 7:3). This composite formulation creates a coating film with enhanced tensile strength and elasticity that can withstand the thermal stress of annealing without losing tension, thereby maintaining both insulation properties and film strength after heat treatment.
Solution Approach 2:
The patent optimizes the weight ratio of colloidal silica to water glass within the range of 3:7 to 7:3, and controls the coating thickness and annealing parameters to achieve the desired balance between tension maintenance and insulation property preservation. By adjusting these parameters, the coating film exhibits optimal mechanical and electrical characteristics after stress relief annealing.
2Loss of energy
If high tension insulation coating film is formed to reduce core loss, then insulation property is improved, but tension is reduced during stress relief annealing leading to core loss increase
Solution Approach 1:
The composite coating system of colloidal silica and water glass creates a flexible yet strong film structure that maintains tension stability during annealing. The synergistic interaction between the two materials allows the coating to accommodate thermal expansion and stress relief while preserving its tensile properties, thereby preventing core loss increase that would normally occur during heat treatment.
Solution Approach 2:
The coating formulation is designed in advance to provide cushioning against the expected tension loss during annealing. The specific composition ratio and film structure are optimized beforehand to compensate for the thermal effects, ensuring that the coating maintains adequate tension throughout the annealing process and prevents core loss deterioration.
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 maintains excellent tension and insulation properties after stress relief annealing, reducing core loss and enhancing the magnetic performance and marketability of the oriented electrical steel sheets.
Implementation Method 1
a second component (B) including at least two colloidal silicas having different average particle diameters
Implementation Method 2
colloidal silicas having different average particle diameters is applied to the steel sheets, maintaining tension and adhesion even after high-temperature annealing
Implementation Method 3
a first component (A) including a composite metal phosphate, a derivative thereof, or a mixture thereof
Implementation Method 4
as one of methods for reducing the core loss of the oriented electrical steel sheet, a method for forming a high tension insulation coating film on a surface has been actively studied
Data Source
AI summary
The present invention relates to a composition for forming an insulation coating film of an oriented electrical steel sheet, including a first component (A) including a composite metal phosphate, a derivative thereof, or a mixture thereof, and a second component (B) including at least two colloidal silicas having different average particle diameters, a method for forming an insulation coating film using the same, and an oriented electrical steel sheet having an insulation coating film formed thereon.