Non-oriented Electrical Steel Sheet Composition for High-Frequency Performance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-oriented electrical steel sheets face challenges in achieving improved high-frequency characteristics while maintaining cost-effectiveness, as conventional methods to reduce Cr-based carbide precipitation increase material costs and lead to embrittlement and core loss deterioration.
Innovation Solution
A non-oriented electrical steel sheet composition with specific ranges of Cr, Si, Al, W, and optional elements like Mo, Ti, Nb, V, Zr, Cu, Sn, Ni, Sb, rare earth metals, and Ca, which suppresses Cr-based carbide precipitation and magnetic aging, enhancing high-frequency characteristics without significant cost increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If Cr content is increased to improve high-frequency characteristic, then specific resistance increases, but Cr-based carbide precipitates causing core loss deterioration
Solution Approach 1:
The patent changes the chemical composition parameters by adding W (0.003-2.0 mass%) alongside Cr (0.3-5.0 mass%) to modify the precipitation behavior. This parameter change suppresses Cr-based carbide formation while maintaining high specific resistance, resolving the contradiction between improving electrical resistance and preventing core loss deterioration.
Solution Approach 2:
The patent creates a composite alloy system combining Cr and W in specific proportions. This composite approach leverages the carbide-forming tendency of Cr to increase resistance while W suppresses harmful precipitation, achieving both high specific resistance and low core loss through synergistic interaction between the two elements.
2Reliability
If Mo content is increased to suppress Cr-based carbide precipitation, then core loss is reduced, but material cost increases significantly
Solution Approach 1:
The patent replaces expensive Mo with cheaper W to achieve the same function of suppressing Cr-based carbide precipitation. By using a more cost-effective element (W) that provides similar or superior performance in preventing carbide formation, the patent reduces material cost while maintaining core loss reduction benefits.
Solution Approach 2:
The patent changes the alloying strategy by substituting Mo with W and optimizing their content ratios. This parameter change in composition achieves effective suppression of Cr-based carbide precipitation at lower material cost, resolving the contradiction between core loss reduction and cost reduction.
3Loss of energy
If Si and Al content are increased to increase specific resistance, then eddy current loss is reduced, but embrittlement occurs
Solution Approach 1:
The patent optimizes the parameters of Si (1.0-3.5 mass%) and Al (0.2-2.0 mass%) content within specific ranges to achieve adequate specific resistance while preventing excessive embrittlement. By carefully controlling these compositional parameters and combining them with Cr and W, the patent balances electrical performance and mechanical ductility.
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 proposed composition effectively increases specific resistance, prevents embrittlement, and reduces core losses at low temperatures, improving high-frequency performance while maintaining cost-effectiveness, suitable for motor applications.
Implementation Method 1
a Cr-based carbide precipitates during manufacturing processes, working processes after the manufacture, and so on, and then a core loss increases and is deteriorated
Implementation Method 2
specific resistance has been increased by an increase of contents of Si, Al, and Cr, and a thickness of the non-oriented electrical steel sheet has been reduced as much as possible. These can reduce an eddy current loss
Implementation Method 3
owing to an appropriate amount of W contained, it is possible to increase specific resistance while avoiding embrittlement and to suppress the precipitation of a Cr-based carbide and magnetic aging to improve a high-frequency characteristic at low cost
Data Source
AI summary
A non-oriented electrical steel sheet contains Cr: 0.3 mass% to 5.3 mass%, Si: 1.5 mass% to 4 mass%, Al: 0.4 mass% to 3 mass%, and W: 0.0003 mass% to 0.01 mass%. A C content is 0.006 mass% or less, a Mn content is 1.5 mass% or less, a S content is 0.003 mass% or less, and a N content is 0.003 mass% or less, and the balance is composed of Fe and inevitable impurities.